Secretion of ExoT was not sufficient to cause FOCI formation.

<p>Mice were infected with PAK+S(R146A/E379A/E381A)bla or PAKΔS+S(R146A/E379A/E381A)bla. At 23 hr post-infection, mice were sacrificed, and their lungs were removed, stained, and sectioned to determine the localization of injected type I pneumocytes. A) Type I pneumocyte injection by PAK+S(R146A/E379A/E381A)bla (ExoS⁺, ExoT⁺) compared to PAKΔS+S(R146A/E379A/E381A)bla (ExoT⁺). Each data point represents a tissue section. One tissue section was analyzed per lung lobe, with at least two lobes analyzed per mouse and 3 mice per condition, for a total of at least 6 tissue sections per condition. Bars indicate medians. B) Representative image of a FOCI from a mouse infected with PAK+S(R146A/E379A/E381A)bla (ExoS⁺, ExoT⁺). Injected type I pneumocytes are outlined in white. Scale bar represents 100 μm. C) Representative image of a FOCI from a mouse infected with PAKΔS+S(R146A/E379A/E381A)bla (ExoT⁺). Injected type I pneumocytes are outlined in white. Scale bar represents 50 μm.