title: Toll-Like Receptor 9 Contributes to Defense against Acinetobacter baumannii Infection.
abstract: Acinetobacter baumannii is a common nosocomial pathogen capable of causing severe diseases associated with significant morbidity and mortality in impaired hosts. Pattern recognition receptors, such as the Toll-like receptors (TLRs), play a key role in pathogen detection and function to alert the immune system to infection. Here, we examine the role for TLR9 signaling in response to A. baumannii infection. In a murine model of A. baumannii pneumonia, TLR9(-/-) mice exhibit significantly increased bacterial burdens in the lungs, increased extrapulmonary bacterial dissemination, and more severe lung pathology compared with those in wild-type mice. Following systemic A. baumannii infection, TLR9(-/-) mice have significantly increased bacterial burdens in the lungs, as well as decreased proinflammatory cytokine and chemokine production. These results demonstrate that TLR9-mediated pathogen detection is important for host defense against the opportunistic pathogen Acinetobacter baumannii.
authors.affiliation: Tennessee Valley Healthcare System, U.S. Department of Veterans Affairs, Nashville, Tennessee, USA Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Noto
authors.affiliation: Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Boyd
authors.affiliation: Tennessee Valley Healthcare System, U.S. Department of Veterans Affairs, Nashville, Tennessee, USA Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Burns
authors.affiliation: Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Varga
authors.affiliation: Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Peek
authors.affiliation: Tennessee Valley Healthcare System, U.S. Department of Veterans Affairs, Nashville, Tennessee, USA Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA eric.skaar@vanderbilt.edu.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Skaar
mesh_terms: D000151:Acinetobacter Infections / Q000235:genetics / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D040981:Acinetobacter baumannii / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D006801:Humans; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000276:immunology*
chemical_list: D016207:Cytokines; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9