Anti SARS-CoV (2003) antibody – Cross-reacts with COVID-19 – Human Fc

General information on Anti-SARS-CoV antibody, cross-reacts with SARS-CoV2

The anti-SARS-CoV antibody (CR3022) is a monoclonal Covid antibody initially identified against the SARS coronavirus of 2003 and originally isolated from a convalescent SARS patient. This antibody targets the Spike protein which is responsible for binding the human cell surface angiotensin-converting enzyme 2 (ACE2) and mediates the virus internalization. Therefore, the Spike protein represents the major antigen of coronaviruses. More specifically, the antibody recognizes the receptor-binding domain (RBD) of the Spike protein, which interacts directly with the ACE2 receptor. Therefore, the Spike protein and its RBD domain constitute attractive targets for antibodies development to efficiently neutralize the SARS-CoV2 infection.
In recent studies, the relatively high identity of RBD in SARS-CoV2 and SARS-CoV suggests that certain anti-SARS CoV antibodies could be effective in neutralizing SARS-CoV2 of 2019. In fact, the anti-SARS-CoV antibody (CR3022) has been shown to bind with the SARS-CoV2 RBD of Spike protein. More specifically, structural studies have shown that this antibody does not compete with ACE2 for the binding to RBD of SARS-CoV2. It suggests that this antibody recognizes an epitope which does not overlap with the ACE2 binding site. Unlike this anti-SARS-CoV antibody CR3022, most known SARS RBD-targeted antibodies are in competition with ACE2 for binding to RBD. This difference in epitope recognition can be used to combine this Covid antibody to other anti-SARS-CoV antibodies to efficiently target the Spike protein. For example, it has been shown during SARS-COV studies that the combination of monoclonal antibody CR3022 with another antibody CR3014 showed a neutralization of SARS-CoV in a synergistic way by targeting different epitopes on the spike receptor-binding domain.
Altogether, the anti-SARS-CoV cross-reacts with SARS-CoV2 suggesting its potential to be developed as therapeutics in combination with other neutralizing antibodies, to form an interesting Covid19 cocktail therapy.