Exploring the role of NCCR variation on JC polyomavirus expression from dual reporter minicircles.

Anne-Sophie L’Honneur,Flore Rozenberg,Uriel Hazan,Stéphanie Bury-Moné,Fanny Laurent-Tchenio,Hervé Leh

doi:10.1371/journal.pone.0199171

Abstract

JC virus (JCV), a ubiquitous human polyomavirus, can cause fatal progressive multifocal leukoencephalopathy (PML) in immune compromised patients. The viral genome is composed of two conserved coding regions separated by a highly variable non-coding control region (NCCR). We analyzed the NCCR sequence from 10 PML JCV strains and found new mutations. Remarkably, the NCCR f section was mutated in most cases. We therefore explored the importance of this section in JCV expression in renal (HEK293H) and glioblastoma (U-87MG) cell lines, by adapting the emerging technology of DNA minicircles. Using bidirectional fluorescent reporters, we revealed that impaired NCCR-driven late expression in glioblastoma cells was restored by a short deletion overlapping e and f sections. This study evidenced a relevant link between JCV NCCR polymorphism and cell-type dependent expression. The use of DNA minicircles opens new insights for monitoring the impact of NCCR variation.

Highlights

Progressive multifocal leukoencephalopathy (PML) is an uncommon and severe demyelinating disease highly associated with underlying immune defects
The incidence of PML sharply increased in the 1980s, when human immunodeficiency virus (HIV) infection/AIDS was identified as a major risk factor for PML [3, 4], later significantly reduced by highly active antiretroviral therapy (HAART) [5]
PML is caused by lytic infection of oligodendrocytes by JC virus (JCV), the first human member of the Polyomaviridae family [9] initially isolated from PML brain lesions in cultured human fetal glial cells [10]

Summary

Introduction

Progressive multifocal leukoencephalopathy (PML) is an uncommon and severe demyelinating disease highly associated with underlying immune defects. The incidence of PML sharply increased in the 1980s, when human immunodeficiency virus (HIV) infection/AIDS was identified as a major risk factor for PML [3, 4], later significantly reduced by highly active antiretroviral therapy (HAART) [5]. Immunomodulatory therapies such as the α-4-β-1 and α-4-β-7-anti-integrin, Natalizumab, in multiple sclerosis patients, were shown to carry a novel PML-inducing risk [6,7,8], raising new interest in the comprehension of the disease. PML is caused by lytic infection of oligodendrocytes by JC virus (JCV), the first human member of the Polyomaviridae family [9] initially isolated from PML brain lesions in cultured human fetal glial cells [10]. JCV infection is highly prevalent in human population and mostly

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Conclusion