title: Alveolar macrophages in pulmonary host defence the unrecognized role of apoptosis as a mechanism of intracellular bacterial killing.
abstract: Alveolar macrophages play an essential role in clearing bacteria from the lower airway, as the resident phagocyte alveolar macrophages must both phagocytose and kill bacteria, and if unable to do this completely must co-ordinate an inflammatory response. The decision to escalate the inflammatory response represents the transition between subclinical infection and the development of pneumonia. Alveolar macrophages are well equipped to phagocytose bacteria and have a large phagolysosomal capacity in which ingested bacteria are killed. The rate-limiting step in control of extracellular bacteria, such as Streptococcus pneumoniae, is the capacity of alveolar macrophages to kill ingested bacteria. Therefore, alveolar macrophages complement canonical microbicidal strategies with an additional level of apoptosis-associated killing to help kill ingested bacteria.
authors.affiliation: Department of Infection and Immunity, University of Sheffield Medical School and Sheffield Teaching Hospitals, Sheffield, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Aberdein
authors.forename: J
authors.initials: J
authors.lastname: Cole
authors.forename: M A
authors.initials: MA
authors.lastname: Bewley
authors.forename: H M
authors.initials: HM
authors.lastname: Marriott
authors.forename: D H
authors.initials: DH
authors.lastname: Dockrell
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D058070:Asymptomatic Diseases; D001433:Bacteriolysis; D003165:Complement System Proteins / Q000276:immunology*; D018450:Disease Progression; D006801:Humans; D007110:Immunity, Active; D042541:Intracellular Space / Q000276:immunology; D008262:Macrophage Activation; D016676:Macrophages, Alveolar / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D011008:Pneumococcal Infections / Q000150:complications / Q000276:immunology*; D011014:Pneumonia / Q000209:etiology / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D003165:Complement System Proteins
keywords: Streptococcus pneumoniae; bacteria; killing; macrophage