Cytokinic profile as a tool in the investigation of bacterial-eutcaryotic crosstalk

• Published in: Microbial ecology in health and disease Vol. 20; no. 3; p. 160
• Main Authors: Lazar, V, Chifiriuc, M C, Bleotu, C, Iordache, C, Lixandru, M, Bucur, M, Dracea, O, Larion, C
• Format: Journal Article
• Language: English
• Published: 01.05.2008
• Subjects: Bacteria; Pseudomonas; Pseudomonas aeruginosa
• ISSN: 0891-060X; 1651-2235

Introduction: The human opportunistic pathogen Pseudomonas (P.) aeruginosa employs a complex hierarchy of QS signalling systems, which not only coordinate expression of virulence factors by the bacterium, but also have immunomodulatory effects on the host organism, including modulation of proinflammatory cyto-kines synthesis, phagocytosis and induction of apoptosis. Purpose: To investigate by ELISA assay the changes of pro/anti-inflammatory status of the immune cells in the presence of the P. aeruginosa native and purified QS molecules, in order to identify the potential functional responses of the mammalian cells and the roles of these molecules in the beneficial or pathogenic effects on host cells. Results: Eventhough the cytokines patterns of macrophages and lymphocytes were similar, however the human lymphocytes responded more intensively than macrophages to the tested microbial products. The cell free supernatants of heat-inactivated P. aeruginosa logphase cultures reproduced the cytokine profile induced by purified mediators in concentrations similar to those reported to be accumulated in log phase cultures, inducing a slight anti-inflammatory effect (stimulating the anti-inflammatory IL-10 and inhibiting the main pro-inflammatory IL-1 -alpha). Conclusion: This study demonstrates the ability of bacterial soluble QS signal molecules to modulate the expression of a variety of cytokines and inflammatory molecules produced by the immune cells and the necessity to find QS inhibitors.