- TLR 2
TLR-2 is a
biomolecule, which plays a role in the human immune system. TLR-2 is a membrane protein, a receptor, which is expressed on the surface of certain cells and recognizes native or foreign substances, and passes on appropriate signals to the cell and/or the nervous system.
TLR-2 is a member of a large family of homologous
Toll-like receptors(TLRs). TLR2 has also been designated as CD282 ( cluster of differentiation282).
TLR-2 is a membrane receptor found at the surface of immune system cells that recognises many bacterial, fungal, viral and
endogenoussubstances. Phagocytosisof bound materials takes place in endosome/ phagosomeand a cellular activation, so that the elements of the innate immune systemtake over such as macrophages, PMN and dendritic cellstasks of the nonspecific immune defense, B1a and form MZB first anti-bodies and uses in the process the specific anti-body formation. Here cytokineis involved e.g. Tumor necrosis factor-alpha(TNF α) and different interleukins ( IL-1alpha, IL-1beta, IL-6, IL-8, IL-12). Before TLRs were discovered, some of the materials specified below were grouped under the term so-called "Moduline". By that rather Th1 appropriate cytokine pattern is seen in most experimental models an immune deviation this way, away of the Th2-expression. Conjugates are developed as vaccinesor already used without a prioriknowledge.
One only 2006 recognized characteristic is the expression of the TLR-2 on the
Tregs(special form of the T-cells), which is brought equally to TCR determined proliferation and functional inactivity. Thereby, a disinhibitionof the early inflammation phase and the specific anti-body formation is reached. After reduction of the exciter number many exciter-specific Tregs are present, which, now without TLR-2-Signal, become active and the specific like the inflammatory immune reaction to restrain (see also TGF beta, Interleukin 10). Older literature, which attributes a direct immune stimulation effect over TLR-2 to a given substance, must be interpreted under circumstances that the used TLR-2-knockouts has regularly quite few Tregs.
polymorphismis described, which reduced to a function restriction and thus usually survival rate with infections/ sepsiswith Gram-positivebacteria leads in particular.
signal transductionis represented in the article toll-like receptor.
TLR-2 is expressed on
microglia, Schwann cells, monocytes, macrophages, dendritic cells, polymorphonuclear leukocytes, B-cells (B1a, MZB, B2), T-cells including regulatory T cells( CD4, CD25). TLR-2 is likewise in the epitheliumof the bronchial tubeand the alveoli. Agonists
*cite journal | author=Aderem A, Ulevitch RJ |title=Toll-like receptors in the induction of the innate immune response. |journal=Nature |volume=406 |issue= 6797 |pages= 782–7 |year= 2000 |pmid= 10963608 |doi= 10.1038/35021228
*cite journal | author=Muzio M, Polentarutti N, Bosisio D, "et al." |title=Toll-like receptor family and signalling pathway. |journal=Biochem. Soc. Trans. |volume=28 |issue= 5 |pages= 563–6 |year= 2001 |pmid= 11044375 |doi=
*cite journal | author=Hallman M, Rämet M, Ezekowitz RA |title=Toll-like receptors as sensors of pathogens. |journal=Pediatr. Res. |volume=50 |issue= 3 |pages= 315–21 |year= 2002 |pmid= 11518816 |doi=
*cite journal | author=Dziarski R, Gupta D |title=Role of MD-2 in TLR2- and TLR4-mediated recognition of Gram-negative and Gram-positive bacteria and activation of chemokine genes. |journal=J. Endotoxin Res. |volume=6 |issue= 5 |pages= 401–5 |year= 2001 |pmid= 11521063 |doi=
*cite journal | author=Lien E, Ingalls RR |title=Toll-like receptors. |journal=Crit. Care Med. |volume=30 |issue= 1 Suppl |pages= S1–11 |year= 2002 |pmid= 11782555 |doi=
*cite journal | author=Xu D, Komai-Koma M, Liew FY |title=Expression and function of Toll-like receptor on T cells. |journal=Cell. Immunol. |volume=233 |issue= 2 |pages= 85–9 |year= 2005 |pmid= 15950961 |doi= 10.1016/j.cellimm.2005.04.019
*cite journal | author=Lorenz E |title=TLR2 and TLR4 expression during bacterial infections. |journal=Curr. Pharm. Des. |volume=12 |issue= 32 |pages= 4185–93 |year= 2007 |pmid= 17100621 |doi=
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