Thymus-derived lymphocyte-dependent rejection of syngeneic papovavirus (SV40) and methylcholanthrene tumors in inbred hamsters.

Treatment of specifically sensitized MHA hamster lymphoid cells with rabbit antisera specific for hamster thymus-derived lymphocytes, in the presence of C, eliminated those cells capable of inhibiting the growth of syngeneic SV40 and methylcholanthrene tumors in vivo. Thymectomized, lethally-irradiated, bone marrow-reconstituted hamsters, shown to be devoid to T cell function, were, after attempted specific sensitization to the two syngeneic tumor cell lines, unable to reject either tumor by direct challenge in vivo. In addition, lymphocytes from such animals were incapable of inhibiting the growth of either tumor cell line in normal syngeneic recepients in the tumor cell neutralization assay. These data strongly support the conclusion that specifically sensitized thymus-derived lymphocytes are required for the rejection of syngeneic SV40 and methylcholanthrene tumors in inbred hamsters.