title: Induction of transplantation tolerance in rats by spleen allografts. I. Evidence that rats tolerant of spleen allografts contain two phenotypically distinct T suppressor cells.
abstract: We have examined suppressor cell activity in transplantation tolerant (TT) rats bearing vascularized spleen allografts in several different donor-recipient combinations. More than 60% of WAG (RT-1u) and 65% of AGUS (RT-1l) spleen allografts were permanently accepted when transplanted to AGUS and PVG (RT-1c) rats, respectively. All (WAG X AGUS)F1 to AGUS and (AGUS X PVG)F1 to PVG spleen allografts survived indefinitely. Unseparated LNC, TDL, and whole T cell or W3/25+, OX8- T cell populations obtained from AGUS rats bearing (WAG X AGUS)F1 spleens exhibited reduced mixed lymphocyte reaction (MLR) responses to the spleen donor, and to some extent to BN(RT1n) third-party stimulators, but responded normally to PVG.A(RT1a) stimulators. Coculture experiments demonstrated that lymph node cells (LNC) and thoracic duct lymphocytes (TDL) of TT rats contain RT1 specific suppressor cells. Furthermore, T cells isolated from all donor-recipient combinations contained two phenotypically distinct suppressor cell populations: a radiosensitive W3/25+, OX8- (Th/i) and a relatively radioresistant W3/25-, OX8+ (Ts/c). These Ts may be responsible for the maintenance of TT.
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000637:transplantation*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000528:radiation effects; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000145:classification / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface