Cell-mediated immunity to chemically xenogenized tumors--VI. The effect of cell treatment with retroviral env antisense oligonucleotides.

The occurrence of aberrant, retrovirus-related proteins is a common finding in immunogenic clones of the triazene-xenogenized L5178Y lymphoma line (L5178Y/DTIC). In clone D-cells, newly expressed 80 kDa antigens related to xenotropic murine leukemia virus env gene products induce specific humoral and cell-mediated responses and possess biologic activity in vivo. To further clarify the relationship between immunogenic properties of clone D and retroviral gene expression, tumor cells were treated in vitro with antisense oligonucleotides complementary to xenotropic and/or polytropic env sequences of murine leukemia virus. The cells were then assayed for expression of antigens recognized by humoral and cell-mediated responses with specificity for clone D. The results demonstrated that inhibition of env mRNA translation adversely affected the expression of immunogenic determinants in the xenogenized tumor cells.