Role and potential therapeutic use of antibodies against herpetic infections

Accepted Manuscript Role and potential therapeutic use of antibodies against herpetic infections Nicola Clementi, Francesca Cappelletti, Elena Criscuolo, Matteo Castelli, Nicasio Mancini, Roberto Burioni, Massimo Clementi PII:

S1198-743X(16)30655-3

DOI:

10.1016/j.cmi.2016.12.023

Reference:

CMI 813

To appear in:

Clinical Microbiology and Infection

Received Date: 10 October 2016 Revised Date:

14 December 2016

Accepted Date: 24 December 2016

Please cite this article as: Clementi N, Cappelletti F, Criscuolo E, Castelli M, Mancini N, Burioni R, Clementi M, Role and potential therapeutic use of antibodies against herpetic infections, Clinical Microbiology and Infection (2017), doi: 10.1016/j.cmi.2016.12.023. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Intended category: Review article

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Title: Role and potential therapeutic use of antibodies against herpetic infections

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Authors and affiliations:

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Nicola Clementi1, Francesca Cappelletti1, Elena Criscuolo1, Matteo Castelli1, Nicasio Mancini1,2,

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Roberto Burioni1,2, Massimo Clementi1,2

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Microbiology and Virology Unit, “Vita-Salute San Raffaele” University, Milan, Italy

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Laboratory of Microbiology and Virology, San Raffaele Hospital, Milan, Italy

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Running title: Herpesviridae and antibodies Corresponding author: Nicola Clementi

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Via Olgettina, 58

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20132 Milan, Italy

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[email protected]

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Phone nr. 0039 02 2643 3144

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Fax nr. 0039 02 2643 4288

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ACCEPTED MANUSCRIPT Abstract

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Background: The cellular adaptive response directed against Herpesviruses is widely described in

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the scientific literature as a pivotal component of the immune system able to control virus

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replication. The role of humoral immunity remains unclear and controversial.

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Aims: Discussing the role of adaptive immunity in Herpesvirus infection control, highlighting the

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potential role of the humoral branch of immunity through the description of human monoclonal

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antibodies directed against herpesviruses.

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Sources: PubMed search for relevant publications related to protective immunity against

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Herpesviridae.

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Content: This review describes the role of adaptive immunity directed against Herpesviridae,

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focusing on human humoral response naturally elicited during their infections. Giving the ever-

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increasing interest in monoclonal antibodies (mAbs) as novel therapeutics, the contribution of

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humoral immunity in controlling productive infection, during both primary infection and

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reactivations, is discussed.

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Implications: Human mAbs directed against the different Herpesviridae species may represent

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novel molecular probes to further characterise the molecular machinery involved in herpesvirus

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infection; and allow the development of novel therapeutics and effective vaccine strategies.

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Introduction

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Eight distinct viruses belonging to the Herpesviridae family [herpes simplex viruses type 1 and type

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2 (HSV1, HSV2), varicella zoster virus (VZV), human cytomegalovirus (CMV), human herpesviruses 6

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and 7 (HHV6, HHV7), Epstein Barr virus (EBV), and human herpesvirus 8, or Kaposi sarcoma-

ACCEPTED MANUSCRIPT associated herpesvirus (KSHV)], represent a health concern worldwide. Although they infect

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different cells and tissues during initial infection, all these viruses share the biological feature of

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undergoing a latency phase after primary infection. It is currently believed that the role of the

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immune response in controlling primary infection and following reactivations is crucial (1). In detail,

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wide agreement exists on the important role of innate immune response as a central mechanism in

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the early control of the infection (particularly important are NK cells and the release of IFN),

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although herpesviruses share several strategies to evade this control (1-3). On the other hand,

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despite a leading role of cellular immunity widely described in the last few decades, the efficacy of

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antibody response in herpesvirus infections is less clear and often questioned. To clarify this point,

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we will address here the role of antibodies during herpesvirus lifecycle, and the possible use of

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target-specific monoclonal antibodies as molecular probes to identify viral epitopes potentially

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important for novel vaccines, or novel therapeutic strategies.

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The role of adaptive cellular response

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Adaptive cellular response plays a pivotal role in controlling herpesviruses infection (4). Activated

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CD4+ and CD8+ T cells are believed to be fundamental for the clearance of the primary HSV-1 and -

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2 infection and in the control of virus reactivations from latency (5, 6). CD8+ T cells main role is

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probably in the efficacious containment of the primary viral spreading. A strong cellular response

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seems not to be strictly necessary for future control of reactivation (7). Similarly, during CMV acute

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infection a robust cellular CD4+ and CD8+ response is generally associated with virus clearance. The

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control of CMV reactivation is partly due to memory T cells response (8, 9).

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Concerning EBV, adoptive immunotherapy with donor T cells has provided effective in virus

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infection control in post-transplant patients, highlighting the role of the cellular component of the

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immune system in controlling EBV acute infection and reactivation in patients at high risk of

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ACCEPTED MANUSCRIPT developing complications from EBV uncontrolled spread (10-12). Similarly, it has been proven that

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the magnitude of T cell response evoked during VZV acute infection directly correlates with early

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control of VZV dissemination and infection-associated signs and symptoms (6). Furthermore, using

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non-human primate models of VZV infection, it has been found that while ablating T cells results in

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more severe disease, removing a subset of B cells does not increase the magnitude of VZV primary

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infection (13). This is of particular relevance, given that patients with agammaglobulinaemia or

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other defects in antibody production do not present with more severe primary VZV disease

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compared to immunocompetent patients (14). Less is known about HHV6 and KSHV infection

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control, but indirect evidence suggests that cellular immune response has a crucial role even in

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these cases. For example, immunosuppressed patients deprived of proliferative T cell responses

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show persistent HHV6 viral replication, meaning that their immune system is not able to

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efficaciously control the virus replication (15). Similarly, the role of cellular immunity in controlling

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KSHV infection and in particular Kaposi’s sarcoma (KS), which is the main malignancy related to

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uncontrolled KSHV replication, has been inferred by several studies taking into account both the

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incidence of KS episodes and T cell levels in patients undergoing KSHV reactivation (16).

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Adaptive humoral response

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For a long time, the role of adaptive humoral response in controlling acute infection and

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reactivation of herpesviruses has been considered marginal (17). However, several recent studies

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suggest that the B cell response may have an important function in limiting the severity of primary

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infection and reducing reactivation events (7, 18, 19). In particular, the role of antibody-mediated

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immune response seems to be crucial: after binding virus components, different classes of

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antibodies are able to interact with other members of the immune response, inducing immune

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system effector functions like phagocytosis, massive cytokine release and antibody-dependent cell-

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ACCEPTED MANUSCRIPT 84

mediated cytotoxicity (ADCC)(14, 20, 21). Several studies have highlighted the contribution of B

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cells in infection control or reactivations caused by herpesviruses (22-28).

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CMV In animal models, anti-CMV antibodies are considered to be important for limiting acute CMV

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infection, reducing viral load and consequently the severity of the disease (8, 22). As a direct proof

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of the importance of humoral response in controlling CMV infection, the treatment of pregnant

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women with anti-CMV-specific hyper-immune globulin preparations can be effective for preventing

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congenital infections (22, 23). Similarly, intravenous immunoglobulin infusions in paediatric

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mismatched liver transplant recipients (donor CMV+, recipient CMV-) receiving a low-dose

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immunosuppressive regimen can significantly reduce the incidence of CMV infection (29). However,

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the use of hyper-immune globulin preparations is still controversial, as some studies demonstrate

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little or negligible beneficial effects from their administration (23, 30).

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VZV

VZV-hyper-immunoglobulins treatment showed similar results against VZV infection. When

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administered to patients >50 years old in association with acyclovir treatment during herpes zoster

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onset, it was capable of reducing incidence of post-herpetic neuralgia and to significantly diminish

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the magnitude of patient symptoms, compared to antiviral drug treatment alone (13). Other Herpesviruses

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Regarding HSV-1 and -2 infection control, B cell response probably has a role in limiting HSV viral

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load during primary infection (17). The importance of the humoral branch of the immune system

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was also demonstrated during EBV-infective mononucleosis. In this case, B cells seem to play a

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fundamental role in both priming and promoting expansion of CD8+ T effector cells (10, 26).

ACCEPTED MANUSCRIPT Unfortunately, due to an even poorer knowledge of the fundamental mechanisms associated to

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HHV6 and KSHV pathogenicity, the role of both cellular and humoral immunity contribution in

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controlling the replication of both viruses is still far from being understood. There is some evidence

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supporting a possible role of antibody response in controlling the infection caused by both viruses.

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The presence of specific anti-HHV6 maternal-derived IgGs correlates with protection of new-borns

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from HHV6 infection. This protection depends on anti-HHV6 IgG levels since it declines

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approximately 5 months after birth (15). Neutralising antibodies elicited by primary infection

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(which generally occurs before the second year of age) persist throughout life and, together with

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cellular immune response, they are able to prevent HHV6 reactivations in healthy individuals (27).

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Unfortunately, even less is known about the role of humoral immunity against KSHV. A recent study

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found lower levels of anti-KHSV neutralising antibodies in AIDS patients developing Kaposi’s

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sarcoma compared to higher neutralising antibody titres in AIDS patients not developing the same

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tumour (28).

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Anti-Herpesviridae monoclonal antibodies: potential drugs or just tools for basic research?

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The scientific literature is rich in evidence about the role of antibodies in limiting herpesviruses

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associated diseases. The most compelling evidence of their importance in controlling severe

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herpesvirus related diseases is probably the usefulness of hyper-immunoglobulin treatment in

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patients undergoing CMV or VZV infections (13, 22, 23, 29). These polyclonal immunoglobulins have

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several drawbacks, such as the intrinsic risk of infection or contamination related to blood-derived

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products, the relatively low amount of truly effective anti-herpetic antibodies within polyclonal

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preparations, and the significant variability in term of potency and specificity observed amongst

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different production batches (31). The use of human monoclonal antibodies (Hu-mAbs) can

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improve the standardisation of antibodies to be administered and therefore the clinical

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ACCEPTED MANUSCRIPT management of herpesvirus reactivations in patients not responding to classical anti-herpetic

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drugs. (31). Moreover, a monoclonal antibody able to effectively target herpesviruses proteins

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fundamental for virus infection and replication, can overcome the limit of natural humoral immune

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response, which can be hampered by multiple antigen exposure during infections. While “naturally

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elicited” antibodies during infection recognise several different viral proteins, and only a small

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fraction of them is useful for the effective clearance of virus load, a single or an association of mAbs

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directed against key virus proteins and endowed with the capability of inhibiting virus replication

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could exercise potent and specific anti-herpesviruses activity, as described for different mAbs

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inhibiting both in vitro and in vivo HSV, CMV or VZV infection (18, 24, 32-36). In recent years,

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several Hu-mAbs neutralising or inhibiting clinically relevant herpesviruses have been described as

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potential candidates for human therapy (34, 37).

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Examples of anti-herpesviruses human monoclonal antibodies Human monoclonal antibodies directed against HSV glycoprotein D (gD) have been described:

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mAbs E317 and AC-8 (32, 33). The first one seems to be able to interact with Nectin-1 and HVEM

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binding domains, thus preventing HSV-1 and -2 entry. In vivo protection has been described only in

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the published patent and not in peer-reviewed publications. mAb AC-8 neutralises HSV-2 (more

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potently) and HSV-1, and protects mice from corneal and intra-cutaneous HSV challenge (Fab

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therapeutic protection has been assessed in mice) when systemically administered. In its topical

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administration, it protects animals from vaginal HSV challenge (18, 38).

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Amongst the described antibodies directed against CMV, MSL-109 is an important example (34).

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This human monoclonal antibody is directed against CMV glycoprotein H and it is able to inhibit in

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vitro virus infection in fibroblasts by laboratory and clinical strains. Based on that important

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feature, MSL-109 was thought to be a perfect candidate against CMV infection (39). Unfortunately,

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ACCEPTED MANUSCRIPT its possible inclusion amongst novel anti-CMV drugs was suspended due to the failure of one of the

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two clinical trials involving its administration to AIDS patients with CMV retinitis (37). An

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explanation to this failure can be found in a later scientific publication describing how its anti-CMV

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activity is completely abrogated by CMV escape mechanisms, consisting in the capability of the

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virus to internalise MSL-109 and incorporate it in the new budding virions, thereby using this

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antibody as a “cover” and inhibiting the binding of other antibodies (40). However, the study of

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MSL-109 mechanism of action has permitted a better elucidation of gH/gL interaction, helping to

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identify a possible new target for anti-CMV therapies (40).

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Another great advantage of mAbs, not strictly related to their neutralising activity, is their capability

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to recognise specific virus components, which is useful for comprehending the herpesvirus life

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cycle. Herpesviruses are extremely complex viruses, provided with a oligomeric entry machinery

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able to interact with a plurality of cellular host membrane integral glycoproteins, resulting, in the

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ability to enter target cells using different routes (external cell membrane fusion or endocytosis)

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(41). This molecular complexity can be summarised as follows: glycoprotein gB is crucial for virus

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entry since it is the envelope protein exerting fusion activity. However, multimeric surface protein

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complexes are needed to efficiently infect host cells, playing a pivotal role in virus tissue tropism

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and triggering of viral fusion (36). These complexes vary among different herpesviruses and involve

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diverse membrane glycoproteins. As an example, both gH and gL are of pivotal importance for

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CMV, VZV EBV infection, while HSV, despite the important role of gH/gL in triggering gB mediated

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fusion, requires also the gD mediated triggering to efficiently enter target cells (36, 42-44) .

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Although the exact molecular events involved in virus fusion are not completely understood for all

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herpesviruses, recent studies (36) demonstrated how even in a single virus such as CMV, the

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capability of using different envelope glycoprotein complexes such as gH/gL/gO and

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ACCEPTED MANUSCRIPT gH/gL/pUL128/pUL130/pUL131 can be responsible for the different tissue tropism. Using mAbs as

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probes to better understand the relationship between virus protein complexes involved in virus

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tropism and entry, and host components, such as the different cell receptors involved in virus

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docking processes, can improve our knowledge of virus life cycle. The availability of these mAbs or

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new mAbs able to recognise different epitopes crucial for virus infectivity could better address the

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development of novel drugs and vaccines, by clarifying the molecular events driving the CMV

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differential tropism (25, 45-48). .

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Monoclonal antibodies engineering can avoid virus escape mechanisms Amongst the plethora of mechanisms used by herpesviruses to elude effective B cell immunity, the

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recognition of IgG Fc region (Figure 1) is the best characterised so far for CMV, HSV and VZV. This

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escape strategy relies on the capability of these viruses to inactivate the effectiveness of

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neutralising IgGs through the Fc receptors present on the virion surface, that bind and disarm the

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antibodies, inhibiting effector functions and preventing the binding to human Fc receptors or

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mediating internalization and degradation of the antibodies themselves (40). This mechanism can

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also hamper the Fc mediated T cell response since non-neutralising antibodies recognising the virus

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(or virus antigens on infected cells) can be bound by Fc receptor of the virus, thus avoiding their

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binding to human Fc receptor that mediates ADCC (20).

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While the naturally elicited antibodies during infection can be particularly susceptible to virus

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escape mechanisms, monoclonal antibodies can be engineered to prevent herpesviruses immune

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control evasion. The virus Fc receptor mechanism can be overcome by modifying the Fc portion of

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monoclonal antibodies (for example using the IgG3 Fc receptor, which is less recognised by virus

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machinery), making them able to avoid the unwanted binding to virus Fc receptor but at the same

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time to maintain the binding with human receptors, thereby inducing antibody-related effector

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ACCEPTED MANUSCRIPT functions (49). Another option may be the engineering of the selected anti-herpetic mAb in

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different antibodies format, such as Fab fragments or ScFv, which do not present the Fc receptor: in

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this case, the virus escape mechanism can be completely circumvented, but at the cost of the loss

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of Fc mediated effector functions and ADCC (10, 33, 38). For this reason, this strategy can be

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chosen only if the monoclonal antibody is endowed with strong neutralising activity by itself and it

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does not rely on effector functions to exert its capability to stop virus infection.

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Figure 1. Schematic representation of the most common Herpesviruses antibodies escape

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mechanisms. Antibodies, after recognizing virus proteins, are able to enhance immune response

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using they Fc portion. As an example, Fcϒ receptor on Fcϒ receptor-expressing cells are able to bind

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antibody Fc portions stimulating cellular immune response, through cytokines release (A).

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Herpesviruses are able to block antibody-mediated effector functions by binding antibody Fc

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portion with their virus Fcϒ receptor. Fcϒ receptors present on infected cells can block antibodies

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already bound to viruses (B), those receptors on virus envelope can block the antibody already

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bound to infected cells (C) or, alternatively, the same receptors can even cause the so called

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“antibody bridging” between virus Fcϒ receptor and target virus protein (D). In all these cases,

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Herpesviruses greatly reduce the efficacy of antibody immune response in enhancing cellular

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immunity.

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Future perspectives

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To date, the therapeutic use of anti-herpesviruses mAbs is not yet approved. This is mainly due to

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the failure of clinical trials, as discussed above. However, past experiences with anti-herpetic mAbs

ACCEPTED MANUSCRIPT can teach us regarding the critical points that should be considered when translating the use of

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mAbs from preclinical phases studies to their use in humans. First of all, tissue tropism of

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herpesviruses is not completely understood (36, 46) (this is particularly true for CMV), therefore

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mAbs able to inhibit replication of laboratory reference strains in lab-infection models, should

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prove their effectiveness also in inhibiting clinical isolates. Unfortunately, laboratory virus culturing

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suffers from several limitations such as the virus adaptation to the in vitro culture system, often

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resulting in the loss of its “natural” tropism. Therefore, mAbs able to inhibit virus infection in cell-

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culture based systems often fail the in vivo testing.

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The second consideration is that human mAbs, especially IgGs, can lose their activity when

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administered in vivo. The reason can be found in the most common immune evasion mechanisms

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of herpesviruses such as antibody internalisation or the binding of the neutralising IgG Fc portions

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by the Fcϒ virus receptors. As discussed above, the new antibody engineering technologies may be

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useful for redrawing the molecular format of anti-HSV neutralising mAbs in order to avoid such

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immune evasion mechanisms. Recent studies have also shown how monoclonal antibodies can be

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used to efficiently redirect cellular immunity given their ability to stimulate the cellular response

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against specific targets that are not recognised “naturally” (50). This approach could be used even

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in the case of herpesviruses, given the importance of an efficacious and well-directed T-cell

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response in infection resolutions.

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Another interesting point is the concordance between mAb origin and the organism in which it is

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tested. For example, if a murine mAb in its IgG format is tested in mice in a preclinical trial, it will

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induce immune system effector functions, stimulating also T cells response, while this is not

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possible if administered in humans (51, 52). Analogously, it is impossible to predict the systemic

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effects of human mAbs tested in mice, unless humanised mice models are being used. Thus it is

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ACCEPTED MANUSCRIPT important to evaluate the different formats of mAbs, in order to choose the most suitable to

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undergo preclinical and clinical studies. Attention must be given to the evaluation of mAbs dose

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and administration routes in animal models, in order to carefully mimic the future possible

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administration in human patients.

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It is important to carefully choose the patients for inclusion in the trials. As an example, for MSL-

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109 (34) two trials were conducted, one with patients with new diagnosis of CMV retinitis and

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another with patients undergoing reactivations. It is not clear if the difference in the cohorts had

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contributed to the difference between the trials results, but the immunological status of patients

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should be carefully evaluated prior the administration of mAbs (37).

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mAbs can be also useful tools to address vaccine design. To date, all the different strategies of

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vaccine against Herpesviruses have several drawbacks and cannot be considered a success. The

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study of neutralising mAbs can help identify new targets to be included in vaccine preparations (53,

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54). The subunit vaccines tested so far have been generally composed of the surface glycoproteins,

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considering their importance in virus life cycle. However, these proteins have not been considered

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as parts of a complex entry machinery composed by different proteins able to interact both one

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each others and with host cell receptors. For example, gB is certainly able to elicit neutralising

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antibodies but, being an immune-dominant protein, also a plethora of non-neutralising antibodies

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when used as a vaccine compound, as in natural occurring herpesviruses infection. New studies

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focus instead on the importance of mAbs directed against other proteins and multimeric complexes

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in neutralising infection, and it is exactly from these new studies involving mAbs that it will be

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possible to identify new targets to be included in novel effective vaccine preparations (35, 48).

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Considering the complex cascade that ultimately leads to herpesviruses fusion, a critical aspect will

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be the strategy used to select these mAbs, especially regarding the antigen of interest. While the

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ACCEPTED MANUSCRIPT aforementioned mAbs have been selected for their capability of recognising either whole viral

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particles or single recombinant proteins, a successful strategy for the identification of mAbs capable

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to interrupt the formation of the supramolecular complex required for fusion may focus on the

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exclusive expression of the proteins composing it. This could allow the identification of both novel

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effective mAbs and protective epitopes able to elicit in vivo an effective humoral response.

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Conclusions

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We briefly reviewed the role of the humoral immune response directed against different

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herpesviruses, giving its increasing importance for the comprehension of the complex virus

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infection machinery. We focused attention on the different uses of human monoclonal antibodies

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describing their potential as novel tools capable of elucidating herpesvirus life cycle and their

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possible use as novel effective therapeutics. Despite the presence of some human mAbs that have

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shown to exert anti-viral activity against HSV or CMV, none of them have been successful in clinical

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trials. This could be due to several reasons, spanning from the limits of in vitro and in vivo studies,

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to the difficult choice of patient for clinical studies.

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Given the lack of efficacy of past vaccines against herpesviruses such as HSV to prevent primary

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infection and reactivations (although they were able to partially reduce the severity of

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reactivations) (55, 56), human monoclonal antibodies can be a useful tool to redraw “classical”

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vaccine approaches. More specifically, some human mAbs are able to efficaciously neutralise

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herpesvirus infection targeting specific regions of virus proteins (21, 32, 33, 41). The study of these

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regions (protective epitopes) can be of extreme importance in order to develop the epitope-based

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vaccines (53, 54), which can potentially overcome the limits of currently available vaccine

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strategies. The current strategies are burdened by immunodominant epitopes within the viral

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ACCEPTED MANUSCRIPT proteins included in the vaccine, often eliciting an antibody response ineffective in controlling

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infections or reactivations. Human mAbs featuring peculiar antiviral properties can therefore help

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identify conserved portions of herpesvirus glycoproteins involved in the crucial steps of virus

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replication in order to design new tailored therapies.

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Transparency declaration: The authors have nothing to disclose. Dr. Clementi has nothing to

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disclose. No external funding was received.

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Acknowledgements: We would like to thank Dr. Olivia Morrow for revising the English of the

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manuscript

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References

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1. Paludan SR, Bowie AG, Horan KA, Fitzgerald KA. Recognition of herpesviruses by the innate immune system. Nature reviews Immunology. 2011;11(2):143-54. Epub 2011/01/27. 2. Mossman KL, Ashkar AA. Herpesviruses and the innate immune response. Viral immunology. 2005;18(2):267-81. Epub 2005/07/23. 3. Duncan CJ, Hambleton S. Varicella zoster virus immunity: A primer. The Journal of infection. 2015;71 Suppl 1:S47-53. Epub 2015/04/29. 4. Smith C, Khanna R. Immune regulation of human herpesviruses and its implications for human transplantation. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2013;13 Suppl 3:9-23; quiz Epub 2013/02/01. 5. Egan KP, Wu S, Wigdahl B, Jennings SR. Immunological control of herpes simplex virus infections. Journal of neurovirology. 2013;19(4):328-45. Epub 2013/08/15. 6. Ouwendijk WJ, Laing KJ, Verjans GM, Koelle DM. T-cell immunity to human alphaherpesviruses. Current opinion in virology. 2013;3(4):452-60. Epub 2013/05/15. 7. Schiffer JT. Mucosal HSV-2 Specific CD8+ T-Cells Represent Containment of Prior Viral Shedding Rather than a Correlate of Future Protection. Frontiers in immunology. 2013;4:209. Epub 2013/08/03. 8. Hanley PJ, Bollard CM. Controlling cytomegalovirus: helping the immune system take the lead. Viruses. 2014;6(6):2242-58. Epub 2014/05/30. 9. Sissons JG, Wills MR. How understanding immunology contributes to managing CMV disease in immunosuppressed patients: now and in future. Medical microbiology and immunology. 2015;204(3):30716. Epub 2015/04/22. 10. Rickinson AB, Long HM, Palendira U, Munz C, Hislop AD. Cellular immune controls over Epstein-Barr virus infection: new lessons from the clinic and the laboratory. Trends in immunology. 2014;35(4):159-69. Epub 2014/03/05. 11. Rouce RH, Louis CU, Heslop HE. Epstein-Barr virus lymphoproliferative disease after hematopoietic stem cell transplant. Current opinion in hematology. 2014;21(6):476-81. Epub 2014/08/28.

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12. Thorley-Lawson DA. Epstein-Barr virus: exploiting the immune system. Nature reviews Immunology. 2001;1(1):75-82. Epub 2002/03/22. 13. Hugler P, Siebrecht P, Hoffmann K, Stucker M, Windeler J, Altmeyer P, et al. Prevention of postherpetic neuralgia with varicella-zoster hyperimmune globulin. Eur J Pain. 2002;6(6):435-45. Epub 2002/11/05. 14. Arvin A, Abendroth A. VZV: immunobiology and host response. In: Arvin A, Campadelli-Fiume G, Mocarski E, Moore PS, Roizman B, Whitley R, et al., editors. Human Herpesviruses: Biology, Therapy, and Immunoprophylaxis. Cambridge2007. 15. Becerra A, Gibson L, Stern LJ, Calvo-Calle JM. Immune response to HHV-6 and implications for immunotherapy. Current opinion in virology. 2014;9:154-61. Epub 2014/12/03. 16. Hislop AD, Sabbah S. CD8+ T cell immunity to Epstein-Barr virus and Kaposi's sarcoma-associated herpes virus. Seminars in cancer biology. 2008;18(6):416-22. Epub 2008/11/15. 17. Chan T, Barra NG, Lee AJ, Ashkar AA. Innate and adaptive immunity against herpes simplex virus type 2 in the genital mucosa. Journal of reproductive immunology. 2011;88(2):210-8. Epub 2011/02/22. 18. Berdugo M, Larsen IV, Abadie C, Deloche C, Kowalczuk L, Touchard E, et al. Ocular distribution, spectrum of activity, and in vivo viral neutralization of a fully humanized anti-herpes simplex virus IgG Fab fragment following topical application. Antimicrobial agents and chemotherapy. 2012;56(3):1390-402. Epub 2011/12/29. 19. Ohlin M, Soderberg-Naucler C. Human antibody technology and the development of antibodies against cytomegalovirus. Molecular immunology. 2015;67(2 Pt A):153-70. Epub 2015/03/25. 20. Corrales-Aguilar E, Hoffmann K, Hengel H. CMV-encoded Fcgamma receptors: modulators at the interface of innate and adaptive immunity. Seminars in immunopathology. 2014;36(6):627-40. Epub 2014/10/08. 21. Armour KL, Atherton A, Williamson LM, Clark MR. The contrasting IgG-binding interactions of human and herpes simplex virus Fc receptors. Biochemical Society transactions. 2002;30(4):495-500. Epub 2002/08/28. 22. Nigro G, Adler SP, La Torre R, Best AM. Passive immunization during pregnancy for congenital cytomegalovirus infection. The New England journal of medicine. 2005;353(13):1350-62. Epub 2005/09/30. 23. Adler SP, Nigro G, Pereira L. Recent advances in the prevention and treatment of congenital cytomegalovirus infections. Seminars in perinatology. 2007;31(1):10-8. Epub 2007/02/24. 24. Funaro A, Gribaudo G, Luganini A, Ortolan E, Lo Buono N, Vicenzi E, et al. Generation of potent neutralizing human monoclonal antibodies against cytomegalovirus infection from immune B cells. BMC biotechnology. 2008;8:85. Epub 2008/11/19. 25. Tomoiu A, Flamand L. Epitope mapping of a monoclonal antibody specific for human herpesvirus 6 variant A immediate-early 2 protein. Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology. 2007;38(4):286-91. Epub 2007/02/27. 26. Thorley-Lawson DA, Hawkins JB, Tracy SI, Shapiro M. The pathogenesis of Epstein-Barr virus persistent infection. Current opinion in virology. 2013;3(3):227-32. Epub 2013/05/21. 27. Okuno T, Takahashi K, Balachandra K, Shiraki K, Yamanishi K, Takahashi M, et al. Seroepidemiology of human herpesvirus 6 infection in normal children and adults. Journal of clinical microbiology. 1989;27(4):651-3. Epub 1989/04/01. 28. Lagos D, Boshoff C. Immunobiology and host response to KSHV infection. In: Arvin A, CampadelliFiume G, Mocarski E, Moore PS, Roizman B, Whitley R, et al., editors. Human Herpesviruses: Biology, Therapy, and Immunoprophylaxis. Cambridge2007. 29. Krampe K, Briem-Richter A, Fischer L, Nashan B, Ganschow R. The value of immunoprophylaxis for cytomegalovirus infection with intravenous immunoglobulin in pediatric liver transplant recipients receiving a low-dose immunosupressive regimen. Pediatric transplantation. 2010;14(1):67-71. Epub 2009/01/30. 30. Revello MG, Lazzarotto T, Guerra B, Spinillo A, Ferrazzi E, Kustermann A, et al. A randomized trial of hyperimmune globulin to prevent congenital cytomegalovirus. The New England journal of medicine. 2014;370(14):1316-26. Epub 2014/04/04.

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31. Pierce LR, Jain N. Risks associated with the use of intravenous immunoglobulin. Transfusion medicine reviews. 2003;17(4):241-51. Epub 2003/10/23. 32. Burioni R, Williamson RA, Sanna PP, Bloom FE, Burton DR. Recombinant human Fab to glycoprotein D neutralizes infectivity and prevents cell-to-cell transmission of herpes simplex viruses 1 and 2 in vitro. Proceedings of the National Academy of Sciences of the United States of America. 1994;91(1):355-9. Epub 1994/01/04. 33. Lee CC, Lin LL, Chan WE, Ko TP, Lai JS, Wang AH. Structural basis for the antibody neutralization of herpes simplex virus. Acta crystallographica Section D, Biological crystallography. 2013;69(Pt 10):1935-45. Epub 2013/10/09. 34. Nokta M, Tolpin MD, Nadler PI, Pollard RB. Human monoclonal anti-cytomegalovirus (CMV) antibody (MSL 109): enhancement of in vitro foscarnet- and ganciclovir-induced inhibition of CMV replication. Antiviral research. 1994;24(1):17-26. Epub 1994/05/01. 35. Xing Y, Oliver SL, Nguyen T, Ciferri C, Nandi A, Hickman J, et al. A site of varicella-zoster virus vulnerability identified by structural studies of neutralizing antibodies bound to the glycoprotein complex gHgL. Proceedings of the National Academy of Sciences of the United States of America. 2015;112(19):605661. Epub 2015/04/29. 36. Gerna G, Percivalle E, Perez L, Lanzavecchia A, Lilleri D. Monoclonal Antibodies to Different Components of the Human Cytomegalovirus (HCMV) Pentamer gH/gL/pUL128L and Trimer gH/gL/gO as well as Antibodies Elicited during Primary HCMV Infection Prevent Epithelial Cell Syncytium Formation. Journal of virology. 2016;90(14):6216-23. Epub 2016/04/29. 37. Borucki MJ, Spritzler J, Asmuth DM, Gnann J, Hirsch MS, Nokta M, et al. A phase II, double-masked, randomized, placebo-controlled evaluation of a human monoclonal anti-Cytomegalovirus antibody (MSL109) in combination with standard therapy versus standard therapy alone in the treatment of AIDS patients with Cytomegalovirus retinitis. Antiviral research. 2004;64(2):103-11. Epub 2004/10/23. 38. De Logu A, Williamson RA, Rozenshteyn R, Ramiro-Ibanez F, Simpson CD, Burton DR, et al. Characterization of a type-common human recombinant monoclonal antibody to herpes simplex virus with high therapeutic potential. Journal of clinical microbiology. 1998;36(11):3198-204. Epub 1998/10/17. 39. Fouts AE, Comps-Agrar L, Stengel KF, Ellerman D, Schoeffler AJ, Warming S, et al. Mechanism for neutralizing activity by the anti-CMV gH/gL monoclonal antibody MSL-109. Proceedings of the National Academy of Sciences of the United States of America. 2014;111(22):8209-14. Epub 2014/05/21. 40. Manley K, Anderson J, Yang F, Szustakowski J, Oakeley EJ, Compton T, et al. Human cytomegalovirus escapes a naturally occurring neutralizing antibody by incorporating it into assembling virions. Cell host & microbe. 2011;10(3):197-209. Epub 2011/09/20. 41. Clementi N, Criscuolo E, Cappelletti F, Burioni R, Clementi M, Mancini N. Novel therapeutic investigational strategies to treat severe and disseminated HSV infections suggested by a deeper understanding of in vitro virus entry processes. Drug discovery today. 2016;21(4):682-91. Epub 2016/03/16. 42. Gianni T, Amasio M, Campadelli-Fiume G. Herpes simplex virus gD forms distinct complexes with fusion executors gB and gH/gL in part through the C-terminal profusion domain. The Journal of biological chemistry. 2009;284(26):17370-82. Epub 2009/04/24. 43. Oliver SL, Yang E, Arvin AM. Dysregulated Glycoprotein B Mediated Cell-Cell Fusion Disrupts Varicella-Zoster Virus and Host Gene Transcription During Infection. Journal of virology. 2016. Epub 2016/11/01. 44. Atanasiu D, Saw WT, Eisenberg RJ, Cohen GH. Regulation of HSV glycoprotein induced cascade of events governing cell-cell fusion. Journal of virology. 2016. Epub 2016/09/16. 45. Arsenault S, Gravel A, Gosselin J, Flamand L. Generation and characterization of a monoclonal antibody specific for human herpesvirus 6 variant A immediate-early 2 protein. Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology. 2003;28(3):284-90. Epub 2003/10/03. 46. Zhou M, Lanchy JM, Ryckman BJ. Human Cytomegalovirus gH/gL/gO Promotes the Fusion Step of Entry into All Cell Types, whereas gH/gL/UL128-131 Broadens Virus Tropism through a Distinct Mechanism. Journal of virology. 2015;89(17):8999-9009. Epub 2015/06/19.

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47. Schultz EP, Lanchy JM, Ellerbeck EE, Ryckman BJ. Scanning Mutagenesis of Human Cytomegalovirus Glycoprotein gH/gL. Journal of virology. 2015;90(5):2294-305. Epub 2015/12/15. 48. Kabanova A, Perez L, Lilleri D, Marcandalli J, Agatic G, Becattini S, et al. Antibody-driven design of a human cytomegalovirus gHgLpUL128L subunit vaccine that selectively elicits potent neutralizing antibodies. Proceedings of the National Academy of Sciences of the United States of America. 2014;111(50):17965-70. Epub 2014/12/03. 49. Budt M, Reinhard H, Bigl A, Hengel H. Herpesviral Fcgamma receptors: culprits attenuating antiviral IgG? International immunopharmacology. 2004;4(9):1135-48. Epub 2004/07/15. 50. Sautto GA, Wisskirchen K, Clementi N, Castelli M, Diotti RA, Graf J, et al. Chimeric antigen receptor (CAR)-engineered T cells redirected against hepatitis C virus (HCV) E2 glycoprotein. Gut. 2016;65(3):512-23. Epub 2015/02/11. 51. Ito A, Ishida T, Yano H, Inagaki A, Suzuki S, Sato F, et al. Defucosylated anti-CCR4 monoclonal antibody exercises potent ADCC-mediated antitumor effect in the novel tumor-bearing humanized NOD/Shiscid, IL-2Rgamma(null) mouse model. Cancer immunology, immunotherapy : CII. 2009;58(8):1195-206. Epub 2008/12/03. 52. Kubach J, Hubo M, Amendt C, Stroh C, Jonuleit H. IgG1 anti-epidermal growth factor receptor antibodies induce CD8-dependent antitumor activity. International journal of cancer. 2015;136(4):821-30. Epub 2014/06/21. 53. Clementi N, Mancini N, Criscuolo E, Cappelletti F, Clementi M, Burioni R. Epitope mapping by epitope excision, hydrogen/deuterium exchange, and peptide-panning techniques combined with in silico analysis. Methods Mol Biol. 2014;1131:427-46. Epub 2014/02/12. 54. Clementi N, Mancini N, Castelli M, Clementi M, Burioni R. Characterization of epitopes recognized by monoclonal antibodies: experimental approaches supported by freely accessible bioinformatic tools. Drug discovery today. 2013;18(9-10):464-71. Epub 2012/11/28. 55. Kern AB, Schiff BL. Vaccine Therapy in Recurrent Herpes Simplex. Archives of dermatology. 1964;89:844-5. Epub 1964/06/01. 56. Skinner GR, Turyk ME, Benson CA, Wilbanks GD, Heseltine P, Galpin J, et al. The efficacy and safety of Skinner herpes simplex vaccine towards modulation of herpes genitalis; report of a prospective double-blind placebo-controlled trial. Medical microbiology and immunology. 1997;186(1):31-6. Epub 1997/06/01.

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