The expression of tumor-associated transplantation antigens (TATA) by 3 different murine melanomas was examined. A comparison was made between different modes of inducing tumor-rejection activity, including immunization with irradiated cells from tissue culture lines, with irradiated cells from solid tumor lines. and with viable cells growing in footpads (followed by amputation). Melanoma cell lines examined included the spontaneous B I6 melanoma, the ultraviolet-light-induced K1735 melanoma, and the dimethylbenzanthracene-induced JBlRH melanoma. The data presented demonstrate that not only do all 3 melanoma lines studied express cell surface antigens sufficient to elicit immune response which result in tumorrejection activity, but that these antigens show crossreactivity among the 3 melanoma lines studied. The specificity of the TATA appears to be restricted to the melanomas, since crossreactivity was not observed with 2 different fibrosarcoma cell lines, or with 2 sarcoma cell lines. In addition, it was found that both the JBlRH and K1735 melanoma cells release (or shed) cell surface antigens which can elicit tumor rejection activity, and that these antigens can be extracted with aqueous butanol, as has been demonstrated with 016 melanoma.
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