The Role of Antibodies in the Treatment of SARS-CoV-2 Virus Infection, and Evaluating Their Contribution to Antibody-Dependent Enhancement of Infection

Figure 1. The crystal structure of SARS-CoV-2 S protein complexed with ACE2 receptor retrieved from the Protein Data Bank (PDB), PDB entry 7DF4. The structure was visualised by PyMOL (The PyMOL Molecular Graphics System, Version 1.7.4 Schrödinger, LLC.). The complex is displayed as (A) surface and (B) loops. The S protein assembles into trimers (coloured red, blue, and green) on the virion surface to form a distinctive “corona”. The RBD domain of the S protein (cyan) binds to the human ACE2 receptor (orange) to promote attachment and fusion.

Figure 2. Schematic representation of antibody neutralisation versus ADE. Panel A indicates the extrinsic ADE mechanism, showing enhanced viral entry. The intrinsic ADE pathway leads to increased virus production by inhibition of the type1 interferon. Figure modified from Zhou et al. [67].