Purified anti-human Siglec-9

Siglecs are cell surface receptors belonging to the immunoglobulin superfamily that recognize sugar antigens. The extracellular domain of siglec-9 contains an IgV region, which binds sialic acid, followed by two IgC regions. Siglec 9 and siglec 6-8,10-12 are CD33 (siglec 3) like siglecs, which have two ITIMs in the cytoplasmic tails, suggesting their functional involvement in signal transduction. It is highly expressed on neutrophils and monocytes, and at lower levels on the subpopulations of T and B lymphocytes and NK cells. Siglec-9 plays a role in negative regulation of T cell activation, and it also affects neutrophil apoptosis.