Dendritic cells have a crucial role in the production of cytokines in mesenteric lymph nodes of B10.BR mice infected with Trichuris muris.

Dendritic cells bridge innate and adaptive immunity and establish protective immunity to pathogens. Protection against the murine nematode parasite Trichuris muris depends on the T helper 2 (Th2) response and requires the Th2 cytokines interleukin 4 (IL-4), IL-10, or IL-13. To examine if the Th2 response to T. muris infection is regulated by CD11c(+)B220(-) dendritic cells in mesenteric lymph nodes, dendritic cell-enriched and dendritic cell-depleted fractions were obtained from mesenteric lymph node cells of T. muris-infected mice, and production of cytokines in cultures of these fractions was measured. At day 14 postinfection, no worm expulsion was observed, and high levels of interferon gamma production occurred in dendritic cell-enriched fractions. Expulsion of worms occurred on days 20 and 25 postinfection, and IL-10 production was induced in dendritic cell-enriched fractions on these 2 days. No cytokine production was observed in mesenteric lymph node cells and dendritic cell-depleted fractions during T. muris infection. The occurrence of worm expulsion was consistent with IL-10 production in dendritic cell-enriched fractions. IL-10 inhibits Th1 cells and promotes the Th2 response, and results from this study suggest that CD11c(+)B220(-) dendritic cells in the mesenteric lymph nodes are required for IL-10 production and the IL-10-dependent protective Th2 response.