Fig. 7: Ileal distribution of fgTiO₂ following Salmonella challenge.

a, b Single-cell image analysis of tilescanned confocal reflectance images collected from transverse sections of mouse ileal tissue from the fgTiO₂-exposed, ΔaroA-Salmonella-infected treatment group (+28-day timepoint, n = 3 animals; FR denotes follicular region with no follicle-associated epithelium). b As in Fig. 6, the subepithelial dome (SED) regions were largely devoid of fgTiO₂ with the majority of the positive cells located at the follicle base in the pigment cell zone or in the interfollicular regions (fgTiO₂-positive cells in the Peyer's patches are displayed in red). b In contrast to all previous data collected without ΔaroA-Salmonella exposure, fgTiO₂-positive cells were now also present in the villous mucosa (VM) (displayed in white). c Montaging positive events from villous mucosa regions showed that particle loading was low compared to Peyer’s patch cells with the majority containing single reflectant foci. d High resolution imaging of optically cross-sectioned villi confirmed reflectant foci deep in the lamina propria in the same manner as observed in humans (Fig. 1c). e The majority of the fgTiO₂-positive events in the villous mucosa also displayed the same autofluorescence signature as was observed in the particle-recipient cells of the SED. The image-data presented in c-e were collected from ileal sections from n = 3 mice. Scale bars: a, b = 250 μm; c–e = 20 μm.