Research Institute of Experimental Medicine, St. Petersburg, Russia
Aim. To study the influence of lypopolysaccharide (LPS) of Gram-negative bacterium (Escherichia coli O55:B5) and lysate of Gram-positive bacteria (Streptococcus pyogenes — group A, type M1, strain 40/58) on the level of expression of important surface molecules of monocyte-derived cells from continuous cell line THP-1 and endothelial cells from continuous cell line EA.hy 926. Materials and methods. Expression of surface molecules HLA-DR, CD11b, CD14, CD16, CD32, and CD54 was assessed using FITC- or PE-labeled monoclonal antibodies (Beckman Coulter, USA). Intensity of fluorescence was measured by flow cytometer Epics Altra manufactured by Beckman Coulter (USA). Results. Studied components of Gram-positive and Gram-negative bacteria stimulated expression of CD14, CD16, CD32, and CD54 molecules on cells from THP-1 line; incubation of cells from EA.hy 926 line in the presence of the same bacterial components increased expression levels of CD54 and HLA-DR molecules. Conclusion. Endothelial cells of EA.hy 926 line was less sensitive to LPS of E.coli and lysate of S.pyogenes compared to monocyte-derived cells of THP-1 line. Usage of THP-1 cells allowed to reveal differences between effects of components of Gram-positive and Gram-negative bacteria. The stimulating effect of LPS was more pronounced compared to effect of S.pyogenes lysate in relation to expression of HLA-DR, CD11b, and CD54 molecules, whereas lysate of S.pyogenes better stimulated expression of CD14, CD16, and CD32 molecules.
Zh. Mikrobiol. (Moscow), 2008, No. 4, P. 60—63