IL-33 mediates the expressions of IL-5 and IL-13 in Angiostrongylus cantonensis-infected mice.

Angiostrongylus cantonensis is the major cause of human eosinophilic meningoencephalitis. C57BL/6 mice were experimentally infected with 35 infectious larvae. Two groups of infected mice received intraperitoneal injections of mouse IL-33 (1μg) or anti-IL-33 monoclonal antibody (mAb) (10μg) 3days post infection (dpi) and subsequent booster shots of the same dose at 5day intervals. Blood samples from each group were collected weekly for assays. IgE levels were significantly increased in all infected mice. The eosinophil percentage and levels of IL-5 and IL-13 significantly increased in the IL-33-treated group relative to infected but non-treated animals. The level of IL-5 decreased in the mAb-treated group. The severity of eosinophilic meningitis was exacerbated in the IL-33 injected group. Taken together, these results suggest that IL-33 mediates the expressions of IL-5 and IL-13, and plays a crucial role in the pathogenesis of angiostrongylosis.