Overview of Pseudovirus Neutralization Assay
Pseudovirus refers to a retrovirus that can integrate the envelope glycoprotein of another virus to form a virus with an exogenous viral envelope, and the genome retains the characteristics of the retrovirus itself.
Some viruses, such as the new coronavirus SARS-CoV-2 (2019-nCoV), SARS-CoV, Ebola virus, H5N1, etc., are highly infectious and highly pathogenic, which have brought great difficulty and danger to the screening of neutralizing antibodies. Compared with natural virus, the pseudovirus can only infect cells in a single round, has broad host range, high titer, and is not easily inactivated by serum complement.
In the pseudovirus luciferase assay (PVLA), the inhibition of viral entry into cells by NtAb is correlated to the decreased levels of luciferase signals in the cells. This method is superior to the conventional assay because of its simplicity, higher sensitivity and accuracy, suitability for high-throughput experiments. In addition, no live virus is used during the test. Therefore, this method could be used as an alternative for safely conducting serologic studies in a rapid response in assessing the threat posed by SARS-CoV-2.
Fig1. Pseudotype-Based Neutralization Assays Principle
SARS-CoV-2 Pseudovirus Neutralization Assay Service
293T/ACE2 cells (ACE2 overexpression 293T cells)
> 100 μg antibody (concentration> 0.2 mg/mL, sterile, pH7.1-7.4) or 100 μL inactivated serum.
At present, we have successfully developed a SARS-CoV-2 pseudovirus with HIV lentiviral vector. The Luciferase luminescence value reaches 106 RLU after the pseudovirus infection, which can meet the requirement for SARS-CoV-2 neutralization assay and screening of neutralization antibodies or serum.