Globally, more than 71 million people are infected with Hepatitis C virus (HCV), with 1-2 million newinfections occurring each year. This major health concern necessitates the development of an effective vaccine.Since HCV rapidly accumulates mutations, vaccines must elicit the production of broadly neutralizing antibodies(bnAbs) in a reproducible fashion. The viral envelope E1E2 glycoprotein is a natural target of neutralizingantibodies. However, two major challenges in production of envelope proteins such as E1E2 are as follows. First,as the candidate protein advances, it will be critical to obtain a product with stable, reproducible, homogenousglycoforms that show high potential for yielding a potent and broadly neutralizing antibody response. Thisensures an optimally potent vaccine with comparable efficacy across batches in preclinical and clinical trials, andmakes it easier to retain the glycan profile through manufacturing. However, variation across host cells, evenclones, can lead to substantial variation in glycosylation. Second, upon identifying a glycoform that provides thedesired broadly neutralizing antibody response, it can be difficult to obtain an effective expression host that caneconomically produce the vaccine subunit proteins in a functional form. Here we are addressing these challengesby producing a well-characterized novel native-like secreted E1E2 (sE1E2) complex in a panel ofglycoengineered mammalian cell lines to obtain more homogeneous glycosylation with predictable and definedstructures. After production of preclinical material of all glycoforms, the most effective glycoforms will be identifiedby rigorous bioanalytical analysis, coupled to nanoparticles, and subjected to immunological assessment ofpolyclonal sera from animals immunized with sE1E2 produced in glycoengineered CHO cell lines, wild-type CHOcell lines, and HEK 293 and Huh7 control cell lines. Thus, this proposed research will identify optimal glyformsand help establish a platform cell line for manufacturing an effective pan-HCV vaccine.
Public Health Relevance Statement: PROJECT NARRATIVE
Hepatitis C virus is a global health concern, yet lacks an approved vaccine. This project will develop and
characterize diverse glycoforms of novel native-like secreted E1E2 glycoprotein complex in a nanoparticle format
to determine the impact of glycan structure on biochemical properties and induction of a cross-neutralizing
antibody response. These studies will thereby identify the optimal glycoform to be used when developing HCV
vaccine candidates, a strategy which could then be applied to any viral glycoprotein antigen.
Project Terms: | <2019 novel corona virus><2019 novel coronavirus><2019-nCoV>
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