| Abstract: | The presence of alien histocompatibility antigens on the cell surface of the 3-methylcholanthrene-induced BALB/c (H-2d) fibrosarcoma C-1, was investigated by serological and transplantation studied. Absorption experiments with monospecific alloantisera showed that C-1 cells expressed their original private (H-2.4 and 31) and public (H-2.3, 8, 28, and 35) specificities. C-1 cells were also able to absorb monospecific antisera directed to the private specificity H-2.23 of the H-2k haplotype, as well as antisera to the public specificities H-2.1, 5, 11 11 and 25 (H-2k and in part H-2q, H-2a and H-2b haplotypes), which are absent from H-2d normal cells. Conversely, other alien specificities (H-2.2, 17, 30, 32, and 33) were not detected on C-1 cells. The C-1 cells were also unable to absorb the activity of an anti-Ia serum (1-28) directed to 1a.1, 2 and 19 (lak) specificities. Transplantation studies showed that resistance against the challenge of C-1 cells could be induced in syngeneic BALB/c mice by preimmunization with normal tissues from C3Hf and AKR (H-2k), A (H-2a) and C57BL/6J (H-2b) strains (expressing all or some of the extra H-2 antigens of the tumor) whereas no protection was obtained with DBA/2 (H-2d) or with W/Fu rat tissues. The anti-tumor activity could be passively transferred by BALB/c lymphoid cells immune to normal C3Hf, AKR, A, and NIH (H-2q) tissues, but no protection was achieved with lymphoid cells immune to DBA/2 or to W/Fu normal rat tissues. These data indicate that foreign H-2 antigens are expressed on C-1 tumor and that they might function as tumor-associated transplantation antigen which was shown to be present and individually distinct on this sarcoma by appropriate in vivo tests. |
