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Mouse and human CD8 + CD28 low regulatory T lymphocytes differentiate in the thymus
Author(s) -
Vuddamalay Yirajen,
Attia Mehdi,
Vicente Rita,
Pomié Céline,
Enault Geneviève,
Leobon Bertrand,
Joffre Olivier,
Romagnoli Paola,
Meerwijk Joost P.M.
Publication year - 2016
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/imm.12600
Subject(s) - cd28 , biology , cd8 , cytotoxic t cell , immunology , population , immune system , t cell , immune tolerance , microbiology and biotechnology , in vitro , medicine , genetics , environmental health
Summary Regulatory T (Treg) lymphocytes play a central role in the control of immune responses and so maintain immune tolerance and homeostasis. In mice, expression of the CD 8 co‐receptor and low levels of the co‐stimulatory molecule CD 28 characterizes a Treg cell population that exerts potent suppressive function in vitro and efficiently controls experimental immunopathology in vivo . It has remained unclear if CD 8 + CD 28 low Treg cells develop in the thymus or represent a population of chronically activated conventional T cells differentiating into Treg cells in the periphery, as suggested by their CD 28 low phenotype. We demonstrate that functional CD 8 + CD 28 low Treg cells are present in the thymus and that these cells develop locally and are not recirculating from the periphery. Differentiation of CD 8 + CD 28 low Treg cells requires MHC class I expression on radioresistant but not on haematopoietic thymic stromal cells. In contrast to other Treg cells, CD 8 + CD 28 low Treg cells develop simultaneously with CD 8 + CD 28 high conventional T cells. We also identified a novel homologous naive CD 8 + CD 28 low T‐cell population with immunosuppressive properties in human blood and thymus. Combined, our data demonstrate that CD 8 + CD 28 low cells can develop in the thymus of mice and suggest that the same is true in humans.