title: Suppression of allergic airway inflammation by helminth-induced regulatory T cells.
abstract: Allergic diseases mediated by T helper type (Th) 2 cell immune responses are rising dramatically in most developed countries. Exaggerated Th2 cell reactivity could result, for example, from diminished exposure to Th1 cell-inducing microbial infections. Epidemiological studies, however, indicate that Th2 cell-stimulating helminth parasites may also counteract allergies, possibly by generating regulatory T cells which suppress both Th1 and Th2 arms of immunity. We therefore tested the ability of the Th2 cell-inducing gastrointestinal nematode Heligmosomoides polygyrus to influence experimentally induced airway allergy to ovalbumin and the house dust mite allergen Der p 1. Inflammatory cell infiltrates in the lung were suppressed in infected mice compared with uninfected controls. Suppression was reversed in mice treated with antibodies to CD25. Most notably, suppression was transferable with mesenteric lymph node cells (MLNC) from infected animals to uninfected sensitized mice, demonstrating that the effector phase was targeted. MLNC from infected animals contained elevated numbers of CD4(+)CD25(+)Foxp3(+) T cells, higher TGF-beta expression, and produced strong interleukin (IL)-10 responses to parasite antigen. However, MLNC from IL-10-deficient animals transferred suppression to sensitized hosts, indicating that IL-10 is not the primary modulator of the allergic response. Suppression was associated with CD4(+) T cells from MLNC, with the CD4(+)CD25(+) marker defining the most active population. These data support the contention that helminth infections elicit a regulatory T cell population able to down-regulate allergen induced lung pathology in vivo.
authors.affiliation: Institute of Immunology and Infection Research, University of Edinburgh, UK.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Wilson
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Taylor
authors.forename: Adam
authors.initials: A
authors.lastname: Balic
authors.forename: Constance A M
authors.initials: CA
authors.lastname: Finney
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Lamb
authors.forename: Rick M
authors.initials: RM
authors.lastname: Maizels
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000008:administration & dosage; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000637:transplantation; D002465:Cell Movement / Q000276:immunology; D016207:Cytokines / Q000037:antagonists & inhibitors; D005260:Female; D007249:Inflammation / Q000276:immunology; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors / Q000502:physiology; D008168:Lung / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009351:Nematospiroides dubius / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000276:immunology; D012130:Respiratory Hypersensitivity / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D017206:Strongylida Infections / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D019138:Antibodies, Blocking; D016207:Cytokines; D018836:Inflammation Mediators; D015375:Receptors, Interleukin-2