Basic Information

Strain Name
C57BL/6-Cd33tm1(CD33)/Bcgen
Stock Number
110823
Common Name
B-hCD33 mice
Source/Investigator
Bcgen (Beijing Biocytogen Co., Ltd)
Related Genes
SIGLEC-3, SIGLEC3, p67
Species
C57BL/6
Appearance
Black
Genotypes
Heterozygous

Description

CD33 or Siglec-3 (sialic acid binding Ig-like lectin 3, SIGLEC3, SIGLEC-3, gp67, p67) is a transmembrane receptor expressed on cells of myeloid lineage. It is usually considered myeloid-specific, but it can be found on some lymphoid cells. The extracellular portion of this receptor contains two immunoglobulin domains (one IgV and one IgC2 domain), placing CD33 within the immunoglobulin superfamily. The intracellular portion of CD33 contains immuno-receptor tyrosine-based inhibitory motifs (ITIMs) that are implicated in inhibition of cellular activity. As a member of the SIGLEC family of lectins, CD33 can be stimulated by any molecule with sialic acid residues such as glycoproteins or glycolipids (preferentially recognizes and binds alpha-2,3- and more avidly alpha-2,6-linked sialic acid-bearing glycans). Upon binding, the immunoreceptor tyrosine-based inhibition motif (ITIM) of CD33, present on the cytosolic portion of the protein, is phosphorylated and acts as a docking site for Src homology 2 (SH2) domain-containing proteins like SHP phosphatases. This results in a cascade that inhibits phagocytosis in the cell. CD33 is the target of gemtuzumab ozogamicin, an antibody-drug conjugate for the treatment of patients with acute myeloid leukemia, which was removed from the market in mid-2010 for a greater number of deaths, but was reintroduced to the market in 2017. Vadastuximab talirine (SGN-CD33A), a novel antibody-drug conjugate being developed by Seattle Genetics, utilizing this company’s ADC technology, is also targeted CD33.

Details

mRNA expression analysis

Strain specific analysis of CD33 gene expression in WT and heterozygous hCD33 mice by RT-PCR. Mouse Cd33 mRNA was detectable in lung of WT and heterozygous B-hCD33. Human CD33 mRNA was detectable only in H/+, but not in +/+ mice.

Protein expression analysis in CD11b+ cells in blood

Strain specific CD33 expression analysis in heterozygous B-hCD33 mice by flow cytometry. Blood were collected from WT and heterozygous B-hCD33 mice, and analyzed by flow cytometry with species-specific anti-CD33 antibody. Mouse CD33 was detectable in WT and heterozygous B-hCD33. Human CD33 was exclusively detectable in heterozygous B-hCD33 but not WT mice.

Protein expression analysis in CD11b+ cells in spleen

Strain specific CD33 expression analysis in heterozygous B-hCD33 mice by flow cytometry. Blood were collected from WT and heterozygous B-hCD33 mice, and analyzed by flow cytometry with species-specific anti-CD33 antibody. Mouse CD33 was detectable in WT and heterozygous B-hCD33. Human CD33 was exclusively detectable in heterozygous B-hCD33 but not WT mice.

 

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