Clone REA492 recognizes the human CD329 antigen, a single-pass type I membrane protein also known as sialic acid-binding Ig-like lectin 9 (Siglec-9). Siglecs are characterized by an amino-terminal V-set immunoglobulin domain that binds to sialic acid residues, followed by a variable number of C2-set immunoglobulin-like domains. CD329 is expressed quite broadly among human blood leukocytes, being found on monocytes, neutrophils, B cells, NK cells, and minor subsets of T cells. Ligation of CD329 induced apoptosis in adult neutrophils in a caspase-dependent manner; in contrast, its activation under inflammatory conditions resulted in a caspase-independent autophagic type of cell death. These disparate actions implicate a unique role for CD329 in modulating cell survival under inflammatory and basal conditions.

Additional information: Clone REA492 displays negligible binding to Fc receptors.