The thymus dependency of murine intestinal intraepithelial lymphocytes (IEL) was studied in an athymic F1 → parent radiation chimera model. IEL, although not splenic or lymph node lymphocytes, from athymic chimeras displayed normal levels of cells bearing the class-specific T cell Ag, CD4 and CD8; the TCR-associated molecule, CD3; and the Thy-1 Ag. Moreover, two-color flow cytometric analyses of IEL from athymic mice demonstrated regulated expression of T cell Ag characteristic of IEL subset populations from thymus-bearing mice. In immunoprecipitation experiments, surface TCR-αβ or TCR-γδ were expressed on IEL, although not on splenic lymphocytes from athymic chimeras. That IEL from athymic chimeras constituted a population of functionally mature effector cells activated in situ, similar to IEL from thymus-bearing mice, was demonstrated by the presence of CD3-mediated lytic activity of athymic lethally irradiated bone marrow reconstituted IEL. These data provide compelling evidence that intestinal T cells do not require thymic influence for maturation and development, and demonstrate that the microenvironment of the intestinal epithelium is uniquely adapted to regulate IEL differentiation.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|Publication status||Published - Jan 1 1990|
ASJC Scopus subject areas
- Immunology and Allergy