COEXPRESSION OF TYPE-I AND TYPE-II IL-1 RECEPTORS IN THE MURINE-T HELPER 2 CELL-LINE D10N

IL-1 receptor heterogeneity in murine lymphocytes was investigated by cross-linking to [I-125]IL-1alpha and competition with IL-1 receptor a ntagonist, and the molecular identity of the IL-1 receptors was identi fied with PCR using primers specific for type I and type II IL-1 recep tors. The thymoma cell line EI4 6.1 exhibits exclusively the 80 kDa re ceptors which proved to be the type I receptor according to PCR analys is. In the pre-B cell fine 70Z/3, predominantly a 60 kDa type II recep tor but also a trace of type I receptor can be identified by PCR. The Th2 cell line D10N expresses both types of IL-1 receptors in equivalen t amounts according to cross-linking experiments and PCR. The prolifer ative response of D10N cells to IL-1 is inhibited by IL-1 ra which acc ording to cross-linking affects the binding to the type I receptor onl y. It is concluded that coexpression of both types of IL-1 receptors m ight be a characteristic of murine Th2 cells and that their growth-dep endence on IL-1 is mediated by the type I receptor.