Immunostaining of claudin-1 and ZO-1 <i>in vivo</i>.

<p>Immunostaining on mouse colonic epithelial cells was performed 24 hours after mouse infection with PhoP^c, AvrA⁻ or AvrA⁻/AvrA⁺. Experimental groups: Control: normal mouse cells; PhoP^c: mice infected with parental PhoP^c with sufficient AvrA protein expression; AvrA⁻: mice infected with PhoP^c AvrA mutant. Tissues were fixed, permeabilized, and stained with claudin-1 and ZO-1 antibodies, followed by A488 secondary antibodies, A594 secondary antibodies, and DAPI. AvrA⁻ infected mice display disruption of the TJ structure. Arrows in Panel ZO-1 show the red staining of ZO-1 protein on the top of the intestinal crypts. White arrow in Panel AvrA- DAPI shows lymphoid aggregation. Please note disorganized structure of ZO-1 in the colonic epithelial cells infected with AvrA- bacterial strain. Images shown are from a single experiment and are representative of three separate experiments. <i>n</i> = 3 animals in each experimental group.