T cell

noun

Immunology.

1. any of several closely related lymphocytes, developed in the thymus, that circulate in the blood and lymph and orchestrate the immune system's response to infected or malignant cells, either by lymphokine secretions or by direct contact: helper T cells recognize foreign antigen on the surfaces of other cells, then they stimulate B cells to produce antibody and signal killer T cells to destroy the antigen-displaying cells; subsequently suppressor T cells return the immune system to normal by inactivating the B cells and killer T cells.

T-cell

noun

1. another name for T-lymphocyte

T cell

1. Any of the lymphocytes that develop in the thymus gland and that act in the immune system by binding antigens to receptors on the surface of their cells in what is called the cell-mediated immune response. T cells are also involved in the regulation of the function of B cells.

2. Also called T lymphocyte

3. See more at cell-mediated immune response Compare B cell

T-cell

1. Key to the immune system, these cells originate in the bone marrow but mature in the thymus (the t stands for thymus). T-cells attack other body cells that are infected by some bacteria, a virus, or another pathogen. (Compare B-cell.)

T-cell counts are used as a diagnostic test to indicate the strength of the immune system in AIDS patients.

The HIV/AIDS virus destroys a type of T-cell, leading to the syndrome characterized by a defective immune system.

Word History and Origins

Origin of T-cell¹

1965–70; T(hymus-derived)

Example Sentences

Such vaccines could induce broader immunity than whole-virus vaccines by eliciting antibody and T-cell responses that target an even wider range of flu viruses.

From Salon

Mrs Sherry had to make a number of trips to London, including a clinical review and T-cell harvesting for the therapy.

From BBC

CAR T-cell therapy takes the patient's own T-cells, modifies them and then reintroduces them back into the blood stream to help fight the cancer.

From BBC

Mr Sherry said he knew of another person from Northern Ireland who was receiving CAR T-cell treatment in Manchester, but the travelling became too much for them and they were unable to continue.

From BBC

Part of our immune defences - a white blood cell called a T-cell - can swoop in and destroy the spreading cancer as it tries to take root.

From BBC