Ex vivo evolution of human antibodies by CRISPR-X: from a naive B cell repertoire to affinity matured antibodies | BMC Biotechnology | Full Text

Ex vivo evolution of human antibodies by CRISPR-X: from a naive B cell repertoire to affinity matured antibodies | BMC Biotechnology | Full Text

BMC Biotechnology

Ex vivo evolution of human antibodies by CRISPR-X: from a naive B cell repertoire to affinity matured antibodies

• Marie-Claire Devilder,
• Melinda Moyon,
• Laetitia Gautreau-Rolland,
• Benjamin Navet,
• Jeanne Perroteau,
• Florent Delbos,
• Marie-Claude Gesnel,
• Richard BreathnachEmail author and
• Xavier SaulquinEmail authorView ORCID ID profile

BMC Biotechnology201919:14

https://doi.org/10.1186/s12896-019-0504-z

©  The Author(s). 2019

• Received: 20 November 2018
• Accepted: 5 February 2019
• Published: 18 February 2019

Keywords

• Human antibodies
• SHM
• CRISPR
• CRISPR-X
• AID
• Tetramers
• HLA
• Cytofluorimetry

Background

Somatic hypermutation promotes affinity maturation of antibodies by targeting the cytidine deaminase AID to antibody genes, followed by antigen-based selection of matured antibodies. Given the importance of antibodies in medicine and research, developing approaches to reproduce this natural phenomenon in cell culture is of some interest.

Results

We use here the CRISPR-Cas 9 based CRISPR-X approach to target AID to antibody genes carried by expression vectors in HEK 293 cells. This directed mutagenesis approach, combined with a highly sensitive antigen-associated magnetic enrichment process, allowed rapid progressive evolution of a human antibody against the Human Leucocyte Antigen A*02:01 allele. Starting from a low affinity monoclonal antibody expressed on Ag-specific naïve blood circulating B cells, we obtained in approximately 6 weeks antibodies with a two log increase in affinity and which retained their specificity.

Conclusion

Our strategy for in vitro affinity maturation of antibodies is applicable to virtually any antigen. It not only allows us to tap into the vast naive B cell repertoire but could also be useful when dealing with antigens that only elicit low affinity antibodies after immunization.