Neutralization Assay with SARS-CoV-1 and SARS-CoV-2 Spike Pseudotyped Murine Leukemia Virions

Abstract

Antibody neutralization is an important prognostic factor in many viral diseases. To easily and rapidly measure titers of neutralizing antibodies in serum or plasma, we developed pseudovirion particles composed of the spike glycoprotein of SARS-CoV-2 incorporated onto murine leukemia virus capsids and a modified minimal MLV genome encoding firefly luciferase. These pseudovirions provide a practical means of assessing immune responses under laboratory conditions consistent with biocontainment level 2.

Viral infection neutralization tests: A focus on severe acute respiratory syndrome‐coronavirus‐2 with implications for convalescent plasma therapy

“…However, in a different study, MMLV was able to pseudotype the SARS‐CoV‐2 Spike protein 24 . These differences could be due to the constructs used to express the Spike protein with the former study expressing a full‐length Spike protein, whilst the latter study expressed a Spike protein with a deletion in the C‐terminal 19 amino acid (aa) that could aid better expression as alluded to earlier 33 . In contrast, pLV pseudotyped both glycoproteins efficiently; however, much higher titres of pLV‐G particles were produced.…”

Insights into neutralizing antibody responses in individuals exposed to SARS-CoV-2 in Chile

“…Although the gold standard strategy is the classic virus neutralization assay, which involves handling the isolated virus under a biosafety level 3 (BSL-3) environment, this type of facility is scarce and of limited access for academic research in Chile. However, the use of envelope-defective reporter viruses such as HIV-1 ( 31 , 32 ), vesicular stomatitis virus (VSV) ( 33 , 34 ), or murine leukemia virus ( 35 ), which can be assembled with heterologous enveloped glycoproteins (pseudotyped particles), represent safe, reliable, robust, fast, sensitive, and successful alternatives to measure NAb titers in plasma samples in a BSL-2 environment. In this work, we describe the characterization, implementation, and validation of an HIV-1–based SARS-CoV-2 pseudotype, which we used in a 96-well plate format to detect and quantify the presence of neutralizing activity in plasma or serum samples from individuals exposed to SARS-CoV-2 in Chile.…”

Successful transfer of anti–SARS-CoV-2 immunity using convalescent plasma in an MM patient with hypogammaglobulinemia and COVID-19

“…Assays were performed as described, using plasmid HIV-1-δ-env-luc with pSARS-Cov-2-S for patient samples and MLV-Ψ(−)Env(-), l -luc-SN and pSARS-Cov-2-S for donor plasma. 18 …”