Cell boundary detection for quantitative studies of the role of tetraspanin CD82 in cell-cell adhesion

Cell-cell adhesion is mediated by interaction of a number of protein complexes residing on the cell plasma membranes. Disruption of these complexes affects structural and functional integrity of tissues. It has been hypothesized that a membrane protein tetraspanin CD82, a known metastasis suppressor, may play a role in regulating cell adhesion. Two proteins of interest (PG and Dsg2) have been fluorescently tagged in cells expressing CD82 and in control cells, and imaged over the course of three hours. This paper describes a fully automatic method for quantitative analysis of PG and Dsg2 fluorescence. Cell boundaries are detected by the application of secondorder steerable Gaussian filters. Cells are then segmented by closing the detected boundaries. Fluorescence levels
are computed from a region lying around ± 1.5 microns from the centre-line between adjacent cells. Mean fluorescence levels obtained for thirty three cell images show that both the levels and the dynamics are different between the control and the CD82-expressing cells, which suggests that CD82 may play a role in cell-cell adhesion.