Rearrangement in the Hypervariable Region of JC Polyomavirus Genomes Isolated from Patient Samples and Impact on...

Area of Science:

• Virology
• Neuroscience
• Genetics

Background:

• JC polyomavirus (JCPyV) establishes persistent, asymptomatic infections in most adults, primarily in the kidneys.
• Reactivation of JCPyV under immunosuppression leads to progressive multifocal leukoencephalopathy (PML), a fatal neurological disease.
• Genetic variations, especially rearrangements in the noncoding control region (NCCR), are key determinants of JCPyV disease outcome.

Purpose of the Study:

• To investigate the frequency and patterns of mutations within the JCPyV NCCR across different patient isolation sites and disease statuses.
• To analyze the impact of NCCR rearrangements on transcription factor binding sites (TFBS).
• To correlate observed genetic alterations with disease outcome in JCPyV infections.

Main Methods:

• Analysis of 989 JCPyV NCCR sequences from patient isolates available in GenBank.
• Comparative analysis of mutation frequencies based on isolation site (e.g., cerebrospinal fluid) and disease status (PML vs. non-PML).
• Identification and quantification of transcription factor binding sites (TFBS) within the NCCR sequences.

Main Results:

• A significantly higher number of TFBS were identified in JCPyV NCCR sequences from PML patients compared to non-PML samples.
• TFBS associated with enhanced JCPyV transcription were found to be more prevalent in isolates from cerebrospinal fluid.
• Specific NCCR mutations and rearrangements were correlated with altered TFBS and disease status.

Conclusions:

• Mutations in the JCPyV NCCR significantly alter TFBS, influencing viral gene transcription.
• The increased prevalence of specific TFBS in PML patients, particularly in cerebrospinal fluid isolates, highlights their role in disease pathogenesis.
• Understanding these NCCR alterations provides critical insights into JCPyV-associated PML and potential therapeutic targets.