MUC1 is a receptor for the Salmonella SiiE adhesin that enables apical invasion into enterocytes
Fig 5
The Salmonella SiiE adhesin is responsible for MUC1-mediated invasion.
(A) Immunofluorescence confocal microscopy imaging of confluent HT29-MTX cells infected with S. Enteritidis wild type and siiE knockout bacteria (mCherry, red) stained for MUC1 (214D4, green) and nuclei (DAPI, blue). (B) Immunofluorescence confocal microscopy imaging as above with non-confluent HT29-MTX cells. (C) Quantification of invaded intracellular S. Enteritidis wild type and siiE knockout bacteria. Confluent HT29-MTX cells were incubated with S. Enteritidis for 1h at MOI 15 and subsequently treated with gentamicin (300 μg/ml). Cells were lysed and surviving intracellular bacteria were quantified by colony counts. Invasion is expressed as percentage of initial inoculum. Values are the mean ± SEM of three independent experiments performed in triplicate. Statistical analysis was performed by Student’s t-test using GraphPad Prism software. * p<0.05; ns, not significant. White scale bars represent 20 μm.