Natural killer cells and T-lymphocytes (NK cells and T-cells)

Natural killer (NK) cells and T-lymphocytes are the primary effector cells of the human immune system, responsible for the surveillance and elimination of malignant and virally infected cells (Abel et al., 2018; Kumar et al., 2018). T-lymphocytes, which include helper (CD4+) and cytotoxic (CD8+) subtypes, mediate adaptive immunity through the recognition of specific antigens via the T-cell receptor (TCR) complex (Kumar et al., 2018). NK cells serve as a critical component of the innate immune system, utilizing a sophisticated array of activating and inhibitory receptors to identify "missing-self" signals on target cells (Abel et al., 2018). In the context of modern oncology, these cells are the fundamental units of immunotherapy; checkpoint inhibitors like pembrolizumab function by blocking inhibitory pathways (e.g., PD-1) on T-cells to restore their anti-tumor activity (Postow et al., 2018). Additionally, adoptive cell therapies such as CAR-T and CAR-NK cells involve the genetic modification of these lymphocytes to express synthetic receptors that target specific tumor-associated antigens (National Cancer Institute, 2023). While these therapies have revolutionized cancer treatment, they are associated with unique toxicities, most notably cytokine release syndrome (CRS) and immune-effector cell-associated neurotoxicity syndrome (ICANS), which result from systemic immune overactivation (Postow et al., 2018).

Other names

NK cellsT-cellsCytotoxic lymphocytesLarge granular lymphocytesThymocytesEffector lymphocytesCD3+ cellsCD56+ cells

Modulation of immune cell activity through checkpoint inhibition, cytokine-mediated stimulation, or genetic engineering to enhance targeted cell lysis (Postow et al., 2018; National Cancer Institute, 2023).