Isotyping and quantitation of the humoral immune response to SARS-CoV-2. Issue 12 (June 2022)

• Record Type: Journal Article
• Authors: Goyins, Krystal A; Yu, Jieh-Juen; Papp, Sara B; Beddard, Rachel; Murthy, Ashlesh K; Chambers, James P; Arulanandam, Bernard P
• Is Part Of: Experimental biology and medicine. Volume 247:Issue 12(2022)
• Page Start: 1055
• Page End: 1060
• Publication Date: 2022-06
• Subjects: COVID-19 -- antibody -- neutralization -- variant -- SARS-CoV-2 -- plasma; Physiology -- Periodicals; Biology, Experimental -- Periodicals; Medicine, Experimental -- Periodicals; 610.72
• DOI: 10.1177/15353702221084966
• Languages: English
• ISSNs: 1535-3702

Abstract

Understanding the immune response to SARS-CoV-2 is important for development of effective diagnostics and vaccines. We report here a broad antibody response to SARS-CoV-2 spike protein receptor binding domain (RBD) in 100 convalescent patient plasma samples. Antibody isotypes IgA, IgM, and IgG exhibited significantly higher anti-RBD titers when compared to SARS-CoV-2 negative controls. IgG subtyping indicated IgG1 and IgG3 to be most abundant. Greater than 90 % of SARS-CoV-2 positive plasma samples tested exhibited significant neutralization capacity using a surrogate virus neutralization assay. Of the IgG subclasses, IgG1 and IgG3 exhibited the highest viral neutralization capacity; whereas, IgG2 and IgG4 viral neutralization was not observed. Comparison of SARS-CoV-2 elicited total IgG binding to emerging variant (alpha, beta, and delta) RBDs indicated decreased binding. Furthermore, neutralization by SARS-CoV-2 convalescent plasma of delta and omicron variant RBDs was significantly decreased suggesting that neutralizing antibodies in convalescent plasma are less effective in inhibiting variants currently in circulation.