title: Dual polarization of human alveolar macrophages progressively increases with smoking and COPD severity.
abstract: It is known that tissue macrophages derive not only from blood monocytes but also from yolk sac or fetal liver, and the tissue of residence guides their function. When isolated, they lose tissue specific signatures, hence studies of human macrophages should be ideally done directly in the tissue. The aim of this study was to investigate directly in human lung tissue the polarization of alveolar macrophage (AM), classic (M1) or alternative (M2), in health and disease, using COPD as a model.
  
  
  
  Surgical lungs from 53 subjects were studied: 36 smokers whose FEV1varied from normal to severe COPD, 11 non-smokers and 6 normal donors. iNOS and CD206 immunohistochemistry was used to quantify the percentage of AM polarized as M1 or M2 in lung sections. RESULTS AND DISCUSSION: The percentage of M1 and M2 increased progressively with smoking and COPD severity, from 26% to 84% for M1 and from 7% to 78% for M2. In donors 74% of AM were negative for M1 and 93% for M2. Confocal microscopy showed co-localization of M1 and M2 in the same AM in severe COPD.
  
  
  
  In normal lungs alveolar macrophages were mostly non-polarized. With smoking and COPD severity, M1 and M2 polarization increased significantly and so did the co-expression of M1 and M2 in the same alveolar macrophage.
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Bazzan
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Graziella
authors.initials: G
authors.lastname: Turato
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Mariaenrica
authors.initials: M
authors.lastname: Tinè
authors.affiliation: Department of Medicine, University of Padova, Padova, Italy.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Radu
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Balestro
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Rigobello
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Biondini
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Schiavon
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Lunardi
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Simonetta
authors.initials: S
authors.lastname: Baraldo
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Rea
authors.affiliation: Department of Medicine, University of Padova, Padova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Simioni
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.
authors.forename: Fiorella
authors.initials: F
authors.lastname: Calabrese
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy. marina.saetta@unipd.it.
authors.forename: Marina
authors.initials: M
authors.lastname: Saetta
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy.|Respiratory Division, Meakins-Christie Laboratories, McGill University, Montreal, Canada.
authors.forename: Manuel G
authors.initials: MG
authors.lastname: Cosio
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D008264:Macrophages / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000276:immunology* / Q000473:pathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology*; D012720:Severity of Illness Index; D012907:Smoking / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology*
keywords: COPD; Cigarette smoking; M1; M2; Macrophages