Are alveolar macrophages M1 or M2?

Alveolar macrophages are the first line of defense against pollutants and pathogenic microbes that initiate an innate immune response in the lung. Two phenotypes of alveolar macrophages have been identified: classically activated macrophage (M1 macrophage) and alternatively activated macrophage (M2 macrophage).

How do you identify an alveolar macrophage?

Tissue-resident alveolar macrophages are identified by CD64high, CD11chigh, F4/80positive, MerTKpositive, and Siglec Fhigh. The arrow represents changes in the transcriptional profile.

What happens when type 2 pneumocytes?

Type II pneumocytes are identified as the synthesizing cells of the alveolar surfactant, which has important properties in maintaining alveolar and airway stability. Lung surfactant can reduce the surface tension and prevent alveolar collapse and the airway walls collapse.

What are interstitial macrophages?

The best-studied type of lung macrophage is by far the alveolar macrophage (AM), a type of macrophage that populates the alveolar and airway lumen. Yet, macrophages also are present in the lung tissue interstitium and these cells have hence been coined “interstitial macrophages” (IMs) ([4] and references therein).

What are pulmonary macrophages?

Pulmonary macrophages form a heterogeneous population of immune cells that fulfil a variety of specialised functions, including maintenance of pulmonary homoeostasis, removal of cellular debris, immune surveillance, microbial clearance, responses to infection and the resolution of inflammation.

What is the difference between type I pneumocytes and type II pneumocytes?

The key difference between type 1 and type 2 pneumocytes is that type 1 pneumocytes are thin and flattened alveolar cells that are responsible for the gas exchange between alveoli and capillaries, while type 2 pneumocytes are cuboidal alveolar cells that are responsible for the secretion of pulmonary surfactants that …