Outer membrane protein P5 is required for resistance of nontypeable Haemophilus influenzae to both the classical and alternative complement pathways
UMass Chan Affiliations
Department of Medicine, Division of Infectious Diseases and ImmunologyDepartment of Microbiology and Physiological Systems
Document Type
Journal ArticlePublication Date
2014-02-01Keywords
AdolescentAdult
Aged
Antibodies, Bacterial
Bacterial Outer Membrane Proteins
*Blood Bactericidal Activity
Complement Pathway, Alternative
Complement Pathway, Classical
Complement System Proteins
Haemophilus influenzae
Humans
Immunoglobulin M
*Microbial Viability
Middle Aged
Protein Binding
Young Adult
Immunity
Immunology of Infectious Disease
Immunopathology
Virology
Metadata
Show full item recordAbstract
The complement system is an important first line of defense against the human pathogen Haemophilus influenzae. To survive and propagate in vivo, H. influenzae has evolved mechanisms for subverting this host defense, most of which have been shown to involve outer surface structures, including lipooligosaccharide glycans and outer surface proteins. Bacterial defense against complement acts at multiple steps in the pathway by mechanisms that are not fully understood. Here we identify outer membrane protein P5 as an essential factor in serum resistance of both H. influenzae strain Rd and nontypeable H. influenzae (NTHi) clinical isolate NT127. P5 was essential for resistance of Rd and NT127 to complement in pooled human serum. Further investigation determined that P5 expression decreased cell surface binding of IgM, a potent activator of the classical pathway of complement, to both Rd and NT127. Additionally, P5 expression was required for NT127 to bind factor H (fH), an important inhibitor of alternative pathway (AP) activation. Collectively, the results obtained in this work highlight the ability of H. influenzae to utilize a single protein to perform multiple protective functions for evading host immunity.Source
Infect Immun. 2014 Feb;82(2):640-9. doi: 10.1128/IAI.01224-13. Epub 2013 Nov 25. Link to article on publisher's siteDOI
10.1128/IAI.01224-13Permanent Link to this Item
http://hdl.handle.net/20.500.14038/30525PubMed ID
24478079Related Resources
Link to Article in PubMedRights
Copyright © 2014, American Society for Microbiology. Publisher PDF posted as allowed by the publisher's author rights policy at http://journals.asm.org/site/misc/ASM_Author_Statement.xhtml.ae974a485f413a2113503eed53cd6c53
10.1128/IAI.01224-13