Fig. 1

Disruption of epithelial integrity by Omicron BA.1 or BA.2 can be avoided by GlyPerA™ treatment. a Pseudostratified epithelia were infected by apical addition of SARS-CoV-2 BA.1 and BA.2 with or without GlyPerA™ treatment and incubated for 48 h. GlyPerA™ solution was added pure or diluted (1/100) 5 min prior infection (GlyPerA pure PRE Omicron, GlyPerA dil. PRE Omicron), and the diluted solution in addition simultaneous with (GlyPerA dil. SIM Omicron) or 45 min post (GlyPerA dil. POST Omicron) infection. TEER was measured on 1 dpi (left) and 2 dpi (right) using a EVOM volt-ohm-meter. TEER in Ω/cm² was determined for all conditions (UI, Omicron, GlyPerA pure PRE Omicron, GlyPerA dil. PRE Omicron, GlyPerA dil. SIM Omicron, GlyPerA dil. POST Omicron) and plotted on a bar graph. Bars represent the mean + SD from 3 independent pseudostratified epithelia measured in triplicates. Statistical significance was calculated using One-way ANOVA with Tukey’s multiple comparisons test. To further validate the drop in TEER, immunofluorescence analyses were performed to stain for the tissue integrity. For this, 2 dpi tissue models were stained using Hoechst (nuclei, blue), acetylated tubulin (cilia, red), MUC5AC (mucus-producing cells, orange) and virus (SARS-CoV-2, green). b Viral RNA was measured from UI, Omicron, GlyPerA pure PRE Omicron, GlyPerA dil. PRE Omicron, GlyPerA dil. SIM Omicron, GlyPerA dil. POST Omicron cultures of pseudostratified epithelia on 3 dpi. The experiment was repeated at least 3 times and statistically significantl differences were determined by one-way ANOVA with Tukey´s multiple comparisons test. All values are means ± SD. In a and b *P < 0.05, **P < 0.01, ***P < 0.001