Highly restricted tumor-specific antigen of radiation leukemia virus-induced murine leukemias

A tumor-specific Ag expressed by the radiation leukemia virus-induced BALB/c leukemia BALBRVC has been serologically and biochemically identified with mAb of rat origin--RH221 and RH16. These mAb recognize two distinct epitopes on a Mr 85,000 glycoprotein. Expression of the RH221/16 Ag was also detected on two radiation leukemia virus-induced C57BL/6 leukemias, B6RV1 and B6RV2. The Ag was not detected on 66 other leukemias, 16 sarcomas, or 19 normal tissues tested. The results of sequential immunoprecipitation and partial peptide analyses of the RH221/16 Ag indicate that this tumor-specific Ag is immunologically and structurally distinct from murine leukemia virus-related determinants expressed on the three RH221/16+ leukemias.