Macrophage Marker Development

Background of Macrophage Marker Development

Macrophages play a crucial role in orchestrating immune responses against pathogens and foreign materials. In response to environmental cues, macrophages have remarkable plasticity and perform a wide range of immune- and homeostasis-related functions. Due to their plasticity, macrophages can polarize into a spectrum of activated phenotypes. The two extremes in the spectrum are represented by the pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes. M1 macrophages are related to inflammation, including secretion of pro-inflammatory cytokines, engulfment of foreign entities, generation of reactive oxygen and nitrogen species, and assistance in T-helper type1 (Th1) cell responses to fight infection. Conversely, M2 macrophages perform anti-inflammatory and wound repair functions. The complexity associated with macrophage activation limits the ability of current biomarker-based methods to rapidly identify unique activation states. Moreover, breaking the balance of M1 and M2 states can result in many health problems, such as infections, cancer, and inflammatory and autoimmune diseases.

Given the significance and complexity of the roles macrophages play in biology and disease, it is necessary to develop markers that distinguish macrophages from other cells or identify their polarization state, which can help select therapeutic approaches.