University of Florida, Center for Molecular Microbiology, Department of Oral Biology, College of Dentistry, PO Box 100424, Gainesville, FL 32610-0424, USA.
Anaerobe. 2012 Feb;18(1):128-34. doi: 10.1016/j.anaerobe.2011.10.005. Epub 2011 Nov 11.
Porphyromonas gingivalis is one of the major etiologic agents of adult periodontitis and has been associated with cardiovascular diseases. It expresses multiple hemagglutinins that are significant virulence factors and play an important role in bacterial attachment and invasion of host cells. The objective of this study was to determine the impact of P. gingivalis hemagglutinin A (HagA) on the attachment to and invasion of human coronary artery endothelial cells (HCAEC) and gingival epithelial cells (GEC). Bacterial strains expressing the HagA protein (or subunits), including Escherichia coli carrying plasmid pEKS5, E. coli carrying plasmid ST2, and Salmonella enterica serovar Typhimurium with plasmid pNM1.1 were used in this study. The strains were tested for their ability to attach to and invade HCAEC and GEC using antibiotic protection assays. In addition, the unique 5' N-terminal non-repeated segment of HagA was purified in recombinant form and a monoclonal antibody was created against the polypeptide. The monoclonal antibody against the unique portion of HagA was tested for inhibitory activity in these assays. The attachment of both E. coli strains expressing HagA fragment to host cells was significantly increased compared to their respective controls. However, they did not invade GEC or HCAEC. Interestingly, HagA expression in the Salmonella strain increased both adherence to and invasion of HCAEC, which may be due to the presence of the entire hagA ORF. A monoclonal antibody against the unique 5' N-terminal portion of HagA reduced invasion. Further experiments are needed to determine the role of the unique and the repeat segments of P. gingivalis HagA.
牙龈卟啉单胞菌是成人牙周炎的主要病原体之一，与心血管疾病有关。它表达多种具有重要毒力的血凝素，在细菌黏附和宿主细胞侵袭中发挥重要作用。本研究旨在确定牙龈卟啉单胞菌血凝素 A（HagA）对人冠状动脉内皮细胞（HCAEC）和牙龈上皮细胞（GEC）黏附和侵袭的影响。本研究使用了表达 HagA 蛋白（或亚基）的细菌株，包括携带质粒 pEKS5 的大肠杆菌、携带质粒 ST2 的大肠杆菌和携带质粒 pNM1.1 的鼠伤寒沙门氏菌。使用抗生素保护试验检测这些菌株黏附并侵袭 HCAEC 和 GEC 的能力。此外，以重组形式纯化了 HagA 的独特 5'N-末端非重复片段，并针对多肽产生了单克隆抗体。在这些测定中，针对 HagA 独特部分的单克隆抗体的抑制活性进行了测试。与各自的对照相比，表达 HagA 片段的两种大肠杆菌菌株对宿主细胞的黏附明显增加。然而，它们不能侵袭 GEC 或 HCAEC。有趣的是，沙门氏菌株中 HagA 的表达增加了对 HCAEC 的黏附和侵袭，这可能是由于 hagAORF 的完整存在。针对 HagA 独特的 5'N-末端部分的单克隆抗体减少了侵袭。需要进一步的实验来确定牙龈卟啉单胞菌 HagA 的独特和重复片段的作用。
