Macrofagele

Macrofagele is a term used in several languages to refer to macrophages, a type of white blood cell that forms part of the innate immune system. They reside in virtually all tissues and originate from circulating monocytes, which migrate into tissues and differentiate in response to local signals. In some tissues, embryonic precursors also contribute to resident macrophage populations, providing long-term maintenance independent of monocytes.

Macrophages perform a range of essential functions. They specialize in phagocytosis, engulfing bacteria, dead cells, and debris, and they kill ingested microbes using reactive oxygen and nitrogen species. They digest material in lysosomes and secrete a variety of cytokines and chemokines that coordinate inflammation and recruit other immune cells. They also function as antigen-presenting cells, processing and presenting antigens on MHC class II molecules to helper T cells, linking innate and adaptive immunity.

Macrophages exhibit substantial plasticity and can adapt to diverse tissue environments. They are often described as having a range of activation states, commonly summarized as M1 (pro-inflammatory) and M2 (anti-inflammatory and tissue remodeling), though this dichotomy is an oversimplification. Signals such as IFN-γ and microbial components drive M1-like responses, while IL-4 and IL-13 promote M2-like activities. In reality, macrophage phenotypes exist along a spectrum influenced by the local milieu.

Clinical relevance and markers: Macrophages influence many health and disease processes, including infections, chronic inflammatory diseases, metabolic disorders, atherosclerosis, and cancer, where tumor-associated macrophages can support tumor growth. Identification relies on marker panels that vary by species and tissue; human macrophages commonly express CD68 and CD163, while mouse macrophages often express F4/80 and CD11b, with no single universal marker.