TLR 2

From Wikipedia, the free encyclopedia

Toll-like receptor 2
PDB rendering based on 1fyw.
Available structures: 1fyw, 1fyx, 1o77
Identifiers
Symbol(s)	TLR2; CD282; TIL4
External IDs	OMIM: 603028 MGI: 1346060 HomoloGene: 20695
Gene ontology Molecular Function: • lipopolysaccharide receptor activity • transmembrane receptor activity • protein binding • peptidoglycan binding • Gram-positive bacterial binding Cellular Component: • plasma membrane • integral to plasma membrane • cell surface Biological Process: • induction of apoptosis • inflammatory response • Toll signaling pathway • positive regulation of tumor necrosis factor biosynthetic process • chloramphenicol transport • innate immune response
RNA expression pattern
More reference expression data
Orthologs
	Human	Mouse
Entrez	7097	24088
Ensembl	ENSG00000137462	ENSMUSG00000027995
Uniprot	O60603	Q811T5
Refseq	NM_003264 (mRNA) NP_003255 (protein)	NM_011905 (mRNA) NP_036035 (protein)
Location	Chr 4: 154.84 - 154.85 Mb	Chr 3: 83.92 - 83.93 Mb
Pubmed search	[1]	[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 differentiation 282).

[edit] Impact

TLR-2 is a membrane receptor found at the surface of immune system cells that recognises many bacterial, fungal, viral and endogenous substances. Phagocytosis of bound materials takes place in endosome/phagosome and a cellular activation, so that the elements of the innate immune system take over such as macrophages, PMN and dendritic cells tasks of the nonspecific immune defense, B1a and form MZB first anti-bodies and uses in the process the specific anti-body formation. Here cytokine is 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 T_h1 appropriate cytokine pattern is seen in most experimental models an immune deviation this way, away of the T_h2-expression. Conjugates are developed as vaccines or already used without a priori knowledge.

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 disinhibition of 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.

Functionally relevant polymorphism is described, which reduced to a function restriction and thus usually survival rate with infections/sepsis with Gram-positive bacteria leads in particular.

The signal transduction is represented in the article toll-like receptor.

[edit] Expression

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 epithelium of the bronchial tube and the alveoli.

[edit] Agonists

[edit] Further reading