Enhanced production of recombinant coxsackievirus A16 using a serum-free HEK293A suspension culture system for bivalent enterovirus vaccine development
Yi-An Chen,
Yu-Sheng Shen,
Chih-Yeu Fang,
Ting-Ting Chan,
Shang-Rung Wu,
Jen-Ren Wang,
Suh-Chin Wu,
Chia-Chyi Liu
Affiliations
Yi-An Chen
Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan; National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
Yu-Sheng Shen
National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
Chih-Yeu Fang
National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
Ting-Ting Chan
School of Dentistry & Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan
Shang-Rung Wu
School of Dentistry & Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan
Jen-Ren Wang
Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan; National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan
Suh-Chin Wu
Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan
Chia-Chyi Liu
National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan; Corresponding author at: Vaccine R&D Center, National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan Town, Miaoli County 35053, Taiwan.
Coxsackievirus A16 (CVA16) is one of the primary pathogens that causes hand, foot, and mouth disease (HFMD) in young children. In previous studies, CVA16 vaccine development has encountered several challenges, such as inefficient replication of the CVA16 virus in present culture systems, the induction of only mild neutralizing antibody titers, and neutralizing antibodies induced by certain vaccine candidates that are unable to protect against CVA16 viral challenge. In this study, we constructed a DNA-launched CVA16 infectious clone (CVA16ic) based on the genomic sequence of the CVA16 N5079 strain to minimize interference from viral quasispecies. The biochemical properties of this CVA16ic strain were similar to those of its parental strain. Serum-free HEK293A suspension cells, which produced higher virus titers than Vero cells, were demonstrated to improve CVA16 production yields. In addition, our study showed that inactivated EV-A71 antigens could enhance the immunogenicity of inactivated CVA16 mature/full particles (F-particles), suggesting that a bivalent CVA16 and EV-A71 vaccine may be an effective strategy for CVA16 vaccine development. These findings are expected to provide novel strategies and accelerate the development of bivalent HFMD vaccines.
