Natural killer cell-mediated cytotoxicity pathway (NKCMC) (NKCMC)

The Natural killer (NK) cell-mediated cytotoxicity pathway is a fundamental component of the innate immune system responsible for the surveillance and elimination of stressed, infected, or neoplastic cells (KEGG: hsa04650). This pathway is regulated by a sophisticated array of germline-encoded activating and inhibitory receptors that integrate signals to determine the NK cell's effector response (Nature Reviews Immunology, 2008). Activating receptors like NKG2D and natural cytotoxicity receptors (NCRs) recognize ligands induced by cellular stress or viral infection, while inhibitory receptors, such as Killer-cell Immunoglobulin-like Receptors (KIRs) and NKG2A, typically recognize MHC class I molecules to prevent the destruction of healthy self cells (PubMed: 11244033). Upon activation, NK cells execute cytotoxicity through the polarized release of lytic granules containing perforin and granzymes, or through the expression of TNF-family death ligands like FasL and TRAIL (StatPearls: Natural Killer Cells). Therapeutic strategies often focus on modulating this pathway using checkpoint inhibitors like Monalizumab (targeting NKG2A) or Lirilumab (targeting KIRs) to enhance anti-tumor immunity (ClinicalTrials.gov). Additionally, many therapeutic antibodies utilize this pathway via Antibody-Dependent Cellular Cytotoxicity (ADCC), where the CD16 receptor binds the Fc portion of antibodies to trigger target cell lysis (Journal of Hematology & Oncology, 2017).

Other names

NK cell cytotoxicityNatural killer cell effector functionNK cell-mediated lysisKEGG pathway hsa04650

Modulation of the balance between activating and inhibitory receptor signaling to trigger NK cell degranulation, cytokine production, and death receptor-mediated apoptosis.