Porphyromonas gingivalis is a causative agent for periodontal disease. Binding of platelets to this gram-negative anaerobe can regulate host hemostatic (thrombus forming) and immune (neutrophil interacting) responses during bacterial infection. Additionally, in response to bacterial pathogens neutrophils can release their DNA, forming highly prothrombotic neutrophil extracellular traps (NETs), which then further enhance platelet responses. This study evaluates the role of P. gingivalis on platelet expression of CD62P, platelet–neutrophil interactions, and labeled neutrophil-associated DNA. Human whole blood was preincubated with varying P. gingivalis concentrations, with or without subsequent addition of adenosine diphosphate (ADP). Flow cytometry was employed to measure platelet expression of CD62P using PerCP-anti-CD61 and PE-anti-CD62P, platelet–neutrophil interactions using PerCP-anti-CD61 and FITC-anti-CD16, and the release of neutrophil DNA using FITC-anti-CD16 and Sytox Blue labeling. Preincubation with a high (6.25 × 10⁶ CFU/mL) level of P. gingivalis significantly increased platelet expression of CD62P in ADP treated and untreated whole blood. In addition, platelet–neutrophil interactions were significantly increased after ADP stimulation, following 5–22 min preincubation of blood with high P. gingivalis CFU. However, in the absence of added ADP, platelet–neutrophil interactions increased in a manner dependent on the preincubation time with P. gingivalis. Moreover, after ADP addition, 16 min preincubation of whole blood with P. gingivalis led to increased labeling of neutrophil-associated DNA. Taken together, the results suggest that the presence of P. gingivalis alters platelet and neutrophil responses to increase platelet activation, platelet interactions with neutrophils, and the level of neutrophil antimicrobial NETs.

中文翻译：

---

血小板和中性粒细胞对人全血中牙龈卟啉单胞菌的反应

牙龈卟啉单胞菌是牙周病的病原体。血小板与这种革兰氏阴性厌氧菌的结合可以在细菌感染期间调节宿主止血（血栓形成）和免疫（中性粒细胞相互作用）反应。此外，作为对细菌病原体的反应，中性粒细胞可以释放其 DNA，形成高度促血栓形成的中性粒细胞胞外陷阱 (NETs)，进而进一步增强血小板反应。本研究评估了P的作用。gingivalis对 CD62P 的血小板表达、血小板-中性粒细胞相互作用和标记的中性粒细胞相关 DNA 的影响。人全血与不同的P预孵育。牙龈炎浓度，随后添加或不添加二磷酸腺苷 (ADP)。流式细胞术用于使用 PerCP-anti-CD61 和 PE-anti-CD62P 测量 CD62P 的血小板表达，使用 PerCP-anti-CD61 和 FITC-anti-CD16 测量血小板-中性粒细胞相互作用，使用 FITC-anti 测量中性粒细胞 DNA 的释放-CD16 和 Sytox Blue 标记。以高 (6.25 × 10 ⁶  CFU/mL) 水平的P进行预孵育。gingivalis显着增加 ADP 处理和未处理全血中 CD62P 的血小板表达。此外，在 ADP 刺激后，血小板-中性粒细胞相互作用显着增加，在高P血液预孵育 5-22 分钟后。牙龈炎CFU。然而，在没有添加 ADP 的情况下，血小板-中性粒细胞相互作用的增加取决于与P的预孵育时间。牙龈炎。此外，在添加 ADP 后，将全血与P预孵育 16 分钟。gingivalis导致中性粒细胞相关 DNA 的标记增加。综上所述，结果表明P的存在。gingivalis改变血小板和中性粒细胞反应以增加血小板活化、血小板与中性粒细胞的相互作用以及中性粒细胞抗菌 NETs 的水平。