CD20 is a 33-37 kD protein, a member of the MS4A family, with four transmembrane spanning regions that present as a homo-oligomeric complexes in the cell surface when associating with MHC class I and II, CD53, CD81, and CD82. CD20 is expressed on B cells and a subset of T cells, but not on plasma cells. CD20 regulates B-cell activation and proliferation. Its ligation promotes transmembrane Ca2+ trafficking. CD20 is an important therapeutic target in the treatment of B cell lymphomas and leukemias.
The exons 2-7 of mouse Cd20 gene that encode the full-length protein were replaced by human CD20 exons 2-7 in B-hCD20 mice.
mRNA expression analysis
Strain specific analysis of CD20 gene expression in wild type (WT) mice and B-hCD20 mice by RT-PCR.
Mouse CD20 mRNA was detectable only in splenocytes of WT mice (+/+). Human CD20 mRNA was detectable only in homozygous B-hCD20 mice (H/H) but not in WT mice (+/+).
Protein expression analysis in B cells
Strain specific CD20 expression analysis in homozygous B-hCD20 mice by flow cytometry.
Splenocytes were collected from WT and homozygous B-hCD20 (H/H) mice, and analyzed by flow cytometry with species-specific anti-CD20 antibody. Mouse CD20 was detectable in WT mice. Human CD20 was exclusively detectable in homozygous B-hCD20 but not WT mice.