Tapeworm infection reduces epithelial ion transport abnormalities in murine dextran sulfate sodium-induced colitis

The rat tapeworm Hymenolepis diminuta was used to test the hypothesis that helminth infection could modulate murine colitis. Mice were infected with f ive H, diminuta cysticercoids, and colitis was evoked via free access to 4% (wt/vol) dextran sulfate sodium (DSS)-containing drinking water for 5 days . BALB/c mice were either infected with H. diminuta and 7 days Later expose d to DSS (prophylactic strategy) or started on DSS and infected with H. dim inuta 48 h later (treatment strategy). Naive and H. diminuta-only-infected mice served as controls. On autopsy, colonic segments were processed for hi stological examination and myeloperoxidase (MPO) measurement or mounted in Ussing chambers for assessment of epithelial ion transport, Cytokines (gamm a interferon [IFN-gamma], interleukin 12 [IL-12], and IL-10) were measured in serum and colonic tissue homogenates, DSS treatment resulted in reduced ion responses (indicated by short-circuit current [Isc]) to electrical nerv e stimulation, the cholinergic agonist carbachol, and the adenylate cyclase activator forskolin compared to controls. H. diminuta infection, either pr ophylactic or therapeutic, caused a significant (P < 0.05) amelioration of these DSS-induced irregularities in stimulated ion transport. In contrast, the histopathology (i.e., mixed immune cell infiltrate, edema, and ulcerati ve damage) and elevated MPO levels that accompany DSS colitis were unaffect ed by concomitant H. diminuta infection, Similarly, there were no significa nt differences in levels of IFN-gamma, IL-12, or IL-10 in serum or tissue f rom any of the treatment groups at the time of autopsy, We suggest that abo lishment of colitis-induced epithelial ion transport abnormalities by H, di minuta infection provides proof-of-principle data and speculate that helmin th therapy may provide relief of disease symptoms in colitis.