title: Chronic intestinal nematode infection exacerbates experimental Schistosoma mansoni infection.
abstract: Mixed-parasite infections are common in many parts of the world, but little is known of the effects of concomitant parasite infections on the immune response or on disease progression. We have investigated the in vivo effects of a chronic gastrointestinal nematode infection on the infectivity and development of the immune response against the common trematode helminth Schistosoma mansoni. The data show that mice carrying an established chronic Trichuris muris infection and coinfected with S. mansoni, had significantly higher S. mansoni worm burdens than mice without coinfection. The increase in S. mansoni worm burden was accompanied by a higher egg burden in the liver. Kinetic analysis of S. mansoni establishment indicate reduced trapping of S. mansoni larvae during skin-to-lung migration, with T. muris-induced alterations in lung cytokine expression and inflammatory foci surrounding lung-stage schistosomula, suggesting that the immunomodulatory effects of chronic T. muris infection elicited at the gut mucosal surface extend to other organs and perhaps specifically to other mucosal surfaces. The data show that a preexisting chronic gastrointestinal nematode infection facilitates the survival and migration of S. mansoni schistosomula to the portal system, and as a result, increases the egg burden and associated pathology of S. mansoni infection.
authors.affiliation: Immunology Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
authors.forename: Quentin D
authors.initials: QD
authors.lastname: Bickle
authors.forename: Julie
authors.initials: J
authors.lastname: Solum
authors.forename: Helena
authors.initials: H
authors.lastname: Helmby
mesh_terms: D000818:Animals; D002908:Chronic Disease; D016207:Cytokines / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012550:Schistosoma mansoni / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000276:immunology / Q000382:microbiology* / Q000473:pathology; D014257:Trichuriasis / Q000276:immunology / Q000382:microbiology*; D014258:Trichuris / Q000276:immunology
chemical_list: D016207:Cytokines