IL-5 contributes to worm expulsion and muscle hypercontractility in a primary T. spiralis infection.
Enteric nematode infections lead to increased interleukin (IL)-5 expression, eosinophilic inflammation, and intestinal smooth muscle hypercontractility. Although eosinophils release inflammatory mediators that cause smooth muscle contraction, the role of IL-5 and eosinophils in enteric smooth muscle hypercontractility is unclear. IL-5-deficient mice and their wild-type controls were infected with the nematode Trichinella spiralis. Intestinal parasites and eosinophils were counted, and jejunal longitudinal muscle contractility was assessed. During infection, IL-5 gene expression increased significantly in wild-type mice and was accompanied by significant intestinal eosinophilia in wild-type but not IL-5-deficient mice. Although both strains developed increased muscle contractility during infection, contraction was significantly less in the IL-5-deficient mice at days 16 and 21 postinfection. In addition, parasite expulsion was transiently delayed at day 16 in IL-5-deficient mice. Thus, in the nematode-infected mouse, IL-5 appears essential for intestinal eosinophilia and contributes to, but is not essential for, the development of muscle hypercontractility. IL-5 also appears to play a minor role in expelling a primary T. spiralis infection from the gut.
Vallance
B A
BA
Intestinal Diseases Research Program, Department of Medicine, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
Blennerhassett
P A
PA
Deng
Y
Y
Matthaei
K I
KI
Young
I G
IG
Collins
S M
SM
D000818:Animals; D001491:Basophils / Q000473:pathology; D002217:Carbachol / Q000494:pharmacology; D002452:Cell Count; D004804:Eosinophils / Q000473:pathology; D005769:Gastrointestinal Motility / Q000187:drug effects; D015870:Gene Expression; D015848:Interleukin-5 / Q000235:genetics / Q000502:physiology*; D007422:Intestines / Q000187:drug effects / Q000469:parasitology / Q000503:physiopathology; D007814:Larva / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics; D018345:Mice, Knockout / Q000235:genetics; D018482:Muscle, Skeletal / Q000469:parasitology; D017160:Trichinella spiralis / Q000502:physiology*; D014235:Trichinellosis / Q000235:genetics / Q000469:parasitology* / Q000473:pathology / Q000503:physiopathology*
D015848:Interleukin-5; D002217:Carbachol