MSU Technologies

CH12F3 Cell Line with Various Knock-Outs

Executive Summary

The CH12F3 mouse B lymphocyte cell lines are useful tools to study the role of DNA metabolism in modulating immunoglobulin genes and DNA repair. Since enzymes involved in DNA metabolism play essential roles in embryogenesis, knockout of these proteins often resulted in lethality in mouse embryonic stem cells. MSU researchers have developed various enzyme-deficient CH12F3 cell lines compatible with cell viability. Key enzymes involved in DNA repair processes, such as ligases, endonucleases, deaminases and more, have been targeted for selective knockouts.

Description of Technology

Antigen-stimulated mature B cells can diversify their immunoglobulin gene by class switch recombination (CSR), somatic hypermutation and gene conversion. A diversification of the constant region of the Ig heavy chain in CSR allows a “switch” of the class (or isotype) of the expressed immunoglobulin, without altering its antigen specificity. Apyrimidinic endonucleases (APE) generate DNA strand incisions, activation-induced cytidine deaminase (AID) and DNA Ligases, which repair DNA double strand breaks (DSB), non-homologous end joint (NHEJ) and alternative end-joining (A-EJ) pathways have been targeted. Additional proteins involved in single strand DNA repairs and others are listed and are currently being developed. CRISPR/Cas9 technology has been used and recombination-mediated cassette exchange (RMCM) allows repeated knock-ins at the same genomic locus.

Key Benefits