Development and Function of Innate Polyclonal TCR alpha beta(+) CD8(+) Thymocytes

作者：Rafei Moutih; Hardy Marie Pierre; Williams Patrick; Vanegas Juan Ruiz; Forner Kathy Ann; Dulude Gael; Labrecque Nathalie; Galipeau Jacques; Perreault Claude^*

来源：The Journal of Immunology, 2011, 187(6): 3133-3144.

DOI：10.4049/jimmunol.1101097

Innate CD8 T cells are found in mutant mouse models, but whether they are produced in a normal thymus remains controversial. Using the RAG2p-GFP mouse model, we found that similar to 10% of TCR alpha beta(+) CD4(-)CD8(+) thymocytes were innate polyclonal T cells (GFP(+)CD44(hi)). Relative to conventional T cells, innate CD8 thymocytes displayed increased cell surface amounts of B7-H1, CD2, CD5, CD38, IL-2R beta, and IL-4Ra alpha and downmodulation of TCR beta. Moreover, they overexpressed several transcripts, including T-bet, Id3, Klf2, and, most of all, Eomes. Innate CD8 thymocytes were positively selected, mainly by nonhematopoietic MHCIa(+) cells. They rapidly produced high levels of IFN-gamma upon stimulation and readily proliferated in response to IL-2 and IL-4. Furthermore, low numbers of innate CD8 thymocytes were sufficient to help conventional CD8 T cells expand and secrete cytokine following Ag recognition. This helper effect depended on CD44-mediated interactions between innate and conventional CD8 T cells. We concluded that innate TCR alpha beta(+) CD8 T cells represent a sizeable proportion of normal thymocytes whose development and function differ in many ways from those of conventional CD8 T cells. The Journal of Immunology, 2011, 187: 3133-3144.

• 出版日期2011-9-15