Regional lymph-node (LN) lymphocytes may constitute an important defence against the spread of human
melanoma beyond regional LNs. The present study was directed to clonal analysis of lymphocytes cultured either directly from the LNs or after stimulation in cultures with autologous
melanoma (MLTC). T-cell clones derived from MLTC reactions had either CD4+ or CD8+ phenotypes. Inhibition studies with
monoclonal antibodies (MAbs) suggested that the CD8+ cytotoxic T-cell (CTL) clones had MHC-class-I-restricted cytotoxic activity against the autologous and a proportion of HLA-class-I-compatible allogeneic
melanomas. The pattern of cytotoxicity against a panel of HLA-typed
melanoma cells and inhibition by (polyclonal) HLA-typing sera suggested the CD8+ CTL were restricted by
HLA-A3. The CD4+ T-cell clones had weak cytotoxic activity which appeared restricted by
HLA-DR2. T cells cultured from unstimulated lymphocytes were all CD4+. One of the clones exhibited cytotoxic activity against both the autologous and HLA-DR2-compatible allogeneic
melanoma cells, whereas another 2 had cytotoxic activity only against a HLA-DR2-compatible allogeneic
melanoma established from a primary
melanoma.
IL-2 production by a 4th non-cytotoxic clone had similar specificity. These results suggest that
HLA-A3 and DR2 may act as restricting elements in recognition of
melanoma antigens by T cells from LNs and that they may have recognized at least 2 different
antigens on the
melanoma cells.