Chao, Y.-C. | bioRxiv Science

bioRxiv2022

Baculovirus Surface Display of Hemagglutinin and Neuraminidase for Monoclonal Antibody Production

The H7N9 influenza virus that emerged in 2013 is a dangerous infectious disease with a high mortality rate of up to 40%. Developing effective monoclonal antibodies (mAbs) to detect and treat the infection of this virus is therefore critical. In this study, we expressed hemagglutinin (HA) and neuraminidase (NA) of H7N9 (A/Anhui/1/2013) on the surface of baculovirus (i.e., HA7-Bac and NA9-Bac). Our results showed that both HA or NA proteins displayed on HA7-Bac or NA9-Bac could well maintain their native biological function. Mice antisera derived from the injections of either HA7-Bac- or NA9-Bac exhibited high inhibitory activity in the hemagglutination and neuraminidase assay of H7N9 virus. mAbs generated by immunization with HA7-Bac exhibited high neutralizing activity against H7N9 virus infectivity in cell assays, whereas mAbs generated by immunization with NA9-Bac inhibited neuraminidase activity. These results proved that baculovirus display of HA and NA from H7N9 could be convenient agents to generate neutralizing mAbs against virus infection.

bioengineering↗

bioRxiv2021

Vaccinia virus-based vaccines confer protective immunity against SARS-CoV-2 virus in Syrian hamsters

COVID-19 in humans is caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that belongs to the beta family of coronaviruses. SARS-CoV-2 causes severe respiratory illness in 10-15% of infected individuals and mortality in 2-3%. Vaccines are urgently needed to prevent infection and to contain viral spread. Although several mRNA- and adenovirus-based vaccines are highly effective, their dependence on the "cold chain" transportation makes global vaccination a difficult task. In this context, a stable lyophilized vaccine may present certain advantages. Accordingly, establishing additional vaccine platforms remains vital to tackle SARS- CoV-2 and any future variants that may arise. Vaccinia virus (VACV) has been used to eradicate smallpox disease, and several attenuated viral strains with enhanced safety for human applications have been developed. We have generated two candidate SARS-CoV-2 vaccines based on two vaccinia viral strains, MVA and v-NY, that express full-length SARS-CoV-2 spike protein. Whereas MVA is growth-restricted in mammalian cells, the v-NY strain is replication-competent. We demonstrate that both candidate recombinant vaccines induce high titers of neutralizing antibodies in C57BL/6 mice vaccinated according to prime-boost regimens. Furthermore, our vaccination regimens generated TH1-biased immune responses in mice. Most importantly, prime-boost vaccination of a Syrian hamster infection model with MVA-S and v-NY-S protected the hamsters against SARS-CoV-2 infection, supporting that these two vaccines are promising candidates for future development. Finally, our vaccination regimens generated neutralizing antibodies that partially cross-neutralized SARS-CoV-2 variants of concern.

immunology↗