title: Age-related change of spleen cells participating in MHC-homozygous F1 anti-parent mixed lymphocyte reactions.
abstract: The stimulatory activity of spleen cells of BALB/c (H-2d) mice in the in vitro proliferative response of spleen cells from the major histocompatibility complex (MHC)-syngeneic (BALB/c x DBA/2)F1 (CDF1) mice increased gradually with the age of the BALB/c mice used, although that for MHC-allogeneic C57BL/6 (H-2b) spleen cells scarcely changed. Cell fractionation experiments indicated that adherent cells and T cells in the F1 responder and in the stimulator, respectively, were requisite for the response. Genetic studies with H-2d-homozygous F1 cells as responders and H-2d-allogeneic and parental cells as stimulators indicated that the response was controlled by an autosomal gene(s), probably by the Mls gene. Then, CDF1 (MLsb/a) anti-BALB/c (Mlsb) response was considered to be the result of Mlsb-T cell response of the irradiated 'stimulator' against Mlsa determinants on adherent cells of the Mlsb/a hybrid mice, or mediated by so-called 'back stimulation'. Thus, the degree of proliferative response in CDF1 anti-BALB/c was well correlated with that in BALB/c anti-CDF1, and increased with age of the BALB/c mice, indicating an age-related increase of T cell response to non-MHC antigens probably in association with self-MHC class II antigens. On the other hand, the anti-allo-MHC class II activity scarcely changed during adult life. These results indicate that self- and allo-class II reactive T cell compartments fluctuate under different mechanisms in terms of T cell repertoire in aging animals.
mesh_terms: D000375:Aging; D000818:Animals; D002448:Cell Adhesion; D002458:Cell Fractionation; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology*; D006579:Heterozygote; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology*
chemical_list: D006183:H-2 Antigens