Basic Information

Strain name
C57BL/6-Cd28tm1(CD28)Ms4a1tm2(MS4A1)/Bcgen
Common name
B-hCD28/hCD20 mice
Background
C57BL/6
Catalog number
121253
Related genes
CD28, CD28 molecule, Tp44; CD20, MS4A1, membrane spanning 4-domains A1, B1, Bp35, CD20, CVID5, LEU-16, MS4A2, S7

Description

CD28 (CD28 molecule) is one of the proteins expressed on T cells that provide co-stimulatory signals required for T cell activation and survival. T cell stimulation through CD28 in addition to the T-cell receptor (TCR) can provide a potent signal for the production of various interleukins (IL-6 in particular). CD28 is the only B7 receptor constitutively expressed on naïve T cells. Association of the TCR of a naive T cell with MHC:antigen complex without CD28:B7 interaction results in a T cell that is anergic. The agonistic antibody of CD28 is now under phase II clinical trials.

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.

Targeting strategy

The exons 2-3 of mouse Cd28 gene that encode the extracellular domain were replaced by human CD28 exons 2-3 in B-hCD28/hCD20 mice. The exons 2-7 of mouse Cd20 gene that encode the full-length protein were replaced by human CD20 exons 2-7 in B-hCD28/hCD20 mice.

Protein expression analysis

Strain specific CD28 expression analysis in homozygous B-hCD28/hCD20 mice by flow cytometry.

Splenocytes were collected from WT and homozygous B-hCD28/hCD20 (H/H;H/H) mice, and analyzed by flow cytometry with species-specific anti-CD28 antibody. Mouse CD28 was detectable in WT mice. Human CD28 was exclusively detectable in homozygous B-hCD28/hCD20 but not WT mice.

 

Strain specific CD20 expression analysis in homozygous B-hCD28/hCD20 mice by flow cytometry.

Splenocytes were collected from WT and homozygous B-hCD28/hCD20 (H/H;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-hCD28/hCD20 but not WT mice.