Porphyromonas gingivalis infection enhanced the adhesion of monocytes to endothelial

Abstract

To observe if Porphyromonas gingivalis (Pg) infection could enhance the adhesion of human monocytic cell line (THP-1) to human umbilical vein endothelial cells (HUVEC). PgATCC33277 was cultured in anaerobic jar, and THP-1 was infected with various concentrations of PgATCC33277 at multiplicity of infection (MOI) of 1: 100 for 8 and 24 hours, respectively. After removal of the free Pg, THP-1 cells were cocultured with HUVEC for 1 hour to observe the adhesion of THP-1 to HUVEC.HUVEC with adhesive THP-1 cells were co-cultured for additional 23 hours. The medium and cells were separately collected. The expression of related chemotactic cytokine[monocyte chemotactic protein 1(MCP-1) and interleukin 8(IL-8)] and intercellular adhesion molecule-1(ICAM-1) were detected with enzyme-linked immunosorbent assay. The adhesion of THP-1 to HUVEC was enhanced (13.8%-35.2%, P = 0.006) and the expression of ICAM-1 of HUVEC was increased from (132.5 ± 7.7) to (164.9 ± 9.1) ng/L (P = 0.005) after infection for 24 hours by Pg. Both of the secreted MCP-1 and IL-8 elevated after infection of Pg for 24 hours from (183.2 ± 3.1) to (221.0 ± 4.9) ng/L (P = 0.012) and from (587.2 ± 5.1) to (787.2 ± 10.3) ng/L (P = 0.002), respectively. Pg could enhance the adhesion of monocytes to endothelial cells and stimulate the inflammation, suggesting that Pg infection may be one of the risk factors in promoting the development of atherosclerosis.