THE INDUCTION OF CELL-ASSOCIATED AND SECRETED IL-1 BY ISCOMS, MATRIX OR MICELLES IN MURINE SPLENIC CELLS

The kinetics of the expression of membrane-associated IL-1 (mIL-1) and soluble IL-1 (sIL-1) was studied in in vitro stimulated spleen cells from non-primed mice or from mice primed with influenza virus antigens incorporated in the immuno-stimulating complexes (iscoms) or as micel les. Matrix, which is the carrier structure for the antigens in the is com, was used as a non-antigen stimulus. The IL-1 produced was assayed in an IL-1-dependent cell line and the specificity was demonstrated i n a blocking experiment with antiserum to IL-1alpha. Soluble IL-1alpha was also quantified in ELISA. Iscoms and matrix induced production of mIL-1 and sIL-1 in cultures from non-treated mice as well as from mic e primed 4 days before with iscoms or micelles. Micelles were a less s trong stimulus and did not induce production of sIL-1. Micelles induce d production of mIL-1 in cultures from non-primed mice or from mice wh ich were recently immunized with micelles. No mIL-1 expression was ind uced by micelles if the spleen cells originated from mice immunized sh ortly before with iscoms. Depletion experiments demonstrated that sl L -1 was produced by adherent cells upon stimulation with iscoms or matr ix. However, factor(s) from the non-adherent cells seem to be necessar y for optimal secretion of sIL-1.