A role for chondroitin sulphate B in the activity of interleukin 12 in stimulating γ-interferon secretion

Abstract We show, using a murine NK cell line which responds quantitatively to rmIL-12, that treatment with ChABCase, but not other GAGases, results in substantial reductions in the secretion of γ-IFN. Likewise, treatment of the cells with a β- d -xyloside inhibitor of proteoglycan biosynthesis inhibits this cytokine response. In both treatments, the addition of soluble, exogenous GAGs does not relieve the inhibition of γ-IFN secretion. We also demonstrate by ELISA that rmIL-12 binds to CS B. Overall, our studies on this in vitro cellular model of the initiation of Th1 immune responses indicate a major role for cell-surface, iduronate-rich, CS proteoglycan in the biological activity of IL-12.