Induction of Siglec-FhiCD101hi eosinophils in the lungs following murine hookworm Nippostrongylus brasiliensis infection.

Helminth-induced eosinophils accumulate around the parasite at the site of infection, or in parasite-damaged tissues well after the helminth has left the site. The role of helminth-elicited eosinophils in mediating parasite control is complex. While they may contribute to direct parasite-killing and tissue repair, their involvement in long-term immunopathogenesis is a concern. In allergic Siglec-FhiCD101hi, eosinophils are associated with pathology. Research has not shown if equivalent subpopulations of eosinophils are a feature of helminth infection. In this study, we demonstrate that lung migration of rodent hookworm Nippostrongylus brasiliensis (Nb) results in a long-term expansion of distinct Siglec-FhiCD101hi eosinophil subpopulations. Nb-elevated eosinophil populations in the bone marrow and circulation did not present this phenotype. Siglec-FhiCD101hi lung eosinophils exhibited an activated morphology including nuclei hyper-segmentation and cytoplasm degranulation. Recruitment of ST2+ ILC2s and not CD4+ T cells to the lungs was associated with the expansion of Siglec-FhiCD101hi eosinophils. This data identifies a morphologically distinct and persistent subset of Siglec-FhiCD101hi lung eosinophils induced following Nb infection. These eosinophils may contribute to long-term pathology following helminth infection.

The Study of Host Immune Responses Elicited by the Model Murine Hookworms Nippostrongylus brasiliensis and Heligmosomoides polygyrus.

Hookworm infections (Necator americanus or Ancylostoma duodenale) represent a major neglected tropical disease, affecting approximately 700 million people worldwide, and can cause severe morbidity due to the need for these worms to feed on host blood. N. brasiliensis and H. polygrus, both rodent parasites, are the two most commonly employed laboratory models of experimental hookworm infection. Both parasites evoke type 2 immune responses, and their use has been instrumental in generating fundamental insight into the molecular mechanisms of type-2 immunity and for understanding how the immune response can control parasite numbers. Here we provide a complete set of methods by which to investigate the natural progression of infection and the host immunological responses in the lung and intestine of H. polygyrus- and N. brasiliensis-infected mice. Detailed information is included about the most important parasitological and immunological measurements to perform at each time point. © 2017 by John Wiley & Sons, Inc.