Tumor Immunity to Murine Plasma Cell Tumors. I. Tumor-Associated Transplantation Antigens of NZB and BALB/c Plasma Cell Tumors 2 3

Abstract

The presence of tumor-associated transplantation antigens on plasma cell tumors (PCT) derived from BALB/c and NZB inbred and hybrid mice was demonstrated by the induction of immunity in vivo against malignant tumor challenge. Immunizations were made by viable tumor cell inoculation followed by removal of the tumor. Whereas most NZB-derived PCT were highly effective at inducing immunity against all NZB PCT, only 1 of 5 BALB/c-type PCT showed similar immunogenicity. Immunization with killed or modified cells was either ineffective or markedly inferior to the use of viable cells. The state of immunity was adoptively transferred with spleen cell suspensions at ratios as low as 1 spleen cell to 1 tumor cell. No evidence that PCT-specific antibodies existed was found. In both in vivo challenge and adoptive transfer studies, immunity, when detectable, was specific for PCT. We suggest there is a shared PCT-specific antigen, which may be associated with a subtype of the Gross virus. The antigen is present to a considerably greater degree on NZB PCTthan on most BALB/c PCT.