INTERLEUKIN-4 ENHANCES GANGLIOSIDE GD3 EXPRESSION ON THE HUMAN FIBROBLAST CELL-LINE WI-38

Human fibroblast cell line WI-38 cultured in vitro was treated with a human recombinant IL-4 at concentrations of 1 to 100 U/ml to examine t he alteration of glycosphingolipid (GSL) expression of the cells, Neut ral GSL of non-treated WI-38 cells consisted of CMH (GlcCer), CDH, CTH , and Gb(4)Cer; CMH and CTH were the major components, The acidic GSL were composed of GM3 as the predominant component and other minor gang liosides including GD3, The neutral GSLs did not change in profile dur ing the treatment with IL-4, while the acidic GSLs showed a prominent change, an increase of GD3 content, The increase of GD3 was detectable with IL-4 concentrations over 1 U/ml, and reached a plateau at 10 U/m l, where the amount of GD3 was almost equal to that of GM3, The GD3 in crease occurred at 24 h after the IL-4 treatment, and lasted for at le ast 96 h, as long as IL-4 remained present in the culture media, The G D3 synthase (sialyltransferase) level was found to be increased in an IL-4 dose-dependent manner, IL-4 did not influence the growth or morph ological appearance of WI-38 cells, The results demonstrate a novel bi ological effect of IL-4, modulating GSL in non-hematopoietic cells,