title: The critical role of complement alternative pathway regulator factor H in allergen-induced airway hyperresponsiveness and inflammation.
abstract: Activation of the alternative pathway of complement plays a critical role in the development of allergen-induced airway hyperresponsiveness (AHR) and inflammation in mice. Endogenous factor H, a potent inhibitor of the alternative pathway, is increased in the airways of sensitized and challenged mice, but its role in regulating inflammation or AHR has been unknown. We found that blocking the tissue-binding function of factor H with a competitive antagonist increased complement activation and tissue inflammation after allergen challenge of sensitized mice. Conversely, administration of a fusion protein that contains the iC3b/C3d binding region of complement receptor 2 linked to the inhibitory region of factor H, a molecule directly targeting complement-activating surfaces, protected mice in both primary and secondary challenge models of AHR and lung inflammation. Thus, although endogenous factor H does play a role in limiting the development of AHR, strategies to deliver the complement-regulatory region of factor H specifically to the site of inflammation provide greater protection than that afforded by endogenous regulators. Such an agent may be an effective therapy for the treatment of asthma.
authors.affiliation: Division of Cell Biology, Department of Pediatrics, National Jewish Health, Denver, CO 80206, USA.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Takeda
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Thurman
authors.forename: Stephen
authors.initials: S
authors.lastname: Tomlinson
authors.forename: Masakazu
authors.initials: M
authors.lastname: Okamoto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Viviana P
authors.initials: VP
authors.lastname: Ferreira
authors.forename: Claudio
authors.initials: C
authors.lastname: Cortes
authors.forename: Michael K
authors.initials: MK
authors.lastname: Pangburn
authors.forename: V Michael
authors.initials: VM
authors.lastname: Holers
authors.forename: Erwin W
authors.initials: EW
authors.lastname: Gelfand
mesh_terms: D000485:Allergens / Q000008:administration & dosage* / Q000276:immunology; D000818:Animals; D001249:Asthma / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016535:Bronchial Hyperreactivity / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D017242:Complement Factor H / Q000502:physiology*; D003170:Complement Pathway, Alternative / Q000276:immunology*; D005260:Female; D007249:Inflammation / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018836:Inflammation Mediators / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000485:Allergens; D018836:Inflammation Mediators; D017242:Complement Factor H; D010047:Ovalbumin