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

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.

Progressive multifocal leukoencephalopathy and the spectrum of JC virus-related disease

“…Whereas early gene expression and late gene expression in archetype and rearranged viral variants were comparable in renal-derived cell lines (HEK293), late gene expression was suppressed in archetype strains in glioblastoma cell lines. Such differences could contribute to tissue-specific replicative advantages of rearranged variants in vivo 33 . The CSF of patients with PML contains multiple NCCR rearrangements, but one sequence usually dominates.…”

Promoter activity of Merkel cell Polyomavirus variants in human dermal fibroblasts and a Merkel cell carcinoma cell line

“…Mutations in the non-coding control region (NCCR) of human polyomaviruses like BKPyV, JCPyV, KIPyV, HPyV7, HPyV9 and HPyV12 have an impact on the transcriptional activity of the promoter, and may affect the virulence of the virus [24][25][26][27][28][29][30][31][32][33]. Whether changes in the NCCR of MCPyV have an effect on the promoter activity, and have pathogenic consequences, has not been investigated.…”

Regulation of Polyomavirus Transcription by Viral and Cellular Factors

“…Additionally, another regulatory region downstream from the enhancer has been identified in the NCRR of JCPyV. JCPyV NCRR reporters harboring a natural deletion in this late gene-adjacent region demonstrate increased viral late gene expression in glial cells compared to the archetype NCRR, indicating a “silencer” function of this region in controlling cell type-specific gene expression [ 18 ].…”

“…The JCPyV archetype (CY, GenBank accession no. AB038249.1) NCRR consists of an early proximal region containing the origin followed by regions a, b, c, d, e, and f. The JCPyV prototype Mad-1 NCRR is arranged as Origin-a-c-e-a-c-e-f [ 18 ]. The BKPyV archetype (WW, GenBank accession no.…”