Immunology
Abstract
Natural killer (NK) cells can be divided into phenotypic subsets based on expression of receptors that bind self-MHC-I molecules, a concept termed licensing or education. Here we show NK cell subsets with different migratory, effector, and immunoregulatory functions in dendritic cell and antigen (ag)-specific CD8+ T cell responses during influenza and murine cytomegalovirus infections. Shortly after infection, unlicensed NK cells localized in draining lymph nodes and produced GM-CSF, which correlated with the expansion and activation of dendritic cells, and resulted in greater and sustained ag-specific T cell responses. In contrast, licensed NK cells preferentially migrated to infected tissues and produced IFN-γ. Importantly, human NK cell subsets exhibited similar phenotypic characteristics. Collectively, our studies demonstrate a critical demarcation between the functions of licensed and unlicensed NK cell subsets, with the former functioning as the classical effector subset and the latter as the stimulator of adaptive immunity helping to prime immune responses.
Authors
Anthony E. Zamora, Ethan G. Aguilar, Can M. Sungur, Lam T. Khuat, Cordelia Dunai, G. Raymond Lochhead, Juan Du, Claire Pomeroy, Bruce R. Blazar, Dan L. Longo, Jeffrey M. Venstrom, Nicole Baumgarth, William J. Murphy
Abstract
DCs are necessary and sufficient for induction of allergic airway inflammation. CD11b+ DCs direct the underlying Th2 immunity, but debate surrounds the function of CD103+ DCs in lung immunity and asthma after an allergic challenge. We challenged
Authors
Laura Conejero, Sofía C. Khouili, Sarai Martínez-Cano, Helena M. Izquierdo, Paola Brandi, David Sancho
Abstract
Allogeneic hematopoietic cell transplantation (allo-HCT) is an effective immunotherapy for a variety of hematologic malignances, yet its efficacy is impeded by the development of graft-versus-host disease (GVHD). GVHD is characterized by activation, expansion, cytokine production, and migration of alloreactive donor T cells. Hence, strategies to limit GVHD are highly desirable. Ceramides are known to contribute to inflammation and autoimmunity. However, their involvement in T-cell responses to alloantigens is undefined. In the current study, we specifically characterized the role of ceramide synthase 6 (CerS6) after allo-HCT using genetic and pharmacologic approaches. We found that CerS6 was required for optimal T cell activation, proliferation, and cytokine production in response to alloantigen and for subsequent induction of GVHD. However, CerS6 was partially dispensable for the T cell–mediated antileukemia effect. At the molecular level, CerS6 was required for efficient TCR signal transduction, including tyrosine phosphorylation, ZAP-70 activation, and PKCθ/TCR colocalization. Impaired generation of C16-ceramide was responsible for diminished allogeneic T cell responses. Furthermore, targeting CerS6 using a specific inhibitor significantly reduced T cell activation in mouse and human T cells in vitro. Our study provides a rationale for targeting CerS6 to control GVHD, which would enhance the efficacy of allo-HCT as an immunotherapy for hematologic malignancies in the clinic.
Authors
M. Hanief Sofi, Jessica Heinrichs, Mohammed Dany, Hung Nguyen, Min Dai, David Bastian, Steven Schutt, Yongxia Wu, Anusara Daenthanasanmak, Salih Gencer, Aleksandra Zivkovic, Zdzislaw Szulc, Holger Stark, Chen Liu, Ying-Jun Chang, Besim Ogretmen, Xue-Zhong Yu
Abstract
Infusion of in vitro–derived T cell progenitor (proT) therapy with hematopoietic stem cell transplant aids the recovery of the thymus damaged by total body irradiation. To understand the interaction between proTs and the thymic microenvironment, WT mice were lethally irradiated and given T cell–deficient (
Authors
Michelle J. Smith, Dawn K. Reichenbach, Sarah L. Parker, Megan J. Riddle, Jason Mitchell, Kevin C. Osum, Mahmood Mohtashami, Heather E. Stefanski, Brian T. Fife, Avinash Bhandoola, Kristin A. Hogquist, Georg A. Holländer, Juan Carlos Zúñiga-Pflücker, Jakub Tolar, Bruce R. Blazar
Abstract
Though recent reports suggest that neutrophil extracellular traps (NETs) are a source of antigenic nucleic acids in systemic lupus erythematosus (SLE), we recently showed that inhibition of NETs by targeting the NADPH oxidase complex via cytochrome b-245, β polypeptide (
Authors
Rachael A. Gordon, Jan M. Herter, Florencia Rosetti, Allison M. Campbell, Hiroshi Nishi, Michael Kashgarian, Sheldon I. Bastacky, Anthony Marinov, Kevin M. Nickerson, Tanya N. Mayadas, Mark J. Shlomchik
Abstract
The
Authors
Izumi Ohigashi, Yuki Ohte, Kazuya Setoh, Hiroshi Nakase, Akiko Maekawa, Hiroshi Kiyonari, Yoko Hamazaki, Miho Sekai, Tetsuo Sudo, Yasuharu Tabara, Hiromi Sawai, Yosuke Omae, Rika Yuliwulandari, Yasuhito Tanaka, Masashi Mizokami, Hiroshi Inoue, Masanori Kasahara, Nagahiro Minato, Katsushi Tokunaga, Keiji Tanaka, Fumihiko Matsuda, Shigeo Murata, Yousuke Takahama
Abstract
Despite expression of immunogenic polypeptides, tumors escape immune surveillance by engaging T cell checkpoint regulators and expanding Tregs, among other mechanisms. What orchestrates these controls is unknown. We report that free C3d, a fragment of the third component of complement, inside tumor cells — or associated with irradiated tumor cells and unattached to antigen — recruits, accelerates, and amplifies antitumor T cell responses, allowing immunity to reverse or even to prevent tumor growth. C3d enhances antitumor immunity independently of B cells, NK cells, or antibodies, but it does so by increasing tumor infiltrating CD8+ lymphocytes, by depleting Tregs, and by suppressing expression of programmed cell death protein 1 (PD-1) by T cells. These properties of C3d appear specific for the tumor and dependent on complement receptor 2, and they incur no obvious systemic toxicity. The heretofore unrecognized properties of free C3d suggest that protein might determine the effectiveness of immune surveillance and that increasing availability of the protein might prove advantageous in the treatment or prevention of cancer and premalignant conditions.
Authors
Jeffrey L. Platt, Inês Silva, Samuel J. Balin, Adam R. Lefferts, Evan Farkash, Ted M. Ross, Michael C. Carroll, Marilia Cascalho
Abstract
Despite recent evidence of improved graft outcomes and safety, the high incidence of early acute cellular rejection with belatacept, a high-affinity CTLA4-Ig, has limited its use in clinical transplantation. Here we define how the incomplete control of endogenous donor-reactive memory T cells results in belatacept-resistant rejection in an experimental model of BALB/c.2W-OVA donor heart transplantation into C57BL/6 recipients presensitized to donor splenocytes. These sensitized mice harbored modestly elevated numbers of endogenous donor-specific memory T cells and alloantibodies compared with naive recipients. Continuous CTLA4-Ig treatment was unexpectedly efficacious at inhibiting endogenous graft-reactive T cell expansion but was unable to inhibit late CD4+ and CD8+ T cell infiltration into the allografts, and rejection was observed in 50% of recipients by day 35 after transplantation. When CTLA4-Ig was combined with the sphingosine 1-phosphate receptor-1 (S1PR1) functional antagonist FTY720, alloantibody production was inhibited and donor-specific IFN-γ–producing T cells were reduced to levels approaching nonsensitized tolerant recipients. Late T cell recruitment into the graft was also restrained, and graft survival improved with this combination therapy. These observations suggest that a rational strategy consisting of inhibiting memory T cell expansion and trafficking into the allograft with CTLA4-Ig and FTY720 can promote allograft survival in allosensitized recipients.
Authors
Stella H. Khiew, Jinghui Yang, James S. Young, Jianjun Chen, Qiang Wang, Dengping Yin, Vinh Vu, Michelle L. Miller, Roger Sciammas, Maria-Luisa Alegre, Anita S. Chong
Abstract
Unconjugated bilirubin (UCB), a product of heme oxidation, has known immunosuppressant properties but the molecular mechanisms, other than antioxidant effects, remain largely unexplored. We note that UCB modulates T helper type 17 (Th17) immune responses, in a manner dependent upon heightened expression of CD39 ectonucleotidase. UCB has protective effects in experimental colitis, where it enhances recovery after injury and preferentially boosts IL-10 production by colonic intraepithelial CD4+ cells. In vitro, UCB confers immunoregulatory properties on human control Th17 cells, as reflected by increased levels of FOXP3 and CD39 with heightened cellular suppressor ability. Upregulation of CD39 by Th17 cells is dependent upon ligation of the aryl hydrocarbon receptor (AHR) by UCB. Genetic deletion of CD39, as in
Authors
Maria Serena Longhi, Marta Vuerich, Alireza Kalbasi, Jessica E. Kenison, Ada Yeste, Eva Csizmadia, Byron Vaughn, Linda Feldbrugge, Shuji Mitshuhashi, Barbara Wegiel, Leo Otterbein, Alan Moss, Francisco J. Quintana, Simon C. Robson
Abstract
Contact hypersensitivity (CHS) is a common skin disease induced by epicutaneous sensitization to haptens. Conflicting results have been obtained regarding pathogenic versus protective roles of mast cells (MCs) in CHS, and this has been attributed in part to the limitations of certain models for studying MC functions in vivo. Here we describe a fluorescent imaging approach that enables in vivo selective labeling and tracking of MC secretory granules by real-time intravital 2-photon microscopy in living mice, and permits the identification of such MCs as a potential source of cytokines in different disease models. We show using this method that dermal MCs release their granules progressively into the surrounding microenvironment, but also represent an initial source of the antiinflammatory cytokine IL-10, during the early phase of severe CHS reactions. Finally, using 3 different types of MC-deficient mice, as well as mice in which IL-10 is ablated specifically in MCs, we show that IL-10 production by MCs can significantly limit the inflammation and tissue pathology observed in severe CHS reactions.
Authors
Laurent L. Reber, Riccardo Sibilano, Philipp Starkl, Axel Roers, Michele A. Grimbaldeston, Mindy Tsai, Nicolas Gaudenzio, Stephen J. Galli
Abstract
Lung transplantation, a cure for a number of end-stage lung diseases, continues to have the worst long-term outcomes when compared with other solid organ transplants. Preclinical modeling of the most common and serious lung transplantation complications are essential to better understand and mitigate the pathophysiological processes that lead to these complications. Various animal and in vitro models of lung transplant complications now exist and each of these models has unique strengths. However, significant issues, such as the required technical expertise as well as the robustness and clinical usefulness of these models, remain to be overcome or clarified. The National Heart, Lung, and Blood Institute (NHLBI) convened a workshop in March 2016 to review the state of preclinical science addressing the three most important complications of lung transplantation: primary graft dysfunction (PGD), acute rejection (AR), and chronic lung allograft dysfunction (CLAD). In addition, the participants of the workshop were tasked to make consensus recommendations on the best use of these complimentary models to close our knowledge gaps in PGD, AR, and CLAD. Their reviews and recommendations are summarized in this report. Furthermore, the participants outlined opportunities to collaborate and directions to accelerate research using these preclinical models.
Authors
Vibha N. Lama, John A. Belperio, Jason D. Christie, Souheil El-Chemaly, Michael C. Fishbein, Andrew E. Gelman, Wayne W. Hancock, Shaf Keshavjee, Daniel Kreisel, Victor E. Laubach, Mark R. Looney, John F. McDyer, Thalachallour Mohanakumar, Rebecca A. Shilling, Angela Panoskaltsis-Mortari, David S. Wilkes, Jerry P. Eu, Mark R. Nicolls
Abstract
ICOS costimulation generates Th17 cells with durable memory responses to tumor. Herein, we found that ICOS induces PI3K/p110δ/Akt and Wnt/β-catenin pathways in Th17 cells. Coinhibiting PI3Kδ and β-catenin altered the biological fate of Th17 cells. Th17 cells inhibited of both pathways expressed less RORγt, which, in turn, reduced their ability to secrete IL-17. Unexpectedly, these cells were more effective (than uninhibited cells) at regressing tumor when infused into mice, leading to long-term curative responses. PI3Kδ inhibition expanded precursor Th17 cells with a central memory phenotype that expressed nominal regulatory properties (low FoxP3), while β-catenin inhibition enhanced Th17 multifunctionality in vivo. Remarkably, upon TCR restimulation, RORγt and IL-17 rebounded in Th17 cells treated with PI3Kδ and β-catenin inhibitors. Moreover, these cells regained β-catenin, Tcf7, and Akt expression, licensing them to secrete heightened IL-2, persist, and eradicate solid tumors without help from endogenous NK and CD8 T cells. This finding shines a light on ways to repurpose FDA-approved drugs to augment T cell–based cancer immunotherapies.
Authors
Kinga Majchrzak, Michelle H. Nelson, Jacob S. Bowers, Stefanie R. Bailey, Megan M. Wyatt, John M. Wrangle, Mark P. Rubinstein, Juan C. Varela, Zihai Li, Richard A. Himes, Sherine S.L. Chan, Chrystal M. Paulos
Abstract
G protein–coupled receptor 15 (GPR15) was recently highlighted as a colon-homing receptor for murine and human CD4+ T cells. The aim of this study was to explore the functional phenotype of human GPR15+CD4+ T cells, focusing on Tregs and effector T cells (Teffs), and to determine whether GPR15 is the driver for the migration of T cells to the colon during ulcerative colitis (UC). In the peripheral blood, GPR15 was expressed on Tregs and Teffs; both GPR15+ T cell subsets produced less IFN-γ and IL-4 but more IL-17 after stimulation and showed a higher migration activity compared with GPR15–CD4+ T cells. In UC patients, GPR15 expression was increased on Tregs in the peripheral blood but not on Teffs. Interestingly, the expression of GPR15 was significantly enhanced on colonic T cells of UC patients in noninflamed biopsies but not in inflamed biopsies. The differential expression of GPR15 in UC patients was accompanied by a significant reduction of bacterial immunoregulatory metabolites in the feces. In conclusion, GPR15 expression on CD4+ T cells is altered in UC patients, which may have implications for the development of therapeutic approaches to target T cell trafficking to the colon.
Authors
Alexandra Adamczyk, Daniel Gageik, Annika Frede, Eva Pastille, Wiebke Hansen, Andreas Rueffer, Jan Buer, Jürgen Büning, Jost Langhorst, Astrid M. Westendorf
Abstract
Humoral immunity is critical for viral control, but the identity and mechanisms regulating human antiviral B cells are unclear. Here, we characterized human B cells expressing T-bet and analyzed their dynamics during viral infections. T-bet+ B cells demonstrated an activated phenotype, a distinct transcriptional profile, and were enriched for expression of the antiviral immunoglobulin isotypes IgG1 and IgG3. T-bet+ B cells expanded following yellow fever virus and vaccinia virus vaccinations and also during early acute HIV infection. Viremic HIV-infected individuals maintained a large T-bet+ B cell population during chronic infection that was associated with increased serum and cell-associated IgG1 and IgG3 expression. The HIV gp140–specific B cell response was dominated by T-bet–expressing memory B cells, and we observed a concomitant biasing of gp140-specific serum immunoglobulin to the IgG1 isotype. These findings suggest that T-bet induction promotes antiviral immunoglobulin isotype switching and development of a distinct T-bet+ B cell subset that is maintained by viremia and coordinates the HIV Env–specific humoral response.
Authors
James J. Knox, Marcus Buggert, Lela Kardava, Kelly E. Seaton, Michael A. Eller, David H. Canaday, Merlin L. Robb, Mario A. Ostrowski, Steven G. Deeks, Mark K. Slifka, Georgia D. Tomaras, Susan Moir, M. Anthony Moody, Michael R. Betts
Abstract
HIV vaginal transmission accounts for the majority of newly acquired heterosexual infections. However, the mechanism by which HIV spreads from the initial site of viral entry at the mucosal surface of the female genital tract to establish a systemic infection of lymphoid and peripheral tissues is not known. Once the virus exits the mucosa it rapidly spreads to all tissues, leading to CD4+ T cell depletion and the establishment of a viral reservoir that cannot be eliminated with current treatments. Understanding the molecular and cellular requirements for viral dissemination from the genital tract is therefore of great importance, as it could reveal new strategies to lengthen the window of opportunity to target the virus at its entry site in the mucosa where it is the most vulnerable and thus prevent systemic infection. Using HIV vaginal infection of humanized mice as a model of heterosexual transmission, we demonstrate that blocking the ability of leukocytes to respond to chemoattractants prevented HIV from leaving the female genital tract. Furthermore, blocking lymphocyte egress from lymph nodes prevented viremia and infection of the gut. Leukocyte trafficking therefore plays a major role in viral dissemination, and targeting the chemoattractant molecules involved can prevent the establishment of a systemic infection.
Authors
Maud Deruaz, Thomas T. Murooka, Sophina Ji, Marc A. Gavin, Vladimir D. Vrbanac, Judy Lieberman, Andrew M. Tager, Thorsten R. Mempel, Andrew D. Luster
Abstract
Myasthenia gravis (MG) with anti–acetylcholine receptor (AChR) Abs is an autoimmune disease characterized by severe defects in immune regulation and thymic inflammation. Because mesenchymal stem cells (MSCs) display immunomodulatory features, we investigated whether and how in vitro–preconditioned human MSCs (cMSCs) could treat MG disease. We developed a new humanized preclinical model by subcutaneously grafting thymic MG fragments into immunodeficient NSG mice (NSG-MG model). Ninety percent of the animals displayed human anti-AChR Abs in the serum, and 50% of the animals displayed MG-like symptoms that correlated with the loss of AChR at the muscle endplates. Interestingly, each mouse experiment recapitulated the MG features of each patient. We next demonstrated that cMSCs markedly improved MG, reducing the level of anti-AChR Abs in the serum and restoring AChR expression at the muscle endplate. Resting MSCs had a smaller effect. Finally, we showed that the underlying mechanisms involved (a) the inhibition of cell proliferation, (b) the inhibition of B cell–related and costimulatory molecules, and (c) the activation of the complement regulator DAF/CD55. In conclusion, this study shows that a preconditioning step promotes the therapeutic effects of MSCs via combined mechanisms, making cMSCs a promising strategy for treating MG and potentially other autoimmune diseases.
Authors
Muriel Sudres, Marie Maurer, Marieke Robinet, Jacky Bismuth, Frédérique Truffault, Diane Girard, Nadine Dragin, Mohamed Attia, Elie Fadel, Nicola Santelmo, Camille Sicsic, Talma Brenner, Sonia Berrih-Aknin
Abstract
Systemic lupus erythematosus (SLE) is often associated with exaggerated B cell activation promoting plasma cell generation, immune-complex deposition in the kidney, renal infiltration of myeloid cells, and glomerular nephritis. Type-I IFNs amplify these autoimmune processes and promote severe disease. Bruton’s tyrosine kinase (Btk) inhibitors are considered novel therapies for SLE. We describe the characterization of a highly selective reversible Btk inhibitor, G-744. G-744 is efficacious, and superior to blocking BAFF and Syk, in ameliorating severe lupus nephritis in both spontaneous and IFNα-accelerated lupus in NZB/W_F1 mice in therapeutic regimens. Selective Btk inhibition ablated plasmablast generation, reduced autoantibodies, and — similar to cyclophosphamide — improved renal pathology in IFNα-accelerated lupus. Employing global transcriptional profiling of spleen and kidney coupled with cross-species human modular repertoire analyses, we identify similarities in the inflammatory process between mice and humans, and we demonstrate that G-744 reduced gene expression signatures essential for splenic B cell terminal differentiation, particularly the secretory pathway, as well as renal transcriptional profiles coupled with myeloid cell–mediated pathology and glomerular plus tubulointerstitial disease in human glomerulonephritis patients. These findings reveal the mechanism through which a selective Btk inhibitor blocks murine autoimmune kidney disease, highlighting pathway activity that may translate to human SLE.
Authors
Arna Katewa, Yugang Wang, Jason A. Hackney, Tao Huang, Eric Suto, Nandhini Ramamoorthi, Cary D. Austin, Meire Bremer, Jacob Zhi Chen, James J. Crawford, Kevin S. Currie, Peter Blomgren, Jason DeVoss, Julie A. DiPaolo, Jonathan Hau, Adam Johnson, Justin Lesch, Laura E. DeForge, Zhonghua Lin, Marya Liimatta, Joseph W. Lubach, Sami McVay, Zora Modrusan, Allen Nguyen, Chungkee Poon, Jianyong Wang, Lichuan Liu, Wyne P. Lee, Harvey Wong, Wendy B. Young, Michael J. Townsend, Karin Reif
Abstract
Influenza A virus (IAV) infections lead to severe inflammation in the airways. Patients with chronic obstructive pulmonary disease (COPD) characteristically have exaggerated airway inflammation and are more susceptible to infections with severe symptoms and increased mortality. The mechanisms that control inflammation during IAV infection and the mechanisms of immune dysregulation in COPD are unclear. We found that IAV infections lead to increased inflammatory and antiviral responses in primary bronchial epithelial cells (pBECs) from healthy nonsmoking and smoking subjects. In pBECs from COPD patients, infections resulted in exaggerated inflammatory but deficient antiviral responses. A20 is an important negative regulator of NF-κB–mediated inflammatory but not antiviral responses, and A20 expression was reduced in COPD. IAV infection increased the expression of miR-125a or -b, which directly reduced the expression of A20 and mitochondrial antiviral signaling (MAVS), and caused exaggerated inflammation and impaired antiviral responses. These events were replicated in vivo in a mouse model of experimental COPD. Thus, miR-125a or -b and A20 may be targeted therapeutically to inhibit excessive inflammatory responses and enhance antiviral immunity in IAV infections and in COPD.
Authors
Alan C-Y. Hsu, Kamal Dua, Malcolm R. Starkey, Tatt-Jhong Haw, Prema M. Nair, Kristy Nichol, Nathan Zammit, Shane T. Grey, Katherine J. Baines, Paul S. Foster, Philip M. Hansbro, Peter A. Wark
Abstract
IL-21 has been shown to play an important role in the CD8 T cell response during acute and chronic viral infections. However, the role of IL-21 signaling in the CD4 T cell response to viral infection remains incompletely defined. In a model of infection with vaccinia virus, we show that intrinsic IL-21 signaling on CD4 T cells was critical for the formation of memory CD4 T cells in vivo. We further reveal that IL-21 promoted CD4 T cell survival in a mechanism dependent on activation of the STAT1 and STAT3 signaling pathways. In addition, the activation of Akt is also required for IL-21–dependent survival of CD4 T cells in vivo. These results identify a critical role for intrinsic IL-21 signaling in CD4 T cell survival and memory formation in response to viral infection in vivo and may provide insights into the design of effective vaccine strategies.
Authors
Yuqing Yuan, Yiping Yang, Xiaopei Huang
Abstract
IL-33 is one of the critical cytokines that activates group 2 innate lymphoid cells (ILC2s) and mediates allergic reactions. Accumulating evidence suggests that IL-33 is also involved in the pathogenesis of several chronic inflammatory diseases. Previously, we generated an IL-5 reporter mouse and revealed that lung IL-5–producing ILC2s played essential roles in regulating eosinophil biology. In this study, we evaluated the consequences of IL-33 administration over a long period, and we observed significant expansion of ILC2s and eosinophils surrounding pulmonary arteries. Unexpectedly, pulmonary arteries showed severe occlusive hypertrophy that was ameliorated in IL-5– or eosinophil-deficient mice, but not in Rag2-deficient mice. This indicates that IL-5–producing ILC2s and eosinophils play pivotal roles in pulmonary arterial hypertrophy. Administration of a clinically used vasodilator was effective in reducing IL-33–induced hypertrophy and repressed the expansion of ILC2s and eosinophils. Taken together, these observations demonstrate a previously unrecognized mechanism in the development of pulmonary arterial hypertrophy and the causative roles of ILC2 in the process.
Authors
Masashi Ikutani, Koichi Tsuneyama, Makoto Kawaguchi, Junya Fukuoka, Fujimi Kudo, Susumu Nakae, Makoto Arita, Yoshinori Nagai, Satoshi Takaki, Kiyoshi Takatsu
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