Edit · T Cell ← View page Saving needs a token. Register to get one. Edits are public and licensed CC-BY-SA-4.0. T cells [[t-cell#1|1]] , also known as T lymphocytes, are a type of white blood cell that plays a central role in [[cell_mediated immunity]]. Derived from [[hematopoietic stem cells]] in the [[bone marrow]]. They mature in the [[thymus]], which is where they get their name ("T" stands for thymus). # Types of T cells ## [[cd4_t-cell|Helper T cells (CD4+ T cells)]] Activate other immune cells, including B cells and CD8+ T cells. Recognize antigens presented by MHC class II molecules. ## [[cd8_t-cell|Cytotoxic T cells (CD8+ T cells)]] Directly destroy infected or cancerous cells. Recognize antigens presented by MHC class I molecules. ## [[treg_t-cell|Regulatory T cells (Tregs)]] Suppress or regulate immune responses, preventing autoimmunity and overactive immune reactions. ## [[memory_t-cell|Memory T cells]] Long-lived cells that "remember" previous encounters with pathogens and can mount a rapid response upon re-exposure. ## Function Recognize and respond to foreign [[antigens]]. Coordinate other parts of the [[immune system]]. Play a role in immune memory, allowing the immune system to respond more rapidly and effectively to previously encountered pathogens. # T cell receptor (TCR) Present on the surface of T cells. Allows T cells to recognize specific antigens in the form of peptide fragments bound to [[MHC molecules]] on the surface of other cells. # Clinical Importance T cells are targeted by HIV, leading to the progressive loss of immune function in AIDS patients. T cell therapies, like [[car-t|CAR-T]], have been developed for certain cancers. Autoimmune diseases can result from dysfunctional T cell activity. # Note T cells are a vital component of the adaptive immune system, distinguishing them from innate immune cells. Their activity is regulated by a balance of activating and inhibitory signals to ensure a proper immune response without damage to the host. # References ## {#1} test note []() Save Cancel Preview · live