Design and Expression of a Dimeric Form of the Human Immunodeficiency Virus Type 1 Antibody 2G12 with Increased Neutralization Potency
Abstract
The antigen-binding fragment of the broadly neutralizing Human Immunodeficiency Virus Type 1 (HIV-1) antibody 2G12 has an unusual 3D domain-swapped structure with two aligned combining sites that facilitates recognition of its carbohydrate epitope on gp120. When expressed as an intact IgG, 2G12 formed typical IgG monomers containing two combining sites and a small fraction of a higher molecular weight species, which showed a significant increase in neutralization potency (50- to 80-fold compared to 2G12 monomer) across a range of clade A and B strains of HIV-1. Here we show that the higher molecular weight species corresponds to a 2G12 dimer containing four combining sites, and present a model for how intermolecular 3D domain swapping could create a 2G12 dimer. Based on the structural model for a 3D domain-swapped 2G12 dimer, we designed and tested a series of 2G12 mutants predicted to increase the ratio of 2G12 dimer to monomer. We report a mutation that effectively increases the 2G12 dimer/monomer ratio without decreasing the expression yield. Increasing the proportion of 2G12 dimer compared with monomer could lead to a more potent reagent for gene therapy or passive immunization.
Additional Information
© 2008, American Society for Microbiology and/or the Listed Authors/Institutions. Received 24 July 2008. Accepted 10 October 2008. JVI Accepts, published online ahead of print on 22 October 2008. We thank Adrian Rice for assistance with light scattering experiments, Lili Yang and David Baltimore for advice concerning the neutralization assay, David Stolzer for making the 3D model figures, Marta Murphy for assistance with figures, and Dennis Burton of the Scripps Research Institute for cDNAs. We also thank the CAVD Neutralizing Antibody Core Laboratories for performing in vitro neutralization assays. This study was supported by a grant from the Bill and Melinda Gates Foundation through the Grand Challenges in Global Health Initiative.Attached Files
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Additional details
- PMCID
- PMC2612297
- Eprint ID
- 12181
- DOI
- 10.1128/JVI.01564-08
- Resolver ID
- CaltechAUTHORS:WESjvi08
- Bill and Melinda Gates Foundation
- Howard Hughes Medical Institute (HHMI)
- Created
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2008-10-28Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field