Extended Data Fig. 8: Membrane-tethered mucins restrict SARS-CoV-2 entry and MUC4 GOF Calu-3 cells possess a denser glycocalyx.

a. Time course tracking infection levels of VSV-CoV-2-S encoding GFP. Infection of NTG, and MUC1 or MUC4 overexpression cell lines with and without StcE treatment, n = 5 biological replicates. The above Incucyte trace is the full dataset for the summary displayed in Fig. 7E. b-c. A glycocalyx density assay measuring the mesh size of the Calu-3 glycocalyx on (b) NTG or (c) MUC4 GOF lines. The assay uses a live-cell two-color fluorescent imaging approach using two types of probes of known sizes: green fluorescent test probes of various sizes as well as Texas-Red dextran with a known size of 2 nm⁶⁸. Scale bars indicate 5 µm. d. Quantification of probe exclusion by the Calu-3 glycocalyx. For each sized probe n = 5 biological replicates (with the exception of the NTG 500 nm probe, with n = 3). For all panels: error bars denote mean ± s.e.m., significance is indicated as: n.s.=not significant, *= P < 0.05, **= P < 0.01, ***=P < 0.001, ****= P < 0.0001.