Jotwani Ravi, Cutler Christopher W
Department of Periodontics, School of Dental Medicine, Stony Brook University, Stony Brook, New York 11794-8703, USA.
Infect Immun. 2004 Mar;72(3):1725-32. doi: 10.1128/IAI.72.3.1725-1732.2004.
Porphyromonas gingivalis is a fimbriated mucosal pathogen implicated in chronic periodontitis (CP). The fimbriae are required for invasion of the gingival mucosa and for induction of CP in animal models of periodontitis. CP is associated with infection of immature dendritic cells (DCs) by P. gingivalis in situ and with increased numbers of dermal DCs (DDCs) and mature DCs in the lamina propria. The role of fimbriae in gaining entry into human DCs and how this modulates the inflammatory and effector immune responses, however, have not been explored. To address this, we generated monocyte-derived DCs (MDDCs) in vitro which phenotypically and functionally resemble DDCs. We show here that virulent fimbriated P. gingivalis 381, in contrast to its fimbria-deficient mutant, P. gingivalis DPG3, efficiently gains entry to MDDCs in a manner dependent on active cell metabolism and cytoskeletal rearrangement. In addition, uptake of 381, unlike DPG3, induces DCs to undergo maturation, upregulate costimulatory molecules, and secrete inflammation cytokines interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor alpha, IL-10, and IL-12. Moreover, MDDCs pulsed with 381 also stimulated a higher autologous mixed lymphocyte reaction and induced a Th1-type response, with gamma interferon (IFN-gamma) being the main cytokine. Monocytes used as controls demonstrated fimbria-dependent uptake of 381 as well but produced low levels of inflammatory cytokines compared to MDDCs. When MDDCs were pulsed with recombinant fimbrillin of P. gingivalis (10 micro g/ml), maturation of MDDCs was also induced; moreover, matured MDDCs induced proliferation of autologous CD4(+) T cells and release of IFN-gamma. Thus, these results establish the significance of P. gingivalis fimbriae in the uptake of P. gingivalis by MDDCs and in induction of immunostimulatory Th1 responses.
牙龈卟啉单胞菌是一种有菌毛的黏膜病原体，与慢性牙周炎（CP）有关。菌毛对于牙龈卟啉单胞菌侵入牙龈黏膜以及在牙周炎动物模型中诱发慢性牙周炎是必需的。慢性牙周炎与牙龈卟啉单胞菌在原位感染未成熟树突状细胞（DCs）以及固有层中真皮DCs（DDCs）和成熟DCs数量增加有关。然而，菌毛在进入人DCs中的作用以及这如何调节炎症和效应免疫反应尚未得到研究。为了解决这个问题，我们在体外生成了单核细胞衍生的DCs（MDDCs），其在表型和功能上类似于DDCs。我们在此表明，与菌毛缺陷突变体牙龈卟啉单胞菌DPG3相比，有毒力的有菌毛牙龈卟啉单胞菌381以依赖于活跃细胞代谢和细胞骨架重排的方式有效地进入MDDCs。此外，与DPG3不同，381的摄取诱导DCs成熟，上调共刺激分子，并分泌炎症细胞因子白细胞介素-1β（IL-1β）、IL-6、肿瘤坏死因子α、IL-10和IL-12。此外，用381脉冲的MDDCs也刺激了更高的自体混合淋巴细胞反应并诱导了Th1型反应，γ干扰素（IFN-γ）是主要细胞因子。用作对照的单核细胞也表现出菌毛依赖性摄取381，但与MDDCs相比，产生的炎症细胞因子水平较低。当用牙龈卟啉单胞菌的重组菌毛蛋白（10μg/ml）脉冲MDDCs时，也诱导了MDDCs的成熟；此外，成熟的MDDCs诱导自体CD4(+)T细胞增殖并释放IFN-γ。因此，这些结果确立了牙龈卟啉单胞菌菌毛在MDDCs摄取牙龈卟啉单胞菌以及诱导免疫刺激Th1反应中的重要性。
