Allogeneic Rat T-Suppressor Inducer Cells with In Vivo and In Vitro Activity
The presence of allogeneic Ag-specific T-suppressor inducer cells with in vivo activity has been demonstrated by Hutchinson (1), using a rat renal allograft model. We now demonstrate the presence of in vivo and in vitro T-suppressor inducer activity in the W3/25+ (CD4+) subset of lymphocytes from WF strain rats rejecting LEW strain heterotopic cardiac allografts transplanted 5 days previously. Adoptive transfer of 2 to 4 × 107 of these immune day 5 W3/25+ [d5 W3/25+] splenocytes, or their sonicates 7 days prior to transplantation, prolongs allograft survival two- to threefold in unmodified or irradiated hosts (200 to 300 rads). This prolongation is specific for the donor strain (Table 1).