Ricciardiello L, Laghi L, Ramamirtham P, Chang C L, Chang D K, Randolph A E, Boland C R
Department of Medicine and Cancer Center, University of California San Diego, and San Diego Veteran Affairs Medical Center, La Jolla, California 92093-0688, USA.
Gastroenterology. 2000 Nov;119(5):1228-35. doi: 10.1053/gast.2000.19269.
BACKGROUND & AIMS: JC virus (JCV), a human polyomavirus, has been found in a limited number of normal human tissues and cancers. The oncogenic potential of this virus is mediated by a transforming protein, the T antigen (TAg). We have previously demonstrated the presence of JCV-TAg in colorectal cancers, in adjacent normal colonic mucosa from these patients, and in the human colon cancer cell line SW480. The mode of transmission of this virus is unclear, and we hypothesized that the gastrointestinal (GI) tract may be a reservoir for the virus.
DNA was extracted from 129 normal GI tissue samples collected from 33 patients. Topoisomerase I-assisted polymerase chain reaction (PCR) was used to detect the virus using exact and degenerate primers. Nested PCR and Southern blot analysis confirmed the identity of the PCR products. Single-stranded conformation polymorphism (SSCP) analysis and sequencing were used to evaluate the presence of viral quasispecies.
JCV sequences were found in 75.8% of patients (70.6% of upper GI and 81.2% of colonic samples); no significant differences in rates of infection were found by site. The use of degenerate primers combined with topoisomerase I treatment led to viral detection in 58.9% of samples, compared with 27.9% of samples using exact primers and topoisomerase I (P < 0.01). SSCP and sequencing analysis confirmed the amplification of viral quasispecies and the authenticity of TAg sequences.
The results show that JCV DNA sequences are highly prevalent in the human upper and lower gastrointestinal tract of immunocompetent individuals.
JC病毒（JCV）是一种人类多瘤病毒，在有限数量的正常人体组织和癌症中被发现。这种病毒的致癌潜力由一种转化蛋白T抗原（TAg）介导。我们之前已证实在结直肠癌、这些患者的相邻正常结肠黏膜以及人结肠癌细胞系SW480中存在JCV - TAg。该病毒的传播方式尚不清楚，我们推测胃肠道（GI）可能是该病毒的储存库。
从33例患者收集的129份正常GI组织样本中提取DNA。使用拓扑异构酶I辅助聚合酶链反应（PCR），通过精确引物和简并引物检测病毒。巢式PCR和Southern印迹分析确认了PCR产物的身份。使用单链构象多态性（SSCP）分析和测序评估病毒准种的存在情况。
在75.8%的患者中发现了JCV序列（上消化道样本中为70.6%，结肠样本中为81.2%）；按部位分析，感染率无显著差异。与使用精确引物和拓扑异构酶I的27.9%的样本相比，使用简并引物联合拓扑异构酶I处理可使58.9%的样本检测到病毒（P < 0.01）。SSCP和测序分析证实了病毒准种的扩增以及TAg序列的真实性。
结果表明，JCV DNA序列在免疫功能正常个体的人类上、下胃肠道中高度普遍存在。
