Anti-CoV-S2 domain (D7) antibody

General information on Anti-CoV-S2 domain (D7) antibody

The majority of COVID-19 candidate antibody therapeutics in the clinical development pipeline almost exclusively bind to the S1 subunit and the receptor-binding domain (RBD) of SARS-CoV-2. This region of the new coronavirus was found to be crucial for initiating viral infection. The S1 subunit binds to human cell surface receptor ACE2 through the RBD, thus leading to viral internalization and starting the viral replication cycle.
Despite its key role in infection, therapeutics that focus solely on this region may have the unintended effect of generating a selective pressure and causing the development of escape mutants with unpredictable consequences for the evolution of the current pandemic. For this reason, experts are urging us to pursue other clinically relevant targets such as the S2 subunit found in the C-terminal region of the spike glycoprotein.
This subunit becomes readily exposed after the formation of the RBD-ACE2 complex which further leads to the proteolytic cleavage of the spike by human furin proteases. After exposure, the S2 suffers significant conformational changes driven by the presence of two identical and inverted heptad repeats (HR1 and HR2).
The anti-CoV-S2 (D7) antibody was designed to target this subunit and aid current efforts to better understand the COVID-19 pathology. It is a fully human IgG immunoglobulin obtained from screening a vast COVID-19 human antibody library (LiAb-SFCOVID-19™) by phage display using recombinantly expressed S2 protein as the target.
The antibody’s affinity towards S2 was further confirmed on ELISA tests using the purified protein. Moreover, its stability and ease of production were determined by transient expression in the mammalian CHO-based system, XtenCHO™.