Description

Background:

• CD79B encodes an Ig-β protein that forms part of the antigenic component in B cells. The CD79A and CD79B proteins together form a heterodimeric complex, and their interaction with immunoglobulin heavy chains is crucial for the expression of B-cell receptor (BCR) on the cell surface and the subsequent initiation of signaling pathways triggered by BCR activation.

Targeting strategy:

• The exons 1-4 of mouse Cd79b gene that encode the extracellular domain were replaced by human CD79B exons 1-4 in B-hCD79B mice.

Validation:

• Mouse CD79B was detectable in wild-type C57BL/6N mice.

• Human CD79B was exclusively detectable in homozygous B-hCD79B mice, but not in wild-type C57BL/6N mice.

Application:

• This product is used to assess the pharmacodynamics and toxicity evaluation of antibody or ADC drugs in the treatment of tumor-related diseases.

Targeting strategy

Gene targeting strategy for B-hCD79B mice. The exons 1-4 of mouse Cd79b gene that encode signal peptide and extracellular domain is replaced by human counterparts in B-hCD79B mice. The genomic region of mouse Cd79b gene that encodes transmembrane domain and cytoplasmic portion is retained. The chimeric CD79B expression is driven by endogenous mouse Cd79b promoter, while mouse Cd79b gene transcription and translation will be disrupted.

mRNA expression analysis

Strain specific analysis of CD79B mRNA expression in wild-type C57BL/6N mice and B-hCD79B mice by RT-PCR. Spleen RNA were isolated from wild-type C57BL/6N mice (+/+) and homozygous B-hCD79B mice (H/H), and then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CD79B primers. Mouse Cd79b mRNA was only detectable in wild-type mice. Human CD79B mRNA was exclusively detectable in homozygous B-hCD79B mice, but not in wild-type mice.

Protein expression analysis

Strain specific CD79B expression analysis in wild-type C57BL/6N mice and homozygous humanized B-hCD79B mice by flow cytometry. Splenocytes and blood were collected from wild-type C57BL/6N mice (+/+) and homozygous B-hCD79B (H/H), and analyzed by flow cytometry with anti-mouse CD79B antibody (R&D, FAB6814V) and anti-human CD79B antibody (Biolegend, 341406) by flow cytometry. Mouse CD79B was only detectable in wild-type C57BL/6N mice. Human CD79B was exclusively detectable in homozygous B-hCD79B mice, but not in wild-type C57BL/6N mice.