Phenotypic analysis of CD4^+CD45RA^+T cells in the inflamed gingiva of the patients with adult periodontitis

免疫学机制已被认为与人类牙周病的发病机制有关。组织病理学研究表明，牙周病变可能是由T细胞免疫调节失衡引起的，T细胞在局部和全身水平的免疫调节网络中都起着中心作用。在我们之前的研究中，一些(39%)成人牙周炎患者(低AMLR患者)的外周血淋巴细胞的自体混合淋巴细胞反应(AMLR)被证明是一种可能的炎症性疾病免疫调节指标。仅在低AMLR患者外周血淋巴细胞中CD45RA阳性细胞(CD4+CD45RA+T细胞)比例较低，而在正常AMLR患者和健康对照组中均未见CD45RA阳性细胞。在本研究中，炎症牙龈…表面CD45RA和CD45RO抗原的表型变化我们检测了成人牙周炎患者外周血中较多的α淋巴细胞与AMLR反应的关系。流式细胞仪检测炎症牙周组织中T细胞比例发现，炎症牙周组织中的CD4^+CD45RA^+CD45RO^-T细胞比例低于外周血，而CD4^+45RA^-CD45RO^+T细胞比例高于外周血，提示炎症牙周组织中未成熟的CD4^+T细胞可能在局部牙周病变抗原的持续刺激下积极分化为记忆细胞群。然而，炎症牙龈中这些T细胞亚群的变化与AMLR反应之间没有明显的相关性，个体受试者外周血中T细胞亚群的表型变化也没有明显的相关性。在牙周炎患者的牙周组织中也发现了CD4^+CD45RA^-CD45RO^-T细胞亚群和CD4^+CD45RA^+CD45RO^+T细胞亚群，但这些T细胞亚群的功能特征尚未见报道。这些结果可能反映了牙周病发展过程中调节性T细胞功能的变化。较少

Immunological mechanisms have been inplicated in the pathogenesis of human periodontal diseases. The histopathological works suggested that periodonatal lesions might be induced by the immunoregulatory imbalance of T cells which have been recognized to play a central role in the immunoregulatory network at both local and systemic levels. In our previous study, the autologous mixed-lymphocyte reaction (AMLR), which is suggested as a possible indicator of immunoregulation in inflammatory diseases, of peripheral blood lymphocytes has been demonstrated to be depressed in some (39%) adult periodontitis patients (low-AMLR patients). We also demonstrated a lower percentage of CD45RA positive cells in CD4-positive cells (CD4^+CD45RA^+T cells) of peripheral blood lympho-cytes only in the low-AMLR patients but noto the normal-AMLR patients nor healthy control subjects. In the present study, the phenotypic alterations of the CD45 antigens (CD45RA and CD45RO) on CD4^+T cells in the inflamed gingiv … More a and peripheral blood lymphocytes from the patients with adult periodontitis were examined in relation to AMLR responses. The flowcytometric analysis of T cell fraction in the inflamed gingiva revealed a relatively lower percentage of CD4^+CD45RA^+CD45RO^-T cells and a higher percentage of CD4^+45RA^-CD45RO^+T cells than those in the peripheral blood, suggesting naive CD4^+T cells in the inflamed gingiva might be actively differentiating into memory cell populations by the continuous stimulation of the local periodontopathic antigens. However, no significant correlation were observed between the alteration of these T cell subsets in the inflamed gingiva and AMLR responses nor the phenotypic alteration in the CD4^+T cell subset of the peripheral blood lymphocytes from the individual subject. The CD4^+CD45RA^-CD45RO^- and CD4^+CD45RA^+CD45RO^+T cell subsets were also found in the inflamed gingiva from the periodontitis patients, although the functional characteristics of these T cell subsets has not been reported. These results might reflect changes in regulatory T cell function induced by development of periodontal diseases. Less