What is the difference between M1 and M2 macrophages?

What is the difference between M1 and M2 macrophages?

M1 macrophages produce nitric oxide (NO) or reactive oxygen intermediates (ROI) to protect against bacteria and viruses. M2 macrophages are alternatively activated by exposure to certain cytokines such as IL-4, IL-10, or IL-13.

What are M1 and M2 monocytes?

M1 macrophages can produce toxic effector molecules such as reactive oxygen species and nitric monoxide, and inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF), and IL-6 (8). Conversely, M2 macrophage polarization is observed in response to Th2-related cytokines such as IL-4 and IL-13 (9).

Are M1 or M2 macrophages more phagocytic?

These results are consistent with reports showing that M2 macrophages have higher phagocytic activity than M1 macrophages [35, 36]. We found that HSV-1 infection did not alter higher phagocytosis in M2-OE mice.

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).

Can macrophages switch between M1 and M2?

It plays an important role in wound healing and tissue repair. In a word, macrophages are a “double-edged sword”, which can not only stop the spread of cancer cells, but also help the growth and spread of cancer cells. M1 and M2 macrophages can also be converted to each other in a specific microenvironment.

Can M1 macrophages switch to M2?

M1–M2 Phenotype Switch Responding to microenviromental cues macrophages can rapidly switch from one phenotype to the other. In fact, activation of NF-κB or IRF family members in macrophages by TLR4 or other TLRs can drive macrophage to either M1 or M2 polarization under various pathological conditions (99–105).

Are tissue resident macrophages M1 or M2?

Macrophages are tissue sentinels that maintain tissue integrity by eliminating/repairing damaged cells and matrices. In this M2-like mode, they can also promote tumor growth. Conversely, M1-like macrophages are key effector cells for the elimination of pathogens, virally infected, and cancer cells.

Do M1 macrophages Phagocytose?

M1 Macrophages are able to effectively phagocytose and kill intracellular bacteria. In order to determine the fate of phagocytosed P. gingivalis in M1 or M2 macrophages, both an invasion (1 hour) and survival assay (24 hours) were performed (Fig 3).

Are microglia M1 or M2?

This suggests that M1 microglia are the dominant phenotype and M2 cells are not present to repair damage.

What are liver macrophages?

In the liver, macrophages are called Kupffer cells. They line tiny blood vessels in the liver, where they do a lot of things, including maintaining the body’s iron levels and clearing away endotoxins produced by gut bacteria.

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).

Are M2 macrophages immunosuppressive?

M2-like macrophages activated by growth factors and cytokines in TME are considered to be M2d subtype with immunosuppressive role and protumor property [5].

How are M1 and M2 macrophages related to each other?

Activated macrophages are usually divided into two categories, M1-like macrophages and M2-like macrophages. Both M1 macrophages and M2 macrophages are closely related to inflammatory responses, among which M1 macrophages are mainly involved in pro-inflammatory responses and M2 macrophages are mainly involved in anti-inflammatory responses.

Which is the polarised state of the macrophage?

The process of macrophage activation is described as the polarisation of the macrophage into two distinct states; the classically activated M1 macrophage and the alternative activated M2 macrophage (Roszer T. 2015).

How are macrophages used in the anti inflammatory response?

Alternatively activated macrophages (M2) were discovered in early 1990s and named according to previously-discovered Th2 cell-mediated anti-inflammatory response. It is shown in vitro that macrophage treatment with IL-4 and IL-13 leads to inhibition of pro-inflammatory signals production and upregulation of scavenging mannose receptor CD206.

How does improper control of M1 macrophage lead to sepsis?

Improper and untimely control of M1 macrophage-mediated inflammatory response can lead to disruption of normal tissue homeostasis and impede vascular repair. An uncontrolled production of pro-inflammatory cytokines during the inflammation can lead to the formation of cytokine storm, thereby contributing to the pathogenesis of severe sepsis.