Characterization of SARS-CoV-2 Specific Antibodies in COVID-19 Patients Reveals Highly Potent Neutralizing IgA
Dr. Weihong Zeng’s manuscript titled with "Characterization of SARS-CoV-2-specific antibodies in COVID-19 patients reveals highly potent neutralizing IgA" was published online at Signal Transduction and Targeted Therapy on 29th Junary, 2021. Congratulations.
The co-first authors of this paper are Weihong Zeng, Huan Ma and Chengchao Ding. Prof. Tengchuan Jin and Prof. Yong Gao are corresponding authors. Congratulations to all authors.
Keywords: COVID-19, SARS-CoV-2, antibody purification, IgA, neutralization assay
The current pandemic of coronavirus disease 2019 (COVID-19) is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). We and others previously found a surprisingly early serum IgA antibody response in the COVID-19 patients, but the contribution of the IgA antibody towards virus neutralization with respect to other antibody isotypes is unknown. In this study, we reported that IgG is the most abundant isotype, it appears following by IgA and IgM. Here, we purified SARS-CoV-2 Nucleocapsid protein (NP) and spike protein receptor binding domain (RBD) specific-IgA, IgM and IgG from a pool of 50 COVID-19 convalescent patients’ serum. The RBD-specific antibodies of all isotypes can block hACE2 binding to RBD, with the IC50 values ranging from 4.68 μg/mL to 9.36 μg/mL. Furthermore, all isotopes can neutralize SARS-CoV-2 infection of Vero-E6, with the IgA, IgM and IgG neutralization ND50 value of 2.42 μg/mL, 20.31 μg/mL, 39.73 μg/mL, respectively. Our studies demonstrate that IgA antibodies to SARS-CoV-2 RBD in COVID-19 patients are potent neutralizing antibodies.