Immunological studies on a hamster‐specific sarcoma virus

Abstract A hamster‐specific sarcoma virus released from cells of a Harvey murine sarcoma virus (H‐MSV)‐induced hamster tumour is shown to have the hamster leukaemia virus group‐specific (gs) antigen, and hence to be a hamster leukaemia virirs (HaL V) pseudotype of the murine sarcoma virus, H‐MSV (HaLV). The hamster leukaemia virus gs antigen is not detectable in non‐producer H‐MSV (HaLV) transformed hamster cells or in Rous sarcoma virus, polyoma or SV40‐transformed cells. Five out of 6 transplanted hamster tumours were found to contain the HaLV gs antigen.