Generation and characterization of xenospecific human suppressor T cells.

DESPITE continuous improvements in pharmacologic strategies aimed to prevent transplant rejection, the unwanted effect of nonspecific immunosuppression and the irreversible nature of vascular rejection remain critical problems. These problems are likely to be resolved only by the development of new means for induction of donorspecific tolerance in adult recipients. Progress in this direction has been made recently through the discovery of immunoregulatory T-suppressor cells that inhibit the activation and proliferation of allospecific human T-helper lymphocytes.1,2 Because xenotransplantation of pig organs into human recipients is one of the most desirable solutions to the organ shortage problem we have explored the possibility of generating human suppressor T-cell lines (Ts), which can inhibit T-helper-cell (Th) reactivity against pig MHC class II antigens.