Effects of amorphous and crystalline nickel sulfide on induction of interferons-alpha/beta and -gamma and interleukin-2.

Pretreatment of rat spleen cells with crystalline or amorphous nickel sulfide (NiS) did not inhibit induction of interferon-gamma or interleukin-2 by concanavalin A. In contrast, pretreatment of murine L-929 cells with crystalline NiS inhibited severely IFN-alpha/beta induction by polyriboinosinic-polyribocytidylic acid, while amorphous NiS did not show any effect. This difference in the effects of both forms of NiS on the spleen and L-929 cells correlated with the cellular internalization of the compound; L-929 cells actively phagocytosed crystalline NiS while the uptake of amorphous NiS by the same type of cells was minimal. The uptake of both crystalline and amorphous NiS by spleen cells was very low.