Showing papers by "Shohei Hori published in 2017"

T follicular helper and T follicular regulatory cells have different TCR specificity.

Abstract: Immunization leads to the formation of germinal centres (GCs) that contain both T follicular helper (Tfh) and T follicular regulatory (Tfr) cells. Whether T-cell receptor (TCR) specificity defines the differential functions of Tfh and Tfr cells is unclear. Here we show that antigen-specific T cells after immunization are preferentially recruited to the GC to become Tfh cells, but not Tfr cells. Tfh cells, but not Tfr cells, also proliferate efficiently on restimulation with the same immunizing antigen in vitro. Ex vivo TCR repertoire analysis shows that immunization induces oligoclonal expansion of Tfh cells. By contrast, the Tfr pool has a TCR repertoire that more closely resembles that of regulatory T (Treg) cells. Our data thus indicate that the GC Tfh and Tfr pools are generated from distinct TCR repertoires, with Tfh cells expressing antigen-responsive TCRs to promote antibody responses, and Tfr cells expressing potentially autoreactive TCRs to suppress autoimmunity.

Maternal High Fiber Diet during Pregnancy and Lactation Influences Regulatory T Cell Differentiation in Offspring in Mice

Abstract: Short-chain fatty acids (SCFAs), the end products of dietary fiber, influence the immune system. Moreover, during pregnancy the maternal microbiome has a great impact on the development of the offspring's immune system. However, the exact mechanisms by which maternal SCFAs during pregnancy and lactation influence the immune system of offspring are not fully understood. We investigated the molecular mechanisms underlying regulatory T cell (Treg) differentiation in offspring regulated by a maternal high fiber diet (HFD). Plasma levels of SCFAs in offspring from HFD-fed mice were higher than in those from no fiber diet-fed mice. Consequently, the offspring from HFD-fed mice had higher frequencies of thymic Treg (tTreg) and peripheral Tregs We found that the offspring of HFD-fed mice exhibited higher autoimmune regulator (Aire) expression, a transcription factor expressed in the thymic microenvironment, suggesting SCFAs promote tTreg differentiation through increased Aire expression. Notably, the receptor for butyrate, G protein-coupled receptor 41 (GPR41), is highly expressed in the thymic microenvironment and Aire expression is not increased by stimulation with butyrate in GPR41-deficient mice. Our studies highlight the significance of SCFAs produced by a maternal HFD for Treg differentiation in the thymus of offspring. Given that Aire expression is associated with the induction of tTregs, the maternal microbiome influences Treg differentiation in the thymus of offspring through GPR41-mediated Aire expression.

Unique properties of thymic antigen-presenting cells promote epigenetic imprinting of alloantigen-specific regulatory T cells.

Abstract: // Garima Garg 1 , Eirini Nikolouli 1 , Matthias Hardtke-Wolenski 2 , Aras Toker 1 , Naganari Ohkura 3,4 , Michael Beckstette 1 , Takahisa Miyao 5 , Robert Geffers 6 , Stefan Floess 1 , Norbert Gerdes 7,8 , Esther Lutgens 7,9 , Anke Osterloh 10 , Shohei Hori 5 , Shimon Sakaguchi 3,4 , Elmar Jaeckel 2 and Jochen Huehn 1 1 Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany 2 Department of Gastroenterology, Hepatology, Endocrinology, Hannover Medical School, Hannover, Germany 3 Department of Experimental Immunology, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Japan 4 Department of Experimental Pathology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan 5 Laboratory for Immune Homeostasis, RIKEN Center for Integrative Medical Sciences, Yokohama City, Kanagawa, Japan 6 Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, Germany 7 Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany 8 Division of Cardiology, Pulmonology, and Vascular Medicine Medical Faculty, University Hospital Dusseldorf, Dusseldorf, Germany 9 Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, AZ, Amsterdam, The Netherlands 10 Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany Correspondence to: Jochen Huehn, email: // Keywords : regulatory T cells, thymic APCs, epigenetic modification, alloantigen-specificity, Immunology and Microbiology Section, Immune response, Immunity Received : October 15, 2016 Accepted : March 03, 2017 Published : March 15, 2017 Abstract Regulatory T cells (Tregs) are potential immunotherapeutic candidates to induce transplantation tolerance. However, stability of Tregs still remains contentious and may potentially restrict their clinical use. Recent work suggested that epigenetic imprinting of Foxp3 and other Treg-specific signature genes is crucial for stabilization of immunosuppressive properties of Foxp3 + Tregs, and that these events are initiated already during early stages of thymic Treg development. However, the mechanisms governing this process remain largely unknown. Here we demonstrate that thymic antigen-presenting cells (APCs), including thymic dendritic cells (t-DCs) and medullary thymic epithelial cells (mTECs), can induce a more pronounced demethylation of Foxp3 and other Treg-specific epigenetic signature genes in developing Tregs when compared to splenic DCs (sp-DCs). Transcriptomic profiling of APCs revealed differential expression of secreted factors and costimulatory molecules, however neither addition of conditioned media nor interference with costimulatory signals affected Foxp3 induction by thymic APCs in vitro . Importantly, when tested in vivo both mTEC- and t-DC-generated alloantigen-specific Tregs displayed significantly higher efficacy in prolonging skin allograft acceptance when compared to Tregs generated by sp-DCs. Our results draw attention to unique properties of thymic APCs in initiating commitment towards stable and functional Tregs, a finding that could be highly beneficial in clinical immunotherapy.