Figure 1
From: Subversion of human intestinal mucosa innate immunity by a Crohn’s disease-associated E. coli
AIEC LF82 invades human normal colonic mucosa innate immune-resident cells. Detection of LF82-GFP in explant cultures of human normal colonic mucosa after a 4-h incubation. (a) Immunoperoxidase staining on paraffin sections with anti-GFP antibodies shows the presence of GFP-bacteria (brown) at the apical pole of the epithelial lining (arrows) and also in the lamina propria (dotted circle), in the subepithelial area where numerous CD68+ macrophages are present (right). Untreated cultures (not infected with LF82-GFP) served as a negative control for GFP staining. (b, c) Immunofluorescence detection of GFP on frozen sections (b) and on cytospin preparations of cells isolated from the colonic mucosa explants after collagenase digestion (c) confirms the presence of GFP bacteria (green) within a few epithelial cells (arrowhead) and lamina propria mononuclear cells resembling macrophages (arrows). (d) Gram stain on cytospin preparations shows bacteria within vacuoles (arrows). (e) CD68 immunofluorescence staining shows the presence of LF82 (green) in some CD68+ lamina propria macrophages (red, arrows). Nuclei appear in blue.
