DOI 10.1007/s00430-009-0111-zORIGINAL INVESTIGATION InXuence of Pseudomonas aeruginosa quorum sensing signal molecule N-(3-oxododecanoyl) homoserine lactone on mast cells

Abstract Quorum sensing system is a cell-to-cell com-munication system that plays a pivotal role in virulence expression in bacteria. Recent advances have demonstrated that the Pseudomonas aeruginosa quorum sensing mole-cule, N-3-oxododecanoyl homoserine lactone (3OC12-HSL), exerts eVects on mammalian cells and modulates host immune response. Mast cells (MCs) are strategically located in the tissues that are constantly exposed to external stimulus. Therefore, it is very much possible that 3OC12-HSL may interact with MCs. Little is known, however, about speciWc eVects of 3OC12-HSL on MCs. To address this, we investigated the inXuence of 3OC12-HSL on cell viability, apoptosis, intracellular calcium and cytokine release in MCs. We found that at high concentrations (100 M), 3OC12-HSL inhibited proliferation and induced apoptosis in P815. The 3OC12-HSL treatment signiWcantly increased intracellular calcium release in both P815 and HMC-1. We also observed that 3OC12-HSL-induced hista-mine release and degranulation in HMC-1 cells. Further-more, 3OC12-HSL-induced IL-6 production at lower concentrations (6.25–12.5 M) but steadily reduced IL-6 production at high concentration (50–100 M). These data demonstrate that P. aeruginosa 3OC12-HSL aVects MCs function