The expression, purification, and characterization of anti-spike protein 6B1 monoclonal antibody

Abstract

In late 2019, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was identified and announced as a pandemic. It is a zoonotic disease that originated from bats and causes severe pneumonia and acute respiratory distress syndrome (ARDS) in humans. The virus binds to the host receptor angiotensin converting enzyme-2 (ACE2) via its trimeric spike glycoprotein. The spike glycoprotein plays a critical role in receptor binding and viral fusion. Thus, various monoclonal antibodies (mAbs) have been developed targeting the spike glycoprotein. However, the continuous emergence of new mutated variants makes the available mAbs treatment less active. Our strategy was to generate mAbs that can neutralize SARS-CoV-2 using hybridoma technology. 6B1 mAb, a mouse Immunoglobin (IgG), was successfully generated, expressed, purified, and characterized. The results indicate that 6B1 IgG has a binding affinity towards the receptor binding domain (RBD) of spike glycoprotein. Multiple attempts were made to form a complex between 6B1 Fab and spike glycoprotein. However, the obtained result indicates that no complex was successfully formed. Therefore, the complexing conditions must be optimized, and further evaluations are required, including neutralization activity and Cryo-electron microscopy (Cry-EM) to obtain a structural landscape of 6B1 mAb against SARS-CoV-2 spike protein.