title: A novel bacterial transport mechanism of Acinetobacter baumannii via activated human neutrophils through interleukin-8.
abstract: Hospital-acquired infections as a result of Acinetobacter baumannii have become problematic because of high rates of drug resistance. Although neutrophils play a critical role in early protection against bacterial infection, their interactions with A. baumannii remain largely unknown. To elucidate the interactions between A. baumannii and human neutrophils, we cocultured these cells and analyzed them by microscopy and flow cytometry. We found that A. baumannii adhered to neutrophils. We next examined neutrophil and A. baumannii infiltration into Matrigel basement membranes by an in vitro transmigration assay. Neutrophils were activated by A. baumannii, and invasion was enhanced. More interestingly, A. baumannii was transported together by infiltrating neutrophils. Furthermore, we observed by live cell imaging that A. baumannii and neutrophils moved together. In addition, A. baumannii-activated neutrophils showed increased IL-8 production. The transport of A. baumannii was suppressed by inhibiting neutrophil infiltration by blocking the effect of IL-8. A. baumannii appears to use neutrophils for transport by activating these cells via IL-8. In this study, we revealed a novel bacterial transport mechanism that A. baumannii exploits human neutrophils by adhering to and inducing IL-8 release for bacterial portage. This mechanism might be a new treatment target.
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan; kamoshida@med.teikyo-u.ac.jp.
authors.forename: Go
authors.initials: G
authors.lastname: Kamoshida
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tansho-Nagakawa
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Takane
authors.initials: T
authors.lastname: Kikuchi-Ueda
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.|Department of Microbiology and Infectious Diseases, Nara Medical University, Nara, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nakano
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.|Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba, Japan; and.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hikosaka
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishida
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Tsuneyuki
authors.initials: T
authors.lastname: Ubagai
authors.affiliation: Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan.
authors.forename: Shouichi
authors.initials: S
authors.lastname: Higashi
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ono
mesh_terms: D000150:Acinetobacter / Q000502:physiology; D000151:Acinetobacter Infections / Q000097:blood / Q000276:immunology / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000472:pathogenicity / Q000502:physiology*; D000818:Animals; D001422:Bacterial Adhesion; D018988:Bacterial Translocation; D002478:Cells, Cultured; D024042:Collagen Type I; D004926:Escherichia coli / Q000502:physiology; D005260:Female; D005782:Gels; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000097:blood / Q000502:physiology*; D008567:Membranes, Artificial; D051379:Mice; D008809:Mice, Inbred C3H; D009504:Neutrophils / Q000382:microbiology*; D010587:Phagocytosis; D011550:Pseudomonas aeruginosa / Q000502:physiology; D016897:Respiratory Burst; D013045:Species Specificity; D059008:Time-Lapse Imaging; D014774:Virulence
chemical_list: D024042:Collagen Type I; D005782:Gels; D016209:Interleukin-8; D008567:Membranes, Artificial
keywords: adhesion; in vitro transmigration assay; invasion; sepsis