Figure 8

Co-localization of EGFR and F-actin at the periphery of C. trachomatis inclusion. (A) HeLa cells were infected with C. trachomatis for 24 h, fixed and processed for confocal imaging to detect C. trachomatis (blue), F-actin (green) and EGFR (red). The merged image shows co-localization of EGFR and F-actin as illustrated by the yellow signal. Dashed box represents the inclusion area, solid box represents area and direction of intensity profile measurement in (C). Scale bars are 5 μm and 2 μm in whole cell and inclusion area images, respectively. (B) nMDP color maps showing heat maps of co-localization areas in whole cell and inclusion area images. Both cell and inclusion boundaries show similar evidence of co-localization ranging from moderate to intense. (C) Intensity profiles of C. trachomatis, EGFR, and F-actin from cell boundary to cell boundary across the inclusion. EGFR and F-actin signals rise and fall in similar patterns along the inclusion boundary (located at approximately 6 μm and 18 μm on the x-axis) indicating co-localization in a similar manner as at the cell boundary (located at approximately 3 μm and 21 μm on the x-axis). (D) Comparison of co-localization parameters between inclusion area images and non-inclusion area images (details in the legend for Additional file 3: Figures S14-S20). All five parameters show significant increase of co-localization in inclusion areas compared with non-inclusion areas. Data presented represent the mean ± standard deviation; n = 8 images within each subset, ***p < 0.001.