Fig.4. DSG2 localization in human epithelial cells and interaction with Ad3.

a) Immunohistochemistry studies on human colon, foreskin and ovarian cancer paraffin sections with DSG2-specific antibodies. Positive staining appears in brown. b) Confocal microscopy immunofluorescence analysis of polarized human colon cancer T84 cells for DSG2 (green) and the intercellular junction protein Claudin 7 (red). Nuclei are blue. XY and XZ planes are shown. c) Ad3 binding to DSG2. T84 cells were incubated with Cy3-labeled Ad3 particles (red) for 15 minutes, washed, and subjected to confocal microscopy. The upper XZ image is a higher magnification. Note that at least two (green) DSG2 signals are associated with one (red) Cy3-Ad3 signal. d) Confocal microscopy of normal human small airway epithelial cells (not grown in Transwell chambers). Cells were incubated with Cy5-labelled PtDd for 15 min and then washed with PBS. The upper XZ panel shows co-localization of DSG2 (red) and E-cadherin (green). The lower XZ panel is the same image showing purple Cy5-PtDd signals co-localized with green E-cadherin signals. The XY panel shows purple (PtDd) and green E-cadherin channels. Thin arrows mark membrane localized PtDd, thick arrows label cytoplasmic DSG2. e) Confocal microscopy immunofluorescence analysis of human cervical carcinoma HeLa cells (upper XZ and XY panels) and HeLa cells incubated for 15 min with Cy3-Ad3 (lower XZ panel).

Scale bars for all confocal microphotographs are 20 µm.