Lack of IL-7 and IL-15 signaling affects interferon-γ production by, more than survival of, small intestinal intraepithelial memory CD8+ T cells
✍ Scribed by Dmitry Isakov; Amiran Dzutsev; Jay A. Berzofsky; Igor M. Belyakov
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 580 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0014-2980
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✦ Synopsis
Abstract
Survival of antigen‐specific CD8^+^ T cells in peripheral lymphoid organs during viral infection is known to be dependent predominantly on IL‐7 and IL‐15. However, little is known about a possible influence of tissue environmental factors on this process. To address this question, we studied survival of memory antigen‐specific CD8^+^ T cells in the small intestine. Here, we show that 2 months after vaccinia virus infection, B8R~20–27~/H2‐K^b^ tetramer^+^ CD8^+^ T cells in the small intestinal intraepithelial (SI‐IEL) layer are found in mice deficient in IL‐15 expression. Moreover, SI‐IEL and lamina propria lymphocytes do not express the receptor for IL‐7 (IL‐7Rα/CD127). In addition, after in vitro stimulation with B8R~20–27~ peptide, SI‐IEL cells do not produce high amounts of IFN‐γ neither at 5 days nor at 2 months postinfection (p.i.). Importantly, the lack of IL‐15 was found to shape the functional activity of antigen‐specific CD8^+^ T cells, by narrowing the CTL avidity repertoire. Taken together, these results reveal that survival factors, as well as the functional activity, of antigen‐specific CD8^+^ T cells in the SI‐IEL compartments may markedly differ from their counterparts in peripheral lymphoid tissues.