Department of Oral Microbiology and Immunology, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
J Endod. 2012 Mar;38(3):351-6. doi: 10.1016/j.joen.2011.12.026. Epub 2012 Jan 28.
Enterococcus faecalis is frequently found in the root canal of teeth, is a major microorganism of endodontic therapy failure, and is associated with chronic apical periodontitis. Human β-defensins (HBDs) are known to play critical roles in defending the host against infectious microbes and producing dental pulp in healthy and patients. The purpose of the present study was to investigate the bactericidal and neutralizing effects of HBDs on E. faecalis and E. faecalis lipoteichoic acid (Ef LTA) as a major virulence factor of E. faecalis.
HBD-1, -2, -3, and -4 were synthesized and investigated the susceptibility against E. faecalis. Also, the neutralizing effects of HBDs on cytokine and intercellular adhesion molecule 1 (ICAM-1) expression by activity of E. faecalis and Ef LTA were analyzed using enzyme-linked immunosorbent assay and flow cytometry.
HBD-1 and -2 were weakly susceptible, and HBD-3 and HBD-4 were strongly susceptible to E. faecalis. All of the HBDs exhibited neutralizing effects on the activity of Ef LTA, and HBD-3 strongly neutralized the activity of E. faecalis in tumor necrosis factor-α, interleukin-8, and ICAM-1 expression. The neutralizing effects of HBDs were to inhibit E. faecalis or Ef LTA binding to the host cells.
These results suggest that the induction of HBDs might have great potential as endodontic therapeutic agents.
粪肠球菌常存在于牙齿的根管中，是根管治疗失败的主要微生物，与慢性根尖周炎有关。人β-防御素（HBDs）在宿主抵抗感染微生物和产生牙髓方面发挥着关键作用，在健康和患病个体的牙髓中均有表达。本研究旨在探讨 HBDs 对粪肠球菌及其主要毒力因子肠球菌脂磷壁酸（Ef LTA）的杀菌和中和作用。
合成 HBD-1、-2、-3 和 -4，并研究其对粪肠球菌的敏感性。还通过酶联免疫吸附试验和流式细胞术分析 HBDs 对粪肠球菌和 Ef LTA 细胞因子和细胞间黏附分子 1（ICAM-1）表达活性的中和作用。
HBD-1 和 -2 对粪肠球菌的敏感性较弱，而 HBD-3 和 HBD-4 对粪肠球菌的敏感性较强。所有 HBDs 均对 Ef LTA 的活性表现出中和作用，HBD-3 对肿瘤坏死因子-α、白细胞介素-8 和 ICAM-1 表达中粪肠球菌的活性具有很强的中和作用。HBDs 的中和作用是抑制粪肠球菌或 Ef LTA 与宿主细胞的结合。
这些结果表明，诱导 HBDs 可能具有作为牙髓治疗剂的巨大潜力。
