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Abstract / Cytokine 63 (2013) 243–314

response correlated strongly with up-regulation of expression for certain IFN-I response genes. Our emerging data seems to concord with snippets of recent evidence in the literature regarding human multiple sclerosis (MS). Thus on the basis of our work with EAE, we propose that MS may be a disease in which for some patients systemic IFN-I signaling is suppressed, and provides a simple explanation as to why to some IFN-therapy is clinically beneficial.

data indicate that the induction of disease coincides with fluctuations in the control of the HPA axis and emphasize a regulatory role for the inflammatory cytokine IL-10 during inflammatory arthritis.

http://dx.doi.org/10.1016/j.cyto.2013.06.118

http://dx.doi.org/10.1016/j.cyto.2013.06.116 116 No significant re-directed CD8 nTreg developed in Helper deficient mice 114 Interferon-alpha therapy enhances the anti-friend virus B cell response through Apobec3 Michael S. Harper a, Bradley S. Barrett a, Diana S. Smith a, Karl J. Heilman a, Sam X. Li a, Ulf Dittmer b, Kim J. Hasenkrug c, Mario L. Santiago a, a Division of Infectious Diseases, University of Colorado Denver, Aurora, CO, United States, b University of Duisburg-Essen, Germany, c Rocky Mountain Laboratories, NIAID, Hamilton, MT, United States Therapeutic administration of IFN-a in clinical trials significantly reduced HIV-1 plasma viral load and HTLV-I proviral load in infected patients. However, the downstream antiretroviral effector(s) of IFN-a therapy remain unknown. Here we use the mouse Friend virus (FV) infection model to interrogate a potential effector protein, Apobec3. Lab and wild strains of mice have one of two forms of Apobec3, one associated with greater resistance to Friend Retrovirus (Rfv3r) and improved neutralizing antibody titers, and one associated with greater susceptibility (Rfv3s). We previously showed that in B6 mice, which are Rfv3r/r, IFN-a treatment inhibits acute FV infection primarily through Apobec3in vivo. This raised the question of whether IFN-therapy could be effective in an Rfv3s/s mouse strain. Additionally, we asked if IFN-treatment could therapeutically improve neutralizing antibody responses through Apobec3. Here we show that an IFN-a treatment regimen potently restricts acute FV in the Rfv3s/s 129 mouse strain independently of Apobec3, suggesting that different IFNeffectors may have evolutionarily gained potency in the absence of resistant Apobec3. However, IFN-a efficacy in later infection was dependent on Apobec3, and was associated with an increase in FV-reactive IgG2a. The increase in FV-reactive IgG2a was associated with an Apobec3-dependent B cell response characterized by increased germinal center and plasmablast formation. These data show that even the weak form of Apobec3 stimulates an enhanced B cell response during IFN-therapy, which confirms the potential of the IFN-Apobec3 axis as an antiretroviral therapeutic target or vaccine adjuvant.

Xiao He, Hu Dai, Peter E Jensen, Department of Pathology, University of Utah, Salt Lake City, UT, USA Natural T regulatory cells (nTreg) are an important subpopulation of CD4+ T cells generated in thymus, and essential in preventing autoimmune diseases. However, the role of MHC-class-II-mediated TCR signaling in nTreg development remains unclear, since nTreg still presents in MHC-class-II gene knock-out mice. We examined nTreg development in Helper Deficient (HD) mice, in which the majority of MHC-class-IIrestricted, CD4 lineage designated T cells is mis-directed to the CD8 lineage due to a mutated zbb0000000/ThPOK, a key regulator of CD4+ cell development, gene. In HD, both percentage and number of conventional CD4+ T cells were reduced 10 folds, compared to wild-type littermates, but the total T cell number remained unchanged since >90% of MHC-class-II restricted CD4 T cells were mis-directed to develop as CD8+ cells. Unexpectedly, the percentage of FoxP3+ cells within the residual CD4+ T cells in HD was increased to >50% in spleen and lymph nodes, compared to 5– 10% of CD4+ T cells in control mice, but the absolute numbers of FoxP3+CD4+ T cells was decreased by >50% in HD. In contrast, FoxP3+CD8+ cells, both percentage and numbers, were not significantly changed in HD. Similarly, there was no increase of re-directed FoxP3+CD8+ T cells in Beta-2-microglobulin KO x HD double mutants. Furthermore, after crossing HD with a FoxP3-EGFP reporter line, >90% EGFP+ T cells were CD4+ cells, with 1% detected EGFP+CD8+ cells. Functionally, the CD4+EGFP+ T cells isolated from HD inhibited TCR-triggered IL-2 production and CD69 up-regulation of CD4+EGFP T cells. In summary, we demonstrated that, in contrast to MHCclass-II-restricted, conventional CD4 designated T cells are mis-directed to CD8 lineage, there is no re-directed CD8 nTreg developed in HD. Our data indicates that either commitment of MHC-class-II-restricted nTreg is earlier than conventional MHC-classII-restricted CD4+ cells or selection/expansion of MHC-class-II-restricted nTreg is not supported in CD8+ T cells. http://dx.doi.org/10.1016/j.cyto.2013.06.119

http://dx.doi.org/10.1016/j.cyto.2013.06.117

115 Interleukin-10 dependent alterations in the hypothalamic–pituitary–adrenal axis and behavior during inflammatory arthritis Ann K. Harvey a, Claire J. Greenhill a, Michael J. Newton b, Mariah J. Lelos b, Stephen B. Dunnett b, Anwen S. Williams a, Sean L. Wyatt b, Simon A. Jones a, a Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, UK, b School of Biosciences, Cardiff University, Cardiff, UK In addition to its widely recognized role as an anti-inflammatory cytokine, interleukin (IL)-10 is emerging as a potential regulator of the hypothalamic–pituitary– adrenal (HPA) axis, a major part of the neuroendocrine system that controls reaction to stress. The HPA axis is a homeostatic feedback process that produces glucocorticosteroids and hormones that govern digestion, mood and certain immune responses. In rheumatoid arthritis (RA), appropriate control of the HPA axis is often lost and contributes to the incidence of fatigue and depression in patients. In parallel, both RA and depression have been linked to abnormal IL-10 production. In IL-10 deficient (IL-10KO) mice, the inflammatory histopathology associated with antigen-induced arthritis (AIA) is enhanced compared to wild-type (WT) controls. However, little is known about the interplay between the immune and neuroendocrine systems during inflammatory arthritis. Here, we consider IL-10 production in neuroendocrine tissues as a potential mediator of HPA axis function and behavior during arthritis. IL-10KO and WT mice were examined by open field test (OFT) to assess locomotor and exploratory activity following AIA onset. HPA tissue samples, assessed for alterations in gene expression, were harvested at Day 3 and Day 28 of AIA. Compared to WT, IL-10KO mice showed elevated adrenal adrenocorticotropic hormone receptor and pituitary pro-opiomelanocortin expression at Day 3. Coinciding with these HPA axis abnormalities, IL-10KO mice displayed reduced locomotor activity, and spent less time exploring the center of the arena (index of anxious-like behavior). While OFT behaviors in both genotypes returned to baseline by Day 7, joint degeneration progressed. At Day 28, severe joint histopathology was concurrent with elevated hypothalamic glucocorticoid receptor and melatonin receptor 1a expression in IL-10KO mice. These

117 Toll-like receptor and RIG-I like helicase crosstalk is essential to protect against lethal infection with vesicular stomatitis virus Julia Heinrich a, Darren Baker b, Gerd Sutter c, Ulrich Kalinke a, a Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany, b BiogenIdec Inc., Cambridge, MA, USA, c Institute for Infectious Diseases and Zoonosis, Ludwig-Maximilians University, Munich, Germany Toll-like receptors (TLR) and RIG-I like helicases (RLH) have been implemented in the induction of protective type I interferon (IFN-I) responses after infection with single-stranded RNA encoded vesicular stomatitis virus (VSV). MyD88Trif/ and Cardif/ deficient mice devoid of either TLR or RLH dependent signaling, respectively, showed moderately enhanced susceptibility to lethal VSV infection upon intravenous challenge. To clarify the redundancy of both sensing mechanisms and the potential role of other recognition systems in VSV infection MyD88TrifCardif/ deficient mice (MyTrCa/) were generated. Surprisingly, MyTrCa/ mice were as sensitive to VSV infection as IFN-I receptor deficient mice, even after challenge with very low viral doses (200 pfu) and died within 1–2 days. Indeed, VSV infected triple deficient mice did not mount IFN-I responses, as evidenced by ELISA analysis of serum samples and monitoring of IFN-induced genes. Vaccination of MyTrCa/ mice with modified vaccinia virus Ankara, which is known to trigger IFN-I responses to some extent TLR and RLH independently, conferred prolonged survival upon VSV infection. Furthermore, adoptive transfer of 10[7] bone marrow (BM) cells in vitro cultivated in the presence of Flt-3L that contain approximately 30% plasmacytoid DC (pDC) prolonged survival of VSV infected triple deficient mice by 2–3 days. Interestingly, adoptive transfer of 107 purified BM-pDC extended survival by 4–6 days, whereas adoptive transfer of conventional DC had no effect. Furthermore, BM chimeric MyTrCa/ mice that were reconstituted with wild-type BM (WT > MyTrCa/) showed an improved survival upon VSV infection. Notably, the survival of MyTrCa/ > WT chimeric mice was similarly extended as observed for WT > MyTrCa/mice. In conclusion our data indicate that VSV induces protective IFN-I responses that depend on TLR and RLH crosstalk on th e level of irradiation sensitive as well as irradiation resistant cells.

Abstract / Cytokine 63 (2013) 243–314 pDC triggering seems to play an essential role to promote initial survival, whereas is not sufficient to confer full protection.

http://dx.doi.org/10.1016/j.cyto.2013.06.120

118 Modulation of Treg and Th17 fate decision by selective ikaros zinc fingers Jennifer Heller a, Hilde Schjerven b, Ju Qiu a, Aileen Lee a, Stephen Smale b, Liang Zhou a, Microbiology & Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, b Microbiology, Immunology, & Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States

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120 Loss of IFN-gamma 30 untranslated region AU-rich element affects B220+ cell populations in novel murine lupus model Deborah L. Hodge a, Cyril Berthet b, Vincenzo Coppola c, Hidekazu Shirota a, Della Reynolds a, Michael Sanford a, Fanching Lin a, Dennis M. Klinman a, Howard A. Young a, a Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA, b Oncodesign, 20 Rue Jean Mazen, Dijon, France, c Department of Molecular Virology, Immunology and Medical Genetics, Ohio State University, 460 W.12th Street, Columbus, OH 43210, USA

a

TGF-b is a common factor important for the differentiation of pro-inflammatory Th17 and anti-inflammatory inducible Treg cells. However, the precise molecular mechanisms underlying the fate decision of differentiating CD4+ T cells in the presence of TGF-b is poorly understood. Here, we show that distinctive N-terminal DNA-binding zinc fingers of Ikaros play essential roles in Treg and Th17 fate decision. Ikaros has a highly conserved DNA-binding domain near the N-terminus with four tandem zinc fingers. Zinc fingers 2 and 3 are required for stable binding to DNA, whereas fingers 1 and 4 appear to be important for differentially modulating binding properties to specific sites at target genes. Our data show that T cells lacking Ikaros zinc finger 4 but not 1 failed to differentiate into Foxp3+ Tregs upon TGF-b stimulation. Instead, TGF-b-polarized Ikaros mutant cells lacking zinc finger 4 displayed aberrant upregulation of Th17-associated cytokines IL-17 and IL-22. In Ikaros zinc finger 4 mutant cells, IL-17 but not IL-22 upregulation is dependent on transcription factor RORct. Despite the enhancement of IL-22 in Ikaros mutant cells lacking zinc finger 4, aryl hydrocarbon receptor, an essential transcription factor required for IL-22 expression, was unexpectedly decreased. Together, our data uncover a novel selective requirement for Ikaros zinc fingers in the differentiation of Treg and Th17 cells and an intricate interplay among various transcription factors in programming Th17 and Treg lineages.

http://dx.doi.org/10.1016/j.cyto.2013.06.121

119 Interleukin-22 protects against intestinal viral infection through enhancement of interferon-k signaling pathway Pedro P. Hernandez a,c, Tanel Mahlakoiv b, Nam Nguyen a, Peter Staeheli b, Andreas Diefenbach a, a Institute of Medical Microbiology and Hygiene, Freiburg, Germany, b Department of Virology, University of Freiburg, Freiburg, Germany, c International Max Planck Research School for Molecular and Cell Biology (IMPRS-MCB), Freiburg, Germany The mucosal immune system has the challenge of being tolerant of the commensal microbiota while at the same time being able to mount an effective immune response to pathogens. It is now an emerging view that immunity against virus infection at barrier surfaces is orchestrated by a mucosal interferon (IFN) system distinct from the various type I IFNs (IFN-I). This is best documented for rotavirus infection, immunity to which is independent of IFN-I but instead is entirely dependent on IFN-k and its receptor (IFN-kR1). IFN-k is closely related to IL-22, a cytokine abundantly produced by innate lymphoid cells at mucosal surfaces. Interestingly, both the IL-22 and IFN-k receptors are exclusively expressed by epithelial cells, allowing immune cells to control epithelial cell function and repair following infections. Given these similarities between the IL-22 and IFN-k system, we investigated crosstalk between and interdependence of these pathways in epithelial cells. Following rotavirus infection, IFN-k is required to up-regulate antiviral host defense genes (i.e., interferon stimulated genes, ISGs) in infected epithelial cells. Interestingly, mice genetically lacking IL-22 were highly susceptible to rotavirus infection similar to mice lacking IFN-k signaling (IFN-kR1-deficient mice). Il22-/- mice had reduced expression of ISGs and we could demonstrate that IL-22 synergistically reinforces the activation of STAT1 after exposure to IFN-k. Stimulation of epithelial cells with a combination of IL-22 and IFN-k enhanced the phosphorylation of STAT1 thereby enhancing the induction of ISGs resulting in an improved antiviral response. Interestingly, this synergism is independent of STAT3 activation, which is essential for the IL-22-induced antibacterial function and regeneration of epithelial cells. Our data reveal a previously unappreciated interdependence of these two mucosal cytokine signaling pathways required for the protection against enteric virus infection.

http://dx.doi.org/10.1016/j.cyto.2013.06.122

Interferon-gamma (IFN-g) is a key player in immunoregulation, inflammation and autoimmunity. We created a mouse with a 162 nt deletion of an AU-rich element (ARE) region in the 3’UTR of the IFN-g gene. The ARE-deleted (ARE-Del) mice have chronic circulating serum IFN-g levels and develop a lupus-like disease characterized by nuclear antigen-specific autoantibodies and glomerulonephritis. B cells and plasmacytoid dendritic cells (pDCs) play a prominent role is systemic lupus erythematosus (SLE) and we find alterations in both B220+ cell types in these mice. The percentage of CD11c+, pDCA1+, B220+, Siglec H+ pDCs increases in bone marrow and spleens from ARE-Del mice. Furthermore, addition of IFN-g to flt-3 driven in vitro bone marrow cultures results in a dramatic increase in the pDC population with increases in IRF8, but not E2-2, mRNA expression that coincides with this expansion. In contrast, the total percentage of B220+, CD19+ B cells is reduced in spleens from ARE-Del mice. There is little impact on the CD23+ follicular B cell subset; however, CD21+ marginal zone (MZ) B cells are greatly reduced or absent. Crossing the ARE-Del mice with TLR7 or IFN-alpha receptor null mice restore MZ B cells to levels seen in WT mice indicating that interplay between type I and type II interferons plays a role in splenic B cell development. Current studies are underway to understand the molecular basis for how these interferons influence B cell maturation. http://dx.doi.org/10.1016/j.cyto.2013.06.123

121 The molecular basis for the differential response of astrocytes and microglia to oncostatin M Meng-Ping Hsu a, Ricardo Frausto a, Stefan Rose-John b, Iain L Campbell a, a School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia, b Department of Biochemistry, University of Kiel, Germany The interleukin (IL)-6/gp130 family of cytokines including IL-6, IL-11, leukemia inhibitory factor (LIF) and oncostatin M (OSM), play important roles in the central nervous system (CNS) during neuroinflammation and neurodevelopment. However, little is known regarding the responses of the key glial cells, astrocytes and microglia to this family of cytokines. To address this issue, the expression of the gp130 cytokine receptors and subsequent signal pathway activation was examined in cultured murine astrocytes and microglia. In astrocytes, both LIFR mRNA and OSMR mRNA were abundant while low levels of IL-6R mRNA and IL-11R mRNA were also detected. In comparison, in microglia there was no detectable LIFR mRNA and OSMR mRNA, and higher levels of IL-6R mRNA and similar levels of IL-11R mRNA. Immunoblotting for the IL-6R and OSMR proteins revealed that both astrocytes and microglia produced IL-6R, however, the OSMR was abundant in astrocytes but not detectable in microglia. Furthermore, in response to OSM, astrocytes but not microglia responded with activation of STAT3 and ERK while microglia but not astrocytes responded to IL-6. However, both cell types responded strongly to hyper-IL6, with activation of STAT3 and ERK. Finally, in both microglia and astrocytes, OSM failed to activate NFjB or induce NOS2 and nitrite production. We conclude: (1) notable differences exist in the expression of some key IL-6/gp130 family cytokine receptors in astrocytes and microglia, and (2) the findings provide a molecular basis for the differential response to OSM by astrocytes versus microglia. Funding support: NHMRC project grant APP632754. http://dx.doi.org/10.1016/j.cyto.2013.06.124

122 Regulation of thymocyte development by protein phosphatase 4 Ching-Yu Huang, En-Wei Hsing, Fang-Hsuean Liao, Wan-I Hsou, Yu-Jun Lin, Yi-Jyun Jhou, Immunology Research Center, National Health Research Institutes, Zhunan, Miaoli County 350, Taiwan