Modulation by interferons of HLA antigen, high-molecular-weight melanoma associated antigen, and intercellular adhesion molecule 1 expression by cultured melanoma cells with different metastatic potential.

The effect of leukocyte (IFN-alpha), fibroblast (IFN-beta), and immune (IFN-gamma) interferon and/or mezerein on the expression of HLA antigens and melanoma-associated antigens by the melanoma cell line MeWo and its metastatic variant MeM 50-10 was investigated, since this information may contribute to our understanding of the molecular mechanism(s) underlying the metastatic process and of the role of cell differentiation and growth suppression in the antigenic changes induced by interferon (IFN). The three types of IFN had no effect on the expression of high-molecular-weight melanoma-associated antigen, but enhanced that of HLA Class 1 antigens and of intercellular adhesion molecule 1 on MeWo and MeM 50-10 cells. The enhancing effect of IFN-gamma was more marked than that of IFN-alpha and IFN-beta. Furthermore IFN-gamma enhanced the expression of intercellular adhesion molecule 1 by MeM 50-10 cells more than by MeWo cells. IFN-beta was shown for the first time to induce HLA Class II antigens; the effect of IFN-beta, like that of IFN-gamma, is differential on the two cell lines and on the gene products of the HLA-D region. Like IFN-gamma, IFN-beta induced only HLA-DR antigens on MeM 50-10 cells. The results of Northern blot analysis with HLA-DR beta, -DQ beta, and -DP beta probes suggest that the differential modulation of the gene products of the HLA-D region by IFN-beta and IFN-gamma reflects transcriptional and posttranscriptional events. The differential susceptibility to modulation by IFN-beta and IFN-gamma of HLA Class II antigens on MeWo and MeM 50-10 cells is an intrinsic property of each cell line, since only small differences were detected in the number and/or affinity of receptors on the two cell lines. Furthermore, the lack of marked effects of mezerein on the antigen-modulating activity of the three types of IFN, in spite of an enhancement of their differentiating activity, suggests that the changes in the antigenic profile induced by IFN do not represent a differentiation-related phenomenon.