Contribution of donor T-lymphocytes to graft immunogenicity

We used genetically T-lymphopenic rats as donors to probe the contribution of T-lymphocytes to graft immunogenicity. Graft survival (GS) of lymphopenic donors was significantly increased as compared to normal donors (median (M) = 17 days vs M = 7d, n = 10). To confirm this observation, we reconstituted 7 lymphopenic rats before organ retrieval with $10 sp7-10 sp8$ purified T-lymphocytes. GS was significantly shorter than with lymphopenic donors (M = 7d, n = 7 vs M = 17d, n = 10). Conversely, we treated 6 normal donors with R7.3 (mouse anti-rat TCR $ alpha/ beta$) monoclonal antibody (mab). GS was significantly increased as compared to normal donors (M = 23d, n = 6 vs M = 7d, n = 10). These experiments demonstrate that grafts of T-lymphopenic donors have a longer survival time. This advantage is lost after reconstitution with normal T-lymphocytes. GS is similarly prolonged after treatment of normal donors with anti-T-lymphocytes mab. Thus, donor T-lymphocytes contribute to the graft immunogenicity in this model