Human PILR-alpha Antibody

Paired immunoglobulin-like type 2 receptor alpha (PILRa; also inhibitory receptor PILR-alpha) are 44-50 kDa paired receptors that consist of highly related activating and inhibitory receptors, and are widely involved in the regulation of the immune system. PILR-alpha is thought to act as a cellular signaling inhibitory receptor by recruiting cytoplasmic phosphatases like PTPN6/SHP-1 and PTPN11/SHP-2 via their SH2 domains that block signal transduction through dephosphorylation of signaling molecules. Human PILR-alpha is synthesized as a 303 amino acid (aa) precursor that contains a 19 aa signal sequence, a 178 aa extracellular domain (ECD), a 21 aa transmembrane segment, and an 85 aa cytoplasmic domain. The ECD contains one Ig-like V-type domain and one potential site for N-linked glycosylation. The cytoplasmic domain contains two ITIM motifs (aa 267-272 and 296-301). Alternate splicing generates multiple shorter isoforms. One is TM and possesses a 35 aa substitution for aa 264-303, while others are soluble, and show a deletion of aa 152-224 that may be coupled to the 35 aa substitution noted above, or simply exhibit a 24 aa substitution for aa 152-303. Mature human PILR-alpha is 45% aa identical to mature mouse PILR-alpha. PILR-alpha is predominantly detected in hemopoietic tissues and is expressed in monocytes, macrophages, and granulocytes, but not lymphocytes. It is also strongly expressed by dendritic cells. PILR-alpha interacts with herpes simplex 1 glycoprotein B and functions as an entry coreceptor for this virus.