T cell
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- Healthline - T Cell Count
- Cleveland Clinic - T-Cells
- TeachMePhysiology - T Cells
- Biology LibreTexts - T Lymphocytes
- Oregon Health and Science University - CAR T-Cell Therapy for Cancer
- National Center for Biotechnology Information - PubMed Central - Human T cell development, localization, and function throughout life
- MedicineNet - Definition of T Cell
- Also called:
- T lymphocyte
- Key People:
- James P. Allison
News •
T cell, type of leukocyte (white blood cell) that is an essential part of the immune system. T cells are one of two primary types of lymphocytes—B cells being the second type—that determine the specificity of immune response to antigens (foreign substances) in the body.
T cells originate in the bone marrow and mature in the thymus. In the thymus, T cells multiply and differentiate into helper, regulatory, or cytotoxic T cells or become memory T cells. They are then sent to peripheral tissues or circulate in the blood or lymphatic system. Once stimulated by the appropriate antigen, helper T cells secrete chemical messengers called cytokines, which stimulate the differentiation of B cells into plasma cells (antibody-producing cells). Regulatory T cells act to control immune reactions, hence their name. Cytotoxic T cells, which are activated by various cytokines, bind to and kill infected cells and cancer cells.
Because the body contains millions of T and B cells, many of which carry unique receptors, it can respond to virtually any antigen.
