A. Sholukh, A. Fiore-Gartland, E. S. Ford, Y. Hou, L. V. Tse, F. Lempp, H. Kaiser, R. Saint Germain, E. Bossard, J. J. Kee, K. Diem, A. Stuart, P. Rupert, C. Brock, M. Buerger, M. Doll, A. Randhawa, L. Stamatatos, R. Strong, C. McLaughlin, K. Jerome, R. Baric, D. Montefiori, L. Corey
medRxiv, 2020
Determinants of protective immunity against SARS-CoV-2 infection require the development of well-standardized, reproducible antibody assays to be utilized in concert with clinical trials to establish correlates of risk and protection. This need has led to the appearance of a variety of neutralization assays used by different laboratories and companies. Using plasma samples from COVID-19 convalescent individuals with mild-to-moderate disease from a localized outbreak in a single region of the western US, we compared three platforms for SARS-CoV-2 neutralization: assay with live SARS-CoV-2, pseudovirus assay utilizing lentiviral (LV) and vesicular stomatitis virus (VSV) packaging, and a surrogate ELISA test. Vero, Vero E6, HEK293T cells expressing human angiotensin converting enzyme 2 (hACE2), and TZM-bl cells expressing hACE2 and transmembrane serine protease 2 (TMPRSS2) were evaluated. Live-virus and LV-pseudovirus assay with HEK293T cells showed similar geometric mean titers (GMTs) ranging 141-178, but VSV-pseudovirus assay yielded significantly higher GMT (310 95%CI 211-454; p < 0.001). Fifty percent neutralizing dilution (ND50) titers from live-virus and all pseudovirus assay readouts were highly correlated (Pearson r = 0.81-0.89). ND50 titers positively correlated with plasma concentration of IgG against SARS-CoV-2 spike and receptor binding domain (RBD) (r = 0.63-0.89), but moderately correlated with nucleoprotein IgG (r = 0.46-0.73). There was a moderate positive correlation between age and spike (Spearman's rho=0.37, p=0.02), RBD (rho=0.39, p=0.013) and nucleoprotein IgG (rho=0.45, p=0.003). ND80 showed stronger correlation with age than ND50 (ND80 rho=0.51 (p=0.001), ND50 rho=0.28 (p=0.075)). Our data demonstrate high concordance between cell-based assays with live and pseudotyped virions.
Cited by 10 publications.
Field of study: Medicine