IL-7Rα-chain-deficient (IL-7Rα(-/-)) and common γ chain-deficient (γc(-/-)) mice both exhibit abnormal thymic and intestinal intraepithelial lymphocyte (IEL) development, but the developmental inhibition is not equivalent. In this report, we assessed whether the defects in T cell development associated with γc(-/-) mice were due to currently defined γc- dependent cytokines by cross-breeding IL-7Rα(-/-) mice to mice lacking either IL-2, IL-4, or IL-2Rβ. IL-2/IL-7Rα and IL-4/IL-7Rα double knockout (DKO) mice demonstrated equivalent thymic development to IL-7Rα(-/-) mice, whereas IL-2Rβ/IL-7Rα DKO mice, which lack IL-2, IL-7, and IL-15 signaling, displayed thymic T cell defects identical to γc(-/-) mice. Collectively, these data indicate that of the γc-dependent cytokines, only IL-7 and IL-15 contribute to the progression and production of thymic T cells. In the IEL, IL7Rα(-/-) mice selectively lack CD8αα TCRγδ cells, whereas IL-2Rβ(-/-) mice show a significant reduction in all CD8αα cells. IL-2(-/-) and IL- 2/IL-7Rα DKO mice demonstrated a reduction in CD8αα IELs to nearly the same extent as IL-2Rβ(-/-) mice, indicating that IL-2 functions in CD8αα IEL development. Moreover, IL-2Rβ/IL-7Rα DKO mice lacked nearly all TCR- bearing IEL, again recapitulating the phenotype of γc(-/-) mice. Thus, these data point to the importance of IL-2, IL-7, and IL-15 as the γc-dependent cytokines essential for IEL development.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|State||Published - Dec 1 1999|
ASJC Scopus subject areas
- Immunology and Allergy