[Lymphocyte cytotoxicity against autologous tumor cells and the effect of interferon-beta on their activities. (1) Evaluation by modification of target tumor cells].

IFN is known to enhance NK activity against cultured cell lines such as K562, but not against frozen autologous tumor cells. In order to obtain increased NK cytotoxicity using IFN-beta, various modifications were performed on autologous tumor cells. IFN-beta induced more enhanced NK cytotoxicity of normal lymphocytes when frozen tumor target cells were cultured for 4-5 days in the medium, or when these cells were treated with Vibrio cholerae neuraminidase (VCN). However, in an autologous setting, IFN-beta did not enhance NK cytotoxicity against either cultured autologous tumor cells or VCN-treated tumor cells. Also, IFN-beta did not enhance cytotoxic T cell activity against autologous tumor cells induced by mixed lymphocyte-tumor cell culture, although IFN-beta was able to induce enhancement of allospecific cytotoxic T cells mediated by mixed lymphocyte culture.