Expulsion of the gastrointestinal nematode Trichinella spiralis is associated with Th2 responses and intestinal inflammation, which correlate with a marked mast cell (MC) response. To address the role of MC-derived cytokines in the induction of protective responses, WBB6F1-KitW/KitW-v (W/Wv) mice were reconstituted with wild-type, tumor necrosis factor (TNF)--/-, or interleukin (IL)-4-/- bone marrow (BM) prior to infection with T. spiralis. W/Wv mice reconstituted with TNF--/- or IL-4-/- BM expelled the parasite less efficiently and showed diminished enteropathy, whereas protective responses were normal in W/Wv mice reconstituted with wild-type BM and were accompanied by intestinal pathology. MC responses were reduced in W/Wv mice reconstituted with IL-4-/- BM and to a lesser extent when reconstituted with TNF--/-. These results suggest that MC-derived IL-4 and TNF may regulate the induction of protective Th2 responses and intestinal inflammation associated with the expulsion of T. spiralis. Significantly, these studies suggest a role for MC-derived cytokines as autocrine growth factors.
- mast cells
- gastrointestinal helminth infection
- biomedical sciences