Expulsion of two gastrointestinal nematode parasites, Nippostrongylus brasi
liensis and Trichinella spiralis, is similar in that both require IL-4R alp
ha expression, but different in that T cells and mast cells are required fo
r IL-4-induced expulsion of T. spiralis but not N. brasiliensis. To examine
the role of IL-4R alpha signaling in immunity to these parasites, we studi
ed worm expulsion in chimeric mice that selectively expressed IL-4R alpha o
n bone marrow-derived or non-bone marrow-derived cells. N. brasiliensis was
expelled by mice that expressed IL-4R alpha only on non-bone marrow-derive
d cells, but not by mice that expressed IL-4R alpha only on bone marrow-der
ived cells. Although T. spiralis expulsion required IL-4R alpha expression
by both bone marrow and non-bone marrow-derived cells, IL-4 stimulation eli
minated the requirement for IL-4R alpha expression by bone marrow-derived c
ells. Thus, direct IL-4R alpha signaling of nonimmune gastrointestinal cell
s may be generally required to induce worm expulsion, even when mast cell a
nd T cell responses are also required.