Fig 1: UspA1 and UspA2 contribute to the adhesion of M. catarrhalis to BECs To evaluate RV-induced CEACAM1 expression in AECs, differentiated ALI cultures (A) from four epithelial cell donors were infected with RV-A16 for 2 hours and then with M. catarrhalis MC14 for 48 hours. Cell donors are represented by different symbols, and expression is relative to donor 1 (circles) (n = 2 per donor; unpaired t-test test). (B) ALI cultures from donor 1 were infected with RV species (A16, A35, B52, B72, C2 and C15) for 2 hours and then with M. catarrhalis MC14 for 48 hours. CEACAM1 expression was evaluated by qPCR. For (C) ALI cultures were infected with RV-C15 for 16 hours and then with M. catarrhalis. CEACAM1 expression was evaluated at 2, 8, 16, 24, and 36 hours following M. catarrhalis infection (n = 4, multiple unpaired t-tests). (D) Following RV-C15 infection for 16 hours, ALI cultures were incubated with mouse anti-pan CEACAM antibodies for 1 hour before adding M. catarrhalis MC14 for 8 hours. Cell-associated M. catarrhalis were quantified by qPCR. Bars represent geometric mean ± SD (n = 4, unpaired t-test). (E) M. catarrhalis strain MC14 was incubated with mouse anti-UspA antibodies for 1 hour and the mixture was added onto the apical surface of the epithelium for 8 or 24 hours following RV-C15 infection. Cell-associated M. catarrhalis was quantified by qPCR. White bars = no antibodies, black bars = anti-UspA antibodies, grey bars = isotype control (Iso). Bars represent geometric mean ± geometric SD (n = 4; unpaired t-test). *P < 0.05, **P<0.01, ****P<0.0001.