Tissue Expression of Human Toll-Like Receptors and Differential Regulation of Toll-Like Receptor mRNAs in Leukocytes in Response to Microbes, Their Products, and Cytokines

Members of the Toll-like receptor (TLR) family mediate dorsoventral patterning and cellular adhesion in insects as well as immune responses to microbial products in both insects and mammals. TLRs are characterized by extracellular leucine-rich repeat domains and an intracellular signaling domain that shares homology with cytoplasmic sequences of the mammalian IL-1 receptor and plant disease resistance genes. Ten human TLRs have been cloned as well as RP105, a protein similar to TLR4 but lacking the intracellular signaling domain. However, only five TLRs have described functions as receptors for bacterial products (e.g., LPS, lipoproteins). To identify potential sites of action, we used quantitative real-time…

• G
  Genentech