特異性：Human Toll-like Receptor 4 (TLR4) The Toll-like receptor (TLR) family is comprised of Type I transmembrane proteins characterized by an extracellular leucine-rich domain and a cytoplasmic tail that contains a conserved region call the Toll/IL-1 (TIR) domain. First discovered in Drosophila, TLRs recognize specific molecular patterns that are present in microbial components and respond to these components in order eliminate or limit invading microbes. To date, ten mammalian homologs of TLRs have been described. TLR4 is involved in the recognition of lipopolysaccharide (LPS), an abundant glycolipid of Gram-negative bacteria. Through its association with MD-2 and CD14, TLR4 recognizes and initiates multiple intracellular signaling events such as the activation of NF- kappa B leading to the ultimate synthesis and release of a number of proinflammatory mediators including interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor- alpha (TNF- alpha). TLR4 has also been associated in the recognition of and lipocheic acid (LTA), Hsp60 and Hsp70.1-10
