Design of a novel, native-like secreted form of the hepatitis C virus E1E2 heterodimer

Published

January 11, 2021

Author(s)

Johnathan D. Guest, Ruixue Wang, Khadija Elkholy, Andrezza Chagas, Kinlin L. Chao, Thomas Cleveland, Young C. Kim, Zhen-Yong Keck, Alexander Marin, Roy Mariuzza, Alexander K. Andrianov, Eric A. Toth, Steven Foung, Brian Pierce, Thomas R. Fuerst

Abstract

Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, in addition to a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to expected size than full-length E1E2, and preservation of native structural elements was confirmed by high affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2, and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.

Citation

Proceedings of the National Academy of Sciences of the United States of America

Pub Type

Journals

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Citation

Guest, J. , Wang, R. , Elkholy, K. , Chagas, A. , Chao, K. , Cleveland, T. , Kim, Y. , Keck, Z. , Marin, A. , Mariuzza, R. , Andrianov, A. , Toth, E. , Foung, S. , Pierce, B. and Fuerst, T. (2021), Design of a novel, native-like secreted form of the hepatitis C virus E1E2 heterodimer, Proceedings of the National Academy of Sciences of the United States of America, [online], https://doi.org/10.1073/pnas.2015149118 (Accessed April 30, 2024)