Rejection of murine cardiac allografts. II. Evidence that splenocytes bearing Lyt2 inhibit responsiveness in long-term heart graft recipients.
Mixed lymphocyte culture--lymphocyte-mediated cytotoxicity (MLC-LMC) reactions by recipient spleen cells were strongly and specifically increased shortly after primarily vascularized heart grafts were placed in mice. Subsequently, in strain combinations in which eventual long-term graft survival occurred, the MLC-LMC became markedly suppressed, unlike the case in situations in which the recipients rejected their allografts. Unseparated spleen cells from long-term recipients are unchanged or slightly depressed in their in vitro MLC-LMC capacity. However, when splenocytes from the long-term B10.A recipients of B10.BR heart grafts were depleted of B cells and Lyt-2-positive cells, they were found to significantly enhance responses when added as third-party cells to MLC-LMC cultures. Similarly depleted splenocytes from naive mice were unaffected or depressed in their ability to contribute to this response as third-party cells. It was concluded that non-Ig-bearing, nonadherent Lyt 2+ lymphocytes from long-term heart graft recipient spleens were present that inhibited the responsiveness of other cells in these spleens.
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D006084:Graft Rejection; D016027:Heart Transplantation; D007111:Immunity, Cellular; D008214:Lymphocytes / Q000145:classification / Q000276:immunology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D013997:Time Factors
D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D011947:Receptors, Antigen, B-Cell