E. coli infection and endotoxic shock induce the expansion of regulatory dendritic cells (111.2)

Abstract

Abstract Regulatory dendritic cells (DCs) have been reported recently. However, whether regulatory DCs are induced in a natural immune response to an infectious disease or endotoxic shock remains to be explored. Here we report that regulatory CD11clowCD45RBhigh DCs become the predominant CD11c-expressing cells in the spleen during E. coli K12 infection, whereas i.p. injection of 2 ml of thioglycolate, which elicits aseptic peritonitis, does not induce regulatory CD11clowCD45RBhigh DCs. On the other hand, injection of isoproterenol for 5 consecutive days before E. coli K12 infection shows little effect on the induction of regulatory CD11clowCD45RBhigh DCs. A similar increase of regulatory CD11clowCD45RBhigh DCs is seen in mice injected with sublethal doses of LPS. The regulatory DCs secret little IL-10 and show marginal effect on the proliferation of T cells, but induce IL-10-expressing CD4 T cells. Taken together our data suggest that a natural immune response to an infectious disease or endotoxic shock induces regulatory CD11clowCD45RBhigh DCs.