IN-VITRO EXPANSION OF TUMOR-SPECIFIC, HLA-RESTRICTED HUMAN CD8(-LYMPHOCYTES() CYTOLYTIC T)

The effect of cytokines with human recombinant interleukin-2 (rIL-2) o n cytolytic T cell (CTL) generation was studied. Lymphocytes were isol ated from involved lymph nodes of melanoma patients and expanded in me dium containing rIL-2 alone or in combination with other human cytokin es (rIL-1, rIL-4, rIL-6, and recombinant human tumor necrosis factor-a lpha (rTNF alpha)). Lymphocytes incubated with rIL-2 alone did not gro w, whereas addition of the other cytokines augmented IL-2-mediated lym phocyte proliferation. In all cultures, the majority of expanded lymph ocytes were CD3(+), CD56(-) T cells. Lymphocytes cultured with rIL-1, rIL-2, rIL-4, and rIL-6 exhibited cytolytic activity specific for auto logous melanoma, which increased during the culture period (24.08 and 58.18% at 16 and 30 days in culture, respectively) without detectable changes in cell surface phenotype and remained high even after 100 day s in culture. Moreover, the cytolytic tic activity was inhibited by mo noclonal antibodies (mAbs) against HLA-class I, CD3, and CD8 molecules but not by mAbs against HLA-class II or CD4 molecules. Lymphokine-act ivated killer (LAK) activity was detected in lymphocytes cultured with rIL-1, rIL-2, and rIL-6 in the presence or absence of rTNF alpha Thes e data indicate that lymphocytes derived from melanoma-invaded lymph n odes and cultured in the presence of rIL-1, rIL-2, rIL-4, and rIL-6 of fers an efficient system to expand CD8(+) CTLs with HLA-restricted cyt olytic specificity against autologous tumor cells. (C) 1994 Academic P ress, Inc.