Extended Data Fig. 7: Biofilms mechanically damage epithelia while constraining pathogenicity.

A. Experimental design for imaging epithelial damage upon WT and ∆wspF infections in AirGels. AirGels were infected with WT or ∆wspF expressing mNeonGreen, and infections were monitored for 11 hours for the observation of lysis and cell viability (propidium iodide staining). B. Representative maximum intensity projection images showing differences in growth and subsequent epithelial cell lysis by WT (top) and ∆wspF (bottom). Note that after 10 h of infection, WT had completely taken over the surface and had lysed the epithelial cells. By contrast, ∆wspF formed large expanding biofilms that opened up nodules that stretched out within the tissue (white circles). See Supplementary Movies 2 and 3 for full time-lapse visualization of these images. C. Representative maximum intensity projection images showing differences in growth and the killing of epithelial cells by WT (top) and ∆wspF (bottom). Note the uniform cytotoxic effect to the WT due to its faster spreading, while ∆wspF biofilms showed only cytotoxic activity towards epithelial cells in the immediate vicinity of the nodules (white circles). See Supplementary Movie 4 for a full time-lapse visualization of these images. All experiments were performed with CF HBE cells. In B-C, for each strain, infections of two distinct AirGels were visualized, with similar patterns. Abbreviations: PI, propidium iodide; WT, wild-type. The data underlying this figure can be found in the source data available with this manuscript (see Data Availability session).