Age-related factors in cyclosporine-induced syngeneic graft-versus-host disease: regulatory role of marrow-derived T lymphocytes

The immunobiological mechanisms accounting for the induction of SGVHD by administration ofCsA after syngeneic BMT are indeed complex and remain enigmatic. Central to by Peripheral T Lymphocytes Thymectomized Lewis rats were irradiated (1 ;050 rad) and reconstituted with syngeneic marrow depleted of T lymphocytes by elutriation. 2 wk after transplant, the recipients were infused with 5 x 10 6 splenic T lymphocytes from rats 6 mo of age, and the animals were treated with CsA or the control diluent for 30 d. On day 30, 3 x 10' efector cells from animals with active SGVHD were adoptively transferred into the thymectomized recipients . Graded doses of splenic T lymphocytes from animals 6 mo of age were adoptively transferred into bone marrow (derived from animals 1 mo of age)-reconstituted syngeneic Lewis recipients on the day of transplant or on the last day of a 30-d course of CsA therapy .