Toll-like receptor: Meaning (information, definition, explanation, facts)

Toll-like receptors are proteins serving as a part of the innate immune system. They are a group of pathogen-associated molecular pattern (PAMP) recognition receptors. They were first discovered in the fruit fly Drosophila melanogaster, but they have close homologues in mammalian immune cells. Their function is the recognition of pathogens and the activation of immune cells directed against those pathogens.

There are several sub-types of Toll-like receptors (TLR1 - TLR10), which recognize different aspects of pathogenic organism, such as bacterial cell-surface lipopolysaccharides and lipoproteins, proteins from bacterial flagella, double-stranded RNA of viruses or the CpG islands of bacterial DNA. Following activation by the bound pathogenic factor, several reactions are possible. The pathogen might be phagocytosed and digested, followed by apoptosis. Another possible reaction is the production of other signalling factors which trigger inflammation.