Natural killer cells (NK cells) and macrophages (NK cells and macrophages)

Natural killer (NK) cells and macrophages are distinct types of innate immune cells that play critical roles in the body's defense against pathogens and malignancies. NK cells are cytotoxic lymphocytes that recognize and kill stressed, virally infected, or transformed cells without prior sensitization, primarily through the release of perforin and granzymes (Source: NIH, StatPearls). Macrophages are versatile phagocytes derived from monocytes that clear cellular debris, present antigens to T cells, and orchestrate inflammatory responses through cytokine secretion and polarization into M1 (pro-inflammatory) or M2 (anti-inflammatory) states (Source: Nature Reviews Immunology). While these cell populations are frequently targeted in immunotherapy—such as through the use of checkpoint inhibitors, cytokines, or CAR-NK cells—they do not represent a single molecular target, receptor, or enzyme. Instead, they are complex cellular components of the immune system whose various surface receptors (e.g., CD16, CSF-1R, SIRPα) serve as the actual therapeutic targets for drug development (Source: PubMed, Journal of Hematology & Oncology). Consequently, the term 'NK cells and macrophages' refers to a cellular therapeutic focus rather than a specific biochemical target.

Other names

NK cellsNatural killer cellsMacrophagesM1/M2 macrophagesLarge granular lymphocytesMonocyte-derived macrophages

Modulation of innate immune cell activity, including activation of NK cell cytotoxicity via cytokine signaling, inhibition of macrophage 'don't eat me' signals (CD47/SIRPα), and polarization of macrophages from pro-tumorigenic M2 to anti-tumorigenic M1 phenotypes.