M2-like macrophage (M2)

M2-like macrophages, also known as alternatively activated macrophages, are a functionally distinct polarization state of macrophages primarily involved in anti-inflammatory responses, tissue repair, and remodeling (Nature Reviews Immunology, 2017). In pathological conditions, particularly within the tumor microenvironment, these cells are often termed tumor-associated macrophages (TAMs) and are hijacked to promote tumor growth, angiogenesis, and immunosuppression (Journal of Clinical Investigation, 2014). They are characterized by the expression of specific markers such as CD206 and CD163 and the secretion of immunosuppressive cytokines like IL-10 and TGF-beta (Frontiers in Immunology, 2020). Therapeutic interventions targeting M2-like macrophages aim to either deplete the population, inhibit their recruitment via the CCL2-CCR2 or CSF1-CSF1R axes, or reprogram them into pro-inflammatory M1-like macrophages to stimulate an anti-tumor immune response (Cell, 2019). While promising, targeting these cells poses challenges, including the risk of systemic immunosuppression and potential interference with normal homeostatic functions of resident macrophages in organs like the liver and lungs (Science Translational Medicine, 2021).

Other names

Alternatively activated macrophageM2 macrophageTumor-associated macrophageTAM

CSF1R inhibition to deplete M2-like macrophages; PI3K-gamma inhibition to reprogram M2 to M1 phenotype; CD47-SIRPalpha axis blockade to enhance phagocytosis; CCR2 antagonism to prevent recruitment.