T cell

noun

: any of several lymphocytes (such as a helper T cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (as by the regulation of T and B cell maturation and proliferation) and others that lyse antigen-bearing cells : t lymphocyte
The immature lymphoid cell, in turn, can be processed into a B cell, which makes infection-fighting antibodies, or a T cell, which recognizes foreign tissue and virally infected cells and directs the activities of the rest of the immune system.Gina Kolata
T cells recognize antigen only in association with cell surface molecules encoded by the major histocompatibility complexMiranda Robertson
see helper t cell, killer t cell compare b cell

Examples of T cell in a Sentence

Recent Examples on the Web For example, if CAR T cells target a different protein or target two proteins at once, the treatment may more throughly eliminate cancer cells. William A. Haseltine, Forbes, 13 Sep. 2024 Rao and his colleagues identified CD4 T cells — or pathogenic T cells — as the ones causing an imbalance of B cells. Joshua Rapp Learn, Discover Magazine, 10 Sep. 2024 Fortunately, immunity from past exposure, in the form of memory T cells, keeps most people from getting severely ill. Tanya Lewis, Scientific American, 16 July 2024 New research suggests that people with lupus have too much of a particular T cell that can cause damage in healthy cells and too little of a different type of T cell that can help with repair. Lauryn Higgins, Flow Space, 15 July 2024 See all Example Sentences for T cell 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'T cell.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

thymus-derived cell

First Known Use

1970, in the meaning defined above

Time Traveler
The first known use of T cell was in 1970

Dictionary Entries Near T cell

Cite this Entry

“T cell.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/T%20cell. Accessed 5 Oct. 2024.

Kids Definition

T cell

noun
: any of the lymphocytes (as a helper T cell) that usually mature in the thymus and take an active part in immune responses compare b cell

Medical Definition

T cell

noun
: any of several lymphocytes (as a helper T cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (as by the regulation of T and B cell maturation and proliferation) and others that lyse antigen-bearing cells

called also T lymphocyte

see cytotoxic t cell, helper t cell, suppressor t cell, t4 cell

More from Merriam-Webster on T cell

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!