The M1 and M2 paradigm of macrophage activation: time for reassessment.

The M1 and M2 paradigm of macrophage activation: time for reassessment. F1000Prime Rep. 2014;6:13 Authors: Martinez FO, Gordon S Abstract Macrophages are endowed with a variety of receptors for lineage-determining growth factors, T helper (Th) cell cytokines, and B cell, host, and microbial products. In tissues, macrophages mature and are activated in a dynamic response to combinations of these stimuli to acquire specialized functional phenotypes. As for the lymphocyte system, a dichotomy has been proposed for macrophage activation: classic vs. alternative, also M1 and M2, respectively. In view of recent research about macrophage functions and the increasing number of immune-relevant ligands, a revision of the model is needed. Here, we assess how cytokines and pathogen signals influence their functional phenotypes and the evidence for M1 and M2 functions and revisit a paradigm initially based on the role of a restricted set of selected ligands in the immune response. PMID: 24669294 [PubMed]
Source: F1000 Medicine Reports - Category: Biomedical Science Tags: F1000Prime Rep Source Type: research