T-lymphocytemedical dictionary

<haematology, immunology> A class of lymphocytes, derived from the thymus gland. They originate from lymphoid stem cells that migrate from the bone marrow to the thymus and differentiate under the influence of the thymic hormones. Various subpopulations have been described.

They help to control cell-mediated immunity and the control of B-cell development, to facilitate antibody production. T lymphocytes assist in the recognition and rejection of foreign tissues and provide immune surveillance for cancer.

They express T-cell antigen receptors (CD3) and lack Fc or C3b receptors. Major T-cell subsets are CD4 (mainly helper cells) and CD8 (mostly cytotoxic or suppressor T-cells). Uncontrolled proliferation of this type of cell gives rise to T-cell leukaemia/lymphoma.

(13 Nov 1997)

T Lisp, T loop of RNA, TLS, TLTP, TLV < Prev | Next > T-lymphocytes, cytotoxic, T-lymphocytes, helper-inducer

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T-lymphocytes, cytotoxicmedical dictionary

Immunised T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (mlc), in vivo during a graft-versus-host (gvh) reaction, or after immunization with an allograft, tumour cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (cml). These cells are distinct from natural killer cells (killer cells, natural) and from killer cells mediating antibody-dependent cell cytotoxicity.

(12 Dec 1998)

T-lymphocytes, helper-inducermedical dictionary

Subpopulation of CD4+ lymphocytes that cooperate with other lymphocytes (either t or b) to initiate a variety of immune functions. For example, helper-inducer T-cells cooperate with B-cells to produce antibodies to thymus-dependent antigens and with other subpopulations of T-cells to initiate a variety of cell-mediated immune functions.

(12 Dec 1998)

TLTP, TLV, T-lymphocyte, T-lymphocytes, cytotoxic < Prev | Next > T-lymphocytes, suppressor-effector

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T-lymphocytes, suppressor-effectormedical dictionary

Subpopulation of CD8+ T-lymphocytes which suppress antibody production or inhibit cellular immune responses. Suppressor-effector cells execute the message received from suppressor-inducer cells (T-lymphocytes, suppressor-inducer).

(12 Dec 1998)

T-lymphocytes, suppressor-inducermedical dictionary

Subpopulation of CD4+ lymphocytes which induce CD8+ suppressor T-cells (T-lymphocytes, suppressor-effector) to suppress antibody production by B-cells. They also stimulate other cellular immune responses.

(12 Dec 1998)

t-lymphocyte subsetsmedical dictionary

A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.

(12 Dec 1998)