Fig. 5

IgG-bound bacteria from IBD patients demonstrate invasive characteristics in human intestinal cell culture. Invasive capacity of Burkholderia cepacia, Burkholderia vietnamiensis, Burkholderia ambifaria, Flavonifractor plautii, Ruminococcus sp. patient 94 (CD), Ruminococcus sp. patient 102 (non-IBD), and Pseudomonas protogens in the HT29-MTX-E12 cell line was examined by a fluorescence in situ hybridization (FISH) using a bacterial probe (orange), the e-cadherin (green) antibody, and DAPI (blue) stain (invasive bacteria identified by confocal microscopy Z-stacking are marked by white arrows) and b quantified using the gentamicin protection assay. c Activation of immune response was examined by qPCR of immune markers IL1β and IL6. LPS and AIEC were utilized as positive controls of immune activation and infection, respectively. Microscopy figures were imaged at × 63 magnification using a Leica SP5 confocal microscope. Statistical analysis was performed by two-tailed t test; *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001; NI: no infection control