Natural Killer T Cells

Natural Killer T Cells are a unique subset of T lymphocytes that bridge the innate and adaptive immune systems. Unlike conventional T cells, NKT cells express both T cell receptors (TCRs) and natural killer (NK) cell markers. This distinctive dual phenotype allows NKT cells to rapidly respond to a wide range of antigens, making them crucial components of the immune system. NKT cells can be classified into two main types: Type I (invariant) NKT cells and Type II NKT cells. Type I NKT cells express an invariant TCR α-chain (Vα14-Jα18 in mice, Vα24-Jα18 in humans) and recognize glycolipid antigens presented by the non-polymorphic MHC-like molecule CD1d. Upon activation, NKT cells rapidly produce cytokines, such as interferon-gamma (IFN-γ) and interleukin-4 (IL-4), influencing the immune response. These cells play diverse roles in immune regulation, participating in antitumor responses, autoimmune diseases, and infectious diseases. Their ability to modulate other immune cells and shape the immune response makes them valuable targets for therapeutic interventions. Understanding the biology of NKT cells has implications for developing immunotherapies and vaccines. Research on NKT cells continues to uncover their roles in health and disease, shedding light on their potential for manipulating immune responses and treating various immunological disorders.