Differential expression and release of LFA‐3 and ICAM‐1 in human melanoma cell lines

We examined 10 different melanoma cell lines for cellular expression and release of ICAM-1 (CD54) and LFA-3 (CD58) and the influence of cytokines, including IFN alpha, IFN gamma and TNF alpha. Cellular ICAM-1 expression and density varies considerably between the melanoma cell lines. While IFN alpha has no effect on cellular ICAM-1 (cICAM-1) expression, IFN gamma and to a lesser extent TNF alpha can effectively up-regulate cICAM-1. Soluble ICAM-1 (sICAM-1) is detected in the supernatants of all lines tested, release of sICAM-1 correlates with cellular expression. LFA-3 does not much differ in its expression level on melanoma lines, and cytokines have little or no effect on its expression. Soluble LFA-3 is released by only 6 out of 10 lines. Its release can effectively be inhibited by IFN gamma in all lines and by TNF alpha in one, while IFN alpha has no effect. These data show that expression and release of LFA-3 and ICAM-1 differ between melanoma cell lines. This may be of importance for the interaction of melanoma cells with immune effector cells in vivo.