- Email: [email protected]
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Abstract / Cytokine 63 (2013) 243–314
Due to restricted expression of its cognate receptor predominantly on epithelial cells, IFN-k has limited antiviral activity in vivo. We previously demonstrated that mice lacking functional receptors for IFN-k (IL28R) are far more susceptible to rotavirus than wild-type mice or mice lacking functional type I IFN receptors (IFNAR). Here we report that unlike in wild-type or IFNAR-deficient mice, gut epithelial cells of suckling IL28R-deficient mice readily supported replication of reovirus type 3. These findings are unexpected as IFNAR expression is believed to be ubiquitous and, thus, is expected to compensate for the IL28R deficiency. We used reporter mice either lacking functional IL28R or functional IFNAR to comparatively characterize IFN-responsive cells in vivo by staining tissue sections with antibodies recognizing the IFNinduced Mx1 protein. As expected, the strongest response to IFN-k was found in epithelial cells lining the respiratory and gastrointestinal tracts. In contrast, stimulation of IL28R-deficient mice with IFN-a led to strong expression of Mx1 in most cell types of the body including lung epithelial cells but, surprisingly, not in intestinal epithelial cells (IEC). We could demonstrate that IECs express the gene for the IFNAR alpha chain only minimally, which explains their poor response to IFN-a. Taken together, we have identified IECs as a cell type where IFN-k has a non-redundant role and dominates the mighty type I IFN system, highlighting its in vivo role in restricting pathogens which challenge the intestinal epithelium.
STIs of the mucosal tract. IFN epsilon (e) is a novel type I IFN that was discovered in our laboratory and intriguingly its expression is localised in the FRT, most notably in uterine epithelial cells. Using our gene targeted mice, we have demonstrated that this novel cytokine protects mice from experimental models of STIs – Chlamydia muridarum and Herpes Simplex virus. We are currently assessing the role of IFNe in patient samples. Intriguingly, the responsiveness of the uterus to pathogens is reduced in the presence of progesterone thus providing a window of opportunity for uptake of infection. We demonstrate here, the differential responsiveness of uterine epithelial cells (UEC) to pathogen stimulation, depending on the stage of cycle, which offers a unique insight into the role of the innate immune response in the hormone regulated environment of the FRT. Deletion of IFNe results in a significant reduction in IFN response genes in the FRT, genes that are important in affording a basal level of protection against infections. We also demonstrate that, although constitutively expressed in UEC, levels of IFNe differ with the stages of menstrual cycle stage and indeed at the progestin-regulated and infection sensitive stage of cycle. Indeed, in UEC from women at different stages of cycle and in particular at the window of vulnerability for infections, recombinant IFNe is effective in inducing IFN response genes including MxA and OAS in UEC. Thus, investigation of the role of IFNe in the FRT may identify new therapeutic strategies for manipulating the innate immune response in infection, through regulation of the endogenous control mechanisms.
http://dx.doi.org/10.1016/j.cyto.2013.06.176 http://dx.doi.org/10.1016/j.cyto.2013.06.178
174 Induction of antigen-specific regulatory T cells as a therapy for autoimmune diseases Anna M. Malara, Conor M. Finlay, Anna M. Stefanska, Kingston H.G. Mills, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland Regulatory T (Treg) cells play a fundamental role in suppressing excessive inflammatory responses to pathogens and in maintaining peripheral tolerance to self-antigens. A breakdown in self tolerance or defect in Treg cells can result in uncontrolled effector T cell responses to self antigens and the development of autoimmune disorders. Conversely, approaches that enhance the generation of autoantigen-specific Treg cells have potential for the prevention or treatment of autoimmune disease. The induction of Treg cells is enhanced by anti-inflammatory cytokines, with IL-10 and IL-27 promoting the generation of IL-10 secreting Tr1-type Treg cells and TGF-b with retinoic acid inducing peripheral conversion of naïve T cells into conventional CD4+CD25+Foxp3+ Tregs. Finally, certain immunomodulatory molecules form bacteria or helminth parasites can activate dendritic cells (DCs) to promote induction of Treg cells in vivo. The aim of this study was to examine the capacity of IL-10, TGF-b or IL-27 or pathogen-derived molecules that induce IL-10 and TGF-b and suppress IL-12 from DCs to act as adjuvants to promote the induction of Treg cells against self antigen and thereby prevent or reduce the clinical course of an autoimmune disease in a mouse model. The results to date have shown that TGF-b enhanced survival of CD4+ T cells and suppressed IFN-c production, but upregulated expression of Foxp3, and this was enhanced by IL-10 and IL-27. In vivo studies demonstrated that a low molecular weight fraction from the helminth parasite, Fasciola hepatica, enhanced the frequency of Foxp3+ Treg cells, whereas supernatant from homogenates of liver fluke enhanced IL-10-seceting T cells. These helminth-derived fractions are currently being tested as adjuvants to induce Treg cells against the self antigen, MOG, and to prevent experimental autoimmune encephalomyelitis.
176 Arid5a contributes to stabilization of IL-6 mRNA, and elevation of IL-6 level in vivo Kazuya Masuda a, Barry Ripley a, Riko Nishimura b, Takashi Mino c, Osamu Takeuchi c, Go Shioi d, Hiroshi Kiyonari d, Tadamitsu Kishimoto a, a Laboratory of Immune Regulation, World Premier International Immunology Frontier Research Center, Graduate School of Dentistry, Osaka University, Osaka, Japan, b Departments of Molecular and Cellular Biochemistry, Graduate School of Dentistry, Osaka University, Osaka, Japan, c Laboratory of Infection and Prevention, Institute for Virus Research, Kyoto University, Kyoto, Japan, d Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Developmental Biology, Kobe, Japan Post-transcriptional regulation of IL-6 has been largely uncharacterized, with the exception of the RNase Regnase-1, which prevents autoimmunity by destabilizing IL6 mRNA. We identified a novel RNA binding protein, AT-rich interactive domain 5a (Arid5a), which stabilizes IL-6 but not TNF-a mRNA through binding to the 30 untranslated region (UTR) of IL-6 mRNA. Arid5a was enhanced in macrophages in response to LPS, IL-1b and IL-6 and also induced in MEFs by IL-1b but not TNF-a. Arid5a deficiency inhibited elevation of IL-6 serum level in LPS-treated mice, and suppressed IL-6 levels and the development of TH17 cells in experimental autoimmune encephalomyelitis (EAE). Importantly, Arid5a inhibited the destabilizing effect of Regnase-1 on IL-6 mRNA. Recently, we have found that Arid5a is induced under TH17 cell condition and Arid5a deficiency abrogates the induction of IL-17-producing CD4+T cells (TH17 cells) in vitro. These results indicate that Arid5a plays an important role in promotion of inflammatory processes and autoimmune diseases. http://dx.doi.org/10.1016/j.cyto.2013.06.179
http://dx.doi.org/10.1016/j.cyto.2013.06.177
177 Maintenance of memory regulatory T cells in peripheral tissues
175 The role of interferon epsilon in the immune response in the female reproductive tract
Megan M. Maurano, Michael D. Rosenblum, Hong-An Truong, Abul K. Abbas, Iris K. Gratz, University of California, San Francisco, USA
a
a
a
a
Niamh E. Mangan , Nollaig Bourke , Ka Yee Fung , Sebastian Stifter , Caroline Gargett b, Paul J. Hertzog a, a Centre for Innate Immunity and Infectious Diseases, Monash Institute of Medical Research, Monash University, Victoria, Australia, b Ritchie Centre, Monash Institute of Medical Research, Monash University, Victoria, Australia In the female reproductive tract (FRT), homeostasis needs to be maintained to enable embryo implantation and development in parallel with priming of the immune system, which protects against localised infection. The FRT is at risk from mucosal pathogens including sexually transmitted infections (STIs) and interestingly, women in the certain stages of cycle are more susceptible to STIs. Epithelial cells are the first line of defense against infections in the FRT, where they form a mucosal barrier as well as produce many cytokines and chemokines to provide a mucosal immune response, however, orchestration of this response is still poorly understood. Type I Interferons (IFNs) are important innate cytokines in the immune response against
The skin has unique immunological characteristics and is especially plagued by T cell mediated inflammatory disorders. To study CD4+ T cell responses to epidermal self-antigen, which are largely undefined, we established a mouse model that features tetracycline-inducible expression of chicken ovalbumin (Ova) in the epidermis under the control of the keratin K5 promoter. Expression of antigen in the skin elicits a T cell (DO11.10) dependent inflammatory dermatitis, which is associated with IFN-c and IL17 production by DO11 T cells. This disease develops despite the presence of high starting numbers of natural DO11 Foxp3-expressing regulatory T cells (Tregs), and, in fact, these Tregs proliferate in response to skin-Ag recognition. Tregs are activated by peripheral self-antigen to increase their suppressive function, and a fraction of these cells survive as memory regulatory T cells (mTregs). mTregs persist in nonlymphoid tissue after cessation of Ag expression and have enhanced capacity to suppress tissue-specific autoimmunity. These mTregs express specific effector memory T cell markers and localize preferentially to hair follicles in skin. Memory Tregs express high levels of both IL-2Ra and IL-7Ra. Using a genetic-deletion approach, we show that IL-2 is required to generate mTregs from naive CD4+ T cell precursors in vivo.
Abstract / Cytokine 63 (2013) 243–314
Due to restricted expression of its cognate receptor predominantly on epithelial cells, IFN-k has limited antiviral activity in vivo. We previously demonstrated that mice lacking functional receptors for IFN-k (IL28R) are far more susceptible to rotavirus than wild-type mice or mice lacking functional type I IFN receptors (IFNAR). Here we report that unlike in wild-type or IFNAR-deficient mice, gut epithelial cells of suckling IL28R-deficient mice readily supported replication of reovirus type 3. These findings are unexpected as IFNAR expression is believed to be ubiquitous and, thus, is expected to compensate for the IL28R deficiency. We used reporter mice either lacking functional IL28R or functional IFNAR to comparatively characterize IFN-responsive cells in vivo by staining tissue sections with antibodies recognizing the IFNinduced Mx1 protein. As expected, the strongest response to IFN-k was found in epithelial cells lining the respiratory and gastrointestinal tracts. In contrast, stimulation of IL28R-deficient mice with IFN-a led to strong expression of Mx1 in most cell types of the body including lung epithelial cells but, surprisingly, not in intestinal epithelial cells (IEC). We could demonstrate that IECs express the gene for the IFNAR alpha chain only minimally, which explains their poor response to IFN-a. Taken together, we have identified IECs as a cell type where IFN-k has a non-redundant role and dominates the mighty type I IFN system, highlighting its in vivo role in restricting pathogens which challenge the intestinal epithelium.
STIs of the mucosal tract. IFN epsilon (e) is a novel type I IFN that was discovered in our laboratory and intriguingly its expression is localised in the FRT, most notably in uterine epithelial cells. Using our gene targeted mice, we have demonstrated that this novel cytokine protects mice from experimental models of STIs – Chlamydia muridarum and Herpes Simplex virus. We are currently assessing the role of IFNe in patient samples. Intriguingly, the responsiveness of the uterus to pathogens is reduced in the presence of progesterone thus providing a window of opportunity for uptake of infection. We demonstrate here, the differential responsiveness of uterine epithelial cells (UEC) to pathogen stimulation, depending on the stage of cycle, which offers a unique insight into the role of the innate immune response in the hormone regulated environment of the FRT. Deletion of IFNe results in a significant reduction in IFN response genes in the FRT, genes that are important in affording a basal level of protection against infections. We also demonstrate that, although constitutively expressed in UEC, levels of IFNe differ with the stages of menstrual cycle stage and indeed at the progestin-regulated and infection sensitive stage of cycle. Indeed, in UEC from women at different stages of cycle and in particular at the window of vulnerability for infections, recombinant IFNe is effective in inducing IFN response genes including MxA and OAS in UEC. Thus, investigation of the role of IFNe in the FRT may identify new therapeutic strategies for manipulating the innate immune response in infection, through regulation of the endogenous control mechanisms.
http://dx.doi.org/10.1016/j.cyto.2013.06.176 http://dx.doi.org/10.1016/j.cyto.2013.06.178
174 Induction of antigen-specific regulatory T cells as a therapy for autoimmune diseases Anna M. Malara, Conor M. Finlay, Anna M. Stefanska, Kingston H.G. Mills, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland Regulatory T (Treg) cells play a fundamental role in suppressing excessive inflammatory responses to pathogens and in maintaining peripheral tolerance to self-antigens. A breakdown in self tolerance or defect in Treg cells can result in uncontrolled effector T cell responses to self antigens and the development of autoimmune disorders. Conversely, approaches that enhance the generation of autoantigen-specific Treg cells have potential for the prevention or treatment of autoimmune disease. The induction of Treg cells is enhanced by anti-inflammatory cytokines, with IL-10 and IL-27 promoting the generation of IL-10 secreting Tr1-type Treg cells and TGF-b with retinoic acid inducing peripheral conversion of naïve T cells into conventional CD4+CD25+Foxp3+ Tregs. Finally, certain immunomodulatory molecules form bacteria or helminth parasites can activate dendritic cells (DCs) to promote induction of Treg cells in vivo. The aim of this study was to examine the capacity of IL-10, TGF-b or IL-27 or pathogen-derived molecules that induce IL-10 and TGF-b and suppress IL-12 from DCs to act as adjuvants to promote the induction of Treg cells against self antigen and thereby prevent or reduce the clinical course of an autoimmune disease in a mouse model. The results to date have shown that TGF-b enhanced survival of CD4+ T cells and suppressed IFN-c production, but upregulated expression of Foxp3, and this was enhanced by IL-10 and IL-27. In vivo studies demonstrated that a low molecular weight fraction from the helminth parasite, Fasciola hepatica, enhanced the frequency of Foxp3+ Treg cells, whereas supernatant from homogenates of liver fluke enhanced IL-10-seceting T cells. These helminth-derived fractions are currently being tested as adjuvants to induce Treg cells against the self antigen, MOG, and to prevent experimental autoimmune encephalomyelitis.
176 Arid5a contributes to stabilization of IL-6 mRNA, and elevation of IL-6 level in vivo Kazuya Masuda a, Barry Ripley a, Riko Nishimura b, Takashi Mino c, Osamu Takeuchi c, Go Shioi d, Hiroshi Kiyonari d, Tadamitsu Kishimoto a, a Laboratory of Immune Regulation, World Premier International Immunology Frontier Research Center, Graduate School of Dentistry, Osaka University, Osaka, Japan, b Departments of Molecular and Cellular Biochemistry, Graduate School of Dentistry, Osaka University, Osaka, Japan, c Laboratory of Infection and Prevention, Institute for Virus Research, Kyoto University, Kyoto, Japan, d Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Developmental Biology, Kobe, Japan Post-transcriptional regulation of IL-6 has been largely uncharacterized, with the exception of the RNase Regnase-1, which prevents autoimmunity by destabilizing IL6 mRNA. We identified a novel RNA binding protein, AT-rich interactive domain 5a (Arid5a), which stabilizes IL-6 but not TNF-a mRNA through binding to the 30 untranslated region (UTR) of IL-6 mRNA. Arid5a was enhanced in macrophages in response to LPS, IL-1b and IL-6 and also induced in MEFs by IL-1b but not TNF-a. Arid5a deficiency inhibited elevation of IL-6 serum level in LPS-treated mice, and suppressed IL-6 levels and the development of TH17 cells in experimental autoimmune encephalomyelitis (EAE). Importantly, Arid5a inhibited the destabilizing effect of Regnase-1 on IL-6 mRNA. Recently, we have found that Arid5a is induced under TH17 cell condition and Arid5a deficiency abrogates the induction of IL-17-producing CD4+T cells (TH17 cells) in vitro. These results indicate that Arid5a plays an important role in promotion of inflammatory processes and autoimmune diseases. http://dx.doi.org/10.1016/j.cyto.2013.06.179
http://dx.doi.org/10.1016/j.cyto.2013.06.177
177 Maintenance of memory regulatory T cells in peripheral tissues
175 The role of interferon epsilon in the immune response in the female reproductive tract
Megan M. Maurano, Michael D. Rosenblum, Hong-An Truong, Abul K. Abbas, Iris K. Gratz, University of California, San Francisco, USA
a
a
a
a
Niamh E. Mangan , Nollaig Bourke , Ka Yee Fung , Sebastian Stifter , Caroline Gargett b, Paul J. Hertzog a, a Centre for Innate Immunity and Infectious Diseases, Monash Institute of Medical Research, Monash University, Victoria, Australia, b Ritchie Centre, Monash Institute of Medical Research, Monash University, Victoria, Australia In the female reproductive tract (FRT), homeostasis needs to be maintained to enable embryo implantation and development in parallel with priming of the immune system, which protects against localised infection. The FRT is at risk from mucosal pathogens including sexually transmitted infections (STIs) and interestingly, women in the certain stages of cycle are more susceptible to STIs. Epithelial cells are the first line of defense against infections in the FRT, where they form a mucosal barrier as well as produce many cytokines and chemokines to provide a mucosal immune response, however, orchestration of this response is still poorly understood. Type I Interferons (IFNs) are important innate cytokines in the immune response against
The skin has unique immunological characteristics and is especially plagued by T cell mediated inflammatory disorders. To study CD4+ T cell responses to epidermal self-antigen, which are largely undefined, we established a mouse model that features tetracycline-inducible expression of chicken ovalbumin (Ova) in the epidermis under the control of the keratin K5 promoter. Expression of antigen in the skin elicits a T cell (DO11.10) dependent inflammatory dermatitis, which is associated with IFN-c and IL17 production by DO11 T cells. This disease develops despite the presence of high starting numbers of natural DO11 Foxp3-expressing regulatory T cells (Tregs), and, in fact, these Tregs proliferate in response to skin-Ag recognition. Tregs are activated by peripheral self-antigen to increase their suppressive function, and a fraction of these cells survive as memory regulatory T cells (mTregs). mTregs persist in nonlymphoid tissue after cessation of Ag expression and have enhanced capacity to suppress tissue-specific autoimmunity. These mTregs express specific effector memory T cell markers and localize preferentially to hair follicles in skin. Memory Tregs express high levels of both IL-2Ra and IL-7Ra. Using a genetic-deletion approach, we show that IL-2 is required to generate mTregs from naive CD4+ T cell precursors in vivo.