TLR 2

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toll-like receptor 2
Identifiers
Symbol(s)	TLR2
Entrez	7097
OMIM	603028
RefSeq	NM_003264
UniProt	O60603
Other data
Locus	Chr. 4 q32

TLR-2 is the name for a biomolecule, which plays a role in the human immune system. It is a membrane protein, a receptor, which sits on the surface of certain cells and which can recognize own body or foreign substances, and passes on appropriate signals to the cell and/or the nervous system.

The TLR-2 discussed here is member of a large family of homologous Toll-like receptors (TLRs).

[edit] Impact

TLR-2 is a diaphragm receptor oriented at the surface and recognizes many bacterial, mycogene, virale and special body-own (endogenous) substances. Generally an admission (Internalisation, Phagozytose) of bound materials takes place in Endosomen/Phagosomen and a cellular activation, so that the elements of the innate immunity take over such as macro phages, PMN and dendritische 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 Zytokine is involved e.g. Tumor necrosis factor alpha (TNF α) and different Interleukine (IL1alpha, IL1beta, IL6, IL8, IL12). Before the TLRs were known, some the materials specified below were seized under the term so-called Moduline. By that rather Th1 appropriate Zytokin pattern is seen in most experimental models an immune deviation this way, away of the Th2-Ausprägung. Konjugate 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 disinhibiting (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 TGFbeta, IL10). Older literature, which attributes a direct immun 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 Polymorphismen 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] Occurrence

TLR-2 is exprimiert on Mikroglia, Schwann cells, Monozyten, macro phages, dendritic cell, PMN, B-cells (B1a, MZB, B2), T-cells including Tregs (CD4+ CD25+ regulatory t cells) (squeezed out). This than hetero dimer (combined molecule) with e.g. partly happens. TLR-1 or TLR-6. TLR-2 is likewise in the Epithelien of the bronchial tube, the alveoli, to find the kidney small channels and the Bowman cap of the Nierenkörperchens. Within the range of the skin he finds on Keratinozyten and tallow glands, here sbc1 induces himself, whereby a bactericidal tallow can be formed.