Enhanced Production of HCV E1E2 Subunit Vaccine Candidates via Protein‐Protein Interaction Identification in Glycoengineered CHO Cells

ABSTRACT Hepatitis C Virus (HCV) is a pervasive bloodborne virus and the leading cause of chronic liver disease and cancer. Thus, the development of an HCV vaccine is of great importance. Prior work has developed candidate vaccines, including more potent glycoengineered viral proteins and secreted forms of the E1E2 envelope heterodimer (sE1E2). However, efforts to express them recombinantly in Chinese hamster ovary (CHO) cells have resulted in very low titers. To address this challenge, here we employed a multi‐omics approach to identify protein interactors that may enhance the secretion of an sE1E2 vaccine candidate. We detected protein‐protein interactions (PPIs) using the Biotinylation by Antibody Recognition (BAR) assay and integrated these data with RNA‐Seq. Through this, we identified and overexpressed proteins that interact with sE1E2 in CHO cells. Among these, CUL4A and YWHAH enhanced sE1E2 secretion in our glycoengineered CHO cells. The integration of omics techniques and genetic engineering in this study provides valuable insights into the host cell proteins that interact with the HCV E1E2 heterodimer, and how they may be harnessed to improve protein secretion in CHO cells to enable more affordable and accessible biotherapeutics.