Host-parasite interactions in a murine model of lymphatic filariasis

How a host eliminates tissue-dwelling nematode parasites is largely unknown. We sought to characterize the host-parasite interactions of Brugia malayi, one of the causative agents of lymphatic filariasis, with a surrogate murine host to determine the mechanism of larval clearance. We characterized the immune responses of infected mice with emphasis on cell populations in the peritoneum, the site of infection. We found that B cells, macrophages, and eosinophils are the major cell types during the rejection of worms. We found that eosinophils and macrophages were also a major component of an inflammatory exudate encasing worms. Further analysis revealed that eosinophils and IL-5, but not nitric oxide, are vital components of immunological defense strategies. These studies are among the first that demonstrate a host-protective role for eosinophils against a helminth parasite. Additionally, these studies have provided novel information, which may be important to combat a terrible, debilitating human disease.