MULTIPLE FOREIGN NON‐H‐2 DETERMINANTS ON THE SURFACE OF A CHEMICALLY‐INDUCED MURINE SARCOMA*

Abstract

By immunizing BALB/c (H-2^d mice against normal tissues from C57BL/6J (H-2^b), C3Hf (H-2^k) and DBA/2 (H-2^d), but not from AKR (H-2^k) strains, resistance was induced to the subsequent challenge of the ‘syngeneic’ methyl-cholanthrene-induced BALB/c sarcoma ST5; lymph node cells from allo-immune BALB/c mice were also able to exert a parallel cytotoxic effect against in vitro cultured ST5 cells. The involvement of foreign H-2 specificities in the observed cross-reactions was ruled out by absorptions of H-2 monospecific sera and by the interallelic combinations used, thus suggesting that non-H-2 histocompatibility antigens were responsible for the above findings. By using the indirect isotopic antiglobulin assay, BALB/c anti-C57BL/6J and anti-C3Hf polyspecific sera were found to bind specifically to cultured ST5 cells. C57BL/6J and C3Hf, but not DBA/2, lymph node cells were able to absorb the anti-ST5 activity of the anti-C57BL/6J serum. These results indicated that ST5 cells expressed on their surface at least two different sets of foreign non-H-2 antigens: one shared by C57BL/6J and C3Hf tissues, and detected by both cell-mediated and serological techniques; the other one belonging to DBA/2 tissues, and revealed mainly at the cell-mediated level.