RBD-specific single-chain antibody protects against acute lung injury in mice

As SARS-CoV-2 variants continue spreading globally, the discovery of broad spectrum therapeutically active antibodies with retaining good protective activity is a global priority. It was reported that infection with SARS-CoV-2 could cause acute lung injury (ALI) in clinical investigations. Therefore, we discovered that anti-RBD scFv is effective against SARS-CoV-2-induced ALI. To begin, we utilized the receptor binding domain (RBD) of spike glycoprotein as a target to produce single-chain antibodies (scFvs) through an intensive phage display technology. The binding affinity and inhibitory effect of the scFvs were evaluated via ELISA and flow cytometry. Moreover, anti-RBD scFv No.35 significantly prevented ALI caused by LPS and SARS-CoV-2 spike RBD protein in mouse model. Thus, the anti-RBD scFv will aid the development of potential antibody treatments and reduce the inflammatory response of SARS-CoV-2.