Co-culture of the alveolar epithelial cells with murine macrophages and stimulation by P. aeruginosa moderately upregulated PRXV expression, as determined by IHC and confocal microscopy. A-D: Typical confocal microscopy images of the A549 cultures, stained for PRXV (green fluorescence, FITC labeled secondary antibody) and co-stained with Propidium Iodine for DNA. A – control cultures (A549, no infection), B – cultures infected with PAO1; C – control co-cultures (A549 + RAW, no infection), D – cultures (A549+RAW264.7), infected with PAO1. At the bottom of each image, a diagram of the distribution of fluorescence intensity along the selected segment (red bar) is given. Green line is PRXV fluorescence intensity, red line is DNA fluorescence intensity. Original magnification × 100. E: MEAN data of relative fluorescence intensity for PRXV staining in co-cultures of the A549 and RAW264.7 cells. F: The RAW264.7 cells expressed higher amounts of PRXV than the A549 cells in co-cultures. Confocal microscopy images of co-cultures – both types of cells are indicated by labeled arrows. Staining for PRXV with FITC-labeled secondary antibody (green fluorescence). Co-staining – Propidium Iodine (red).