Toll-like receptor 8
Toll-like receptor 8 gene is mapped on chromosomes Xp22.3-p22.2 containing 2 exons with the initiator methionine encoded on exon 1 and the other protein encoded on exon 2 that span at about 15.5kb with 1,041 amino acids containing signal peptide such as multiple leucine-rich repeats and cysteine-rich region in its extracellular domain. It is largely expressed in peripheral blood leukocytes and lungs but lower expression in spleen, placenta, bone marrow which lies in close proximity at 16kb to TLR7 gene.
Toll-like receptor 8 has a single-stranded GU-rich RNA as a natural ligand proposing that recognition occurs in lysosomal compartment since signaling requires acidification of compartments. This protein distinguishes G-rich oligonucleotides.
Toll-like receptor 8 is relatively high expression in CD4-positive regulatory (Treg) cells that vigorously suppress host immune responses in which Treg cell presents in tumor-infiltrating lymphocyte line wherein TLR8 engagement fallout in DC maturation that enables to activate immature T-cells to render effector cells intractable to Treg cells found that a set of oligonucleotides could trigger TLR8 causing a reversal suppressive function of naturally occurring CD4-positive and CD25 revealing that this reversal of Treg suppression is dependent on TLR8 compared to other TLRs.
Gene name: TLR8
Protein name: Toll-like receptor 8