- Email: [email protected]
Nanodelivery Vehicles for Mucosal Vaccines
C H A P T E R
26 Nanodelivery Vehicles for Mucosal Vaccines Rika Nakahashi-Ouchida1,2, Yoshikazu Yuki1,2 and Hiroshi Kiyono1,2,3,4 1
Division of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, University of Tokyo, Tokyo, Japan 2International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, University of Tokyo, Tokyo, Japan 3Mucosal Immunology and Allergy Therapeutics, Graduate School of Medicine, Chiba University, Chiba, Japan 4 Division of Gastroenterology, Department of Medicine, (CU-UCSD cMAV) Center for Mucosal Immunology, Allergy and Vaccines, University of California, San Diego, CA, United States
I. INTRODUCTION Infectious agents such as viruses and bacteria generally invade the host via the mucosal surfaces of the respiratory and gastrointestinal tracts. To protect the host from invasion and to prevent the spread of pathogens, the induction of neutralizing antibody-based humoral immunity and/or cell-mediated immunity against pathogens at the mucosal surface is a logical strategy [1]. Oral and nasal vaccines that can effectively induce antigen-specific immune responses at mucosal surfaces and in systemic immune compartments [2,3] and mucosal vaccines that target various infectious diseases are currently under development [4]. The nasal cavity is considered to be a particularly attractive site for antigen deposition because the Mucosal Vaccines DOI: https://doi.org/10.1016/B978-0-12-811924-2.00026-2
nasal mucosa has the capacity to facilitate an active antigen uptake, processing, and presenting system in the form of microfold (M) cells and dendritic cells (DCs), and because it also has the nasopharyngeal-associated lymphoid tissue (NALT) for the induction of antigenspecific immune responses in respiratory tissues [5,6]. Furthermore, the nasal cavity is enriched with blood vessels, so antigens are rapidly transported into the circulation and are ultimately deposited in peripheral lymph nodes for initiation of antigen-specific systemic immune responses [7]. In addition to the induction of antigen-specific immune responses in the upper and lower respiratory tracts, nasal vaccination has been shown to effectively induce antigen-specific immune responses at distal mucosal surfaces, particularly the
461
© 2020 Elsevier Inc. All rights reserved.
462
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
reproductive tract [8] (Chapter 2: Anatomical Uniqueness of the Mucosal Immune System (GALT, NALT, iBALT) for the Induction and Regulation of Mucosal Immunity and Tolerance and Chapter 18: Mucosal Regulatory System for the Balanced Immunity in the Middle Ear and Nasopharynx). Although the nasal cavity is an attractive location for mucosal vaccination, there are physical and chemical protective barriers that must be overcome for successful nasal vaccination. For example, mucociliary clearance is an innate defense mechanism that uses ciliary movement and a mucous layer to exclude inhaled microbes and foreign substances, including vaccine antigens, from the nasal cavity [9]. Moreover, epithelial cells provide a physical barrier in the form of tight junctions between cells and a chemical barrier in the form of antimicrobial peptide secretion. In addition to these barriers, metabolic enzymes secreted by nasal glands, mucus produced by goblet cells, and transudate from plasma are present in the nasal cavity. Thus, there is a high possibility that vaccine antigens delivered to the nasal cavity will be decomposed or excluded before an antigen-specific immune response is evoked [10]. Because of these protective barriers in the nasal cavity, the accessibility to and adsorption of nasally administered vaccine antigen by the mucosal immune system means that nasal vaccination is less effective than other types of vaccination (e.g., subcutaneous or intramuscular injection). Consequently, large amounts of antigen are often required for administration, and all the while only a weak antigen-specific immune response is induced [11]. To date, this issue has been addressed by the use of various combinations of live vectors, inactivated antigens, artificial-antigen-delivery vehicles, and sometimes mucosal adjuvants [12 14]. An inactivated intranasal influenza vaccine (Nasalflu) containing Escherichia coli heat-labile toxin as an adjuvant was approved for use in Switzerland during the 2001 02 influenza season [15]. Although the vaccine was found to
induce protective immunity, several cases of facial nerve palsy (Bell’s palsy) were reported during postmarketing surveillance, and the vaccine was withdrawn as a result of safety concerns [15]. This incident clearly highlighted the potential for nasal vaccines to affect the central nervous system via the olfactory nerve and raised the bar for nasal vaccine development. Thus, effective and safe nasal vaccines should be able to (1) overcome various physical and chemical barriers at the nasal mucosa for efficient delivery of vaccine antigen, (2) induce an effective antigen-specific immune response with or without a mucosal adjuvant, and (3) have a suitable safety profile and not influence the central nervous system.
II. CHARACTERISTICS OF THE NASAL IMMUNE SYSTEM A. Structure and Function of Nasopharyngeal-Associated Lymphoid Tissue The mucosal immune system can be subdivided into inductive and effector sites (Fig. 26.1). The inductive sites are collectively referred to as mucosa-associated lymphoid tissue (MALT), and this is where antigensampling M cells are located and follicleassociated epithelium and immunocompetent cells such as T and B lymphocytes, DCs, and macrophages accumulate in high numbers [8]. In rodents, the nasal immune system contains NALT, which is located basally on both sides of the rodent nasal cavity, and is responsible for the initiation of antigen-specific immune responses [16]. In humans, the paired palatine tonsils and the unpaired nasopharyngeal tonsils (adenoids), which are two components of Waldeyer’s ring, are thought to be functionally related to the NALT in rodent [17]. The NALT is covered with follicle-associated epithelium, which contains M cells, which specialize in the uptake transcytosis of antigens from the
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
II. CHARACTERISTICS OF THE NASAL IMMUNE SYSTEM
463
FIGURE 26.1 The mucosal immune system. Antigens are taken up by microfold (M) cells and then captured by antigenpresenting cells such as dendritic cells. Antigen-primed T and B lymphocytes express homing or polymeric molecules and chemokine receptors and migrate to the effector site through the thoracic ducts and blood circulation. IgA1 B cells differentiate into plasma cells by IgA-enhancing cytokines such as IL-6 and IL-10 secreted from Th2 cells. Dimeric IgA secreted from plasma cells is transported to the mucosal surface as secretory secretory IgA (SIgA) through the polymeric Ig receptor (pIgR) expressed on the basal membrane of epithelial cells.
mucosal lumen to antigen-presenting cells (e.g., DCs) for processing and presentation to T and B lymphocytes. There is also a special subset of M cells, called respiratory M cells, that exist as a monolayer on top of the single layer of epithelium that covers the lateral surfaces of the nasal turbinates [18]. Respiratory M cells resemble classical M cells with their depressed surface and irregular microvilli, but unlike classical M cells, they do not have a pocket on their basolateral side [18]. Like classical M cells, respiratory
M cells can take up soluble protein or bacterial antigens and therefore are an antigen-sampling pathway for the nasal immune system.
B. Mechanism for the Induction of Antigen-Specific Nasal Immune Responses After antigens have been captured by M cells, these are transported via transcytosis to antigen-presenting cells such as DCs located
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
464
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
beneath the epithelial layer or follicleassociated epithelium (Fig. 26.1). DCs process these antigens and present the peptide together with major histocompatibility complex II to CD41 T cells located at induction sites. Antigen-primed CD41 T cells secret cytokines such as transforming growth factor beta and interleukin 5 (IL-5) and promote isotype class switching in B cells from immunoglobulin M to A [19 21]. Eventually, the antigen-specific T cells and IgA1 B cells migrate to effector sites via the thoracic ducts, blood circulation, and lymphocyte homing system (discussed in the next section) [22]. IgA1 B cells then terminally differentiate into plasma cells that secrete dimeric or polymeric IgA in the presence of IL6 and IL-10 produced by T helper cells [23]. At effector sites, dimeric or polymeric IgA binds to polymeric immunoglobulin receptor, a transmembrane protein expressed on the basement membrane of nasal epithelial cells, and then forms secretory IgA (SIgA), which is secreted into the lumen [24]. SIgA promotes the clearance of pathogens via direct binding and neutralizing activity to prevent pathogen invasion and proliferation at mucosal surfaces. Thus, SIgA plays a central role in the mucosal immune system as a first line of defense [25,26] (Chapter 4: Protective Activities of Mucosal Antibodies).
C. Lymphocyte Imprinting and Homing Mechanisms in the Nasal Immune System The lymphocyte homing system interconnects the inductive and effector sites of the mucosal immune system [27]. In the case of the nasal immune system, antigen-stimulated lymphocytes express α4β1 integrin, which is a receptor for vascular cell adhesion molecule-1 and C-C motif chemokine receptor 10, which is a receptor for C-C motif chemokine ligand 28 [28 30]. Because vascular cell adhesion molecule-1 and C-C motif chemokine ligand 28 are predominantly expressed by vascular
endothelial cells and epithelial cells in mucosal tissues, α4β1- and C-C motif chemokine receptor 10-positive lymphocytes preferentially migrate from the NALT to the respiratory tract, salivary glands, mammary glands, lacrimal glands, and genitourinary tract via the thoracic ducts and blood circulation after antigen stimulation and acquiring these imprinting molecules [31]. It has been shown that the thymic stromal lymphopoietin thymic stromal lymphopoietin receptor signaling cascade is important for the induction of antigen-specific IgA production following nasal administration of antigens [32]. This signaling cascade has been shown to enhance IgA production via the induction of IL-6 production in mucosal DCs after nasal immunization of antigen together with cholera toxin adjuvant, suggesting that adjuvants that promote activation of the thymic stromal lymphopoietin-mediated signaling may be useful for effective mucosal vaccine development.
III. DRUG-DELIVERY SYSTEMS FOR NASAL VACCINES The use of various nanoparticle-based delivery systems for nasal vaccines has been examined (Table 26.1). The chemical and physical properties of nanomaterials can be controlled via surface modification, which makes it easy to encapsulate vaccine antigens and/or adjuvants within the nanomaterials or make vaccine antigen nanomaterial complexes via noncovalent binding or covalent interactions [51]. Liposomes have been examined for their suitability as carriers for mucosal vaccines. Since liposomes are amphipathic, antigens and adjuvants can be encapsulated within the aqueous space regardless of their hydrophilicity and hydrophobicity [52]. To maximize vaccine immunogenicity, the physicochemical properties of liposomes, such as their size, lipid composition, and structure, can be adjusted on the
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
465
III. DRUG-DELIVERY SYSTEMS FOR NASAL VACCINES
TABLE 26.1
Studies Using Nanoparticles for Nasal Vaccines
Delivery system
Materials
Antigens
Reference
Lipid nanoparticles
Liposome
Ovalbumin
[33]
Multivalent group A streptococcal M protein
[34]
Formaldehyde-killed whole cell of Yersinia pestis
[35]
Ovalbumin
[36]
Ovalbumin
[37]
X8P
Influenza A
[38]
W205EC
Bacillus anthracis
[39]
Polylactic acid (PLA)
Tetanus toxoid
[40]
Poly(lactic-glycolic acid) (PLGA)
Enterotoxigenic Escherichia coli colonization factor CS6
[41]
Chitosan PLGA
Tetanus toxoid
[42]
Chitosan
Influenza subunit
[43]
RSV M2 protein expressing plasmid
[44]
VP1 protein of Coxsackie virus B3
[45]
Glycol chitosan PLGA
Hepatitis B surface antigen
[46]
PLA polyethylene glycol
Tetanus toxoid
[47]
cCHP
Botulinum type A neurotoxin fragment
[48]
Pneumococcal surface protein A
[49]
Pneumococcal surface protein A
[50]
Emulsion
Polymeric nanoparticles
W805EC
basis of the specific characteristics of the vaccine antigen [52]. Several studies have utilized liposomes for the development of nasal vaccines [33 35]. For example, nasal immunization with a liposome-formulated Yersinia pestis formaldehyde-killed whole cell vaccine significantly enhanced not only the antigen-specific immune response in systemic immune compartments, but also the amount of IgA and IgG in mucosal secretions in the lung and nasal cavity and consequently protected mice from intranasal lethal challenge with Y. pestis when compared with mice immunized with the formaldehyde-killed whole-cell vaccine alone [35] (Chapter 19: Current and New Approaches for Mucosal Vaccine Delivery).
Nanomaterial emulsions (nanoemulsions), which are water-in-oil formulations stabilized by small amounts of surfactant, can also be used to deliver vaccines because they can trap antigens inside their core [53]. For instance, nasal administration of the nanoemulsion W805EC, which is composed of cetylpyridinium chloride, Tween 80, ethanol, and soybean oil, promoted engulfment and antigen presentation by DCs and evoked an immune response to the model antigen ovalbumin in mice [36,37]. Other nanoemulsions have been examined for the development of influenza or Bacillus anthracis vaccines [38,39]. In the case of influenza, the nanoemulsion X8P, which is composed of tributyl phosphate, Triton X-100, and soybean oil in
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
466
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
water, was mixed with inactivated influenza A to create a vaccine. Nasal vaccination with this mixture protected mice from death or viral pneumonitis after lethal challenge with a congenic strain of influenza virus [38]. Similarly, the nanoemulsion W205EC, which is composed of cetylpyridinium chloride, Tween 20, and ethanol in water with hot-pressed soybean oil, has been used as an adjuvant in a mixture with B. anthracis antigen rPA [39]. Nasal immunization with one or two doses of the mixture elicited an antigen-specific systemic IgG response as well as bronchial IgA and IgG responses and T helper 1 (Th1)-polarized cytokine secretion by splenocytes in mice. High titers of toxin-neutralizing serum IgG obtained in both mice and guinea pigs were found to protect the guinea pigs from intradermal or intranasal lethal challenge with B. anthracis [39]. Of the different nanoparticles examined to date, polymers are the best-studied carriers, with polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) being the most-studied synthetic polymers [54]. With these two polymers, it is possible to control the rate of release of vaccine antigen by changing the composition ratio and molecular weight of PLA and glycolic acid in the formulation [40,55]. Furthermore, these synthetic polymers are superior in biocompatibility and biodegradability and have high practicability, and they have been approved by the US Food and Drug Administration for use in nanomedicine formulations [56]. Tetanus toxoid has been adsorbed onto PLA, and E. coli colonization factor CS6 has been encapsulated in PLGA microspheres [40,41]. Nasal administration of PLA-adsorbed tetanus toxoid to guinea pigs enhanced the antigenspecific immune response compared to those administered free antigen [40]. Similarly, nasal administration of CS6 encapsulated in PLGA led to greater fecal IgG and IgA immune responses compared to mice that were administered noncapsulated antigen [41]. New formulations using PLA or PLGA to polymerize with polyethylene glycol (PEG) or chitosan are being
tested to improve the stability of vaccine formulations [42]. It has been reported that nasal administration of tetanus toxoid-encapsulated in PLA PEG nanoparticles (PLA polymerized with PEG) generates high, long-lasting tetanus toxoid-specific immunity compared to tetanus toxoid-encapsulated in PLA alone [42]. Chitosan is a well-studied natural polymer [57]. It has mucoadhesive properties and can loosen the tight junctions between epithelial cells, so it is a potentially useful molecule for promoting antigen uptake at the mucosal surface [58]. To take advantage of these characteristics of chitosan, nanoparticles containing N-trimethyl chitosan and monovalent influenza A subunit H3N2 have been developed as a prototype chitosan-based nasal influenza vaccine. Nasal immunization with this vaccine resulted in potent inhibition of hemagglutination that was dependent on the induction of antigenspecific IgG and SIgA responses [43]. Similarly, a plasmid DNA encoding the cytotoxic T lymphocyte epitope derived from respiratory syncytial virus (RSV) M2 protein has been combined with chitosan to develop a vaccine against RSV [44]. Nasal immunization with the chitosan DNA RSV vaccine induced a virusspecific cytotoxic T lymphocyte response in mice, and a significant reduction in virus titer was observed in the lung after RSV challenge compared with the results in a nonimmunized control group [44]. As a vaccine against Coxsackie virus B3 infection, which is the cause of acute and chronic myocarditis, nasal immunization of chitosan-DNA expressing VP1, a major structural protein of Coxsackie virus B3, induced antigen-specific serum IgG and mucosal SIgA responses and resulted in protection against intraperitoneal injection of a lethal dose of Coxsackie virus B3 in mice [45]. Furthermore, an immunogenicity study in mice revealed that nasal administration with hepatitis B virus antigen in combination with glycol chitosan PLGA polymers was more effective at inducing systemic and mucosal immune responses when compared to the antigen encapsulated with
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA
PLGA or chitosan PLGA polymers [46]. Glycol chitosan improves vaccine retention because this polymer remains on the mucous membrane owing to its better mucoadhesiveness arising from its positive charge, which leads to sustained antigen release. Furthermore, the effectiveness of hydrophilic PEG PLA particles as nasal transporters has been demonstrated by using tetanus toxoid as a model antigen [47]. In the presence of lysozyme, PLA nanoparticles immediately aggregate, whereas PEG PLA particles remain in their soluble form. Tetanus toxoid-specific antibody titers induced following nasal administration of PEG PLA tetanus toxoid are significantly higher and more prolonged than those following nasal administration of PLA tetanus toxoid [47]. It is thought that the PEG coating stabilizes the PLA particles in the mucosal fluid and facilitates the transport of the antigen to the nasal epithelium, where it elicits a long-lasting antigen-specific antibody immune response [47]. Cross-linked hydrogel vaccine antigen complexes can also be used to deliver vaccines to mucosal surfaces [48]. For instance, cationic formulations of cholesteryl-bearing pullulan (cCHP) nanogel can attach to negatively charged nasal mucosal epithelium because it has a positive charge [48]. As a result, sustained antigen release from the encapsulated vaccine and subsequent antigen uptake elicit antigen-specific immune responses both in systemic (e.g., IgG) and mucosal (e.g., IgA) compartments. The use of cCHP nanogel in nasal vaccines against infectious and noninfectious diseases is discussed in the remaining sections of this chapter.
IV. CCHP NANOGEL AS A DRUGDELIVERY SYSTEM FOR NASAL VACCINES cCHP nanogel is composed of cholesterolbound pullulan molecules that associate via
467
hydrophobic interactions to create a spherical structure (diameter, approx. 40 nm) [59 61]. Vaccine antigens can be easily incorporated into and released from the internal space of the cCHP nanogel sphere as a natural form owing to the artificial chaperone function of CHP nanogel [59]. To enhance attachment of CHP nanogel to the negatively charged mammalian nasal mucosal surface [62], cCHP nanogel in which an amino group has also been introduced to the pullulan molecules has been developed (Fig. 26.2) [59]. It has been shown that cCHP nanogel containing the C-terminus fragment of heavy chain of botulinum neurotoxin type A (BoHc) attaches strongly to the nasal mucosal epithelium after nasal administration (Fig. 26.3) [48]. After attachment, the BoHc antigen is gradually released from the cCHP nanogel and taken up by nasal epithelial cells and M cells for at least 12 hours after administration [48]. In addition, it has been shown that approximately 40% of nasal DCs take up the BoHc antigen after nasal administration of cCHP BoHc nanogel compared with only 2% after nasal administration of BoHc antigen alone, resulting in greater BoHc-specific serum IgG and SIgA responses and protection from lethal challenge with neurotoxin [48]. With respect to safety, the antigen itself does not migrate to the olfactory bulb after nasal administration, having no effect on the olfactory nerve [48,63]. These data suggest that cCHP nanogels are a safe, adjuvant-free means of delivering vaccine antigens to the nasal cavity and can induce effective antigen-specific immune responses in both systemic and mucosal compartments.
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA To verify the suitability of using cCHP nanogel to deliver vaccine antigen to the nasal cavity, a cCHP nanogel-based nasal vaccine
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
468
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
FIGURE 26.2
Schematic illustration of cCHP nanogel with artificial chaperone function. cCHP consists of a cholesterylgroup-bearing pullulan (CHP) introduced cationic amino group. cCHP nanogel can encapsulate proteins in the interior space through hydrophobic interactions and are effectively retained in the nasal mucosa, which is negatively charged following intranasal vaccination.
against respiratory infection has been developed. Streptococcus pneumoniae is a pathogen that causes bacterial pneumonia mainly in infants and the elderly and can lead to death as a result of severe upper respiratory tract infection [64]. Two intramuscular injection types of vaccines against pneumonia have been developed: pneumococcal polysaccharide vaccine (PPSV) and pneumococcal polysaccharide conjugate vaccine
(PCV) [65]. PPSV contains capsular polysaccharides purified from various serotypes of S. pneumoniae and induces antigen-specific responses in a T-cell-independent manner [66]. PCV is a conjugate vaccine containing capsular polysaccharides, a carrier protein (Corynebacterium diphtheriae mutant 197, a nontoxic mutant of diphtheria toxin), and an aluminum phosphate adjuvant that induces a T cell-dependent immune
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA
469
FIGURE 26.3 Uptake of cCHP antigen complex from the paranasal sinuses in the nasal mucosa. The BoHc/A antigens are gradually released from the cCHP nanogel and taken up by nasal epithelial cells and M cells in NALT for at least 12 h after administration. The NKM 16-2-4 is an M-cell-specific monoclonal antibody.
response [67]. Although these vaccines have potent immunogenicity against multiple major serotypes that cause bacterial pneumonia (23 serotypes in PPSV, 13 serotypes in PCV), their efficacy is lost once serotype replacement occurs [68,69]. Therefore, a vaccine effective against all serotypes of S. pneumoniae is required.
To address this issue, pneumococcal surface protein A (PspA), which is expressed by all serotypes of S. pneumoniae, has been examined as a promising candidate antigen for next-generation pneumococcal vaccines that can induce crossreactive immune responses against different serotypes [70,71]. Indeed, nasal administration of a
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
470
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
PspA Vibrio vulnificus-derived flagellin fusion protein induced antigen-specific IgG and IgA responses both in serum and at mucosal surfaces, and provided protective immunity against lethal challenge with S. pneumoniae in mice [72]. In addition, nasal immunization using chitosan DNA nanoparticles expressing PspA suppressed pneumococcal colony formation in the nasal cavity of mice [73]. Also, a unique antigen-delivery method targeting Claudin 4, a major cell adhesion molecule in the tight junctions of NALT epithelial cells, has been developed [74]. For instance, a PspA C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) fusion protein has been shown to bind to Claudin 4 after nasal immunization and induces the production of PspA-specific IgG in serum and SIgA in nasal and bronchoalveolar lavage fluids [74]. As a result, mice nasally vaccinated with PspA C-CPE are protected from pneumococcal respiratory infection. In addition, nasal administration of PspA together with Flt3 ligand expression plasmid and CpG oligodeoxynucleotide as mucosal adjuvants induced PspAspecific SIgA in 2-year-old or pregnant mice, resulting in inhibition of bacterial colonization both in aged mice and in offspring of the vaccinated group [75]. Therefore, PspA is a promising new candidate vaccine antigen for the vaccination of children and elderly people [70,71]. Based on the advantages of PspA for the generation of protective immunity against all serotypes of S. pneumoniae, cCHP PspA nanogel has been developed, and its safety and efficacy have been investigated both in mice and in nonhuman primates [49,50]. When cCHP PspA nanogel was intranasally administered to mice three times at 1-week intervals, antigen-specific IgG was significantly increased both in serum and in bronchial fluid [49]. Antigen-specific SIgA in nasal fluid was also elevated. In contrast, administration of PspA antigen alone failed to induce an antigenspecific antibody response [49]. These results indicate that PspA antigen is efficiently
delivered to nasal epithelium and taken up by DCs in the nasal cavity for the initiation of an antigen-specific immune response. Furthermore, bacterial growth after S. pneumoniae infection was suppressed both in the lung and in the nasal cavity of the mice vaccinated with cCHP PspA nanogel, but not in the mice that received PspA alone [49]. Consequently, the cCHP PspA vaccinated mice survived after lethal challenge with S. pneumoniae [49]. The protective immunity elicited by the cCHP PspA nanogel was a humoral immune response, and was accompanied by the production of both Th2- and Th17type cytokines by antigen-specific CD41 T cells, which are associated with protective immunity against S. pneumoniae [49]. To examine the clinical applicability the cCHP-based pneumococcal vaccine in humans, the safety and immunogenicity of cCHP PspA were analyzed in cynomolgus macaques (Macaca fascicularis) [50]. To confirm the deposition and fate of vaccine antigen in the nasal cavity, olfactory bulbs, and central nervous system, a positron emission tomography study combined with magnetic resonance imaging was performed after nasal administration of 18Flabeled PspA in the macaques. cCHP 18F-PspA nanogel was retained at the nasal epithelium for as long as 6 hours after administration, whereas 18 F-PspA antigen alone had been eliminated from the nasal cavity by 3 hours after administration [50]. Furthermore, no nanogel-delivered antigen was found in the olfactory bulb or brain, even at 6 hours after nasal immunization, suggesting that the cCHP PspA nanogel nasal vaccine does not have neurological side effects. When the cCHP PspA nanogel was nasally administered to cynomolgus macaques five times at 2-week intervals, PspA-specific IgG was markedly elevated in serum and then gradually diminished over a period of 8 months [50]. Similarly, PspA-specific SIgA was elevated in nasal washes as well as bronchoalveolar lavage fluids, and it then decreased in the same manner as did PspA-specific IgG in the serum. After
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
VII. CONCLUDING REMARKS AND FUTURE PERSPECTIVES
these macaques received a nasal administration of cCHP PspA nanogel at 9 months after the final immunization, PspA-specific IgG and SIgA were rapidly boosted to the levels achieved with the primary responses [50]. This suggests that the cCHP PspA nanogel vaccine effectively induces antigen-specific immunological memory. In addition, mice that received PspA-specific antibodies transferred from the macaques exhibited protection against lethal challenge with S. pneumoniae via the production of neutralizing antibodies [50]. Together, these results show that the cCHP PspA nanogel is a promising nasal vaccine candidate for the prevention and control of diseases caused by S. pneumoniae.
VI. APPLICATION OF CCHP NASAL VACCINES AGAINST NONINFECTIOUS DISEASES Recently, cCHP nasal vaccines against obesity and hypertension have been developed, confirming that cCHP vaccines are effective against not only infectious diseases, but also lifestyle-related diseases [76,77]. In the antiobesity vaccine, a ghrelin PspA fusion protein was used, where ghrelin is the vaccine antigen and PspA is the carrier protein. Ghrelin is a peptide hormone produced in the stomach that promotes secretion of growth hormone from the pituitary gland, which stimulates the hypothalamus to enhance appetite [76]. When the ghrelin PspA fusion protein was encapsulated in a cationic nanogel mixed with cyclic guanosine diphosphate as an adjuvant and administered to diet-induced obese mice, both ghrelin-specific IgG in the serum and energy consumption were increased. As a result, both the amount of visceral fat and the body weight were decreased in treated mice compared with untreated mice [76]. A hypertension vaccine has also been developed. Angiotensin II receptor type 1 (AT1R)
471
promotes the functional and structural integrity of the arterial wall and contributes to vascular homeostasis, but it also causes an increase in blood pressure [77]. When an AT1R PspA conjugate was encapsulated in a nanogel mixed with cyclic guanosine diphosphate and administered to hypertensive rats, both AT1R- and PspA-specific IgG levels were elevated in the serum, the onset of hypertension was attenuated, and the rats were protected from lethal challenge with S. pneumoniae [77]. Since hypertension is reported to increase the mortality risk from pneumonia, a single nasal vaccine against both diseases would be of great value. From the results of these two studies, cCHPbased nasal vaccines are expected to be a major part of the next generation of therapies for the treatment of lifestyle-related diseases because of their noninvasiveness and long period of efficacy.
VII. CONCLUDING REMARKS AND FUTURE PERSPECTIVES Nanomaterials are promising tools for improving the immunogenicity of vaccines and effectively delivering antigens and/or adjuvants to mucosal surfaces. It is possible to increase the efficiency of antigen uptake into mucosal tissues, including MALT, by modifying the size and surface properties of these nanomaterials. cCHP nanogel is a vaccine-delivery system that is close to being ready for use in the clinical setting. After nasal administration, cCHP nanogel has excellent safety and efficacy profiles with respect to the induction of protective immunity in both the systemic and mucosal immune compartments. Although cCHP nanogel itself has no biological adjuvant activity, it delivers vaccine antigens to the nasal epithelium and follicle-associated epithelium of the NALT and to DCs in the nasal cavity; therefore, it is capable of inducing antigen-specific
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
472
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
immune responses in both systemic and mucosal immune compartments even in the absence of an adjuvant. As a result, it induces humoral immune responses providing protection against infection. cCHP nanogel-based nasal vaccines are showing promise as the next generation of vaccines to prevent infectious diseases. However, before these vaccines can be used in the clinical setting, manufacturing techniques and guidelines for their preparation must first be developed through collaboration among industry, academia, and government.
ABBREVIATIONS AT1R BoHc cCHP C-CPE DC Ig IL MALT NALT PCV PEG PLA PLGA PPSV PspA RSV SIgA
angiotensin II receptor type 1 Botulinum type A neurotoxin fragment cationic formulation of cholesterylgroup-bearing pullulan C-terminal fragment of Clostridium perfringens enterotoxin dendritic cell immunoglobulin interleukin mucosa-associated lymphoid tissue nasopharynx-associated lymphoid tissue pneumococcal polysaccharide conjugate vaccine polyethylene glycol polylactic acid poly(lactic-co-glycolic acid) pneumococcal polysaccharide vaccine pneumococcal surface protein A respiratory syncytial virus secretory IgA
References [1] Kiyono H, Kunisawa J, McGhee JR, Mestecky J. The mucosal immune system. In: Paul WE, editor. Fundamental immunology. Philadelphia: Lippincott Williams & Wilkins; 2008. p. 983 1030.
[2] Nochi T, Takagi H, Yuki Y, Yang L, Masumura T, Mejima M, et al. Rice-based mucosal vaccine as a global strategy for cold-chain- and needle-free vaccination. Proc Natl Acad Sci USA 2007;104(26):10986 91. [3] Azegami T, Yuki Y, Kiyono H. Challenges in mucosal vaccines for the control of infectious diseases. Int Immunol 2014;26(9):517 28. [4] Ogra PL. Mucosal immunity: some historical perspective on host-pathogen interactions and implications for mucosal vaccines. Immunol Cell Biol 2003;81:23 33. [5] Nochi T, Yuki Y, Matsumura A, Mejima M, Terahara K, Kim DY, et al. A novel M cell-specific carbohydratetargeted mucosal vaccine effectively induces antigenspecific immune responses. J Exp Med 2007;204 (12):2789 96. [6] Kiyono H, Fukuyama S. NALT- versus Peyer’s-patchmediated mucosal immunity. Nat Rev Immunol 2004;4 (9):699 710. [7] Dkhar LK, Bartley J, White D, Seyfoddin A. Intranasal drug delivery devices and interventions associated with post-operative endoscopic sinus surgery. Pharm Dev Technol 2018;23(3):282 94. [8] Holmgren J, Czerkinsky C. Mucosal immunity and vaccines. Nat Med 2005;11:45 53. [9] Jones N. The nose and paranasal sinuses physiology and anatomy. Adv Drug Deliv Rev 2001;51(1 3):5 19. [10] Oliveria P, Fortuna A, Alves G, Falcao A. Drugmetabolizing enzymes and efflux transporters in nasal epithelium: influence on the bioavailability of intranasally administered drugs. Curr Drug Metab 2016;17 (7):628 47. [11] Haan L, Verweij WR, Holtrop M, Brands R, van Scharrenburg GJ, Palache AM, et al. Nasal or intramuscular immunization of mice with influenza subunit antigen and the B subunit of Escherichia coli heat-labile toxin induces IgA- or IgG-mediated protective mucosal immunity. Vaccine 2001;19:2898 907. [12] Riese P, Sakthivel P, Trittel S, Guzma´n CA. Intranasal formulations: promising strategy to deliver vaccines. Expert Opin Drug Deliv 2014;11(10):1619 34. [13] Srivastava A, Gowda DV, Madhunapantula SV, Shinde CG, Iyer M. Mucosal vaccines: a paradigm shift in the development of mucosal adjuvants and delivery vehicles. APMIS 2015;123(4):275 88. [14] Aoshi T. Modes of action for mucosal vaccine adjuvants. Viral Immunol 2017;30(6):463 70. [15] Mutsch M, Zhou W, Rhodes P, Bopp M, Chen RT, Linder T, et al. Use of the inactivated intranasal influenza vaccine and the risk of Bell’s palsy in Switzerland. N Engl J Med 2004;350(9):896 903. [16] Kuper CF, Koornstra PJ, Hameleers DM, Biewenga J, Spit BJ, Duijvestijn AM, et al. The role of nasopharyngeal lymphoid tissue. Immunol Today 1992;13:219 24.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
REFERENCES
[17] Rerry M, Whyte A. Immunology of the tonsils. Immunol Today 1998;19:414 20. [18] Kim DY, Sato A, Fukuyama S, Sagara H, Nagatake T, Kong IG, et al. The airway antigen sampling system: respiratory M cells as an alternative gateway for inhaled antigens. J Immunol 2011;186(7):4253 62. [19] Sonoda E, Matsumoto R, Hitoshi Y, Ishii T, Sugimoto M, Araki S, et al. Transforming growth factor beta induces IgA production and acts additively with interleukin 5 for IgA production. J Exp Med 1989;170: 1415 20. [20] Coffman RL, Lebman DA, Shrader B. Transforming growth factor beta specifically enhances IgA production by lipopolysaccharide-stimulated murine B lymphocytes. J Exp Med 1989;170(3):1039 44. [21] Horikawa K, Takatsu K. Interleukin-5 regulates genes involved in B-cell terminal maturation. Immunology 2006;118:497 508. [22] Neutra MR, Kozlowski PA. Mucosal vaccines: the promise and the challenge. Nat Rev Immunol 2006;6 (2):148 58. [23] McGhee JR, Fujihashi K, Beagley KW, Kiyono H. Role of interleukin-6 in human and mouse mucosal IgA plasma cell responses. Immunol Res 1991;10(3 4): 418 22. [24] Kaetzel CS. The polymeric immunoglobulin receptor: bridging innate and adaptive immune responses at mucosal surfaces. Immunol Rev 2005;206:83 99. [25] Williams RC, Gibbons RJ. Inhibition of bacterial adherence by secretory immunoglobulin A: a mechanism of antigen disposal. Science 1972;177:697 9. [26] Taylor HP, Dimmock NJ. Mechanism of neutralization of influenza virus by secretory IgA is different from that of monomeric IgA or IgG. J Exp Med 1985;161: 198 209. [27] Brandtzaeg P. Mucosal immunity: induction, dissemination, and effector functions. Scand J Immunol 2009;70(6):505 15. [28] Bentley AM, Durham SR, Robinson DS, Menz G, Storz C, Cromwell O, et al. Expression of endothelial and leukocyte adhesion molecules intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 in the bronchial mucosa in steady-state and allergen-induced asthma. J Allergy Clin Immunol 1993;92(6):857 68. [29] Campbell JJ, Brightling CE, Symon FA, Qin S, Murphy KE, Hodge M, et al. Expression of chemokine receptors by lung T cells from normal and asthmatic subjects. J Immunol 2001;166(4):2842 8. [30] Brinkman CC, Peske JD, Engelhard VH. Peripheral tissue homing receptor control of naı¨ve, effector, and memory CD8 T cell localization in lymphoid and nonlymphoid tissues. Front Immunol 2013;4:241.
473
[31] Brandtzaeg P, Johansen FE. Mucosal B cells: phenotypic characteristics, transcriptional regulation, and homing properties. Immunol Rev 2005;206:32 63. [32] Joo S, Fukuyama Y, Park EJ, Yuki Y, Kurashima Y, Ouchida R, et al. Critical role of TSLP-responsive mucosal dendritic cells in the induction of nasal antigen-specific IgA response. Mucosal Immunol 2017;10(4):901 11. [33] Patel GB, Ponce A, Zhou H, Chen W. Structural characterization of archaeal lipid mucosal vaccine adjuvant and delivery (AMVAD) formulations prepared by different protocols and their efficacy upon intranasal immunization of mice. J Liposome Res 2008;18 (2):127 43. [34] Hall MA, Stroop SD, Hu MC, Walls MA, Reddish MA, Burt DS, et al. Intranasal immunization with multivalent group A streptococcal vaccines protect mice against intranasal challenge infections. Infect Immun 2004;72(5):2507 12. [35] Baca-Estrada ME, Foldvari MM, Snider MM, Harding KK, Kournikakis BB, Babiuk LA, et al. Intranasal immunization with liposome-formulated Yersinia pestis vaccine enhances mucosal immune responses. Vaccine 2000;18(21):2203 11. [36] Makidon PE, Nigavekar SS, Bielinska AU, Mank N, Shetty AM, Suman J, et al. Characterization of stability and nasal delivery systems for immunization with nanoemulsion-based vaccines. J Aerosol Med Pulm Drug Deliv 2010;23(2):77 89. [37] Myc A, Kukowska-Latallo JF, Smith DM, Passmore C, Pham T, Wong P, et al. Nanoemulsion nasal adjuvant W805EC induces dendritic cell engulfment of antigenprimed epithelial cells. Vaccine 2013;31(7):1072 9. [38] Myc A, Kukowska-Latallo JF, Bielinska AU, Cao P, Myc PP, Janczak K, et al. Development of immune response that protects mice from viral pneumonitis after a single intranasal immunization with influenza A virus and nanoemulsion. Vaccine 2003;21(25 26):3801 14. [39] Bielinska AU, Janczak KW, Landers JJ, Makidon P, Sower LE, Peterson JW, et al. Mucosal immunization with a novel nanoemulsion-based recombinant anthrax protective antigen vaccine protects against Bacillus anthracis spore challenge. Infect Immun 2007;75 (8):4020 9. [40] Almeida AJ, Alpar HO, Brown MR. Immune response to nasal delivery of antigenically intact tetanus toxoid associated with poly (l-lactic acid) microspheres in rats, rabbits and guinea-pigs. J Pharm Pharmacol 1993;45:198 203. [41] Byrd W, Cassels FJ. Intranasal immunization of BALB/c mice with enterotoxigenic Escherichia coli colonization factor CS6 encapsulated in biodegradable poly(DL-lactideco-glycolide) microspheres. Vaccine 2006;24(9):1359 66.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
474
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
[42] Vila A, Sa´nchez A, Tobı´o M, Calvo P, Alonso MJ. Design of biodegradable particles for protein delivery. J Control Release 2002;78(1 3):15 24. [43] Amidi M, Romeijn SG, Verhoef JC, Junginger HE, Bungener L, Huckriede A, et al. N-trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination: biological properties and immunogenicity in a mouse model. Vaccine 2007;25(1):144 53. [44] Iqbal M, Lin W, Jabbal-Gill I, Davis SS, Steward MW, Illum L. Nasal delivery of chitosan-DNA plasmid expressing epitopes of respiratory syncytial virus (RSV) induces protective CTL responses in BALB/c mice. Vaccine 2003;21(13 14):1478 85. [45] Xu W, Shen Y, Jiang Z, Wang Y, Chu Y, Xiong S. Intranasal delivery of chitosan-DNA vaccine generates mucosal SIgA and anti-CVB3 protection. Vaccine 2004;22(27 28):3603 12. [46] Pawar D, Mangal S, Goswami R, Jaganathan KS. Development and characterization of surface modified PLGA nanoparticles for nasal vaccine delivery: effect of mucoadhesive coating on antigen uptake and immune adjuvant activity. Eur J Pharm Biopharm 2013;85(3 Pt A):550 9. [47] Vila A, Sa´nchez A, Evora C, Soriano I, Vila Jato JL, Alonso MJ. PEG-PLA nanoparticles as carriers for nasal vaccine delivery. J Aerosol Med 2004;17 (2):174 85. [48] Nochi T, Yuki Y, Takahashi H, Sawada S, Mejima M, Kohda T, et al. Nanogel antigenic protein-delivery system for adjuvant-free intranasal vaccines. Nat Mater 2010;9(7):572 8. [49] Kong IG, Sato A, Yuki Y, Nochi T, Takahashi H, Sawada S, et al. Nanogel-based PspA intranasal vaccine prevents invasive disease and nasal colonization by Streptococcus pneumoniae. Infect Immun 2013;81 (5):1625 34. [50] Fukuyama Y, Yuki Y, Katakai Y, Harada N, Takahashi H, Takeda S, et al. Nanogel-based pneumococcal surface protein A nasal vaccine induces microRNAassociated Th17 cell responses with neutralizing antibodies against Streptococcus pneumoniae in macaques. Mucosal Immunol 2015;8(5):1144 53. [51] Peek LJ, Middaugh CR, Berkland C. Nanotechnology in vaccine delivery. Adv Drug Deliv Rev 2008;60 (8):915 28. [52] Baca-Estrada ME, Foldvari M, Babiuk SL, Babiuk LA. Vaccine delivery: lipid-based delivery systems. J Biotechnol 2000;83:91 104. [53] Kim MG, Park JY, Shon Y, Kim G, Shim G, Oh YK. Nanotechnology and vaccine development. Asian J Pharm Sci 2014;9:227 35.
[54] Ko¨ping-Ho¨gga˚rd M, Sa´nchez A, Alonso MJ. Nanoparticles as carriers for nasal vaccine delivery. Expert Rev Vaccines 2005;4(2):185 96. [55] Akagi T, Baba M, Akashi M. Biodegradable nanoparticles as vaccine adjuvants and delivery systems: regulation of immune responses by nanoparticle-based vaccine. Adv Polym Sci 2012;247:31 64. [56] Bobo D, Robinson KJ, Islam J, Thurecht KJ, Corrie SR. Nanoparticle-based medicines: a review of FDAapproved materials and clinical trials to date. Pharm Res 2016;33(10):2373 87. [57] Kang ML, Cho CS, Yoo HS. Application of chitosan microspheres for nasal delivery of vaccines. Biotechnol Adv 2009;27(6):857 65. [58] Dodane V, Khan MA, Merwin JR. Effect of chitosan on epithelial permeability and structure. Int J Pharm 1999;182:21 32. [59] Ayame H, Morimoto N, Akiyoshi K. Self-assembled cationic nanogels for intracellular protein delivery. Bioconjug Chem 2008;19(4):882 90. [60] Sasaki Y, Akiyoshi K. Nanogel engineering for new nanobiomaterials: from chaperoning engineering to biomedical applications. Chem Rec 2010;10(6):366 76. [61] Nakahashi-Ouchida R, Yuki Y, Kiyono H. Development of a nanogel-based nasal vaccine as a novel antigen delivery system. Expert Rev Vaccines 2017;16(12):1231 40. [62] Baldwin AL, Wu NZ, Stein DL. Endothelial surface charge of intestinal mucosal capillaries and its modulation by dextran. Microvasc Res 1991;42(2):160 78. [63] Yuki Y, Nochi T, Harada N, Katakai Y, Shibata H, Mejima M, et al. In vivo molecular imaging analysis of a nasal vaccine that induces protective immunity against botulism in nonhuman primates. J Immunol 2010;185(9):5436 43. [64] Cilloniz C, Amaro R, Torres A. Pneumococcal vaccination. Curr Opin Infect Dis 2016;29(2):187 96. [65] Dinleyici EC. Current status of pneumococcal vaccines: lessons to be learned and new insights. Expert Rev Vaccines 2010;9(9):1017 22. [66] Haas KM, Blevins MW, High KP, Pang B, Swords WE, Yammani RD. Aging promotes B-1b cell responses to native, but not protein-conjugated, pneumococcal polysaccharides: implications for vaccine protection in older adults. J Infect Dis 2014;209(1):87 97. [67] Laferriere C. The immunogenicity of pneumococcal polysaccharides in infants and children: a metaregression. Vaccine 2011;29(40):6838 47. [68] Richter SS, Heilmann KP, Dohrn CL, Riahi F, Diekema DJ, Doern GV. Pneumococcal serotypes before and after introduction of conjugate vaccines, United States, 1999-2011(1). Emerg Infect Dis 2013;19(7):1074 83.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
475
REFERENCES
[69] Weinberger DM, Malley R, Lipsitch M. Serotype replacement in disease after pneumococcal vaccination. Lancet 2011;378(9807):1962 73. [70] Berry AM, Yother J, Briles DE, Hansman D, Paton JC. Reduced virulence of a defined pneumolysin-negative mutant of Streptococcus pneumoniae. Infect Immun 1989;57(7):2037 42. [71] McDaniel LS, Yother J, Vijayakumar M, McGarry L, Guild WR, Briles DE. Use of insertional inactivation to facilitate studies of biological properties of pneumococcal surface protein A (PspA). J Exp Med 1987;165 (2):381 94. [72] Nguyen CT, Kim SY, Kim MS, Lee SE, Rhee JH. Intranasal immunization with recombinant PspA fused with a flagellin enhances cross-protective immunity against Streptococcus pneumoniae infection in mice. Vaccine 2011;29(34):5731 9. [73] Xu J, Dai W, Wang Z, Chen B, Li Z, Fan X. Intranasal vaccination with chitosan-DNA nanoparticles expressing pneumococcal surface antigen a protects mice against nasopharyngeal colonization by
[74]
[75]
[76]
[77]
Streptococcus pneumoniae. Clin Vaccine Immunol 2011;18(1):75 81. Suzuki H, Watari A, Hashimoto E, Yonemitsu M, Kiyono H, Yagi K, et al. C-Terminal Clostridium perfringens enterotoxin-mediated antigen delivery for nasal pneumococcal vaccine. PLoS One 2015;10(5):e0126352. Fukuyama Y, King JD, Kataoka K, Kobayashi R, Gilbert RS, Hollingshead SK, et al. A combination of Flt3 ligand cDNA and CpG oligodeoxynucleotide as nasal adjuvant elicits protective secretory-IgA immunity to Streptococcus pneumoniae in aged mice. J Immunol 2011;186(4):2454 61. Azegami T, Yuki Y, Sawada S, Mejima M, Ishige K, Akiyoshi K, et al. Nanogel-based nasal ghrelin vaccine prevents obesity. Mucosal Immunol 2017;10(5): 1351 60. Azegami T, Yuki Y, Hayashi K, Hishikawa A, Sawada SI, Ishige K, et al. Intranasal vaccination against angiotensin II type 1 receptor and pneumococcal surface protein A attenuates hypertension and pneumococcal infection in rodents. J Hypertens 2018;36(2):387 94.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
26 Nanodelivery Vehicles for Mucosal Vaccines Rika Nakahashi-Ouchida1,2, Yoshikazu Yuki1,2 and Hiroshi Kiyono1,2,3,4 1
Division of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, University of Tokyo, Tokyo, Japan 2International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, University of Tokyo, Tokyo, Japan 3Mucosal Immunology and Allergy Therapeutics, Graduate School of Medicine, Chiba University, Chiba, Japan 4 Division of Gastroenterology, Department of Medicine, (CU-UCSD cMAV) Center for Mucosal Immunology, Allergy and Vaccines, University of California, San Diego, CA, United States
I. INTRODUCTION Infectious agents such as viruses and bacteria generally invade the host via the mucosal surfaces of the respiratory and gastrointestinal tracts. To protect the host from invasion and to prevent the spread of pathogens, the induction of neutralizing antibody-based humoral immunity and/or cell-mediated immunity against pathogens at the mucosal surface is a logical strategy [1]. Oral and nasal vaccines that can effectively induce antigen-specific immune responses at mucosal surfaces and in systemic immune compartments [2,3] and mucosal vaccines that target various infectious diseases are currently under development [4]. The nasal cavity is considered to be a particularly attractive site for antigen deposition because the Mucosal Vaccines DOI: https://doi.org/10.1016/B978-0-12-811924-2.00026-2
nasal mucosa has the capacity to facilitate an active antigen uptake, processing, and presenting system in the form of microfold (M) cells and dendritic cells (DCs), and because it also has the nasopharyngeal-associated lymphoid tissue (NALT) for the induction of antigenspecific immune responses in respiratory tissues [5,6]. Furthermore, the nasal cavity is enriched with blood vessels, so antigens are rapidly transported into the circulation and are ultimately deposited in peripheral lymph nodes for initiation of antigen-specific systemic immune responses [7]. In addition to the induction of antigen-specific immune responses in the upper and lower respiratory tracts, nasal vaccination has been shown to effectively induce antigen-specific immune responses at distal mucosal surfaces, particularly the
461
© 2020 Elsevier Inc. All rights reserved.
462
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
reproductive tract [8] (Chapter 2: Anatomical Uniqueness of the Mucosal Immune System (GALT, NALT, iBALT) for the Induction and Regulation of Mucosal Immunity and Tolerance and Chapter 18: Mucosal Regulatory System for the Balanced Immunity in the Middle Ear and Nasopharynx). Although the nasal cavity is an attractive location for mucosal vaccination, there are physical and chemical protective barriers that must be overcome for successful nasal vaccination. For example, mucociliary clearance is an innate defense mechanism that uses ciliary movement and a mucous layer to exclude inhaled microbes and foreign substances, including vaccine antigens, from the nasal cavity [9]. Moreover, epithelial cells provide a physical barrier in the form of tight junctions between cells and a chemical barrier in the form of antimicrobial peptide secretion. In addition to these barriers, metabolic enzymes secreted by nasal glands, mucus produced by goblet cells, and transudate from plasma are present in the nasal cavity. Thus, there is a high possibility that vaccine antigens delivered to the nasal cavity will be decomposed or excluded before an antigen-specific immune response is evoked [10]. Because of these protective barriers in the nasal cavity, the accessibility to and adsorption of nasally administered vaccine antigen by the mucosal immune system means that nasal vaccination is less effective than other types of vaccination (e.g., subcutaneous or intramuscular injection). Consequently, large amounts of antigen are often required for administration, and all the while only a weak antigen-specific immune response is induced [11]. To date, this issue has been addressed by the use of various combinations of live vectors, inactivated antigens, artificial-antigen-delivery vehicles, and sometimes mucosal adjuvants [12 14]. An inactivated intranasal influenza vaccine (Nasalflu) containing Escherichia coli heat-labile toxin as an adjuvant was approved for use in Switzerland during the 2001 02 influenza season [15]. Although the vaccine was found to
induce protective immunity, several cases of facial nerve palsy (Bell’s palsy) were reported during postmarketing surveillance, and the vaccine was withdrawn as a result of safety concerns [15]. This incident clearly highlighted the potential for nasal vaccines to affect the central nervous system via the olfactory nerve and raised the bar for nasal vaccine development. Thus, effective and safe nasal vaccines should be able to (1) overcome various physical and chemical barriers at the nasal mucosa for efficient delivery of vaccine antigen, (2) induce an effective antigen-specific immune response with or without a mucosal adjuvant, and (3) have a suitable safety profile and not influence the central nervous system.
II. CHARACTERISTICS OF THE NASAL IMMUNE SYSTEM A. Structure and Function of Nasopharyngeal-Associated Lymphoid Tissue The mucosal immune system can be subdivided into inductive and effector sites (Fig. 26.1). The inductive sites are collectively referred to as mucosa-associated lymphoid tissue (MALT), and this is where antigensampling M cells are located and follicleassociated epithelium and immunocompetent cells such as T and B lymphocytes, DCs, and macrophages accumulate in high numbers [8]. In rodents, the nasal immune system contains NALT, which is located basally on both sides of the rodent nasal cavity, and is responsible for the initiation of antigen-specific immune responses [16]. In humans, the paired palatine tonsils and the unpaired nasopharyngeal tonsils (adenoids), which are two components of Waldeyer’s ring, are thought to be functionally related to the NALT in rodent [17]. The NALT is covered with follicle-associated epithelium, which contains M cells, which specialize in the uptake transcytosis of antigens from the
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
II. CHARACTERISTICS OF THE NASAL IMMUNE SYSTEM
463
FIGURE 26.1 The mucosal immune system. Antigens are taken up by microfold (M) cells and then captured by antigenpresenting cells such as dendritic cells. Antigen-primed T and B lymphocytes express homing or polymeric molecules and chemokine receptors and migrate to the effector site through the thoracic ducts and blood circulation. IgA1 B cells differentiate into plasma cells by IgA-enhancing cytokines such as IL-6 and IL-10 secreted from Th2 cells. Dimeric IgA secreted from plasma cells is transported to the mucosal surface as secretory secretory IgA (SIgA) through the polymeric Ig receptor (pIgR) expressed on the basal membrane of epithelial cells.
mucosal lumen to antigen-presenting cells (e.g., DCs) for processing and presentation to T and B lymphocytes. There is also a special subset of M cells, called respiratory M cells, that exist as a monolayer on top of the single layer of epithelium that covers the lateral surfaces of the nasal turbinates [18]. Respiratory M cells resemble classical M cells with their depressed surface and irregular microvilli, but unlike classical M cells, they do not have a pocket on their basolateral side [18]. Like classical M cells, respiratory
M cells can take up soluble protein or bacterial antigens and therefore are an antigen-sampling pathway for the nasal immune system.
B. Mechanism for the Induction of Antigen-Specific Nasal Immune Responses After antigens have been captured by M cells, these are transported via transcytosis to antigen-presenting cells such as DCs located
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
464
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
beneath the epithelial layer or follicleassociated epithelium (Fig. 26.1). DCs process these antigens and present the peptide together with major histocompatibility complex II to CD41 T cells located at induction sites. Antigen-primed CD41 T cells secret cytokines such as transforming growth factor beta and interleukin 5 (IL-5) and promote isotype class switching in B cells from immunoglobulin M to A [19 21]. Eventually, the antigen-specific T cells and IgA1 B cells migrate to effector sites via the thoracic ducts, blood circulation, and lymphocyte homing system (discussed in the next section) [22]. IgA1 B cells then terminally differentiate into plasma cells that secrete dimeric or polymeric IgA in the presence of IL6 and IL-10 produced by T helper cells [23]. At effector sites, dimeric or polymeric IgA binds to polymeric immunoglobulin receptor, a transmembrane protein expressed on the basement membrane of nasal epithelial cells, and then forms secretory IgA (SIgA), which is secreted into the lumen [24]. SIgA promotes the clearance of pathogens via direct binding and neutralizing activity to prevent pathogen invasion and proliferation at mucosal surfaces. Thus, SIgA plays a central role in the mucosal immune system as a first line of defense [25,26] (Chapter 4: Protective Activities of Mucosal Antibodies).
C. Lymphocyte Imprinting and Homing Mechanisms in the Nasal Immune System The lymphocyte homing system interconnects the inductive and effector sites of the mucosal immune system [27]. In the case of the nasal immune system, antigen-stimulated lymphocytes express α4β1 integrin, which is a receptor for vascular cell adhesion molecule-1 and C-C motif chemokine receptor 10, which is a receptor for C-C motif chemokine ligand 28 [28 30]. Because vascular cell adhesion molecule-1 and C-C motif chemokine ligand 28 are predominantly expressed by vascular
endothelial cells and epithelial cells in mucosal tissues, α4β1- and C-C motif chemokine receptor 10-positive lymphocytes preferentially migrate from the NALT to the respiratory tract, salivary glands, mammary glands, lacrimal glands, and genitourinary tract via the thoracic ducts and blood circulation after antigen stimulation and acquiring these imprinting molecules [31]. It has been shown that the thymic stromal lymphopoietin thymic stromal lymphopoietin receptor signaling cascade is important for the induction of antigen-specific IgA production following nasal administration of antigens [32]. This signaling cascade has been shown to enhance IgA production via the induction of IL-6 production in mucosal DCs after nasal immunization of antigen together with cholera toxin adjuvant, suggesting that adjuvants that promote activation of the thymic stromal lymphopoietin-mediated signaling may be useful for effective mucosal vaccine development.
III. DRUG-DELIVERY SYSTEMS FOR NASAL VACCINES The use of various nanoparticle-based delivery systems for nasal vaccines has been examined (Table 26.1). The chemical and physical properties of nanomaterials can be controlled via surface modification, which makes it easy to encapsulate vaccine antigens and/or adjuvants within the nanomaterials or make vaccine antigen nanomaterial complexes via noncovalent binding or covalent interactions [51]. Liposomes have been examined for their suitability as carriers for mucosal vaccines. Since liposomes are amphipathic, antigens and adjuvants can be encapsulated within the aqueous space regardless of their hydrophilicity and hydrophobicity [52]. To maximize vaccine immunogenicity, the physicochemical properties of liposomes, such as their size, lipid composition, and structure, can be adjusted on the
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
465
III. DRUG-DELIVERY SYSTEMS FOR NASAL VACCINES
TABLE 26.1
Studies Using Nanoparticles for Nasal Vaccines
Delivery system
Materials
Antigens
Reference
Lipid nanoparticles
Liposome
Ovalbumin
[33]
Multivalent group A streptococcal M protein
[34]
Formaldehyde-killed whole cell of Yersinia pestis
[35]
Ovalbumin
[36]
Ovalbumin
[37]
X8P
Influenza A
[38]
W205EC
Bacillus anthracis
[39]
Polylactic acid (PLA)
Tetanus toxoid
[40]
Poly(lactic-glycolic acid) (PLGA)
Enterotoxigenic Escherichia coli colonization factor CS6
[41]
Chitosan PLGA
Tetanus toxoid
[42]
Chitosan
Influenza subunit
[43]
RSV M2 protein expressing plasmid
[44]
VP1 protein of Coxsackie virus B3
[45]
Glycol chitosan PLGA
Hepatitis B surface antigen
[46]
PLA polyethylene glycol
Tetanus toxoid
[47]
cCHP
Botulinum type A neurotoxin fragment
[48]
Pneumococcal surface protein A
[49]
Pneumococcal surface protein A
[50]
Emulsion
Polymeric nanoparticles
W805EC
basis of the specific characteristics of the vaccine antigen [52]. Several studies have utilized liposomes for the development of nasal vaccines [33 35]. For example, nasal immunization with a liposome-formulated Yersinia pestis formaldehyde-killed whole cell vaccine significantly enhanced not only the antigen-specific immune response in systemic immune compartments, but also the amount of IgA and IgG in mucosal secretions in the lung and nasal cavity and consequently protected mice from intranasal lethal challenge with Y. pestis when compared with mice immunized with the formaldehyde-killed whole-cell vaccine alone [35] (Chapter 19: Current and New Approaches for Mucosal Vaccine Delivery).
Nanomaterial emulsions (nanoemulsions), which are water-in-oil formulations stabilized by small amounts of surfactant, can also be used to deliver vaccines because they can trap antigens inside their core [53]. For instance, nasal administration of the nanoemulsion W805EC, which is composed of cetylpyridinium chloride, Tween 80, ethanol, and soybean oil, promoted engulfment and antigen presentation by DCs and evoked an immune response to the model antigen ovalbumin in mice [36,37]. Other nanoemulsions have been examined for the development of influenza or Bacillus anthracis vaccines [38,39]. In the case of influenza, the nanoemulsion X8P, which is composed of tributyl phosphate, Triton X-100, and soybean oil in
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
466
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
water, was mixed with inactivated influenza A to create a vaccine. Nasal vaccination with this mixture protected mice from death or viral pneumonitis after lethal challenge with a congenic strain of influenza virus [38]. Similarly, the nanoemulsion W205EC, which is composed of cetylpyridinium chloride, Tween 20, and ethanol in water with hot-pressed soybean oil, has been used as an adjuvant in a mixture with B. anthracis antigen rPA [39]. Nasal immunization with one or two doses of the mixture elicited an antigen-specific systemic IgG response as well as bronchial IgA and IgG responses and T helper 1 (Th1)-polarized cytokine secretion by splenocytes in mice. High titers of toxin-neutralizing serum IgG obtained in both mice and guinea pigs were found to protect the guinea pigs from intradermal or intranasal lethal challenge with B. anthracis [39]. Of the different nanoparticles examined to date, polymers are the best-studied carriers, with polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) being the most-studied synthetic polymers [54]. With these two polymers, it is possible to control the rate of release of vaccine antigen by changing the composition ratio and molecular weight of PLA and glycolic acid in the formulation [40,55]. Furthermore, these synthetic polymers are superior in biocompatibility and biodegradability and have high practicability, and they have been approved by the US Food and Drug Administration for use in nanomedicine formulations [56]. Tetanus toxoid has been adsorbed onto PLA, and E. coli colonization factor CS6 has been encapsulated in PLGA microspheres [40,41]. Nasal administration of PLA-adsorbed tetanus toxoid to guinea pigs enhanced the antigenspecific immune response compared to those administered free antigen [40]. Similarly, nasal administration of CS6 encapsulated in PLGA led to greater fecal IgG and IgA immune responses compared to mice that were administered noncapsulated antigen [41]. New formulations using PLA or PLGA to polymerize with polyethylene glycol (PEG) or chitosan are being
tested to improve the stability of vaccine formulations [42]. It has been reported that nasal administration of tetanus toxoid-encapsulated in PLA PEG nanoparticles (PLA polymerized with PEG) generates high, long-lasting tetanus toxoid-specific immunity compared to tetanus toxoid-encapsulated in PLA alone [42]. Chitosan is a well-studied natural polymer [57]. It has mucoadhesive properties and can loosen the tight junctions between epithelial cells, so it is a potentially useful molecule for promoting antigen uptake at the mucosal surface [58]. To take advantage of these characteristics of chitosan, nanoparticles containing N-trimethyl chitosan and monovalent influenza A subunit H3N2 have been developed as a prototype chitosan-based nasal influenza vaccine. Nasal immunization with this vaccine resulted in potent inhibition of hemagglutination that was dependent on the induction of antigenspecific IgG and SIgA responses [43]. Similarly, a plasmid DNA encoding the cytotoxic T lymphocyte epitope derived from respiratory syncytial virus (RSV) M2 protein has been combined with chitosan to develop a vaccine against RSV [44]. Nasal immunization with the chitosan DNA RSV vaccine induced a virusspecific cytotoxic T lymphocyte response in mice, and a significant reduction in virus titer was observed in the lung after RSV challenge compared with the results in a nonimmunized control group [44]. As a vaccine against Coxsackie virus B3 infection, which is the cause of acute and chronic myocarditis, nasal immunization of chitosan-DNA expressing VP1, a major structural protein of Coxsackie virus B3, induced antigen-specific serum IgG and mucosal SIgA responses and resulted in protection against intraperitoneal injection of a lethal dose of Coxsackie virus B3 in mice [45]. Furthermore, an immunogenicity study in mice revealed that nasal administration with hepatitis B virus antigen in combination with glycol chitosan PLGA polymers was more effective at inducing systemic and mucosal immune responses when compared to the antigen encapsulated with
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA
PLGA or chitosan PLGA polymers [46]. Glycol chitosan improves vaccine retention because this polymer remains on the mucous membrane owing to its better mucoadhesiveness arising from its positive charge, which leads to sustained antigen release. Furthermore, the effectiveness of hydrophilic PEG PLA particles as nasal transporters has been demonstrated by using tetanus toxoid as a model antigen [47]. In the presence of lysozyme, PLA nanoparticles immediately aggregate, whereas PEG PLA particles remain in their soluble form. Tetanus toxoid-specific antibody titers induced following nasal administration of PEG PLA tetanus toxoid are significantly higher and more prolonged than those following nasal administration of PLA tetanus toxoid [47]. It is thought that the PEG coating stabilizes the PLA particles in the mucosal fluid and facilitates the transport of the antigen to the nasal epithelium, where it elicits a long-lasting antigen-specific antibody immune response [47]. Cross-linked hydrogel vaccine antigen complexes can also be used to deliver vaccines to mucosal surfaces [48]. For instance, cationic formulations of cholesteryl-bearing pullulan (cCHP) nanogel can attach to negatively charged nasal mucosal epithelium because it has a positive charge [48]. As a result, sustained antigen release from the encapsulated vaccine and subsequent antigen uptake elicit antigen-specific immune responses both in systemic (e.g., IgG) and mucosal (e.g., IgA) compartments. The use of cCHP nanogel in nasal vaccines against infectious and noninfectious diseases is discussed in the remaining sections of this chapter.
IV. CCHP NANOGEL AS A DRUGDELIVERY SYSTEM FOR NASAL VACCINES cCHP nanogel is composed of cholesterolbound pullulan molecules that associate via
467
hydrophobic interactions to create a spherical structure (diameter, approx. 40 nm) [59 61]. Vaccine antigens can be easily incorporated into and released from the internal space of the cCHP nanogel sphere as a natural form owing to the artificial chaperone function of CHP nanogel [59]. To enhance attachment of CHP nanogel to the negatively charged mammalian nasal mucosal surface [62], cCHP nanogel in which an amino group has also been introduced to the pullulan molecules has been developed (Fig. 26.2) [59]. It has been shown that cCHP nanogel containing the C-terminus fragment of heavy chain of botulinum neurotoxin type A (BoHc) attaches strongly to the nasal mucosal epithelium after nasal administration (Fig. 26.3) [48]. After attachment, the BoHc antigen is gradually released from the cCHP nanogel and taken up by nasal epithelial cells and M cells for at least 12 hours after administration [48]. In addition, it has been shown that approximately 40% of nasal DCs take up the BoHc antigen after nasal administration of cCHP BoHc nanogel compared with only 2% after nasal administration of BoHc antigen alone, resulting in greater BoHc-specific serum IgG and SIgA responses and protection from lethal challenge with neurotoxin [48]. With respect to safety, the antigen itself does not migrate to the olfactory bulb after nasal administration, having no effect on the olfactory nerve [48,63]. These data suggest that cCHP nanogels are a safe, adjuvant-free means of delivering vaccine antigens to the nasal cavity and can induce effective antigen-specific immune responses in both systemic and mucosal compartments.
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA To verify the suitability of using cCHP nanogel to deliver vaccine antigen to the nasal cavity, a cCHP nanogel-based nasal vaccine
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
468
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
FIGURE 26.2
Schematic illustration of cCHP nanogel with artificial chaperone function. cCHP consists of a cholesterylgroup-bearing pullulan (CHP) introduced cationic amino group. cCHP nanogel can encapsulate proteins in the interior space through hydrophobic interactions and are effectively retained in the nasal mucosa, which is negatively charged following intranasal vaccination.
against respiratory infection has been developed. Streptococcus pneumoniae is a pathogen that causes bacterial pneumonia mainly in infants and the elderly and can lead to death as a result of severe upper respiratory tract infection [64]. Two intramuscular injection types of vaccines against pneumonia have been developed: pneumococcal polysaccharide vaccine (PPSV) and pneumococcal polysaccharide conjugate vaccine
(PCV) [65]. PPSV contains capsular polysaccharides purified from various serotypes of S. pneumoniae and induces antigen-specific responses in a T-cell-independent manner [66]. PCV is a conjugate vaccine containing capsular polysaccharides, a carrier protein (Corynebacterium diphtheriae mutant 197, a nontoxic mutant of diphtheria toxin), and an aluminum phosphate adjuvant that induces a T cell-dependent immune
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
V. DEVELOPMENT OF A NANOGEL-BASED NASAL VACCINE AGAINST PNEUMONIA
469
FIGURE 26.3 Uptake of cCHP antigen complex from the paranasal sinuses in the nasal mucosa. The BoHc/A antigens are gradually released from the cCHP nanogel and taken up by nasal epithelial cells and M cells in NALT for at least 12 h after administration. The NKM 16-2-4 is an M-cell-specific monoclonal antibody.
response [67]. Although these vaccines have potent immunogenicity against multiple major serotypes that cause bacterial pneumonia (23 serotypes in PPSV, 13 serotypes in PCV), their efficacy is lost once serotype replacement occurs [68,69]. Therefore, a vaccine effective against all serotypes of S. pneumoniae is required.
To address this issue, pneumococcal surface protein A (PspA), which is expressed by all serotypes of S. pneumoniae, has been examined as a promising candidate antigen for next-generation pneumococcal vaccines that can induce crossreactive immune responses against different serotypes [70,71]. Indeed, nasal administration of a
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
470
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
PspA Vibrio vulnificus-derived flagellin fusion protein induced antigen-specific IgG and IgA responses both in serum and at mucosal surfaces, and provided protective immunity against lethal challenge with S. pneumoniae in mice [72]. In addition, nasal immunization using chitosan DNA nanoparticles expressing PspA suppressed pneumococcal colony formation in the nasal cavity of mice [73]. Also, a unique antigen-delivery method targeting Claudin 4, a major cell adhesion molecule in the tight junctions of NALT epithelial cells, has been developed [74]. For instance, a PspA C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) fusion protein has been shown to bind to Claudin 4 after nasal immunization and induces the production of PspA-specific IgG in serum and SIgA in nasal and bronchoalveolar lavage fluids [74]. As a result, mice nasally vaccinated with PspA C-CPE are protected from pneumococcal respiratory infection. In addition, nasal administration of PspA together with Flt3 ligand expression plasmid and CpG oligodeoxynucleotide as mucosal adjuvants induced PspAspecific SIgA in 2-year-old or pregnant mice, resulting in inhibition of bacterial colonization both in aged mice and in offspring of the vaccinated group [75]. Therefore, PspA is a promising new candidate vaccine antigen for the vaccination of children and elderly people [70,71]. Based on the advantages of PspA for the generation of protective immunity against all serotypes of S. pneumoniae, cCHP PspA nanogel has been developed, and its safety and efficacy have been investigated both in mice and in nonhuman primates [49,50]. When cCHP PspA nanogel was intranasally administered to mice three times at 1-week intervals, antigen-specific IgG was significantly increased both in serum and in bronchial fluid [49]. Antigen-specific SIgA in nasal fluid was also elevated. In contrast, administration of PspA antigen alone failed to induce an antigenspecific antibody response [49]. These results indicate that PspA antigen is efficiently
delivered to nasal epithelium and taken up by DCs in the nasal cavity for the initiation of an antigen-specific immune response. Furthermore, bacterial growth after S. pneumoniae infection was suppressed both in the lung and in the nasal cavity of the mice vaccinated with cCHP PspA nanogel, but not in the mice that received PspA alone [49]. Consequently, the cCHP PspA vaccinated mice survived after lethal challenge with S. pneumoniae [49]. The protective immunity elicited by the cCHP PspA nanogel was a humoral immune response, and was accompanied by the production of both Th2- and Th17type cytokines by antigen-specific CD41 T cells, which are associated with protective immunity against S. pneumoniae [49]. To examine the clinical applicability the cCHP-based pneumococcal vaccine in humans, the safety and immunogenicity of cCHP PspA were analyzed in cynomolgus macaques (Macaca fascicularis) [50]. To confirm the deposition and fate of vaccine antigen in the nasal cavity, olfactory bulbs, and central nervous system, a positron emission tomography study combined with magnetic resonance imaging was performed after nasal administration of 18Flabeled PspA in the macaques. cCHP 18F-PspA nanogel was retained at the nasal epithelium for as long as 6 hours after administration, whereas 18 F-PspA antigen alone had been eliminated from the nasal cavity by 3 hours after administration [50]. Furthermore, no nanogel-delivered antigen was found in the olfactory bulb or brain, even at 6 hours after nasal immunization, suggesting that the cCHP PspA nanogel nasal vaccine does not have neurological side effects. When the cCHP PspA nanogel was nasally administered to cynomolgus macaques five times at 2-week intervals, PspA-specific IgG was markedly elevated in serum and then gradually diminished over a period of 8 months [50]. Similarly, PspA-specific SIgA was elevated in nasal washes as well as bronchoalveolar lavage fluids, and it then decreased in the same manner as did PspA-specific IgG in the serum. After
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
VII. CONCLUDING REMARKS AND FUTURE PERSPECTIVES
these macaques received a nasal administration of cCHP PspA nanogel at 9 months after the final immunization, PspA-specific IgG and SIgA were rapidly boosted to the levels achieved with the primary responses [50]. This suggests that the cCHP PspA nanogel vaccine effectively induces antigen-specific immunological memory. In addition, mice that received PspA-specific antibodies transferred from the macaques exhibited protection against lethal challenge with S. pneumoniae via the production of neutralizing antibodies [50]. Together, these results show that the cCHP PspA nanogel is a promising nasal vaccine candidate for the prevention and control of diseases caused by S. pneumoniae.
VI. APPLICATION OF CCHP NASAL VACCINES AGAINST NONINFECTIOUS DISEASES Recently, cCHP nasal vaccines against obesity and hypertension have been developed, confirming that cCHP vaccines are effective against not only infectious diseases, but also lifestyle-related diseases [76,77]. In the antiobesity vaccine, a ghrelin PspA fusion protein was used, where ghrelin is the vaccine antigen and PspA is the carrier protein. Ghrelin is a peptide hormone produced in the stomach that promotes secretion of growth hormone from the pituitary gland, which stimulates the hypothalamus to enhance appetite [76]. When the ghrelin PspA fusion protein was encapsulated in a cationic nanogel mixed with cyclic guanosine diphosphate as an adjuvant and administered to diet-induced obese mice, both ghrelin-specific IgG in the serum and energy consumption were increased. As a result, both the amount of visceral fat and the body weight were decreased in treated mice compared with untreated mice [76]. A hypertension vaccine has also been developed. Angiotensin II receptor type 1 (AT1R)
471
promotes the functional and structural integrity of the arterial wall and contributes to vascular homeostasis, but it also causes an increase in blood pressure [77]. When an AT1R PspA conjugate was encapsulated in a nanogel mixed with cyclic guanosine diphosphate and administered to hypertensive rats, both AT1R- and PspA-specific IgG levels were elevated in the serum, the onset of hypertension was attenuated, and the rats were protected from lethal challenge with S. pneumoniae [77]. Since hypertension is reported to increase the mortality risk from pneumonia, a single nasal vaccine against both diseases would be of great value. From the results of these two studies, cCHPbased nasal vaccines are expected to be a major part of the next generation of therapies for the treatment of lifestyle-related diseases because of their noninvasiveness and long period of efficacy.
VII. CONCLUDING REMARKS AND FUTURE PERSPECTIVES Nanomaterials are promising tools for improving the immunogenicity of vaccines and effectively delivering antigens and/or adjuvants to mucosal surfaces. It is possible to increase the efficiency of antigen uptake into mucosal tissues, including MALT, by modifying the size and surface properties of these nanomaterials. cCHP nanogel is a vaccine-delivery system that is close to being ready for use in the clinical setting. After nasal administration, cCHP nanogel has excellent safety and efficacy profiles with respect to the induction of protective immunity in both the systemic and mucosal immune compartments. Although cCHP nanogel itself has no biological adjuvant activity, it delivers vaccine antigens to the nasal epithelium and follicle-associated epithelium of the NALT and to DCs in the nasal cavity; therefore, it is capable of inducing antigen-specific
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
472
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
immune responses in both systemic and mucosal immune compartments even in the absence of an adjuvant. As a result, it induces humoral immune responses providing protection against infection. cCHP nanogel-based nasal vaccines are showing promise as the next generation of vaccines to prevent infectious diseases. However, before these vaccines can be used in the clinical setting, manufacturing techniques and guidelines for their preparation must first be developed through collaboration among industry, academia, and government.
ABBREVIATIONS AT1R BoHc cCHP C-CPE DC Ig IL MALT NALT PCV PEG PLA PLGA PPSV PspA RSV SIgA
angiotensin II receptor type 1 Botulinum type A neurotoxin fragment cationic formulation of cholesterylgroup-bearing pullulan C-terminal fragment of Clostridium perfringens enterotoxin dendritic cell immunoglobulin interleukin mucosa-associated lymphoid tissue nasopharynx-associated lymphoid tissue pneumococcal polysaccharide conjugate vaccine polyethylene glycol polylactic acid poly(lactic-co-glycolic acid) pneumococcal polysaccharide vaccine pneumococcal surface protein A respiratory syncytial virus secretory IgA
References [1] Kiyono H, Kunisawa J, McGhee JR, Mestecky J. The mucosal immune system. In: Paul WE, editor. Fundamental immunology. Philadelphia: Lippincott Williams & Wilkins; 2008. p. 983 1030.
[2] Nochi T, Takagi H, Yuki Y, Yang L, Masumura T, Mejima M, et al. Rice-based mucosal vaccine as a global strategy for cold-chain- and needle-free vaccination. Proc Natl Acad Sci USA 2007;104(26):10986 91. [3] Azegami T, Yuki Y, Kiyono H. Challenges in mucosal vaccines for the control of infectious diseases. Int Immunol 2014;26(9):517 28. [4] Ogra PL. Mucosal immunity: some historical perspective on host-pathogen interactions and implications for mucosal vaccines. Immunol Cell Biol 2003;81:23 33. [5] Nochi T, Yuki Y, Matsumura A, Mejima M, Terahara K, Kim DY, et al. A novel M cell-specific carbohydratetargeted mucosal vaccine effectively induces antigenspecific immune responses. J Exp Med 2007;204 (12):2789 96. [6] Kiyono H, Fukuyama S. NALT- versus Peyer’s-patchmediated mucosal immunity. Nat Rev Immunol 2004;4 (9):699 710. [7] Dkhar LK, Bartley J, White D, Seyfoddin A. Intranasal drug delivery devices and interventions associated with post-operative endoscopic sinus surgery. Pharm Dev Technol 2018;23(3):282 94. [8] Holmgren J, Czerkinsky C. Mucosal immunity and vaccines. Nat Med 2005;11:45 53. [9] Jones N. The nose and paranasal sinuses physiology and anatomy. Adv Drug Deliv Rev 2001;51(1 3):5 19. [10] Oliveria P, Fortuna A, Alves G, Falcao A. Drugmetabolizing enzymes and efflux transporters in nasal epithelium: influence on the bioavailability of intranasally administered drugs. Curr Drug Metab 2016;17 (7):628 47. [11] Haan L, Verweij WR, Holtrop M, Brands R, van Scharrenburg GJ, Palache AM, et al. Nasal or intramuscular immunization of mice with influenza subunit antigen and the B subunit of Escherichia coli heat-labile toxin induces IgA- or IgG-mediated protective mucosal immunity. Vaccine 2001;19:2898 907. [12] Riese P, Sakthivel P, Trittel S, Guzma´n CA. Intranasal formulations: promising strategy to deliver vaccines. Expert Opin Drug Deliv 2014;11(10):1619 34. [13] Srivastava A, Gowda DV, Madhunapantula SV, Shinde CG, Iyer M. Mucosal vaccines: a paradigm shift in the development of mucosal adjuvants and delivery vehicles. APMIS 2015;123(4):275 88. [14] Aoshi T. Modes of action for mucosal vaccine adjuvants. Viral Immunol 2017;30(6):463 70. [15] Mutsch M, Zhou W, Rhodes P, Bopp M, Chen RT, Linder T, et al. Use of the inactivated intranasal influenza vaccine and the risk of Bell’s palsy in Switzerland. N Engl J Med 2004;350(9):896 903. [16] Kuper CF, Koornstra PJ, Hameleers DM, Biewenga J, Spit BJ, Duijvestijn AM, et al. The role of nasopharyngeal lymphoid tissue. Immunol Today 1992;13:219 24.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
REFERENCES
[17] Rerry M, Whyte A. Immunology of the tonsils. Immunol Today 1998;19:414 20. [18] Kim DY, Sato A, Fukuyama S, Sagara H, Nagatake T, Kong IG, et al. The airway antigen sampling system: respiratory M cells as an alternative gateway for inhaled antigens. J Immunol 2011;186(7):4253 62. [19] Sonoda E, Matsumoto R, Hitoshi Y, Ishii T, Sugimoto M, Araki S, et al. Transforming growth factor beta induces IgA production and acts additively with interleukin 5 for IgA production. J Exp Med 1989;170: 1415 20. [20] Coffman RL, Lebman DA, Shrader B. Transforming growth factor beta specifically enhances IgA production by lipopolysaccharide-stimulated murine B lymphocytes. J Exp Med 1989;170(3):1039 44. [21] Horikawa K, Takatsu K. Interleukin-5 regulates genes involved in B-cell terminal maturation. Immunology 2006;118:497 508. [22] Neutra MR, Kozlowski PA. Mucosal vaccines: the promise and the challenge. Nat Rev Immunol 2006;6 (2):148 58. [23] McGhee JR, Fujihashi K, Beagley KW, Kiyono H. Role of interleukin-6 in human and mouse mucosal IgA plasma cell responses. Immunol Res 1991;10(3 4): 418 22. [24] Kaetzel CS. The polymeric immunoglobulin receptor: bridging innate and adaptive immune responses at mucosal surfaces. Immunol Rev 2005;206:83 99. [25] Williams RC, Gibbons RJ. Inhibition of bacterial adherence by secretory immunoglobulin A: a mechanism of antigen disposal. Science 1972;177:697 9. [26] Taylor HP, Dimmock NJ. Mechanism of neutralization of influenza virus by secretory IgA is different from that of monomeric IgA or IgG. J Exp Med 1985;161: 198 209. [27] Brandtzaeg P. Mucosal immunity: induction, dissemination, and effector functions. Scand J Immunol 2009;70(6):505 15. [28] Bentley AM, Durham SR, Robinson DS, Menz G, Storz C, Cromwell O, et al. Expression of endothelial and leukocyte adhesion molecules intercellular adhesion molecule-1, E-selectin, and vascular cell adhesion molecule-1 in the bronchial mucosa in steady-state and allergen-induced asthma. J Allergy Clin Immunol 1993;92(6):857 68. [29] Campbell JJ, Brightling CE, Symon FA, Qin S, Murphy KE, Hodge M, et al. Expression of chemokine receptors by lung T cells from normal and asthmatic subjects. J Immunol 2001;166(4):2842 8. [30] Brinkman CC, Peske JD, Engelhard VH. Peripheral tissue homing receptor control of naı¨ve, effector, and memory CD8 T cell localization in lymphoid and nonlymphoid tissues. Front Immunol 2013;4:241.
473
[31] Brandtzaeg P, Johansen FE. Mucosal B cells: phenotypic characteristics, transcriptional regulation, and homing properties. Immunol Rev 2005;206:32 63. [32] Joo S, Fukuyama Y, Park EJ, Yuki Y, Kurashima Y, Ouchida R, et al. Critical role of TSLP-responsive mucosal dendritic cells in the induction of nasal antigen-specific IgA response. Mucosal Immunol 2017;10(4):901 11. [33] Patel GB, Ponce A, Zhou H, Chen W. Structural characterization of archaeal lipid mucosal vaccine adjuvant and delivery (AMVAD) formulations prepared by different protocols and their efficacy upon intranasal immunization of mice. J Liposome Res 2008;18 (2):127 43. [34] Hall MA, Stroop SD, Hu MC, Walls MA, Reddish MA, Burt DS, et al. Intranasal immunization with multivalent group A streptococcal vaccines protect mice against intranasal challenge infections. Infect Immun 2004;72(5):2507 12. [35] Baca-Estrada ME, Foldvari MM, Snider MM, Harding KK, Kournikakis BB, Babiuk LA, et al. Intranasal immunization with liposome-formulated Yersinia pestis vaccine enhances mucosal immune responses. Vaccine 2000;18(21):2203 11. [36] Makidon PE, Nigavekar SS, Bielinska AU, Mank N, Shetty AM, Suman J, et al. Characterization of stability and nasal delivery systems for immunization with nanoemulsion-based vaccines. J Aerosol Med Pulm Drug Deliv 2010;23(2):77 89. [37] Myc A, Kukowska-Latallo JF, Smith DM, Passmore C, Pham T, Wong P, et al. Nanoemulsion nasal adjuvant W805EC induces dendritic cell engulfment of antigenprimed epithelial cells. Vaccine 2013;31(7):1072 9. [38] Myc A, Kukowska-Latallo JF, Bielinska AU, Cao P, Myc PP, Janczak K, et al. Development of immune response that protects mice from viral pneumonitis after a single intranasal immunization with influenza A virus and nanoemulsion. Vaccine 2003;21(25 26):3801 14. [39] Bielinska AU, Janczak KW, Landers JJ, Makidon P, Sower LE, Peterson JW, et al. Mucosal immunization with a novel nanoemulsion-based recombinant anthrax protective antigen vaccine protects against Bacillus anthracis spore challenge. Infect Immun 2007;75 (8):4020 9. [40] Almeida AJ, Alpar HO, Brown MR. Immune response to nasal delivery of antigenically intact tetanus toxoid associated with poly (l-lactic acid) microspheres in rats, rabbits and guinea-pigs. J Pharm Pharmacol 1993;45:198 203. [41] Byrd W, Cassels FJ. Intranasal immunization of BALB/c mice with enterotoxigenic Escherichia coli colonization factor CS6 encapsulated in biodegradable poly(DL-lactideco-glycolide) microspheres. Vaccine 2006;24(9):1359 66.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
474
26. NANODELIVERY VEHICLES FOR MUCOSAL VACCINES
[42] Vila A, Sa´nchez A, Tobı´o M, Calvo P, Alonso MJ. Design of biodegradable particles for protein delivery. J Control Release 2002;78(1 3):15 24. [43] Amidi M, Romeijn SG, Verhoef JC, Junginger HE, Bungener L, Huckriede A, et al. N-trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination: biological properties and immunogenicity in a mouse model. Vaccine 2007;25(1):144 53. [44] Iqbal M, Lin W, Jabbal-Gill I, Davis SS, Steward MW, Illum L. Nasal delivery of chitosan-DNA plasmid expressing epitopes of respiratory syncytial virus (RSV) induces protective CTL responses in BALB/c mice. Vaccine 2003;21(13 14):1478 85. [45] Xu W, Shen Y, Jiang Z, Wang Y, Chu Y, Xiong S. Intranasal delivery of chitosan-DNA vaccine generates mucosal SIgA and anti-CVB3 protection. Vaccine 2004;22(27 28):3603 12. [46] Pawar D, Mangal S, Goswami R, Jaganathan KS. Development and characterization of surface modified PLGA nanoparticles for nasal vaccine delivery: effect of mucoadhesive coating on antigen uptake and immune adjuvant activity. Eur J Pharm Biopharm 2013;85(3 Pt A):550 9. [47] Vila A, Sa´nchez A, Evora C, Soriano I, Vila Jato JL, Alonso MJ. PEG-PLA nanoparticles as carriers for nasal vaccine delivery. J Aerosol Med 2004;17 (2):174 85. [48] Nochi T, Yuki Y, Takahashi H, Sawada S, Mejima M, Kohda T, et al. Nanogel antigenic protein-delivery system for adjuvant-free intranasal vaccines. Nat Mater 2010;9(7):572 8. [49] Kong IG, Sato A, Yuki Y, Nochi T, Takahashi H, Sawada S, et al. Nanogel-based PspA intranasal vaccine prevents invasive disease and nasal colonization by Streptococcus pneumoniae. Infect Immun 2013;81 (5):1625 34. [50] Fukuyama Y, Yuki Y, Katakai Y, Harada N, Takahashi H, Takeda S, et al. Nanogel-based pneumococcal surface protein A nasal vaccine induces microRNAassociated Th17 cell responses with neutralizing antibodies against Streptococcus pneumoniae in macaques. Mucosal Immunol 2015;8(5):1144 53. [51] Peek LJ, Middaugh CR, Berkland C. Nanotechnology in vaccine delivery. Adv Drug Deliv Rev 2008;60 (8):915 28. [52] Baca-Estrada ME, Foldvari M, Babiuk SL, Babiuk LA. Vaccine delivery: lipid-based delivery systems. J Biotechnol 2000;83:91 104. [53] Kim MG, Park JY, Shon Y, Kim G, Shim G, Oh YK. Nanotechnology and vaccine development. Asian J Pharm Sci 2014;9:227 35.
[54] Ko¨ping-Ho¨gga˚rd M, Sa´nchez A, Alonso MJ. Nanoparticles as carriers for nasal vaccine delivery. Expert Rev Vaccines 2005;4(2):185 96. [55] Akagi T, Baba M, Akashi M. Biodegradable nanoparticles as vaccine adjuvants and delivery systems: regulation of immune responses by nanoparticle-based vaccine. Adv Polym Sci 2012;247:31 64. [56] Bobo D, Robinson KJ, Islam J, Thurecht KJ, Corrie SR. Nanoparticle-based medicines: a review of FDAapproved materials and clinical trials to date. Pharm Res 2016;33(10):2373 87. [57] Kang ML, Cho CS, Yoo HS. Application of chitosan microspheres for nasal delivery of vaccines. Biotechnol Adv 2009;27(6):857 65. [58] Dodane V, Khan MA, Merwin JR. Effect of chitosan on epithelial permeability and structure. Int J Pharm 1999;182:21 32. [59] Ayame H, Morimoto N, Akiyoshi K. Self-assembled cationic nanogels for intracellular protein delivery. Bioconjug Chem 2008;19(4):882 90. [60] Sasaki Y, Akiyoshi K. Nanogel engineering for new nanobiomaterials: from chaperoning engineering to biomedical applications. Chem Rec 2010;10(6):366 76. [61] Nakahashi-Ouchida R, Yuki Y, Kiyono H. Development of a nanogel-based nasal vaccine as a novel antigen delivery system. Expert Rev Vaccines 2017;16(12):1231 40. [62] Baldwin AL, Wu NZ, Stein DL. Endothelial surface charge of intestinal mucosal capillaries and its modulation by dextran. Microvasc Res 1991;42(2):160 78. [63] Yuki Y, Nochi T, Harada N, Katakai Y, Shibata H, Mejima M, et al. In vivo molecular imaging analysis of a nasal vaccine that induces protective immunity against botulism in nonhuman primates. J Immunol 2010;185(9):5436 43. [64] Cilloniz C, Amaro R, Torres A. Pneumococcal vaccination. Curr Opin Infect Dis 2016;29(2):187 96. [65] Dinleyici EC. Current status of pneumococcal vaccines: lessons to be learned and new insights. Expert Rev Vaccines 2010;9(9):1017 22. [66] Haas KM, Blevins MW, High KP, Pang B, Swords WE, Yammani RD. Aging promotes B-1b cell responses to native, but not protein-conjugated, pneumococcal polysaccharides: implications for vaccine protection in older adults. J Infect Dis 2014;209(1):87 97. [67] Laferriere C. The immunogenicity of pneumococcal polysaccharides in infants and children: a metaregression. Vaccine 2011;29(40):6838 47. [68] Richter SS, Heilmann KP, Dohrn CL, Riahi F, Diekema DJ, Doern GV. Pneumococcal serotypes before and after introduction of conjugate vaccines, United States, 1999-2011(1). Emerg Infect Dis 2013;19(7):1074 83.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY
475
REFERENCES
[69] Weinberger DM, Malley R, Lipsitch M. Serotype replacement in disease after pneumococcal vaccination. Lancet 2011;378(9807):1962 73. [70] Berry AM, Yother J, Briles DE, Hansman D, Paton JC. Reduced virulence of a defined pneumolysin-negative mutant of Streptococcus pneumoniae. Infect Immun 1989;57(7):2037 42. [71] McDaniel LS, Yother J, Vijayakumar M, McGarry L, Guild WR, Briles DE. Use of insertional inactivation to facilitate studies of biological properties of pneumococcal surface protein A (PspA). J Exp Med 1987;165 (2):381 94. [72] Nguyen CT, Kim SY, Kim MS, Lee SE, Rhee JH. Intranasal immunization with recombinant PspA fused with a flagellin enhances cross-protective immunity against Streptococcus pneumoniae infection in mice. Vaccine 2011;29(34):5731 9. [73] Xu J, Dai W, Wang Z, Chen B, Li Z, Fan X. Intranasal vaccination with chitosan-DNA nanoparticles expressing pneumococcal surface antigen a protects mice against nasopharyngeal colonization by
[74]
[75]
[76]
[77]
Streptococcus pneumoniae. Clin Vaccine Immunol 2011;18(1):75 81. Suzuki H, Watari A, Hashimoto E, Yonemitsu M, Kiyono H, Yagi K, et al. C-Terminal Clostridium perfringens enterotoxin-mediated antigen delivery for nasal pneumococcal vaccine. PLoS One 2015;10(5):e0126352. Fukuyama Y, King JD, Kataoka K, Kobayashi R, Gilbert RS, Hollingshead SK, et al. A combination of Flt3 ligand cDNA and CpG oligodeoxynucleotide as nasal adjuvant elicits protective secretory-IgA immunity to Streptococcus pneumoniae in aged mice. J Immunol 2011;186(4):2454 61. Azegami T, Yuki Y, Sawada S, Mejima M, Ishige K, Akiyoshi K, et al. Nanogel-based nasal ghrelin vaccine prevents obesity. Mucosal Immunol 2017;10(5): 1351 60. Azegami T, Yuki Y, Hayashi K, Hishikawa A, Sawada SI, Ishige K, et al. Intranasal vaccination against angiotensin II type 1 receptor and pneumococcal surface protein A attenuates hypertension and pneumococcal infection in rodents. J Hypertens 2018;36(2):387 94.
IV. CURRENT AND NEW APPROACHES FOR MUCOSAL VACCINE DELIVERY