superantigen

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superantigen

 [soo″per-an´tĭ-jen]
any of a group of powerful antigens occurring in various bacteria and viruses that bind outside of the normal T cell receptor site and are able to react with multiple T cell receptor molecules, thus activating T cells nonspecifically. Included are staphylococcal enterotoxins and toxins causing toxic shock syndrome and exfoliative dermatitis.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

su·per·an·ti·gen

(sū'pĕr-an'ti-jen),
An antigen that interacts with the T-cell receptor in a domain outside the antigen recognition site. This interaction induces the activation of larger numbers of T cells than are induced by antigens that are presented in the antigen recognition site leading to the release of numerous cytokines. A single superantigen may potentially activate as much as 15% of the lymphocytic repertoire.
See also: antigen.
Farlex Partner Medical Dictionary © Farlex 2012

superantigen

One of a class of molecules that react with a substantial proportion of the whole population of T cells in the body. They include Staphylococcus aureus ENTEROTOXINS. Staphylococcal enterotoxin A (SEA) is a powerful T-cell mitogen and can give rise to the release of large quantities of CYTOKINES and LEUKOTRIENES. This is believed to be one of the bases of the TOXIC SHOCK SYNDROME.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
The data was presented in a poster tagged "Combining tumor-targeted superantigens with anti-CTLA-4 results in synergistic anti-tumor effects in B16 tumor bearing mice".
They are also capable of producing acetic acids, lipopolysaccha - rides, peptidoglycans, superantigens, heat shock proteins and bacterial DNA--all in precise proportion to nourish each other, inhibit challengers and/or benefit the host.
Moreover, ETs stimulate cytokine release with subsequent edema, which physically forces layers of skin apart at the desmosomes (8), probably acting as superantigens (9, 10).
Microbial superantigens also can induce T-cell resistance to steroids, suggesting a possible role for infection in the development of resistance, he said.
aureus can elaborate superantigens, "which have the ability to stimulate the production of alternative glucocorticoid receptors.
Staphylococcal superantigens induce lymphotactin production by human CD4+ and CD8+ T cells.
"The inflammatory milieu in the airways of these patients is driving up the expression of the [beta] receptor." Microbial superantigens also can induce T-cell resistance to steroids, suggesting a possible role for infection in the development of resistance, he said.
Specific topics include a survey of immunology, superantigens, antigen presenting cells, cell mediated immune defense, cytokines as molecular mediators, interleukens, interferons as viral inhibitors and immune response mediators, interferon signaling through Janus kinases and signal transducers and activators of transcription, flow cytometry, immunoassays, genetic engineering of antibody molecules, autoantibodies and autoimmunity, synovial mast cells in inflammatory arthritis and the molecular and cell biology of HIV/AIDS.
The TCRs also bind a class of microbial proteins, known as superantigens, that stimulate T cells bearing particular V[beta] elements (24).
The immunopathogenesis of food allergies may be governed by more than one immunologic mechanism, including immediate manifestations mediated by IgE; inflammatory reactions caused by immune complexes, lectins, and superantigens; and delayed hypersensitivity reactions associated with specific T lymphocytes (Helm and Burks 2000).