Induction of continuous I-A expression by murine peritoneal macrophages: lack of correlation with T cell responses of Bcgr and Bcgs mice.

The induction of continuous I-A expression by L3T4 and Lyt2 lymphocyte subpopulations from Bcgr and Bcgs mice was compared. We found that the induction of continuous I-A expression was independent of the Bcg genotype of the T cells. T cells from congenic Bcgs BALB/c mice and C.D2Bcgr mice could not induce continuous I-A expression in vitro and were deficient in their ability to produce IFN-gamma in vitro. In contrast, T cells from other strains of Bcgr and Bcgs mice could induce continuous I-A expression. Both recombinant IL-2 and IL-4 acted synergistically with low levels of IFN-gamma to induce continuous I-A expression by macrophages from Bcgr mice.