Development and function of innate polyclonal TCRalphabeta+ CD8+ thymocytes.
J Immunol
; 187(6): 3133-44, 2011 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-21844388
ABSTRACT
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 â¼10% of TCRαß(+) 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-2Rß, and IL-4Rα and downmodulation of TCRß. 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-γ 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 TCRαß(+) 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.
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Base de dados:
MEDLINE
Assunto principal:
Diferenciação Celular
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Subpopulações de Linfócitos T
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Receptores de Antígenos de Linfócitos T alfa-beta
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Linfócitos T CD8-Positivos
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Imunidade Inata
Limite:
Animals
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article