A basic studies to develop the immune therapy for periodontal diseases by employing glycolipids derived from periodontal bacteria as antigens.

本研究首次尝试利用牙周细菌糖脂抗原建立牙周病的免疫治疗方法。据报道，T细胞的存在是通过树突状细胞(DC)上表达的CD1分子识别糖脂抗原的。这些现象使我们有了一个假设，即牙周细菌对糖脂的免疫反应参与了牙周患者的宿主防御。为了阐明这一问题的可能性，我们试图鉴定来自牙周细菌、CD1分子和T细胞群的糖脂抗原。我们成功地从放线菌伴生菌、牙龈假单胞菌和齿假单胞菌等三种细菌的声波提取液中获得了高极性糖脂。将这些糖脂混合并加入到DC的培养中，由表达在DC上的CD1分子高效递呈。我们将健康志愿者的T细胞与来自无关捐赠者的DC共同培养了几周。因此，我们成功地从3名健康供者身上建立了16个T细胞系，它们对这些细菌的糖脂抗原具有特异性反应。为了确定诱导T细胞增殖反应的糖脂抗原，我们将提取的材料分成几个组分，并在每个组分作为抗原的情况下评估T细胞的增殖反应。结果表明，有几个组分可诱导T细胞反应，且这些组分诱导的T细胞大多为CD4阳性。这些结果表明，牙周细菌来源的几种糖脂可能是诱导CD4+T细胞增殖反应的抗原。

This study is the first trial to establish the immune therapy for periodontal diseases by using glycolipid antigens derived from periodontal bacteria. It has been reported that the existence of T cells recognize the glycolipid antigens in context of CD1 molecules expressed on dendritic cells(DCs). These phenomena led us to have a hypothesis that the immune responses against glycolipids from periodontal bacteria were involved in the host defense of periodontal patients. To clarify the possibility of this issue, we tried to identify the glycolipid antigens derived from periodontal bacteria, CD1 molecules and T cell populations. We succeeded in obtaining the glycolipids showing high polarity derived from sonic extracts of three bacteria, including A.actinomycetemcomitans, P.gingivalis and T denticola. These glycolipids were mixed and added in the culture of DCs to be presented efficiently by CD1 molecules expressed on DCs. We co-cultured T cells from healthy volunteers with these DCs derived from irrelevant donors for several weeks. As a result, we succeeded in establishing 16 T cell lines from 3 healthy donors, which showed specific response against glycolipid antigens derived from these bacteria. To identify the glycolipid antigens inducing T cell proliferative responses, we separated the extract materials into several fractions and evaluated T cell proliferative responses in the presence of each fraction as antigen. As a result, it was revealed that there were several fractions inducing T cell responses, and that most of T cells induced by these fractions were CD4 positive. These findings elucidated that several glycolipids derived from periodontal bacteria would be possible antigens to induce the proliferative responses of CD4 positive T cells.