mRNA expression analysis
Strain specific analysis of CD3E gene expression in wild type (WT) mice and B-hCD3E/hHER2 mice by RT-PCR.Mouse Cd3e mRNA was detectable only in spleen of WT mice (+/+). Human CD3E mRNA was detectable only in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+).
Strain specific analysis of HER2 gene expression in wild type (WT) mice and B-hCD3E/hHER2 mice by RT-PCR. Mouse Erbb2 mRNA was detectable only in liver of WT mice (+/+). Human ERBB2 mRNA was detectable only in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+).
Protein expression analysis
Strain specific CD3E expression analysis in homozygous B-hCD3E/hHER2 mice by flow cytometry.Splenocytes were collected from wild type (WT) mice (+/+) and homozygous B-hCD3E/hHER2 mice (H/H;H/H), and analyzed by flow cytometry with species-specific anti-CD3E antibody. Mouse CD3E was detectable in WT mice (+/+). Human CD3E was exclusively detectable in homozygous B-hCD3E/hHER2 mice (H/H;H/H) but not in WT mice (+/+).
IHC analysis of HER2 expression
Immunohistochemical (IHC) analysis of HER2 expression in homozygous B-hCD3E/hHER2 mice. The mammary gland tissues were collected from WT and homozygous B-hHER2 mice (H/H; H/H) and analyzed by IHC with anti-Her2 antibody. HER2 was detectable in WT mice and homozygous B-hHER2 mice due to the cross-reactivity of the antibody. The arrow indicates tissue cells with positive HER2 staining (brown).
In vivo efficacy of anti-human CD3/HER2 BsAbs
Antitumor activity of anti-human CD3/HER2 BsAbs (provided by a client) in B-hCD3E/HER2 mice. (A) Anti-human CD3/HER2 antibody BsAbs inhibited B-hHER2 MC38 plus tumor growth in B-hCD3E/HER2 mice. Murine colon cancer B-hHER2 MC38 plus cells were subcutaneously implanted into homozygous B-hCD3E/HER2 mice (female, 7-9-week-old, n=6). Mice were grouped when tumor volume reached approximately 100 mm3, at which time they were intraperitoneally injected with anti-human CD3/HER2 BsAbs Ab1 (provided by a client) indicated in panel. (B) Body weight changes during treatment. As shown in panel A, anti-human CD3/HER2 BsAbs Ab1 (provided by a client) was efficacious in controlling tumor growth in B-hCD3E/HER2 mice, demonstrating that the B-hCD3E/HER2 mice provide a powerful preclinical model for in vivo evaluation of anti-human CD3/HER2 BsAbs. Values are expressed as mean ± SEM.
* When publishing results obtained using this animal model, please acknowledge the source as follows: The animal model [B-hCD3E/hHER2 mice] (Cat# 121249) was purchased from Biocytogen.
