T cell

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Related to T-lymphocyte: small lymphocyte

T lym·pho·cyte

a lymphocyte formed in the bone marrow from which it migrates to the thymic cortex to become an immunologically competent cell; T lymphocytes have long lifespans (months to years) and are responsible for cell-mediated immunity; T lymphocytes form rosettes with sheep erythrocytes and differentiate and divide in the presence of transforming agents (mitogens); T lymphocytes have characteristic T cell receptor-CD3 complexes as surface markers and may be further categorized by function, such as helper and cytotoxic.
See also: B lymphocyte.
Synonym(s): T cell

T cell

n.
Any of the lymphocytes that mature in the thymus and have the ability to recognize specific peptide antigens through the receptors on their cell surface. Also called T lymphocyte.

T cell

a lymphocyte that participates in cellular immunity, including cell-to-cell communication. The major T cell categories are T-helper and T-suppressor cytotoxic cells. Compare B cell. See also antibody, immune response. Also called T lymphocyte.

T cell

Cardiology
A specialised myocyte found in clusters in the sinus node, which is intermediate in size, structure, and organisation between P cells and normal atrial myocytes, and connect swith either of these cells; perinodal T cells surround the sinus tract and are thought to “bundle” impulses leaving the sinus node and to filter premature ectopic atrial impulses.

Immunology
A thymus-derived white cell responsible for cell-mediated immunity and immunoregulation which is the most complex cell of the immune system, given:
(1) The diversity of T-cell types, including T cells with activator, cytotoxic, delayed hypersensitivity and suppressor activities;
(2) The wide range of cytokines, growth factors and immune modulators produced by activated T cells;
(3) The complexity of T-cell interaction with exogenous and endogenous antigens (e.g., mediation of delayed hypersensitivity, graft-versus-host disease);
(4) The complexity of T-cell maturation in the thymus.

50 to 70% of circulating WBCs are granulocytes (neutrophils); the rest are lymphocytes, of which T cells (defined as having “pan T cell” markers), CD2 and CD7 and other T-cell markers (e.g., CD1, CD3, and CD5) comprise 70 to 85%; B cells comprise 15 to 30%.

T lym·pho·cyte

(lim'fŏ-sīt)
A thymocyte-derived lymphocyte of immunologic importance that is responsible for cell-mediated immunity. These cells have the characteristic T3 surface marker and may be further divided into subsets according to function, such as helper, suppressor, and cytotoxic.
See also: B lymphocyte
Synonym(s): T cell.

T cell

One of the two broad categories of LYMPHOCYTE, the other being the B cell group. Subsets of T cells with different functions include cytotoxic T cells (CD8+ T cells) which destroy tumour cells and cells infected with viruses; helper T cells (CD4+ T cells) which assist the immune response, and are a target of HIV infection; REGULATORY T CELLS, formerly called suppressor T cells, which are essential for the maintenance of immunological tolerance; and natural Killer T cells (NKT cells).

T cell

A type of white blood cell produced in the thymus gland that regulates the immune system's response to diseased or malignant cells. It is possible that a subcategory of T cells known as CD4 cells plays a role in Ménière's disease.

T lym·pho·cyte

(lim'fŏ-sīt)
Lymphocyte formed in bone marrow from which it migrates to thymic cortex to become an immunologically competent cell.

T cell,

n a small, circulating lymphocyte produced in the bone marrow that matures in the thymus. T cells primarily mediate cellular immune responses, such as graft rejection and delayed hypersensitivity.

T cell

see T lymphocyte.

T c. receptor
antigen specific heterodimeric proteins, either αβ or γδ, present on the surface of T lymphocytes, the specificity of which is generated by somatic mutation and somatic recombination of a relatively small number of genes and is similar to that responsible for the generation of antibody diversity.

Patient discussion about T cell

Q. How are cancer cells similar to normal cells, and how are they different? I know that a similarity would be cells regenerate, and a difference would be cancer cells grow uncontrollably. Is there anything else?

A. I learned a lot of new things from the answers. Thanks.

Q. what is difference between normal cell and a cell infected with cancer?

A. Malignant cells (cancerous cells, which is the correct term, since cancer isn't transmitted from cell to cell like microbes), are immortalized cells: the life span of each cell in our body is tightly regulated according to the body's needs, so cells don't multiply endlessly and eventually undergo programmed death (called apoptosis). Cancerous cells succeed to overcome this regulation, and therefore become immortalized: either excessive multiplication or avoidance of death.

You may read more here:
http://www.mayoclinic.com/health/cancer/CA99999

Q. What tests can the doctors do to see if I have cancer cells still in me? Am using my friend user name. I had a mastectomy in October of the 3cms lump. They also removed lymph nodes from armpit. They found that 2 nodes were slightly infected and 2 blood vessels leading away were the same. My oncologist says I should start chemo for 5 months followed by 5 wks of radiotherapy. I am awaiting the results from bone, heart, lungs and blood tests. What tests can the doctors do to see if I have cancer cells still in me?

A. You need to have your own self examination, which you can get guidance from doctor and all the tests which you already had and the tests which you are awaiting. Like you may have clinical examination, mammograms- which you already had, breast biopsy, ultrasonography, post biopsy pathology test, HER-2 gene test to find the speed of your tumor growth. Tests to check cancer spread – like lymph, bone, liver and lungs whose results you are waiting for.

More discussions about T cell
References in periodicals archive ?
Calcineurin has been identified as a key signaling enzyme in T-lymphocyte activation.
The report reviews Cytotoxic T-Lymphocyte Protein 4 (CTLA-4 or CD152) targeted therapeutics under development by companies and universities/research institutes based on information derived from company and industry-specific sources
FcyRIIIa (CD16) induction on human t lymphocytes and CD16pos T-lymphocyte amplification," Journal of Immunotherapy, vol.
Impact of hepatitis C viral replication on CD4+ T-lymphocyte progression in HIV-HCV coinfection before and after antiretroviral therapy.
T-lymphocyte count <100 cells/[micro]l are recommended to be screened for cryptococcal antigenaemia.
Multivariate associations with death among TB-HIV patients were examined by using a generalized linear model with a log link and robust SEs to generate relative risk (RR) estimates (14); the model was a priori specified to include time period, age, sex, race/ethnicity, foreign birth, HIV risk factor, CD4+ T-lymphocyte count, sputum smear positivity, and interval between the diagnoses of HIV infection and TB.
WIC is currently investigating whether T-lymphocytes or T-cells (which are a type of white blood cell) can help improve the accuracy of the prognosis for a patient with colon cancer.
The primary endpoints of the study were to demonstrate differences in early immune outcome by evaluating cytokine responses (interleukin-1[beta], interleukin-6, and TNF-[alpha]) and T-lymphocyte subsets in both groups of patients within 5 days postoperatively.
In the first phase of the programme, lab-based screening will begin at almost 500 health facilities in Gauteng and the Free State, served by three National Health Laboratory Service (NHLS) laboratories performing CD4+ T-lymphocyte testing.
Specifically, in mice with SS-like disorders, infusions of MSCs caused T-lymphocyte death with FASL/FAS signaling and lessened symptoms of the immune disorder.
This mutation of the "cg" (for common gamma chain) gene on the X chromosome results in very low T-lymphocyte and NK-lymphocyte counts but the B-lymphocyte count is high.
In addition, the data demonstrated statistically significant differences in changes in IEL and both alpha/beta and gamma/delta T-lymphocyte subsets.