title: Induction of early alloantigen tolerance in thymus and spleen.
abstract: Both thymocytes and splenocytes from B6 (H-2b) mice injected as neonates with C3H(H-2k) or (B6 X C3H)F1 cells exhibited specific nonresponsiveness to the H-2KD alloantigens in question. Thus, tolerance could be induced in strain combinations which did not share H-2 antigens. Induction of specific allotolerance did not require the presence of Thy-1.2+, Ia+ or G10-Sepharose-adherent cells in the donor inoculum, however injection of irradiated (1200 rad) cells was ineffective. Evidence of specific unresponsiveness was found as early as 5 days after birth and was not abrogated by adding either irradiated normal spleen cells or exogenous interleukin-2 in vitro. In fact, in some experiments there was evidence for the presence of stimulated helper T cells within the population of 'tolerant' cytotoxic T cells exposed to alloantigen. However, this could reflect the operation of a syngeneic mixed lymphocyte reaction directed at, for instance, fetal calf serum components expressed in the context of the tolerated Ia determinants.
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007108:Immune Tolerance; D007519:Isoantigens / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D007519:Isoantigens