Induction of Continuous I‐A Expression by Murine Peritoneal Macrophages: Lack of Correlation With T Cell Responses of Bcg r and Bcg s Mice

The induction of continuous I‐A expression by L3T4 and Lyt2 lymphocyte subpopulations from Bcg r and Bcg s mice was compared. We found that the induction of continuous I‐A expression was independent of the Bcg geneotype of the T cells. T cells from congenie Beg s BALB/c mice and C.D2Bcg r 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 Bcg r and Bcg s 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 Bcg r mice.