Recombinant Human PILR-alpha Fc Chimera Protein, CF

Recombinant Human PILR-alpha Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: PILR-alpha

Paired immunoglobulin-like type 2 receptor-alpha (PILRA) is one of two members that belong to a small family of immunoregulatory Ig-superfamily receptors (1-4). It is a counterpart to PILRB and the PILRs represent one of many pairs of Ig-like domain-containing receptors that participate in immune regulation (1, 2). Mature human PILRA consists of an extracellular domain (ECD) with one V-type Ig-like domain, a transmembrane domain, and a cytoplasmic domain with two immunoreceptor Tyr‑based inhibitory (ITIM) motifs. Given that ITIMs are known to interact with phosphatases such as PTPN6 and PTPN11, the presence of these motifs makes PILRA an inhibitory receptor (1-4). The ECD of human PILRA shares 42% and 40% amino acid sequence identity with mouse and rat PILRA, respectively. Three potential isoforms for human PILRA have been reported. PILRA is expressed by neutrophils, macrophages, monocytes, mast cells, APCs, microglia, neurons, cardiac muscle and renal proximal plus pancreatic duct eipthelium (4, 7, 8). It has multiple binding partners, including CD99 (4, 9), glycoprotein B/gB of HSV1 (in human) (7), PANP (PILR-associated neural protein) (8) and NPDC1 plus collectin-12 (10). Although PILRA and PILRB are highly similar in their ECD amino acid sequence, they do not necessarily share the same ligands, as PILRB fails to bind to gB and PANP (8, 10). PILRA binding appears to be dependent upon the presence of a poorly-defined peptide sequence coupled to a sialylated, O-linked carbohydrate motif but its exact function remains unclear (5, 9-12). Up-regulation of PILRA in the early stage of immune reaction and its subsequent binding to CD99 may lead to a down-regulation of the inflammatory response (10). Genome-wide association studies (GWAS) have linked PILRA to Alzheimer's Disease (AD) through association of PILRB with ZCWPW1 (13,14). It was further supported that ZCWPW1 locus SNP rs1476679 was associated with reduced PILRA levels suggesting a potential role for the gene in AD (15). The missense variant (G78R, rs1859788) of PILRA is thought to be the causal allele for the confirmed AD risk locus. The variant reduced the binding of PILRA to several ligands including a novel ligand, complement component 4A, and herpes simplex virus 1 (HSV-1) glycoprotein B (16). The observed protection from AD risk by PILRA G78R variant provided a new candidate for the therapeutic target.

Related Research Areas

• Dendritic Cell ITIM/ITAM Immunoreceptors
• ITIM/ITAM Immunoreceptors and Related Molecules