title: Innate immunity against Legionella pneumophila during pulmonary infections in mice.
abstract: Legionella pneumophila is an etiological agent of the severe pneumonia known as Legionnaires' disease (LD). This gram-negative bacterium is thought to replicate naturally in various freshwater amoebae, but also replicates in human alveolar macrophages. Inside host cells, legionella induce the production of non-endosomal replicative phagosomes by injecting effector proteins into the cytosol. Innate immune responses are first line defenses against legionella during early phases of infection, and distinguish between legionella and host cells using germline-encoded pattern recognition receptors such as Toll-like receptors , NOD-like receptors, and RIG-I-like receptors, which sense pathogen-associated molecular patterns that are absent in host cells. During pulmonary legionella infections, various inflammatory cells such as macrophages, neutrophils, natural killer (NK) cells, large mononuclear cells, B cells, and CD4+ and CD8+ T cells are recruited into infected lungs, and predominantly occupy interstitial areas to control legionella. During pulmonary legionella infections, the interplay between distinct cytokines and chemokines also modulates innate host responses to clear legionella from the lungs. Recognition by NK cell receptors triggers effector functions including secretion of cytokines and chemokines, and leads to lysis of target cells. Crosstalk between NK cells and dendritic cells, monocytes, and macrophages provides a major first-line defense against legionella infection, whereas activation of T and B cells resolves the infection and mounts legionella-specific memory in the host.
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.
authors.forename: Bonggoo
authors.initials: B
authors.lastname: Park
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.|Department of Biomicrosystem Technology, Korea University, Seoul, 136-701, Korea.
authors.forename: Gayoung
authors.initials: G
authors.lastname: Park
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.
authors.forename: Seon Ah
authors.initials: SA
authors.lastname: Lim
authors.affiliation: Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea. kyunglee@korea.ac.kr.
authors.forename: Kyung-Mi
authors.initials: KM
authors.lastname: Lee
mesh_terms: D000818:Animals; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology; D004195:Disease Models, Animal; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology; D016952:Legionella pneumophila / Q000276:immunology*; D007877:Legionnaires' Disease / Q000276:immunology* / Q000382:microbiology; D016676:Macrophages, Alveolar / Q000276:immunology / Q000382:microbiology; D051379:Mice; D009000:Monocytes / Q000276:immunology / Q000382:microbiology; D009504:Neutrophils / Q000276:immunology; D018410:Pneumonia, Bacterial / Q000276:immunology*; D051192:Receptors, Pattern Recognition / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D016207:Cytokines; D051192:Receptors, Pattern Recognition
keywords: Legionella pneumophila; NOD-like receptor; Natural killer cells; Pattern recognition receptor; Pulmonary infection; Toll-like receptor