Diagnostics (Basel) . Use of Lateral Flow Immunoassay to Characterize SARS-CoV-2 RBD-Specific Antibodies and Their Ability to React with the UK, SA and BR P.1 Variant RBDs

[tetano]

Diagnostics (Basel)


. 2021 Jun 30;11(7):1190.
doi: 10.3390/diagnostics11071190.
Use of Lateral Flow Immunoassay to Characterize SARS-CoV-2 RBD-Specific Antibodies and Their Ability to React with the UK, SA and BR P.1 Variant RBDs


Enqing Tan ¹ , Erica Frew ¹ , Jeff Cooper ² , John Humphrey ² , Matthew Holden ¹ , Amanda Restell Mand ¹ , Jun Li ² , Shaya Anderson ² , Ming Bi ² , Julia Hatler ² , Anthony Person ² , Frank Mortari ³ , Kevin Gould ⁴ , Shelly Barry ¹



Affiliations

• PMID: 34208912
• DOI: 10.3390/diagnostics11071190

Abstract

Identifying anti-spike antibodies that exhibit strong neutralizing activity against current dominant circulating variants, and antibodies that are escaped by these variants, has important implications in the development of therapeutic and diagnostic solutions and in improving understanding of the humoral response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We characterized seven anti-SARS-CoV-2 receptor binding domain (RBD) antibodies for binding activity, pairing capability, and neutralization activity to SARS-CoV-2 and three variant RBDs via lateral flow immunoassays. The results allowed us to group these antibodies into three distinct epitope bins. Our studies showed that two antibodies had broadly potent neutralizing activity against SARS-CoV-2 and these variant RBDs and that one antibody did not neutralize the South African (SA) and Brazilian P.1 (BR P.1) RBDs. The antibody escaped by the SA and BR P.1 RBDs retained binding activity to SA and BR P.1 RBDs but was unable to induce neutralization. We demonstrated that lateral flow immunoassay could be a rapid and effective tool for antibody characterization, including epitope classification and antibody neutralization kinetics. The potential contributions of the mutations (N501Y, E484K, and K417N/T) contained in these variants' RBDs to the antibody pairing capability, neutralization activity, and therapeutic antibody targeting strategy are discussed.

Keywords: ACE2; COVID-19; SARS-CoV-2 variant; epitope binning; lateral flow immunoassay; neutralizing antibody; rapid neutralization test; receptor binding domain (RBD); spike protein; therapeutic antibody cocktail.