Recombinant Human CD22 protein (Catalog#11958-H08H)
This antibody was obtained from a rabbit immunized with purified, recombinant Human CD22 (rh CD22; Catalog#11958-H08H; P20273-1; Met1-Arg687).
Monoclonal Rabbit IgG Clone #340
0.2 μm filtered solution in PBS
This antibody is shipped as liquid solution at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
This antibody can be stored at 2℃-8℃ for one month without detectable loss of activity. Antibody products are stable for twelve months from date of receipt when stored at -20℃ to -80℃. Preservative-Free. Avoid repeated freeze-thaw cycles.
Immunofluorescence staining of CD22 in Hela cells. Cells were fixed with 4% PFA, blocked with 10% serum, and incubated with rabbit anti-Human CD22 monoclonal antibody (1:60) at 4℃ overnight. Then cells were stained with the Alexa Fluor® 488-conjugated Goat Anti-rabbit IgG secondary antibody (green) and counterstained with DAPI (blue).
Immunochemical staining of human CD22 in human spleen with rabbit monoclonal antibody at 1:200 dilution, formalin-fixed paraffin embedded sections.
Immunochemical staining of human CD22 in human tonsil with rabbit monoclonal antibody at 1:200 dilution, formalin-fixed paraffin embedded sections.
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.