Anti-IL-9 vaccination prevents worm expulsion and blood eosinophilia in Trichuris muris-infected mice

摘要

Production of neutralizing anti-lL-9 antibodies was induced in mice by immunization with mouse IL-9 coupled to ovalbumin. ln the six mouse strains tested. a strong and long-lasting anti-IL-9 response developed with seric inhibitory titers of 10--3 to 10--s, as measured in an in vitro lL-9-dependent cell proliferation assay. In vivo. this immunization completely abrogated the increase in mast-cell pro- tease-1 levels as well as the eosinophilia observed in mice after implantation of an IL-9-secreting tumor. We took advantage of this method to assess the role of lL-9 in infections with nematode to uris muris, where IL-9 production correlates with the resistant phenotype. C57BL/6 mice, which normally expel the parasite, became susceptible after anti-lL-9 immunization. demonstrating that IL-9 plays a critical role in this model. In addition. neutraliza- tion of IL-9 also inhibited parasite-induced blood eosinophilia. Taken together. the present data demonstrate the potency of our strategy to antagonize IL-9 in vivo and shows that this cytokine plays a major role in resistance against T muris infection.