Immune homeostasis in the respiratory tract and its impact on heterologous infection.
Innate immunity at mucosal surfaces requires additional restraint to prevent inflammation to innocuous antigens or commensal microorganisms. The threshold above which airway macrophages become activated is raised by site-specific factors including the receptors for transforming growth factor beta, interleukin 10 and CD200; the ligands for which are produced by, or expressed on, respiratory epithelium. We discuss such site-specific regulation and how this is continually altered by prior infections. Resetting of innate reactivity represents a strategy for limiting excessive inflammation, but in some may pre-dispose to secondary bacterial pneumonia.
Wissinger
Erika
E
Imperial College London, National Heart and Lung Institute, Leukocyte Biology Section, Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom.
Goulding
John
J
Hussell
Tracy
T
D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001424:Bacterial Infections / Q000276:immunology*; D005786:Gene Expression Regulation; D006801:Humans; D007113:Immunity, Innate; D007156:Immunologic Memory; D016753:Interleukin-10 / Q000276:immunology; D016676:Macrophages, Alveolar / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D064446:Orexin Receptors; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012137:Respiratory System / Q000276:immunology* / Q000382:microbiology; D016212:Transforming Growth Factor beta / Q000276:immunology
D015703:Antigens, CD; D000954:Antigens, Surface; C477337:CD200R1 protein, human; D064446:Orexin Receptors; D011956:Receptors, Cell Surface; D016212:Transforming Growth Factor beta; D016753:Interleukin-10; C042739:antigens, CD200