Opportunistic DNA Recombination With Epstein-Barr Virus at Sites of Control Region Rearrangements Mediating JC Virus Neurovirulence

Concurrent JCPyV-DNAemia Is Correlated With Poor Graft Outcome in Kidney Transplant Recipients With Polyomavirus-associated Nephropathy

BACKGROUND

Co-infection of JC polyomavirus (JCPyV) and BK polyomavirus (BKPyV) is uncommon in kidney transplant recipients, and the prognosis is unclear. This study aimed to investigate the effect of concurrent JCPyV-DNAemia on graft outcomes in BKPyV-infected kidney transplant recipients with polyomavirus-associated nephropathy (PyVAN).

METHODS

A total of 140 kidney transplant recipients with BKPyV replication and PyVAN, 122 without concurrent JCPyV-DNAemia and 18 with JCPyV-DNAemia were included in the analysis. Least absolute shrinkage and selection operator regression analysis and multivariate Cox regression analysis were used to identify prognostic factors for graft survival. A nomogram for predicting graft survival was created and evaluated.

RESULTS

The median tubulitis score in the JCPyV-DNAemia-positive group was higher than in JCPyV-DNAemia-negative group ( P  = 0.048). At last follow-up, the graft loss rate in the JCPyV-DNAemia-positive group was higher than in the JCPyV-DNAemia-negative group (50% versus 25.4%; P  = 0.031). Kaplan-Meier analysis showed that the graft survival rate in the JCPyV-DNAemia-positive group was lower than in the JCPyV-DNAemia-negative group ( P  = 0.003). Least absolute shrinkage and selection operator regression and multivariate Cox regression analysis demonstrated that concurrent JCPyV-DNAemia was an independent risk factor for graft survival (hazard ratio = 4.808; 95% confidence interval: 2.096-11.03; P  < 0.001). The nomogram displayed favorable discrimination (C-index = 0.839), concordance, and clinical applicability in predicting graft survival.

CONCLUSIONS

Concurrent JCPyV-DNAemia is associated with a worse graft outcome in BKPyV-infected kidney transplant recipients with PyVAN.

Co-Detection of EBV and Human Polyomavirus JCPyV in a Case of AIDS-Related Multifocal Primary Central Nervous System Diffuse Large B-Cell Lymphoma

The human neurotropic Polyomavirus JCPyV is the widespread opportunistic causative pathogen of the fatal demyelinating disease progressive multifocal leukoencephalopathy; however, it has also been implicated in the oncogenesis of several types of cancers. It causes brain tumors when intracerebrally inoculated into rodents, and genomic sequences of different strains and expression of the viral protein large T-Antigen have been detected in a wide variety of glial brain tumors and CNS lymphomas. Here, we present a case of an AIDS-related multifocal primary CNS lymphoma in which JCPyV genomic sequences of the three regions of JCPyV and expression of T-Antigen were detected by PCR and immunohistochemistry, respectively. No capsid proteins were detected, ruling out active JCPyV replication. Sequencing of the control region revealed that Mad-4 was the strain of JCPyV present in tumor cells. In addition, expression of viral proteins LMP and EBNA-1 from another ubiquitous oncogenic virus, Epstein-Barr, was also detected in the same lymphocytic neoplastic cells, co-localizing with JCPyV T-Antigen, suggesting a potential collaboration between these two viruses in the process of malignant transformation of B-lymphocytes, which are the site of latency and reactivation for both viruses.

Identification of viral-mediated pathogenic mechanisms in neurodegenerative diseases using network-based approaches

During the course of a viral infection, virus-host protein-protein interactions (PPIs) play a critical role in allowing viruses to replicate and survive within the host. These interspecies molecular interactions can lead to viral-mediated perturbations of the human interactome causing the generation of various complex diseases. Evidences suggest that viral-mediated perturbations are a possible pathogenic etiology in several neurodegenerative diseases (NDs). These diseases are characterized by chronic progressive degeneration of neurons, and current therapeutic approaches provide only mild symptomatic relief; therefore, there is unmet need for the discovery of novel therapeutic interventions. In this paper, we initially review databases and tools that can be utilized to investigate viral-mediated perturbations in complex NDs using network-based analysis by examining the interaction between the ND-related PPI disease networks and the virus-host PPI network. Afterwards, we present our theoretical-driven integrative network-based bioinformatics approach that accounts for pathogen-genes-disease-related PPIs with the aim to identify viral-mediated pathogenic mechanisms focusing in multiple sclerosis (MS) disease. We identified seven high centrality nodes that can act as disease communicator nodes and exert systemic effects in the MS-enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways network. In addition, we identified 12 KEGG pathways, 5 Reactome pathways and 52 Gene Ontology Immune System Processes by which 80 viral proteins from eight viral species might exert viral-mediated pathogenic mechanisms in MS. Finally, our analysis highlighted the Th17 differentiation pathway, a disease communicator node and part of the 12 underlined KEGG pathways, as a key viral-mediated pathogenic mechanism and a possible therapeutic target for MS disease.

Progressive multifocal leukoencephalopathy in dimethyl fumarate-treated multiple sclerosis patients

Dimethyl fumarate (DMF), a fumaric acid with antioxidant and immunomodulatory properties, is among the most commonly used oral therapies for relapsing multiple sclerosis (MS). Progressive multifocal leukoencephalopathy (PML) has been associated with several disease-modifying therapies (DMTs), including DMF in treating MS. We present detailed clinical characteristics of nine PML cases and show that the PML incidence in DMF-treated patients is 0.02 per 1000 patients. In addition to persistent severe lymphopenia, older age appears to be a potential risk for PML. However, younger patients without lymphopenia were also observed to develop PML. DMF-associated PML has occurred in patients with absolute lymphocyte counts (ALCs) above the guideline threshold, suggesting that changes in specific subsets might be more important than total ALC. Furthermore, since DMF has been found to decrease immune cell migration by decreasing the expression of adhesive molecules, the cerebrospinal fluid (CSF) immune profile may also be useful for assessing PML risk in DMF-treated patients. This review provides an up-to-date assessment of PML cases occurring in DMF-treated patients and discusses other potential considerations in light of our current understanding of DMF's mechanism of action on the immune system in the periphery and in the central nervous system (CNS).

Regulation of expansion of CD11c+ B cells and anti-viral immunity by epithelial V-like antigen

Prior work demonstrated that epithelial V-like antigen (EVA), a cell surface adhesion molecule, is expressed in B lymphocytes and is necessary for the efficacy of anti-alpha₄ integrin treatment of experimental autoimmune encephalomyelitis (EAE), the mouse model of human multiple sclerosis. EVA deficiency is associated with a severe clinical phenotype of EAE in the presence or absence of treatment. Histological analysis revealed enhanced B cell-mediated autoimmunity and deposition of antibody and complement within the brain and spinal cord. Here our goal was to determine the molecular mechanism of EVA regulation of B lymphocyte function. Analysis of bone marrow from MOG-immunized mice revealed increased expansion of CD11c⁺ B cells in EVA-deficient mice as compared to wild type controls. In vitro studies of mouse bone marrow B lymphocytes revealed enhanced proliferation of the CD11c⁺ population in response to the Tlr7/8 agonist R848. An increase in R848-induced proliferation of CD11c⁺ B cells was also seen in vitro in Daudi cells, a human B cell line, following knockdown of the mpzl2 gene that encodes EVA. These mechanisms were characterized further by global expression analysis of bone marrow from immunized EVA-deficient and wild type control mice. These data revealed increased expression of B cell associated genes and decreased expression of the anti-viral oligoadenylate synthase genes, Oas1 and Oas2, in the knockout condition. In Daudi cells, R848 treatment induced an increase in Oas2 expression in control cells that was not observed in EVA-deficient cells. EVA deficiency also was associated with increased transcription of an Epstein-Barr virus gene during lytic replication. These results suggest EVA expression and signaling prevent expansion of CD11c⁺ B lymphocytes, a cellular phenotype associated with autoimmunity, increase expression of anti-viral oligoadenylate synthase genes, and reduce replication of a DNA virus.

The Progressive Multifocal Leukoencephalopathy Consortium as a Model for Advancing Research and Dialogue on Rare Severe Adverse Drug Reactions

Progressive multifocal leukoencephalopathy (PML) is a rare but serious disease. Caused by the JC virus (JCV), it occurs in individuals with weakened immune systems and is a potential adverse reaction for certain immunomodulatory drugs. The PML Consortium was created to find better methods to predict, prevent, and treat PML. The Consortium brought together the pharmaceutical industry with academic, regulatory, and patient communities to advance research and dialogue on PML through a not-for-profit, collaborative approach involving a grant program, scientific workshops and conferences, and disease awareness efforts. Over nearly a decade, the Consortium contributed to the PML and JCV fields by advancing research, scientific exchange, and awareness of PML. In addition to advancing knowledge and helping to build cross-sector consensus on research priorities, the Consortium's grant program filled a funding gap and brought new investigators into PML and JCV research. Additionally, the Consortium's workshops and conferences created platforms for exchange that drove dialogue on knowledge gaps and future research directions. The Consortium also contributed to the scientific knowledge base with two literature reviews, one on PML treatment studies and a second on T cell deficiencies as a risk factor for PML and the brain as a site for conversion of harmless JCV into a pathogenic virus. Finally, the Consortium addressed a significant information gap with its disease awareness website for healthcare professionals, patients, and caregivers. Beyond its impact on the PML and JCV fields, the PML Consortium is important because it provides a precedent for how the pharmaceutical industry, academic researchers, patient organizations, and government can work together to address rare diseases, in particular rare adverse events. This kind of collaboration could be replicated to speed progress in addressing other rare diseases and adverse events, with significant potential benefits for the scientific, medical, and patient communities. FUNDING: PML Consortium (PML Consortium, Washington, DC).

Understanding Progressive Multifocal Leukoencephalopathy Risk in Multiple Sclerosis Patients Treated with Immunomodulatory Therapies: A Bird's Eye View

The increased use of newer potent immunomodulatory therapies for multiple sclerosis (MS), including natalizumab, fingolimod, and dimethyl fumarate, has expanded the patient population at risk for developing progressive multifocal leukoencephalopathy (PML). These MS therapies shift the profile of lymphocytes within the central nervous system (CNS) leading to increased anti-inflammatory subsets and decreased immunosurveillance. Similar to MS, PML is a demyelinating disease of the CNS, but it is caused by the JC virus. The manifestation of PML requires the presence of an active, genetically rearranged form of the JC virus within CNS glial cells, coupled with the loss of appropriate JC virus-specific immune responses. The reliability of metrics used to predict risk for PML could be improved if all three components, i.e., viral genetic strain, localization, and host immune function, were taken into account. Advances in our understanding of the critical lymphocyte subpopulation changes induced by these MS therapies and ability to detect viral mutation and reactivation will facilitate efforts to develop these metrics.

Viruses and Multiple Sclerosis: From Mechanisms and Pathways to Translational Research Opportunities

Viruses are directly or indirectly implicated in multiple sclerosis (MS). Here, we review the evidence on the virus-related pathophysiology of MS, introduce common experimental models, and explore the ways in which viruses cause demyelination. By emphasizing knowledge gaps, we highlight future research directions for effective MS diagnostics and therapies: (i) identifying biomarkers for at-risk individuals, (ii) searching for direct evidence of specific causative viruses, (iii) establishing the contribution of host genetic factors and viruses, and (iv) investigating the contribution of immune regulation at extra-CNS sites. Research in these areas is likely to be facilitated by the application of high-throughput technologies, the development of systems-based bioinformatic approaches, careful selection of experimental models, and the acquisition of high-quality clinical material for tissue-based research.

Significance of Interviral Recombination as Novel Mechanism for Extending Viral Disease Repertoire

The recent observation of interviral recombination between members of two distinct classes of DNA viruses has opened the gates to a new field of human disease development. In all cases studied thus far interviral recombination is a rare event that requires special circumstances for intracellular interaction of participating viral genomes. The rarity and special requirements do not detract from the potential clinical significance of resulting recombinants, as exemplified by recombination between JC viral and Epstein-Barr viral genomes. This significance depends largely upon the mechanisms of recombination that would generate specific forms of recombinant viral genomes. At this time little is known regarding mechanisms of interviral recombination. DNA break-induced replication seems presently to be a highly plausible means of initiating formation of different, potentially active recombination products. Generalizing interviral recombination to a variety of viruses will open a fertile field for discovery as multiple diseases of mysterious etiology are investigated.