Figure 6

(A) SARS-CoV-2 replication by quantitative PCR in primary bronchial airway epithelial cell cultures from children (n = 14) and adults (n = 10) infected in parallel with SARS-CoV-2 WA-01 alone at MOI = 0.5 (red circles), SARS-CoV-2 infection 72 h following pre-infection with HRV-16 (MOI = 0.5: blue triangles), pre- and concurrent treatment with recombinant IFNβ1 (orange squares), and pre- and concurrent treatment with recombinant IFNλ2 (green diamonds). Viral copy number was quantified by PCR in RNA harvested 96 h after SARS-CoV-2 infection. Pre-infection of primary bronchial AECs with HRV-16 significantly reduced SARS-CoV-2 replication (median copy number 267,264 vs 14,788, p = 0.002). Treatment of bronchial AEC cultures with recombinant IFNβ1 or IFNλ2 also significantly reduced SARS-CoV-2 replication (median copy number 267,264 to 11,947, p = 0.0001; median copy number 267,264 to 11,856, p = 0.0002, respectively). Kruskal–Wallis one-way ANOVA on ranks was used to compare all experimental conditions. Dunn’s test was used for comparisons between SARS-CoV-2 alone and individual experimental conditions. Bars indicate median values. (B,C) In cultures from 3 pediatric donors, AECs were infected either with SARS-CoV-2 alone (red boxplots) or with HRV-16 followed 72 h later by infection with SARS-CoV-2, using three different MOIs (0.5, 0.1, 0.01) of HRV-16 pre-infection (blue box plots) followed by infection with SARS-CoV-2 WA-01, SARS-CoV-2 Delta, or SARS-CoV-2 Omicron each at MOIs of 0.5 or 0.1. Viral copy number was quantified by PCR in RNA harvested from AEC cultures (in duplicate from each donor AEC line) 96 h following infection with SARS-CoV-2 strains. Friedman ANOVA for panels (B) and (C) both p < 0.0001. Post hoc Dunn’s tests: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.