Target Synonym: Lyb;SIGLEC2FLJ;B-cell receptor CD;T-cell surface antigen Leu;sialic acid binding Ig-like lectin;Sialic acid-binding Ig-like lectin;B-cell receptor CD22;BL-CAM;B-lymphocyte cell adhesion molecule;CD22 antigenMGC130020;CD22 molecule;sialic acid binding Ig-like lectin 2;Sialic acid-binding Ig-like lectin 2;Siglec-2;SIGLEC2FLJ22814;T-cell surface antigen Leu-14;Lyb-8;Siglec2;Cd22;Lyb8;Siglec-2
Background: CD22 is a member of the immunoglobulin superfamily, SIGLEC family of lectins. It is first expressed in the cytoplasm of pro-B and pre-B cells, and on the surface as B cells mature to become IgD+. CD22 serves as an adhesion receptor for sialic acid-bearing ligands expressed on erythrocytes and all leukocyte classes. In addition to its potential role as a mediator of intercellular interactions, signal transduction through CD22 can activate B cells and modulate antigen receptor signaling in vitro. The phenotype of CD22-deficient mice suggests that CD22 is primarily involved in the generation of mature B cells within the bone marrow, blood, and marginal zones of lymphoid tissues. CD22 recruits the tyrosine phosphatase Src homology 2 domain-containing phosphatase 1 (SHP-1) to immunoreceptor tyrosine-based inhibitory motifs (ITIMs) and inhibits B-cell receptor (BCR)-induced Ca2+ signaling on normal B cells. CD22 interacts specifically with ligands carrying alpha2-6-linked sialic acids. As an inhibitory coreceptor of the B-cell receptor (BCR), CD22 plays a critical role in establishing signalling thresholds for B-cell activation. Like other coreceptors, the ability of CD22 to modulate B-cell signalling is critically dependent upon its proximity to the BCR, and this in turn is governed by the binding of its extracellular domain to alpha2,6-linked sialic acid ligands. However, genetic studies in mice reveal that some CD22 functions are regulated by ligand binding, whereas other functions are ligand-independent and may only require expression of an intact CD22 cytoplasmic domain at the B-cell surface. CD19 regulates CD22 phosphorylation by augmenting Lyn kinase activity, while CD22 inhibits CD19 phosphorylation via SHP-1.
Immunogen: Recombinant Mouse CD22 Protein
Buffer: 0.2 μm filtered solution in PBS
Dilution: WB 1:500-1:2000;IP 0.5-2 μL/mg of lysate
Calculated MW: 95 kDa
Observed MW: 150 kDa