P. aeruginosa infection up-regulated expression of PRXV protein in cultures of the A549 epithelial cells, and co-cultures of A549 and RAW264.7, only in the presence of serum. A: Western blot analyses of PRXV expression in co-cultures of the A549 and RAW 264.7 cells, stimulated with PAO1 without serum, actin used as control. No up-regulation of PRXV occurred in cells. Note, that the amount of RAW264.7 used alone, was equal to the amount of cells, added to the A549 cells (5:1 – A549:RAW). B: Expression of PRXV was up-regulated in the epithelial cells following contact with bacteria (PAO1) in the presence of serum and in co-culture with immune cells (RAW 264.7). Western blot analyses of PRXV expression in co-cultures. Immunostaining for actin used as control. C: Expression of PRXV is moderately up-regulated in the A549 cells by P. aeruginosa PAO1 and by co-culture with RAW 264.7, with and without bacterial inflammation. Quantitative photometric data from Western blot analyses performed in 3 separate cultures. * – p < 0.05.