Immunology
Abstract
In human myocarditis and its sequela dilated cardiomyopathy (DCM), the mechanisms and immune phenotype governing disease and subsequent heart failure are not known. Here, we identified a Th17 cell immunophenotype of human myocarditis/DCM with elevated CD4+IL17+ T cells and Th17-promoting cytokines IL-6, TGF-β, and IL-23 as well as GM-CSF–secreting CD4+ T cells. The Th17 phenotype was linked with the effects of cardiac myosin on CD14+ monocytes, TLR2, and heart failure. Persistent heart failure was associated with high percentages of IL-17–producing T cells and IL-17–promoting cytokines, and the myocarditis/DCM phenotype included significantly low percentages of FOXP3+ Tregs, which may contribute to disease severity. We demonstrate a potentially novel mechanism in human myocarditis/DCM in which TLR2 peptide ligands from human cardiac myosin stimulated exaggerated Th17-related cytokines including TGF-β, IL-6, and IL-23 from myocarditic CD14+ monocytes in vitro, and an anti-TLR2 antibody abrogated the cytokine response. Our translational study explains how an immune phenotype may be initiated by cardiac myosin TLR ligand stimulation of monocytes to generate Th17-promoting cytokines and development of pathogenic Th17 cells in human myocarditis and heart failure, and provides a rationale for targeting IL-17A as a therapeutic option.
Authors
Jennifer M. Myers, Leslie T. Cooper, David C. Kem, Stavros Stavrakis, Stanley D. Kosanke, Ethan M. Shevach, DeLisa Fairweather, Julie A. Stoner, Carol J. Cox, Madeleine W. Cunningham
Abstract
Conventional memory CD8+ T cells and mucosal-associated invariant T cells (MAIT cells) are found in blood, liver, and mucosal tissues and have similar effector potential following activation, specifically expression of IFN-γ and granzyme B. To better understand each subset’s unique contributions to immunity and pathology, we interrogated inflammation- and TCR-driven activation requirements using human memory CD8+ T and MAIT cells isolated from blood and mucosal tissue biopsies in ex vivo functional assays and single cell gene expression experiments. We found that MAIT cells had a robust IFN-γ and granzyme B response to inflammatory signals but limited responsiveness when stimulated directly via their TCR. Importantly, this is not due to an overall hyporesponsiveness to TCR signals. When delivered together, TCR and inflammatory signals synergize to elicit potent effector function in MAIT cells. This unique control of effector function allows MAIT cells to respond to the same TCR signal in a dichotomous and situation-specific manner. We propose that this could serve to prevent responses to antigen in noninflamed healthy mucosal tissue, while maintaining responsiveness and great sensitivity to inflammation-eliciting infections. We discuss the implications of these findings in context of inflammation-inducing damage to tissues such as BM transplant conditioning or HIV infection.
Authors
Chloe K. Slichter, Andrew McDavid, Hannah W. Miller, Greg Finak, Brenda J. Seymour, John P. McNevin, Gabriela Diaz, Julie L. Czartoski, M. Juliana McElrath, Raphael Gottardo, Martin Prlic
Abstract
Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
Authors
Maria Lucia L. Madariaga, Philip J. Spencer, Kumaran Shanmugarajah, Kerry A. Crisalli, David C. Chang, James F. Markmann, Nahel Elias, A. Benedict Cosimi, David H. Sachs, Tatsuo Kawai
Abstract
CD4+ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren’s syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4+CD45RA– T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies.
Authors
Michelle L. Joachims, Kerry M. Leehan, Christina Lawrence, Richard C. Pelikan, Jacen S. Moore, Zijian Pan, Astrid Rasmussen, Lida Radfar, David M. Lewis, Kiely M. Grundahl, Jennifer A. Kelly, Graham B. Wiley, Mikhail Shugay, Dmitriy M. Chudakov, Christopher J. Lessard, Donald U. Stone, R. Hal Scofield, Courtney G. Montgomery, Kathy L. Sivils, Linda F. Thompson, A. Darise Farris
Abstract
Eosinophilic inflammation and Th2 cytokine production are central to the pathogenesis of asthma. Agents that target either eosinophils or single Th2 cytokines have shown benefits in subsets of biomarker-positive patients. More broadly effective treatment or disease-modifying effects may be achieved by eliminating more than one inflammatory stimulator. Here we present a strategy to concomitantly deplete Th2 T cells, eosinophils, basophils, and type-2 innate lymphoid cells (ILC2s) by generating monoclonal antibodies with enhanced effector function (19A2) that target CRTh2 present on all 4 cell types. Using human CRTh2 (hCRTh2) transgenic mice that mimic the expression pattern of hCRTh2 on innate immune cells but not Th2 cells, we demonstrate that anti-hCRTh2 antibodies specifically eliminate hCRTh2+ basophils, eosinophils, and ILC2s from lung and lymphoid organs in models of asthma and
Authors
Tao Huang, Meredith Hazen, Yonglei Shang, Meijuan Zhou, Xiumin Wu, Donghong Yan, Zhonghua Lin, Margaret Solon, Elizabeth Luis, Hai Ngu, Yongchang Shi, Arna Katewa, David F. Choy, Nandhini Ramamoorthi, Erick R. Castellanos, Mercedesz Balazs, Min Xu, Wyne P. Lee, Marissa L. Matsumoto, Jian Payandeh, Joseph R. Arron, Jo-Anne Hongo, Jianyong Wang, Isidro Hötzel, Cary D. Austin, Karin Reif
Abstract
DC-based vaccines that initiate T cell responses are well tolerated and have demonstrated efficacy for tumor immunotherapy, with the potential to be combined with other therapies. Targeting vaccine antigens (Ag) directly to the DCs in vivo is more effective than cell-based therapies in mouse models and is therefore a promising strategy to translate to humans. The human CD141+ DCs are considered the most clinically relevant for initiating CD8+ T cell responses critical for killing tumors or infected cells, and they specifically express the C-type lectin-like receptor CLEC9A that facilitates presentation of Ag by these DCs. We have therefore developed a human chimeric Ab that specifically targets CLEC9A on CD141+ DCs in vitro and in vivo. These human chimeric Abs are highly effective at delivering Ag to DCs for recognition by both CD4+ and CD8+ T cells. Given the importance of these cellular responses for antitumor or antiviral immunity, and the superior specificity of anti-CLEC9A Abs for this DC subset, this approach warrants further development for vaccines.
Authors
Kirsteen M. Tullett, Ingrid M. Leal Rojas, Yoshihito Minoda, Peck S. Tan, Jian-Guo Zhang, Corey Smith, Rajiv Khanna, Ken Shortman, Irina Caminschi, Mireille H. Lahoud, Kristen J. Radford
Abstract
Secreted by activated cells or passively released by damaged cells, extracellular HMGB1 is a prototypical damage-associated molecular pattern (DAMP) inflammatory mediator. During the course of developing extracorporeal approaches to treating injury and infection, we inadvertently discovered that haptoglobin, the acute phase protein that binds extracellular hemoglobin and targets cellular uptake through CD163, also binds HMGB1. Haptoglobin-HMGB1 complexes elicit the production of antiinflammatory enzymes (heme oxygenase-1) and cytokines (e.g., IL-10) in WT but not in CD163-deficient macrophages. Genetic disruption of haptoglobin or CD163 expression significantly enhances mortality rates in standardized models of intra-abdominal sepsis in mice. Administration of haptoglobin to WT and to haptoglobin gene-deficient animals confers significant protection. These findings reveal a mechanism for haptoglobin modulation of the inflammatory action of HMGB1, with significant implications for developing experimental strategies targeting HMGB1-dependent inflammatory diseases.
Authors
Huan Yang, Haichao Wang, Yaakov A. Levine, Manoj K. Gunasekaran, Yongjun Wang, Meghan Addorisio, Shu Zhu, Wei Li, Jianhua Li, Dominique P.V. de Kleijn, Peder S. Olofsson, H. Shaw Warren, Mingzhu He, Yousef Al-Abed, Jesse Roth, Daniel J. Antoine, Sangeeta S. Chavan, Ulf Andersson, Kevin J. Tracey
Abstract
Central clonal deletion has been considered the critical factor responsible for the robust state of tolerance achieved by chimerism-based experimental protocols, but split-tolerance models and the clinical experience are calling this assumption into question. Although clone-size reduction through deletion has been shown to be universally required for achieving allotolerance, it remains undetermined whether it is sufficient by itself. Therapeutic Treg treatment induces chimerism and tolerance in a stringent murine BM transplantation model devoid of myelosuppressive recipient treatment. In contrast to irradiation chimeras, chronic rejection (CR) of skin and heart allografts in Treg chimeras was permanently prevented, even in the absence of complete clonal deletion of donor MHC-reactive T cells. We show that minor histocompatibility antigen mismatches account for CR in irradiation chimeras without global T cell depletion. Furthermore, we show that Treg therapy–induced tolerance prevents CR in a linked suppression–like fashion, which is maintained by active regulatory mechanisms involving recruitment of thymus-derived Tregs to the graft. These data suggest that highly efficient intrathymic and peripheral deletion of donor-reactive T cells for specificities expressed on hematopoietic cells preclude the expansion of donor-specific Tregs and, hence, do not allow for spreading of tolerance to minor specificities that are not expressed by donor BM.
Authors
Nina Pilat, Benedikt Mahr, Lukas Unger, Karin Hock, Christoph Schwarz, Andreas M. Farkas, Ulrike Baranyi, Fritz Wrba, Thomas Wekerle
Abstract
To date, the major target of biologic therapeutics in systemic lupus erythematosus (SLE) has been the B cell, which produces pathogenic autoantibodies. Recently, targeting type I IFN, which is elaborated by plasmacytoid dendritic cells (pDCs) in response to endosomal TLR7 and TLR9 stimulation by SLE immune complexes, has shown promising results. pDCs express high levels of the IL-3Rα chain (CD123), suggesting an alternative potential targeting strategy. We have developed an anti-CD123 monoclonal antibody, CSL362, and show here that it affects key cell types and cytokines that contribute to SLE. CSL362 potently depletes pDCs via antibody-dependent cell-mediated cytotoxicity, markedly reducing TLR7, TLR9, and SLE serum-induced IFN-α production and IFN-α-upregulated gene expression. The antibody also inhibits TLR7- and TLR9-induced plasmablast expansion by reducing IFN-α and IL-6 production. These effects are more pronounced than with IFN-α blockade alone, possibly because pDC depletion reduces production of other IFN subtypes, such as type III, as well as non-IFN proinflammatory cytokines, such as IL-6. In addition, CSL362 depletes basophils and inhibits IL-3 signaling. These effects were confirmed in cells derived from a heterogeneous population of SLE donors, various IFN-dependent autoimmune diseases, and healthy controls. We also demonstrate in vivo activity of CSL362 following its s.c. administration to cynomolgus monkeys. This spectrum of effects provides a preclinical rationale for the therapeutic evaluation of CSL362 in SLE.
Authors
Shereen Oon, Huy Huynh, Tsin Yee Tai, Milica Ng, Katherine Monaghan, Mark Biondo, Gino Vairo, Eugene Maraskovsky, Andrew D. Nash, Ian P. Wicks, Nicholas J. Wilson
Proteomics analysis reveals a Th17-prone cell population in presymptomatic graft-versus-host disease
Abstract
Gastrointestinal graft-versus-host-disease (GI-GVHD) is a life-threatening complication occurring after allogeneic hematopoietic cell transplantation (HCT), and a blood biomarker that permits stratification of HCT patients according to their risk of developing GI-GVHD would greatly aid treatment planning. Through in-depth, large-scale proteomic profiling of presymptomatic samples, we identified a T cell population expressing both CD146, a cell adhesion molecule, and CCR5, a chemokine receptor that is upregulated as early as 14 days after transplantation in patients who develop GI-GVHD. The CD4+CD146+CCR5+ T cell population is Th17 prone and increased by ICOS stimulation. shRNA knockdown of CD146 in T cells reduced their transmigration through endothelial cells, and maraviroc, a CCR5 inhibitor, reduced chemotaxis of the CD4+CD146+CCR5+ T cell population toward CCL14. Mice that received CD146 shRNA–transduced human T cells did not lose weight, showed better survival, and had fewer CD4+CD146+CCR5+ T cells and less pathogenic Th17 infiltration in the intestine, even compared with mice receiving maraviroc with control shRNA–transduced human T cells. Furthermore, the frequency of CD4+CD146+CCR5+ Tregs was increased in GI-GVHD patients, and these cells showed increased plasticity toward Th17 upon ICOS stimulation. Our findings can be applied to early risk stratification, as well as specific preventative therapeutic strategies following HCT.
Authors
Wei Li, Liangyi Liu, Aurelie Gomez, Jilu Zhang, Abdulraouf Ramadan, Qing Zhang, Sung W. Choi, Peng Zhang, Joel K. Greenson, Chen Liu, Di Jiang, Elizabeth Virts, Stephanie L. Kelich, Hong Wei Chu, Ryan Flynn, Bruce R. Blazar, Helmut Hanenberg, Samir Hanash, Sophie Paczesny
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