Quantitative regulation of the thermal stability of enveloped virus vaccines by surface charge engineering to prevent the self-aggregation of attachment glycoproteins

Authors: SHANG, YU - Hubei Academy Of Agricultural Sciences; LI, LI - Hubei Academy Of Agricultural Sciences; ZHANG, TENGFEI - Hubei Academy Of Agricultural Sciences; LUO, QINGPING - Hubei Academy Of Agricultural Sciences; Yu, Qingzhong; ZENG, ZHE - Hubei Academy Of Agricultural Sciences; LI, LINTAO - Hubei Academy Of Agricultural Sciences; JIA, MIAOMIAO - Hubei Academy Of Agricultural Sciences; TANG, GUOYI - Hubei Academy Of Agricultural Sciences; FAN, SANLIN - Hubei Academy Of Agricultural Sciences

Submitted to: PLoS Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2022
Publication Date: 6/9/2022
Citation: Shang, Y., Li, L., Zhang, T., Luo, Q., Yu, Q., Zeng, Z., Li, L., Jia, M., Tang, G., Fan, S. 2022. Quantitative regulation of the thermal stability of enveloped virus vaccines by surface charge engineering to prevent the self-aggregation of attachment glycoproteins. PLoS Pathogens. 18(6). Article e1010564. https://doi.org/10.1371/journal.ppat.1010564.
DOI: https://doi.org/10.1371/journal.ppat.1010564

Interpretive Summary: The thermal stability of enveloped virus vaccines, such as influenza and Newcastle disease virus (NDV) vaccines, significantly affects vaccine storage life and protective efficacy when exposed to environmental heat. To improve enveloped viral vaccine “shelf-life” and potency, in the present study, we investigate the mechanism for viral thermostability using NDV vaccines as a model. By sequence analysis and electron microscopy, we identified the negative surface charge of the vial attachment glycoprotein as a critical determinant of viral thermal stability. It prevented the temperature-induced aggregation of glycoprotein and subsequent detachment from the virion surface. Then the virus could bind to and infect cells efficiently after heat treatment. Employing genetic engineering, we increased the negative surface charge of the attachment glycoproteins of NDV and influenza A virus (IAV) vaccines. The engineered live and inactivated vaccines could be used efficiently after storage at 37°C for at least 10 and 60 days, respectively. Based on these data, we proposed a novel surface-charge-mediated mechanism for viral thermal stability, which could be used to design thermal stable enveloped virus vaccines rationally.

Technical Abstract: The development of thermostable vaccines can relieve the bottleneck of existing vaccines caused by thermal instability and subsequent poor efficacy, which is one of the predominant reasons for the millions of deaths caused by vaccine-preventable diseases. Research into the mechanism of viral thermostability may provide strategies for developing thermostable vaccines. Using Newcastle disease virus (NDV) as model, we identified the negative surface charge of attachment glycoprotein as a novel determinant of viral thermostability. It prevented the temperature-induced aggregation of glycoprotein and subsequent detachment from virion surface. Then structural stability of virion surface was improved and virus could bind to and infect cells efficiently after heat-treatment. Employing the approach of surface charge engineering, thermal stability of NDV and influenza A virus (IAV) vaccines was successfully improved. The increase in the level of vaccine thermal stability was determined by the value-added in the negative surface charge of the attachment glycoprotein. The engineered live and inactivated vaccines could be used efficiently after storage at 37°C for at least 10 and 60 days, respectively. Thus, our results revealed a novel surface-charge-mediated link between HN protein and NDV thermostability, which could be used to design thermal stable NDV and IAV vaccines rationally.