Figure 6.

Clusters of spike glycans can act as mutation-resistant epitopes for SARS-CoV-2 inhibitor design. (A) Schematic display of SARS-CoV-2 mutation and immune escape. Since glycans are heavily conserved on the SARS-CoV-2 spike, it implies that they can act as robust “cold spots” for the development of therapeutics. However, SARS-CoV-2 Omicron strains have mutated significantly to escape immune detection, which implies they could further mutate to compensate for the loss of a single glycan site. Thus, it is necessary to identify clusters of glycans that will effectively eliminate viral infectivity if they are removed from the spike protein, making it far less likely for prophylactics against glycan clusters from losing efficacy against further-mutated SARS-CoV-2 strains. (B,C) Depiction of the two cluster strains that were designed: N17/61/74Q and N122/149/234Q. (D) Direct infectivity of cluster-N-linked glycosylation mutants normalized to wild-type/Wuhan-strain SARS-CoV-2 spike pseudovirus. (E) Trans-infectivity of cluster-N-linked glycosylation mutants normalized to wild-type/Wuhan-strain SARS-CoV-2 spike pseudovirus. The infectivity signal from the N17/61/74Q strain was so poor that the trans-infectivity signal was at the lower limit of detection for our plate reader/instrumentation (Figure S9A,B). (A–C) SARS-CoV-2 spike structures are adapted from PDB ID: 7NT9 by Rosa, A.