ROLE OF HUMAN T LYMPHOTROPIC VIRUS TYPE I ON PATHOGENESIS OF SJOGREN'S SYNDROME

人类T细胞嗜淋巴细胞病毒I型（HTLV-I）是一种人类逆转录病毒，最初被鉴定为成人T细胞白血病的病原体，并且与HTLV-I相关的脊髓病/热带痉挛性截瘫（HAM/TSP）密切相关。我们曾证实干燥综合征（SS）患者HTLV-Ⅰ阳性率为23.0%，显著高于正常献血员（3.4%）。经Mantel-Haenszel程序估计，SS患者与正常献血者相比，HTLV-I感染的年龄校正汇总优势比为3.1。此外，SS患者中HTLV-I感染的比例估计为17.6%。首先，我们调查了SS是否合并HAM患者。对14例HAM患者的临床、组织学表现及血清自身抗体进行了分析。 ...更多信息 唾液腺根据欧洲共同体提出的SS初步诊断标准，8例患者确诊为SS，4例患者诊断为可能SS。8例HAM患者中，类风湿因子、抗核抗体、抗SS-A（Ro）和抗SS-B（La）抗体的检出率与HTLV-Ⅰ阳性和阴性SS患者比较，差异无统计学意义。CD 4 ^+ T细胞在HAM患者以及HTLV-I阳性和阴性患者的唾液腺中优先浸润，然后研究了HTLV-I阳性和阴性SS患者唇唾液腺中的细胞凋亡。在唇腺上皮细胞（腺泡和导管）中检测到细胞凋亡。Fas抗原在唇腺上皮细胞上表达。Fas配体在浸润的淋巴细胞中表达。采用巢式两步法PCR检测了7例HTLV-I阳性SS患者外周血淋巴细胞和唇腺组织中HTLV-I前病毒DNA的存在情况，发现HTLV-I基因组的LTR、gag、pol和pX 4个独立区域，从所有血清学阳性患者的外周血淋巴细胞和组织DNA中容易地扩增出。用半定量PCR方法检测了各样本中HTLV-Ⅰ的拷贝数，结果显示：组织与淋巴细胞的拷贝数比值是可变的，但4例SS患者中3例无HAM基因，其拷贝数比值很高。这些发现表明，HTLV-I感染的细胞可能积聚在这些患者的唾液腺中。从以上结果看来，HAM患者的外周血T细胞可能优先浸润到唾液腺中，然后浸润的T细胞诱导SS外分泌器官的病理变化。因此，我们研究了HAM患者循环T细胞通过重建基底膜的迁移活性。在Transwell细胞培养箱中测定淋巴细胞的迁移活性。我们将来自HAM患者和正常人的循环CD 4 ^+细胞置于Transwell细胞培养箱中，然后计数移行细胞的数量。HAM患者外周血CD 4 ^+细胞比例明显高于正常人。此外，在HAM患者的迁移性CD 4 ^+细胞中定量检测到的HTLV-I前病毒DNA的频率是非迁移性CD 4 ^+细胞的2 ~ 8倍。这些结果表明，HAM患者中HTLV-I感染的CD 4 ^+细胞通过重组基底膜的跨膜迁移活性上调，我们的研究结果有力地支持了HTLV-I参与了流行区SS患者的发病机制的观点。少

Human T-cell lymphotropic virus type I (HTLV-I) is a human retrovirus, originally identified as an aetiological agent of adult T cell leukemia, and closely associated with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). We previously demonstrated that the HTLV-I seroprevalence in Sjogren's syndrome (SS) patients was 23.0%, which was significantly higher than those of the normal blood donors (3.4%). The age-adjusted summary odds ratio of HTLV-I infection in SS patients as compared with normal blood donors, estimated by the Mantel-Haenszel procedure, was 3.1. Furthermore, etiologic fraction, the proportion of SS patients attributable to HTLV-I infection, was estimated to be 17.6%.At first, we investigated whether SS was complicated with HAM patients. The clinical feature and histological findings of SS and the prevalence of serum autoantibodies were examined 14 patients with HAM.All patients with HAM histologically showed a mononuclear cell infiltration in the labial … More salivary glands. According to the preliminary criteria for SS proposed by the European Community, definitive SS was diagnosed in 8 patients and probable SS in 4 patients. There was no significant difference in the prevalence of autoantibodies including rheumatoid factor, anti-nuclear, anti-SS-A (Ro) and anti-SS-B (La) antibodies among 8 HAM patients with definitive SS,HTLV-I-seropositive and- seronegative SS patients. The CD4^+ T cells preferentially infiltrated into the salivary glands in HAM patients as well as the salivary glands of patients with HTLV-I-seropositive and -seronegative patients.Next, apoptosis in labial salivary glands from HTLV-I-seropositive and -seronegative SS patients was studied. Apoptotic cell death was detected in epithelial cells (acinus and ducts) of labial salivary glands. Fas antigen was found on epithelial cells in labial salivary glands. Fas ligand was stained in the infiltrated lymphocytes. There was no significant difference in above findings between HTLV-I-seropositive and -seronegative SS patients.We examined the presence of HTLV-I provirus DNA of both peripheral blood lymphocytes and labial salivary glands form 7 HTLV-I seropositive patients with SS by nested two-step PCR.All 4 independent regions of the HTLV-I genomic, including LTR,gag, pol and pX,were readily amplified from DNA of peripheral blood lymphocytes and tissues of all the seropositive patients. Next, we studied the copy number of HTLV-I in each sample DNA by semiquantitative PCR.The ratio of the copy number between tissue and lymphocytes was variable, but 3 out of 4 SS patients without HAM gene very high values. These findings suggest that HTLV-I infected cells may accumulate in the salivary gland of these patients. From the above findings, it seems likely that peripheral blood T cells from HAM patients preferentially infiltrate into the salivary glands, and then the infiltrated T cells induce SS the pathological changes in the exocrine organs. We studied, therefore, transmigratory activity of circulating T cells from HAM patients through reconstituted basement membrane. Transmigratory activity of lymphocytes was assayd in Transwell cell-culture chambers. We applied the circulating CD4^+ cells from patients with HAM and normal subjects on Transwell cell-culture chambers, and then counted the number of transmigrated cells. The percentage of transmigrated CD4^+ cells from HAM patients was significantly higher than that from normal subjects. Furthermore, HTLV-I proviral DNA quantified in the transmigrated CD4^+ cells from HAM patients were 2 to 8 fold more frequent than that in the non-transmigrated CD4^+ cells. These findings indicate that HTLV-I infected CD4^+ cells of HAM patients have up-regulated transmigratory activity through reconstituted basement membrane.In summary, our findings strongly support the idea that HTLV-I is involved in the pathogenesis of the disease in a subset of patients with SS in endemic areas. Less