A thymocyte-derived lymphocyte of immunological importance that is long-lived (months to years) and is responsible for cell-mediated immunity. T lymphocyte cells form rosettes with sheep erythrocytes and, in the presence of transforming agents (mitogens), differentiate and divide. These cells have the characteristic T3 surface marker and may be further divided into subsets according to function, such as helper, cytotoxic, etc.

(t lymphocyte) A type of immune cell that can attack foreign cells, cancer cells, and cells infected with a virus. T lymphocytes can also help control immune responses. A T lymphocyte is a type of white blood cell.

(t lymphocyte) A type of white blood cell that is produced in the bone marrow and is part of the body's immune system. Also called a T cell.

Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.

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...