Agostini H T, Ryschkewitsch C F, Singer E J, Stoner G L
Laboratory of Experimental Neuropathology, NINDS National Institutes of Health, Bethesda, Maryland 20892, USA.
J Neurovirol. 1996 Aug;2(4):259-67. doi: 10.3109/13550289609146889.
The human polyomavirus JC (JCV), which exists in different geographically based genotypes, causes the central demyelinating disease known as progressive multifocal leukoencephalopathy (PML). A coding region recombinant JCV Type 1/Type 3 (Type 4) is excreted in the urine of some 16% of individuals in the USA. In addition, occasional 'crossovers' in viral DNA sequence at type-specific sites in the coding region occur between JCV genotypes amplified from PML brain. For recombination to occur requires the existence of two different genotypes in the same host. Here we provide evidence from direct cycle sequencing of PCR products that different genotypes of JCV can be found in a single tissue sample. After non-type-specific PCR amplification, cycle sequencing produced 'split bands' at type determining sites which were resolved into type or subtype-specific sequences by subcloning of the PCR products. PCR products with split bands at typing sites were found in two brain samples and in one cerebrospinal fluid (CSF) from AIDS patients with PML and in the urine of four immunocompetent individuals. This indicates that co-infection with two viral types does not depend on severe immunocompromise. Combinations of genotypes found were Types 1A & 1B, 1A & 2, 1B & 2 and 2 & 3. In one doubly infected patient the major JCV type excreted in the urine changed within 1 week.
人类多瘤病毒JC（JCV）存在不同的基于地理位置的基因型，可引发称为进行性多灶性白质脑病（PML）的中枢脱髓鞘疾病。编码区重组JCV 1型/3型（4型）在美国约16%的个体尿液中排出。此外，从PML脑扩增的JCV基因型之间，在编码区的型特异性位点的病毒DNA序列偶尔会发生“交叉”。重组的发生需要同一宿主中存在两种不同的基因型。在此，我们通过对PCR产物进行直接循环测序提供证据，表明在单个组织样本中可发现不同基因型的JCV。非型特异性PCR扩增后，循环测序在型决定位点产生“分裂条带”，通过PCR产物亚克隆将其解析为型或亚型特异性序列。在两名患有PML的艾滋病患者的脑样本和一份脑脊液（CSF）以及四名免疫功能正常个体的尿液中，发现了在分型位点有分裂条带的PCR产物。这表明两种病毒类型的共同感染并不依赖于严重的免疫功能低下。发现的基因型组合有1A与1B、1A与2、1B与2以及2与3。在一名双重感染患者中，尿液中排出的主要JCV类型在1周内发生了变化。
