develops from capable of elicited macrophage M1 macrophage classically activated macrophage An elicited macrophage that is recruited into the tissues in response to injury and infection as part of an inflammatory response, expresses high levels of pro-inflammatory cytokines, ROS and NO, and shows potent microbicidal activity. inflammatory macrophage Inflammatory macrophages, also sometimes referred to as M1 or classically activated macrophages, play an important role in the inflammatory response. The M1/M2 classification is based upon macrophage polarization rather than macrophage location and refers to macrophage activation towards either a more inflammatory or more resolving phenotype, respectively, although the functional diversity of macrophages is more nuanced than such a dichotomy suggests. Inflammatory macrophages are derived from monocytes recruited to a site of infection or injury. M1 macrophages are classically activated, typically by IFN-γ or lipopolysaccharide (LPS). Upon sensing signs of inflammation, they quickly respond by increasing their pro-inflammatory activity. They achieve this by producing a range of signaling molecules, such as nitric oxide, reactive oxygen species, and numerous cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1, -6 and -12. The release of these potent molecules helps to recruit other immune cells to the site, killing off pathogenic organisms and facilitation inflammation. At the same time, M1 macrophages can also present antigens to T cells, thereby helping to induce an adaptive immune response. Over time, these macrophages may transition in phenotype and function to help resolve the inflammation and promote tissue repair. Despite the beneficial role of inflammatory macrophages in dealing with pathogens, chronic activation of these cells can lead to harmful effects. Over time, continuous production of pro-inflammatory molecules can cause damage to tissues and organs. This is seen in certain chronic inflammatory diseases, such as atherosclerosis, diabetes, obesity, asthma, and various autoimmune disorders. In such situations, the normally protective function of inflammatory macrophages is not properly controlled, which can contribute to disease pathology. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) https://cellxgene.cziscience.com/cellguide/CL_0000863 Markers: Express: TNFa, IL1b, IL6, iNOS, NADPH-oxidase; produce: reactive oxygen species, nitric oxide; role or process: immune, inflammation (inflammatory response). M0 macrophage interleukin-1 beta production interleukin-6 production tumor necrosis factor production superoxide anion generation defense response to bacterium regulation of nitric oxide biosynthetic process