Expression of alien histocompatibility antigens on SJL/J tumors detected by cell-mediated and serological analyses

Reticulum cell sarcoma (RCS) cells of SJL/J (H-2 super(s)) mice have been shown to express antigens that are cross-reactive with allogeneic cells of the H-2 super(d) and H-2 super(b) haplotypes by cell-mediated cytotoxicity, antibody-mediated cytotoxicity, immunofluorescence, and quantitative absorption assays. These alien antigens have been detected on both spontaneous and in vivo- and in vitro-passaged RCS cells to varying degrees. The in vitro cell lines were able to stimulate a syngeneic cytotoxic T cell response detected in a 4-h super(51)Cr release assay. H-2 super(d) specificities were also detected in cultured RCS tumor cells by cytotoxic antibody. Although these antigens may not be inappropriate for the SJL/J strain, their differential expression on tumor cells may be significant in the etiology of the tumor.