Cytokine combinations for induction of antigen-specific cytolytic T lymphocytes from peripheral blood lymphocytes.

We studied effects of varied cytokine combinations on allogeneic cytotoxic T lymphocyte (CTL) generation in a mixed lymphocyte-tumor cell culture. Sensitized with allogeneic melanoma cell line (MM-8.1 or MM-28), peripheral blood mononuclear cells (PBMC) were cultured in medium containing various combinations of cytokines that included human recombinant interleukin-2 (rIL-2) alone (MB-2), rIL-2 and rIL-4 (MB-2,4) and rIL-1, rIL-2, rIL-4 and rIL-6 (MB-1,2,4,6). Lymphocytes proliferated for more than 50 days and manifested stimulating cell-specific cytotoxicities in 1 of 5 cultures with MB-2, in 4 of 5 with MB-2,4 and in 5 of 5 with MB-1,2,4,6. Lymphocytes grew up to 10(6) fold in culture with MB-2,4 or MB-1,2,4,6 at day 90-100. Stimulating cell MM-8.1 (HLAABC+,DR-) induced CD3+, CD8+, CD56- CTLs and MM-28 (HLA-ABC+, DR+) mainly generated CD3+, CD4+, CD56- CTLs. Monoclonal antibodies against HLA-ABC and HLA-DR molecules suppressed the stimulating cell-specific cytolytic activity of CD8+ and CD4+ CTLs, respectively. These data indicate that combination of rIL-1, rIL-2, rIL-4 and rIL-6 offer an efficient system to generate allogeneic, tumor-specific CTLs from PBMCs and that HLA molecules expressed on stimulating cells play an important role in CTL generation.