EXPRESSION OF DIFFERENT IMMUNOLOGICAL MARKERS BY CULTURED HUMAN MELANOCYTES

The expression of different immunological markers by cultured human me lanocytes (MC) in relation to immune phenomena, were investigated on t en different MC cell lines from early (1st) to late (22nd) passage. Fo ur melanocyte lines (MC-a) which had undergone changes in growth behav iour during prolonged culture were included in the study, together wit h two melanoma lines. Cytospin preparations of the cells were stained for the presence of a set of different immunological markers and a mel anoma-associated antigen (MAA). All MC lines, including the MC-a and t he melanoma lines, showed expression of MHC class I, IL-1, IL-2, ICAM- 1 and the MAA, NKI-Beteb, during all passages tested. Interestingly, f our of the MC lines showed staining for the Fc receptor. A tendency to wards a stronger expression of ICAM-1 on a higher percentage of cells was observed on MC with increasing passage number, the MC-a and the me lanoma lines. Expression of the MAA was strongly reduced for the MC-a lines in comparison with the MC and the M14 melanoma lines. Positive s taining for the HLA class II molecules was obtained on MC of intermedi ate and late passages, and on the MC-a and the melanoma lines in the d ecreasing order HLA-DR, DP and DQ. Additionally, we carried out a prel iminary study showing that cultured MC also produce IL-1 and IL-6. How ever, we were not able to show the production of biologically active I L-2 testing several cultured MC lines. Nevertheless, the overall resul ts taken together suggest that MC are immunologically important cells that are susceptible to changes during long-term culture.