[Immunogenicity of viable tumor cells--comparison of immunogenicity between xenogenized tumor cells and BCG-tumor cell vaccine].

We compared the immunogenicity of FV-KMT-17 (fibrosarcoma, KMT-17 cells which had been xenogenized by infection with Friend leukemia virus (FV] and BCG + KMT-17 (KMT-17 cells which had been admixed with BCG), both of which can be used as viable tumor cell vaccines. The strength of immunogenicity shown by ETD50 (50% effective tumor dose), the number of immunizing cells required for a 50% suppression of growth of 10(7) KMT-17 cells, was 2.1 X 10(3) in FV-KMT-17 and 36.3 X 10(3) in BCG + KMT-17. The LTD50 (50% lethal tumor dose) which was required to kill 50% of rats immunized with 10(5) FV-KMT-17 was more than 10,000 times as high as the amount of LTD50 in normal rats. The LTD50 in rats immunized with the same number of BCG + KMT-17 was only 3,680 times higher than the amount in normal rats. These results indicate that the immunogenicity of FV-KMT-17 is much stronger than that of BCG + KMT-17. The difference in immunogenicity between the two vaccines was also observed in the tumor -neutralizing activities of spleen cells obtained from rats which had been immunized with them, as measured by Winn assay. Moreover, the antitumor activity of spleen cells from rats immunized with FV-KMT-17 concentrated in the carrageenan-non-sensitive and plastic nonadherent cells, while that of spleen cells from rats immunized with BCG + KMT-17 was observed in both carrageenan-sensitive and plastic adherent cells as well as nonadherent cells.(ABSTRACT TRUNCATED AT 250 WORDS)