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The bacterium, nontypeable Haemophilus influenzae , enhances host antiviral response by inducing Toll‐like receptor 7 expression
Author(s) -
Sakai Akihiro,
Koga Tomoaki,
Lim JaeHyang,
Jono Hirofumi,
Harada Kazutsune,
Szymanski Erika,
Xu Haidong,
Kai Hirofumi,
Li JianDong
Publication year - 2007
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2007.05899.x
Subject(s) - tlr2 , haemophilus influenzae , tlr7 , microbiology and biotechnology , biology , toll like receptor , pathogen , tlr4 , regulator , virology , innate immune system , immunology , antibiotics , immune system , gene , biochemistry
The incidence of mixed viral/bacterial infections has increased recently because of the dramatic increase in antibiotic‐resistant strains, the emergence of new pathogens, and the resurgence of old ones. Despite the relatively well‐known role of viruses in enhancing bacterial infections, the impact of bacterial infections on viral infections remains unknown. In this study, we provide direct evidence that nontypeable Haemophilus influenzae (NTHi), a major respiratory bacterial pathogen, augments the host antiviral response by up‐regulating epithelial Toll‐like receptor 7 (TLR7) expression in vitro and in vivo . Moreover, NTHi induces TLR7 expression via a TLR2‐MyD88‐IRAK‐TRAF6‐IKK‐NF‐κB‐dependent signaling pathway. Interestingly, CYLD, a novel deubiquitinase, acts as a negative regulator of TLR7 induction by NTHi. Our study thus provides new insights into a novel role for bacterial infection in enhancing host antiviral response and further identifies CYLD for the first time as a critical negative regulator of host antiviral response.