Differentiation and functional maturation of bone marrow-derived intestinal epithelial T cells expressing membrane T cell receptor in athymic radiation chimeras.
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-alpha beta or TCR-gamma delta 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.
Mosley
R L
RL
Department of Biological Science, University of Tulsa, OK 74104.
Styre
D
D
Klein
J R
JR
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation / Q000276:immunology; D002454:Cell Differentiation; D004847:Epithelial Cells; D005434:Flow Cytometry; D007413:Intestinal Mucosa / Q000166:cytology* / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D011828:Radiation Chimera; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology* / Q000502:physiology; D013934:Thymectomy
D000945:Antigens, Differentiation, T-Lymphocyte; D011948:Receptors, Antigen, T-Cell