Exploration of broadly neutralizing antibody fragments produced in bacteria for the control of HIV

• Published in: Human vaccines & immunotherapeutics Vol. 13; no. 11; pp. 2726 - 2737
• Main Authors: Lloyd, Sarah B., Niven, Keith P., Kiefel, Ben R., Montefiori, David C., Reynaldi, Arnold, Davenport, Miles P., Kent, Stephen J., Winnall, Wendy R.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 02.11.2017; Taylor & Francis Group
• Subjects: 10E8; Antibodies, Neutralizing - administration & dosage; Antibodies, Neutralizing - biosynthesis; Antibodies, Neutralizing - therapeutic use; Bacteria - immunology; Broadly neutralizing antibodies; Diabodies; E. coli Expression; Escherichia coli - genetics; Escherichia coli - immunology; HIV Antibodies - administration & dosage; HIV Antibodies - biosynthesis; HIV Antibodies - chemistry; HIV Antibodies - therapeutic use; HIV Infections - immunology; HIV Infections - prevention & control; HIV Infections - therapy; HIV Infections - virology; HIV-1 - immunology; Human immunodeficiency virus; Humans; Neutralization Tests; PGT121; Proof of Concept Study; Research Paper; Single-Chain Antibodies - biosynthesis; Single-Chain Antibodies - immunology; Single-chain variable fragment antibodies; Tandem-scFv; PGT121; Tandem-scFv; 10E8; Broadly neutralizing antibodies; Diabodies; E. coli Expression; Single-chain variable fragment antibodies; Human immunodeficiency virus
• ISSN: 2164-5515; 2164-554X
• DOI: 10.1080/21645515.2017.1368935

While broadly neutralizing antibodies (bnAbs) are a promising preventative and therapeutic tool for HIV infection, production is difficult and expensive. Production of antibody-like fragments in bacterial cytoplasm provides a cheaper alternative. This work explored the transplantation of the complementarity determining regions of the anti-HIV bnAbs PGT121 and 10E8 onto a single-chain variable fragment (scFv) scaffold, previously discovered through a novel screening platform. The scaffolded 10E8 scFv, but not the scaffolded PGT121 scFv, was soluble in bacterial cytoplasm, enabling efficient production in bacteria. Three additional multimeric constructs employing the scaffolded 10E8 scFv were also generated and soluble versions produced in bacteria. However, the constructs were found to have substantially lost anti-HIV binding function and had completely abrogated neutralizing activity. Overall, while this study provides a proof-of-concept for anti-HIV bnAb construct production in bacterial cytoplasm, future refinement of these technologies will be required to realize the goal of producing inexpensive and effective bnAb-like tools for the control of HIV.