EXPRESSION OF THE MULV-TUMOR-ASSOCIATED ANTIGEN IS RESTRICTED TO MULV-TRANSFORMED CELLS

Immunization of mice with Moloney murine leukemia virus (MoMuLV) induc es the generation of a population of CTL which recognizes a non-viral, tumor-associated antigen (TAA) expressed on MuLV-induced tumors. To d etermine whether this TAA could be used as a pre-leukemic or leukemic cell marker, CTL clones directed against Moloney viral and TAA antigen were used to analyze viral and TAA antigen expression on chronically infected and leukemic lymphoid cells obtained from mice inoculated neo natally with MoMuLV. Although both sets of cells could be recognized a nd lysed by viral antigen specific CTL, they are not recognized by TAA -specific CTL. Only after transformed cell lines were established from leukemic spleen cells could susceptibility to TAA-specific CTL be obs erved. Thus, the appearance of the MoMuLV-TAA was restricted to MoMuLV -transformed cells.