SIRP⍺ antibodies

Signal regulatory proteins (SIRP) are a multigene family of immunoreceptors encoded in humans by a cluster of genes on chromosome 20p13. The family consists of five members with variable levels of amino acid sequence homology, including SIRPα, SIRPβ1, SIRPβ2, SIRPγ, and SIRPδ. The glycoprotein SIRPα, also known as CD172a, SHPS-1, BIT (rat homologue), p84 (mouse homologue), MFR, MYD-1, or PTPNS1 is the primordial and also the best conserved member of the family. SIRPα is an inhibitory receptor expressed on myeloid cells, including macrophages, dendritic cells (DCs) and neutrophils.

SIRPα recognizes its ligand CD47, a receptor expressed on all normal cells, but often overexpressed on cancer cells. Tumors use CD47 as “don’t eat me” signal to evade destruction by innate immune system. An unbiased single-nucleotide polymorphism (SNP) analysis of human SIRPα, based on data available at EnsEMBL (https://www.ensembl.org), revealed that SIRPαV1, SIRPαV2 and SIRPαV8 are the most prominent haplotypes present among the human population. Of these, SIRPαV1 and SIRPαV2 differ the most in their IgV domain sequence. While SIRPαV1 is the most abundant allele among European, Admixed American, and African populations, the SIRPαV2 allele is the most commonly found allele in the East Asian population.

GenHunter has 5 monoclonal antibodies against SIRPα: 2 neutralizing mAbs (NAb) and 3 binding mAbs. This includes those against human SIRPαV1-Fc, SIRPαV2-Fc, and SIRPαV8-Fc fusion proteins as well as 2 monoclonal pan-allele SIRPα neutralizing mAbs (NAb, i.e. neutralizing human SIRPαV1, SIRPαV2 and SIRPαV8).