Characterization of dendritic cells generated from peripheral blood of patients with malignant melanoma

Dendritic cells (DCs) are professional antigen presenting cells. Two x 10(7 ) peripheral blood mononuclear cells (PBMCs) from each of 6 melanoma patien ts and 4 normal donors were incubated in 6-well plates. The adherent cells were cultured in GM-CSF (800 U/ml) and IL-4 (1000 U/ml) for 10 days. Anti-C D80, anti-CD86, anti-HLA-DR, anti-HLA-class I monoclonal antibodies and sup ernatant from two melanoma cell lines were incubated with DCs before respon der T cells were added in mixed lymphocyte reaction (MLR). The mean yields of DCs were 3.6 x 10(5) and 9.3 x 10(5) for donor and the melanoma patients respectively. MLR was inhibited by anti-CD80, anti-CD86, anti-HLA-DR, anti -HLA-Class I and supernatant of melanoma cultures. The characteristics of D Cs generated from melanoma patients were comparable to those from donors. D C function was inhibited by soluble factors in melanoma cultures. Further s tudies are warranted to characterize these inhibitory factors.