RT Journal Article SR Electronic T1 Chronic helminth infection protects mice from type III hypersensitivity (HYP6P.277) JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 118.22 OP 118.22 VO 192 IS 1 Supplement A1 Evans, Holly A1 Mitre, Edward YR 2014 UL http://www.jimmunol.org/content/192/1_Supplement/118.22.abstract AB In this study we evaluated the effects chronic helminth infection has on type III hypersensitivity, an allergic reaction driven by antigen/antibody immune complex deposition. Mice were sensitized to ovalbumin (OVA) and 4 weeks later infected with Litomosoides sigmodontis for 10 weeks. Chronically infected animals exhibited significantly reduced ear swelling 12-24 hours after intradermal ear challenge with OVA. Although total IgG levels were higher in sensitized + infected mice than sensitized mice, OVA-specific IgG1 and IgG2a were all significantly reduced in mice that were chronically infected. Immune complexes in the ear tissue were detected by fluorescence microscopy and were found to be larger and more focal in infected animals. Histological analysis of infected mice showed reductions in edema, necrosis, and cellular recruitment compared to sensitized animals. Furthermore, a chemokine array performed on ear tissue 6 hours after OVA challenge showed that infected animals had reduced production of neutrophil-specific chemokines MIP-2 and KC. These data demonstrate that a 10 week L. sigmodontis infection protects against type III hypersensitivity responses. Future studies aim to further elucidate the immunological pathways mediating protection against type III hypersensitivity, and to evaluate whether worm-derived therapies can be useful in protection against diseases in which immune complex deposition is involved such as lupus nephritis.