Fig. 5. Immunohistological visualization of engineered EcN strains in tissue sections.

These sections are taken from proximal colons of mice receiving different bacteria. Sectioning protocol was designed to preserve mucus and luminal content. Sections were stained with fluorescently labeled antibodies: anti-E-cadherin (green), anti-Muc2 (red), and anti-LPS (blue). The first column shows bright-field images of the sections. The last column shows an overlay of all stains. The white dotted lines represent the boundary of the epithelium and mucus layers. The leftmost parts represent the epithelium, the center parts represent the mucus layers and the rightmost parts represent the lumen (scale bar = 100 μm).