Toll-like receptor
class of proteins that play a key role in the innate immune system / From Wikipedia, the free encyclopedia
Toll-like receptors (TLRs) are proteins which act in the innate immune system and the digestive system. They are membrane-spanning, that is, they reach from the outside of the cell to the inside.
TLRs recognize molecules which come from microbes. Once microbes get through physical barriers such as the skin or intestinal tract mucosa, they are recognized by TLRs. The TLRs set up an immune cell response.
TLR signalling leads to the induction or suppression of genes that orchestrate the inflammatory response. In all, thousands of genes are activated by TLR signalling, and the TLRs are one of the most important means of gene modulation.
Toll-like receptors have also been shown to be an important link between innate and adaptive immunity through their presence in dendritic cells.