Invariant natural killer T cell (iNKT cell) (iNKT cell)

Invariant natural killer T cells (iNKT cells) are a subset of T lymphocytes characterized by an invariant T cell receptor (TCR) that recognizes lipid antigens presented by the non-polymorphic MHC class I-like molecule CD1d. They rapidly produce large quantities of cytokines, including IFN-γ and IL-4, upon activation and play pivotal roles in bridging innate and adaptive immunity by influencing multiple immune cell types, such as dendritic cells, NK cells, B cells, and conventional T cells. iNKT cells are involved in immune surveillance against tumors, responses to infectious agents, and modulation of inflammatory and autoimmune diseases. Activation can occur by direct recognition of glycolipid antigens (e.g., α-GalCer) or indirectly through cytokine-driven pathways (e.g., IL-12, IL-18, IL-33) during infection or inflammation, sometimes independent of TCR engagement. Because their activation affects a broad immune cascade, iNKT cells are of high interest both as effectors and as therapeutic targets or adjuvants in immunomodulation, but present both efficacy and toxicity challenges depending on the context.

Other names

Invariant NKT celliNKT cellCD1d-restricted NKT cellType I NKT cell

Agonist-induced activation via CD1d-restricted presentation of glycolipid antigens\nCytokine-mediated activation (notably by IL-12, IL-18, and IL-33, independent of TCR engagement)\nEnhancement of dendritic cell maturation and cross-priming via CD40L, IFN-γ, and other cytokines