title: Eosinophils mediate protective immunity against secondary nematode infection.
abstract: Eosinophils are versatile cells that regulate innate and adaptive immunity, influence metabolism and tissue repair, and contribute to allergic lung disease. Within the context of immunity to parasitic worm infections, eosinophils are prominent yet highly varied in function. We have shown previously that when mice undergo primary infection with the parasitic nematode Trichinella spiralis, eosinophils play an important immune regulatory role that promotes larval growth and survival in skeletal muscle. In this study, we aimed to address the function of eosinophils in secondary infection with T. spiralis. By infecting eosinophil-ablated mice, we found that eosinophils are dispensable for immunity that clears adult worms or controls fecundity in secondary infection. In contrast, eosinophil ablation had a pronounced effect on secondary infection of skeletal muscle by migratory newborn larvae. Restoring eosinophils to previously infected, ablated mice caused them to limit muscle larvae burdens. Passive immunization of naive, ablated mice with sera or Ig from infected donors, together with transfer of eosinophils, served to limit the number of newborn larvae that migrated in tissue and colonized skeletal muscle. Results from these in vivo studies are consistent with earlier findings that eosinophils bind to larvae in the presence of Abs in vitro. Although our previous findings showed that eosinophils protect the parasite in primary infection, these new data show that eosinophils protect the host in secondary infection.
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
authors.forename: Lu
authors.initials: L
authors.lastname: Huang
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
authors.forename: Nebiat G
authors.initials: NG
authors.lastname: Gebreselassie
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
authors.forename: Lucille F
authors.initials: LF
authors.lastname: Gagliardo
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
authors.forename: Maura C
authors.initials: MC
authors.lastname: Ruyechan
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853;
authors.forename: Kierstin L
authors.initials: KL
authors.lastname: Luber
authors.affiliation: Department of Biochemistry and Molecular Biology, Division of Hematology/Oncology, Mayo Clinic Arizona, Scottsdale, AZ 85259; and.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Molecular Biology, Division of Pulmonary Medicine, Mayo Clinic Arizona, Scottsdale, AZ 85259.
authors.forename: James J
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853; jaa2@cornell.edu.
authors.forename: Judith A
authors.initials: JA
authors.lastname: Appleton
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology; D060085:Coinfection; D047093:Eosinophil Major Basic Protein / Q000235:genetics; D047209:Eosinophil Peroxidase / Q000235:genetics; D004804:Eosinophils / Q000276:immunology* / Q000637:transplantation; D007116:Immunization, Passive; D007814:Larva / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology; D051381:Rats; D017160:Trichinella spiralis / Q000276:immunology* / Q000472:pathogenicity; D014235:Trichinellosis / Q000276:immunology* / Q000469:parasitology / Q000473:pathology
chemical_list: D000909:Antibodies, Helminth; D047209:Eosinophil Peroxidase; D047093:Eosinophil Major Basic Protein