Establishment of paired tumor cells and autologous virus-transformed cell lines to define humoral immune responses in melanoma and sarcoma patients.

Peripheral blood lymphocytes and skin fibroblasts from 12 cancer patients were infected with Epstein-Barr virus (EBV) or SV40 virus. The EBV-transformed lymphoblasts and SV40-transformed fibroblasts were grown as continuous cell lines and expressed the same histocompatibility antigens as tumor cell lines established from the same cancer patients. Sera from 350 melanoma and 195 sarcoma patients were tested for antibody reactive with membrane antigens on three of these tumor cell lines (two melanomas and one sarcoma) by immune adherence (IA) and indirect immunofluorescence (IMI) assays. Antibodies to HLA and other non-tumor-related antigens were completely removed from the most reactive sera by quantitative absorption with 4 x 10(7) lymphoblasts or 10(7) transformed fibroblasts autologous to the tumor target cells. These paired cell lines were used to monitor humoral immune responses in melanoma and sarcoma patients receiving allogeneic tumor cell vaccines.