Differences of sensitivity to autologous cytotoxic lymphocytes between primary tumor and its cervical lymph node metastases.

Antigenic differences between primary tumors and their cervical lymph node metastases of 12 patients with head and neck cancers were examined by measuring their sensitivity to cytotoxic lymphocytes (CL). Cytotoxicity was induced by autologous mixed lymphocyte (CL). Cytotoxicity was induced by autologous mixed lymphocyte tumor cell culture (MLTC), and further cultivation with recombinant interleukin-2 (rIL-2). The effector cells which were used in this study consisted of OKT3+8+ and OKT3+4+ subpopulations. Their cytotoxic nature was different from lymphokine activated killer cell (LAK cell) activity. Cytotoxicity of CLs stimulated by autologous primary tumor cells (CLP) was observed in 7 out of 12 patients (58.3%). In contrast, cytotoxicity of CLs stimulated by metastatic tumor cells (CLM) was observed in 4 out of 12 patients (33.3%). In the cases in which both CLP and CLM were successfully induced, cross-reactivity tests and cold target inhibition tests were performed. These results suggested that a reduction in immunogenicity had occurred at the metastatic site, and sensitivity against autologous CL was different between primary and metastatic tumor cells.