Jh (C57BL/6)

• B cell deficient mice are useful for basic mechanistic studies of immunologic mechanisms as well as host mice in syngeneic tumor studies using immunogenic test articles.
• Carries a deletion of the endogenous murine J segments of the Ig heavy chain locus.
• In homozygotes, all four JH gene segments are absent, resulting in cells that cannot produce a complete, recombined version of the variable region of the heavy chain.
• B cell development halts at the pro-B cell stage without pre-B cell or mature B cells in the bone marrow. There are significantly fewer B220+ cells in spleen, which are exclusively pro-B cells without IgD. See Phenotypic Data section below.
• This model is expected to have normal T cell development based on published data from a similar model on the BALB/c background.
• For use in syngeneic experiments, this model is on the C57BL/6NTac background and will successfully engraft cell lines of C57BL/6 origin.
• Tumor growth kinetics may vary in immunodeficient mice compared to wild type mice of the same strain. A pilot study to evaluate tumor growth is best practice.

See the Related Taconic Biosciences Insight:

• Antibody-deficient mice overcome obstacles to efficacy testing of biologics

Origin:

The Jh (C57BL/6) mouse was developed by Taconic Biosciences. The model was created through CRISPR/Cas9-mediated gene editing to delete the entire Igh-J locus including all four transcripts. Targeting occurred in C57BL/6NTac embryos. The selected G1 founder was screened for off-target effects and the targeted locus was sequenced to confirm targeting specificity. Heterozygous animals were intercrossed to generate homozygous mice. The line is maintained by crossing homozygous mice. 
 

Download the Taconic Biosciences' Infographic:
The Jh mouse permits clinically relevant dosing of immunogenic test articles in syngeneic tumor model systems
See how the Jh mouse can enable syngeneic tumor studies for drugs with immunogenicity problems.

• This Model was generated using CRISPR/Cas9 technology. Taconic uses CRISPR/Cas9 technology to generate and/or distribute gene-edited models under licenses from The Broad Institute, Inc., the Massachusetts Institute of Technology, the President and Fellows of Harvard College, the University of Iowa Research Foundation and ERS Genomics.
• This Model and biological materials derived from it may only be used for purchasers' internal research purposes in the Field, unless purchaser otherwise has rights from the Broad covering such use. "Field" means use as a research tool for research purposes, and expressly excludes any (a) clinical use, (b) human, veterinary, livestock or agricultural use, or (c) manufacture, distribution, sale, promotion, use or other exploitation as a testing service, therapeutic or diagnostic for humans or animals.
• The Models and biological materials derived from them will not be sold or used to perform services for third parties (unless purchaser is acting on behalf of a third party to which they have communicated these Conditions of Use and which third party has accepted these Conditions of Use), or otherwise used for commercial purposes.
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Figure 1: B cell development halts at pro-B cell stage without pre-B cell or mature B cells in the bone marrow and there is no IgD expression.

Figure 2: There are significantly fewer B220+ cells in spleen, which are exclusively pro-B cells without IgD.

Jh (C57BL/6) - Taconic model #17758. Males at MPF health standard. Data provided by an anonymous biotech company.