Immunoglobulin fragment F(ab')2 against RBD potently neutralizes SARS-CoV-2 in vitro.

Immunoglobulin fragment F(ab')2 against RBD potently neutralizes SARS-CoV-2 in vitro. Antiviral Res. 2020 Jul 10;:104868 Authors: Pan X, Zhou P, Fan T, Wu Y, Zhang J, Shi X, Shang W, Fang L, Jiang X, Shi J, Sun Y, Zhao S, Gong R, Chen Z, Xiao G Abstract COVID-19, which is caused by the emerging human coronavirus SARS-CoV-2, has become a global pandemic that poses a serious threat to human health. To date, no vaccines or specific antiviral drugs have been approved for the treatment of this disease in clinic. Herein, therapeutic antibodies for SARS-CoV-2 were obtained from hyperimmune equine plasma. First, a recombinant SARS-CoV-2 spike protein receptor-binding domain (RBD) was obtained in gram-level quantities through high-cell density fermentation of Chinese hamster ovary cells. Then, the binding of the RBD to the SARS-CoV-2 receptor, human angiotensin-converting enzyme 2, was verified by several biochemical methods. The efficacy of the RBD in triggering antibody response in vivo was subsequently tested in both mice and equines, and the results showed that the RBD triggered high-titer neutralizing antibody production in vivo. Immunoglobulin F(ab')2 fragments were prepared from equine antisera via removal of the Fc region from the immunoglobulins. Finally, a neutralization test with live virus demonstrated that RBD-specific F(ab')2 inhibited SARS-CoV-2 with an EC50 of 0.07 μg/ml and an EC80 of 0.18 μg/ml, showing a potent inhibitory...
Source: Antiviral Research - Category: Virology Authors: Tags: Antiviral Res Source Type: research