Alveolar and lung interstitial macrophages: Definitions, functions, and roles in lung fibrosis

J Leukoc Biol. 2021 Jul;110(1):107-114. doi: 10.1002/JLB.3RU0720-418R. Epub 2020 Nov 6.

Abstract

Mϕs are the main innate immune cells in the lung at homeostasis, with important roles in host defence and immune modulation. Alveolar Mϕs (AMs) and interstitial Mϕs (IMs) are the two lung Mϕ subsets, so called according to the sites they reside in. These subsets are also defined by their origins and immunological microenvironment, which endow these cells with distinct features and plasticity. This review summarizes the latest definitions and functions of lung Mϕs during homeostasis and provides exemplar of their divergent roles in lung fibrosis.

Keywords: Mϕs; asthma; fibrosis; lung.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cellular Microenvironment
  • Disease Susceptibility
  • Homeostasis
  • Humans
  • Immunity, Innate*
  • Lung / immunology
  • Lung / metabolism
  • Lung / pathology
  • Macrophages, Alveolar / immunology*
  • Macrophages, Alveolar / metabolism*
  • Macrophages, Alveolar / pathology
  • Pulmonary Alveoli / immunology*
  • Pulmonary Alveoli / metabolism*
  • Pulmonary Alveoli / pathology
  • Pulmonary Fibrosis / etiology
  • Pulmonary Fibrosis / metabolism
  • Pulmonary Fibrosis / pathology