The Application of a Safe Neutralization Assay for Ebolavirus Using Lentivirus-Based Pseudotyped Virus

Abstract

Background: Ebolavirus (EBOV) is responsible for several EBOV disease (EVD) outbreaks in Africa, with a fatality rate of up to 90%. During 2014-2016, An epidemic of EVD spread throughout Sierra Leone, Guinea and Liberia, and killed over 11,000 people. EBOV began to circulate again in the Democratic Republic of Congo in 2018. Due to the need for a BSL-4 facility to manipulate this virus, the development and improvement of specific therapeutics has been hindered. As a result, it is imperative to perform reliable research on EBOV under lowered BSL restrictions. Methods: Based on lentivirus vector, we developed a safe EBOV pseudotyped virus, which was used into a neutralization assay. The tropism and neutralizing activity of both authentic EBOV and EBOV pseudotyped virus were compared, using three different samples of antibody-based agents against EBOV. Findings: Our results demonstrated that the tropism of EBOV pseudotyped virus was similar to that of authentic EBOV, but with only one infection cycle. After utilizing to neutralization assay in the absence of BSL-4 restrictions, the EBOV pseudotyped virus-based assay showed similar results with the live EBOV neutralization assay and indirect ELISA. Interpretation: The remarkable simplicity and safety of EBOV pseudotyped virus-based neutralization assay highlight its potential to further application in assessment of immunogenicity of EBOV vaccine candidates. Funding: This work was supported by the National Science and Technology Major Projectof the Ministry of Science and Technology of China (grants 2015ZX09102025). Declaration of Interest: The authors have no conflicts of interest to declare. Ethical Approval: All animal studies in this work were approved bythe Animal Care and Use Committee of Chinese People’s Liberation Army (No. SYXK2009-045). All efforts were made to minimize animal suffering.