• CD22 is primarily expressed in B cells, with low levels also found in oligodendrocytes, granulocytes, and ovarian stromal cells. CD22 acts as an inhibitory co-receptor on the surface of B cells, suppressing signal transduction induced by B cell receptors through binding to sialic acid expressed on antigen-presenting cells. CD22 is highly expressed in B cell malignancies such as non-Hodgkin lymphoma and in autoimmune diseases like systemic lupus erythematosus, making it a popular therapeutic target for these conditions.
• The genome of mouse Cd22 gene that encode extracellular domain was replaced by the corresponding human CD22 genome in B-hCD22 mice(C).
• Human CD22 was exclusively detectable in homozygous B-hCD22 mice(C).
• This product is used for the pharmacological and safety evaluation of B-cell malignancies such as non Hodgkin lymphoma and autoimmune diseases such as systemic lupus erythematosus.

Gene targeting strategy for B-hCD22 mice(C). The exons 4-11 of mouse Cd22 gene that encode extracellular domain were replaced by human counterparts in B-hCD22 mice(C). The genomic region of mouse Cd22 gene that encodes transmembrane domain and cytoplasmic portion was retained. The promoter, 5’UTR and 3’UTR region of the mouse gene were retained. The chimeric CD22 expression was driven by endogenous mouse Cd22 promoter, while mouse Cd22 gene transcription and translation will be disrupted.

Strain specific CD22 expression analysis in wild-type BALB/c mice and homozygous humanized B-hCD22 mice(C) by flow cytometry. Splenocytes were collected from wild-type BALB/c mice and homozygous B-hCD22 mice(C). Protein expression was analyzed with anti-mouse CD22 antibody (Biolegend, 126105) and anti-human CD22 antibody (Biolegend, 363505) by flow cytometry. Mouse CD22 was only detectable in wild-type BALB/c mice. Human CD22 was exclusively detectable in homozygous B-hCD22 mice(C), but not in wild-type BALB/c mice.

Strain specific CD22 expression analysis in wild-type BALB/c mice and homozygous humanized B-hCD22 mice(C) by flow cytometry. Blood cells were collected from wild-type BALB/c mice and homozygous B-hCD22 mice(C). Protein expression was analyzed with anti-mouse CD22 antibody (Biolegend, 126105) and anti-human CD22 antibody (Biolegend, 363505) by flow cytometry. Mouse CD22 was only detectable in wild-type BALB/c mice. Human CD22 was exclusively detectable in homozygous B-hCD22 mice(C), but not in wild-type BALB/c mice.