Lymphocyte gene expression and JC virus noncoding control region sequences are linked with the risk of progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML)-derived noncoding control region (NCCR) sequences permitted greater early viral gene expression than kidney-associated NCCR sequences. This was driven in part by binding of the transcription factor Spi-B to unique PML-associated Spi-B binding sites. Spi-B is upregulated in developing B cells in response to natalizumab therapy, a known risk factor for PML. Naturally occurring JCV sequence variation, together with drug treatment-induced cellular changes, may synergize to create an environment leading to an increased risk of PML.

Differentiation of human fetal multipotential neural progenitor cells to astrocytes reveals susceptibility factors for JC virus.

Viral infections of the central nervous system (CNS) are of increasing concern, especially among immunocompromised populations. Rodent models are often inappropriate for studies of CNS infection, as many viruses, including JC virus (JCV) and HIV, cannot replicate in rodent cells. Consequently, human fetal brain-derived multipotential CNS progenitor cells (NPCs) that can be differentiated into neurons, oligodendrocytes, or astrocytes have served as a model in CNS studies. NPCs can be nonproductively infected by JCV, while infection of progenitor-derived astrocytes (PDAs) is robust. We profiled cellular gene expression at multiple times during differentiation of NPCs to PDAs. Several activated transcription factors show commonality between cells of the brain, in which JCV replicates, and lymphocytes, in which JCV is likely latent. Bioinformatic analysis determined transcription factors that may influence the favorable transcriptional environment for JCV in PDAs. This study attempts to provide a framework for understanding the functional transcriptional profile necessary for productive JCV infection.

Molecular biology, epidemiology, and pathogenesis of progressive multifocal leukoencephalopathy, the JC virus-induced demyelinating disease of the human brain.

Progressive multifocal leukoencephalopathy (PML) is a debilitating and frequently fatal central nervous system (CNS) demyelinating disease caused by JC virus (JCV), for which there is currently no effective treatment. Lytic infection of oligodendrocytes in the brain leads to their eventual destruction and progressive demyelination, resulting in multiple foci of lesions in the white matter of the brain. Before the mid-1980s, PML was a relatively rare disease, reported to occur primarily in those with underlying neoplastic conditions affecting immune function and, more rarely, in allograft recipients receiving immunosuppressive drugs. However, with the onset of the AIDS pandemic, the incidence of PML has increased dramatically. Approximately 3 to 5% of HIV-infected individuals will develop PML, which is classified as an AIDS-defining illness. In addition, the recent advent of humanized monoclonal antibody therapy for the treatment of autoimmune inflammatory diseases such as multiple sclerosis (MS) and Crohn's disease has also led to an increased risk of PML as a side effect of immunotherapy. Thus, the study of JCV and the elucidation of the underlying causes of PML are important and active areas of research that may lead to new insights into immune function and host antiviral defense, as well as to potential new therapies.

Centring the health of women across the HIV research continuum.

Despite tremendous advances in HIV research, women and gender diverse people-particularly women from racial and ethnic groups under-represented in research, transgender women, and young women-remain disproportionately affected by HIV. Women and gender diverse people face unique challenges and have been under-represented in HIV research. The National Institutes of Health (NIH) is tasked to apply fundamental knowledge about the nature and behaviour of living systems to enhance health, lengthen life, and reduce disability. Rigorous exploration of-and interventions for-the individual, social, biological, structural, and environmental factors that influence HIV prevention, transmission, treatment, and cure is crucial to advance research for women, girls, and gender diverse people across the lifespan. In this Position Paper, we introduce a framework for an intersectional, equity-informed, data-driven approach to research on HIV and women and highlight selected issues for women and gender diverse people, including HIV prevention, HIV cure, ageing with HIV, substance use and misuse, violence, pregnancy, and breastfeeding or chestfeeding. This framework underlines a new HIV and Women Signature Programme from the NIH Office of AIDS Research and Office of Research on Women's Health that advances the NIH vision for women's health, in which all women receive evidence-based HIV prevention, treatment, and care across their lifespan tailored to their unique needs, circumstances, and goals. The time is now to centre the health of women, girls, and gender diverse people across the HIV research continuum.

JC virus promoter/enhancers contain TATA box-associated Spi-B-binding sites that support early viral gene expression in primary astrocytes.

JC virus (JCV) is the aetiological agent of the demyelinating disease progressive multifocal leukoencephalopathy, an AIDS defining illness and serious complication of mAb therapies. Initial infection probably occurs in childhood. In the working model of dissemination, virus persists in the kidney and lymphoid tissues until immune suppression/modulation causes reactivation and trafficking to the brain where JCV replicates in oligodendrocytes. JCV infection is regulated through binding of host factors such as Spi-B to, and sequence variation in the non-coding control region (NCCR). Although NCCR sequences differ between sites of persistence and pathogenesis, evidence suggests that the virus that initiates infection in the brain disseminates via B-cells derived from latently infected haematopoietic precursors in the bone marrow. Spi-B binds adjacent to TATA boxes in the promoter/enhancer of the PML-associated JCV Mad-1 and Mad-4 viruses but not the non-pathogenic, kidney-associated archetype. The Spi-B-binding site of Mad-1/Mad-4 differs from that of archetype by a single nucleotide, AAAAGGGAAGGGA to AAAAGGGAAGGTA. Point mutation of the Mad-1 Spi-B site reduced early viral protein large T-antigen expression by up to fourfold. Strikingly, the reverse mutation in the archetype NCCR increased large T-antigen expression by 10-fold. Interestingly, Spi-B protein binds the NCCR sequence flanking the viral promoter/enhancer, but these sites are not essential for early viral gene expression. The effect of mutating Spi-B-binding sites within the JCV promoter/enhancer on early viral gene expression strongly suggests a role for Spi-B binding to the viral promoter/enhancer in the activation of early viral gene expression.

Transport and Permeation Properties of Dapivirine: Understanding Potential Drug-Drug Interactions.

The dapivirine (DPV) vaginal ring was developed by the nonprofit International Partnership for Microbicides (IPM) for reducing the risk of HIV infection. A clinical study (IPM 028) showed that concomitant use of the DPV ring and miconazole (MIC) altered DPV pharmacokinetic profile. In this work, we investigated whether or not DPV transport and permeation contributed to the observed DPV-MIC interaction. Our study evaluated the interaction between DPV and several transporters that are highly expressed in the human female reproductive tract, including MRP1, MRP4, P-gp, BCRP, and ENT1, using vesicular and cellular systems. We also evaluated the impact of DPV/MIC on cellular tight junctions by monitoring transepithelial electrical resistance with the Ussing chamber. Lastly, we evaluated the effect of MIC on DPV permeability across human cervical tissue. Our findings showed that DPV was not a substrate of MRP1, MRP4, P-gp, BCRP, or ENT1 transporters. Additionally, DPV did not inhibit the activity of these transporters. DPV, MIC, and their combination also did not disrupt cellular tight junctions. MIC did not affect DPV tissue permeability but significantly reduced DPV tissue levels. Therefore, our results suggest that the DPV-MIC interaction is not due to these five transporters, altered tight junction integrity, or altered tissue permeability.

Hexadecyloxypropyl-cidofovir (CMX001) suppresses JC virus replication in human fetal brain SVG cell cultures.

JC virus (JCV) is a polyomavirus that infects human oligodendrocytes, leading to development of progressive multifocal leukoencephalopathy (PML), an often fatal demyelinating disease occurring in immunocompromised individuals. Currently there are no effective therapies for the treatment of PML that result in clearance of JCV from the brain. Cidofovir (CDV) is an acyclic nucleoside phosphonate that inhibits DNA polymerases and has been used for the treatment of PML. However, CDV demonstrated little efficacy as a treatment for PML and causes substantial side effects to patients. To improve efficacy and reduce the toxicity of CDV, a lipid-ester derivative, CMX001, was generated by Chimerix and is currently in multicenter phase II clinical trials for the prevention or control of cytomegalovirus infection in hematopoietic stem cell transplant recipients and of BK virus in the urine of stem cell or renal allograft recipients. CMX001 caused minimal cytotoxic effects in human fetal brain SVG cells when used at concentrations between 0.01 µM and 0.1 µM. CMX001 resulted in a dose-dependent decrease in the number of JCV-infected cells during initial infection and nearly eliminated JCV-infected cells during an established infection. In addition, CMX001 treatment resulted in a 60% reduction in JCV DNA copy number during initial infection, which suggests that suppression of JCV infection by CMX001 is likely due to inhibition of virus DNA replication. This study demonstrates that CMX001 suppresses JCV infection at concentrations that have limited toxicity to human brain cells, indicating its potential use to limit JCV replication in infected patients.

Transcription factor Spi-B binds unique sequences present in the tandem repeat promoter/enhancer of JC virus and supports viral activity.

Progressive multifocal leukoencephalopathy (PML) is an often fatal demyelinating disease caused by lytic infection of oligodendrocytes with JC virus (JCV). The development of PML in non-immunosuppressed individuals is a growing concern with reports of mortality in patients treated with mAb therapies. JCV can persist in the kidneys, lymphoid tissue and bone marrow. JCV gene expression is restricted by non-coding viral regulatory region sequence variation and cellular transcription factors. Because JCV latency has been associated with cells undergoing haematopoietic development, transcription factors previously reported as lymphoid specific may regulate JCV gene expression. This study demonstrates that one such transcription factor, Spi-B, binds to sequences present in the JCV promoter/enhancer and may affect early virus gene expression in cells obtained from human brain tissue. We identified four potential Spi-B-binding sites present in the promoter/enhancer elements of JCV sequences from PML variants and the non-pathogenic archetype. Spi-B sites present in the promoter/enhancers of PML variants alone bound protein expressed in JCV susceptible brain and lymphoid-derived cell lines by electromobility shift assays. Expression of exogenous Spi-B in semi- and non-permissive cells increased early viral gene expression. Strikingly, mutation of the Spi-B core in a binding site unique to the Mad-4 variant was sufficient to abrogate viral activity in progenitor-derived astrocytes. These results suggest that Spi-B could regulate JCV gene expression in susceptible cells, and may play an important role in JCV activity in the immune and nervous systems.

RUNX1 permits E4orf6-directed nuclear localization of the adenovirus E1B-55K protein and associates with centers of viral DNA and RNA synthesis.

The localization of the adenovirus E1B-55K-E4orf6 protein complex is critical for its function. Prior studies demonstrated that E4orf6 directs the nuclear localization of E1B-55K in human cells and in rodent cells that contain part of human chromosome 21. We show here that the relevant activity on chromosome 21 maps to RUNX1. RUNX1 proteins are transcription factors that serve as scaffolds for the assembly of proteins that regulate transcription and RNA processing. After transfection, the RUNX1a, RUNX1b, and RUNX1-DeltaN variants allowed E4orf6-directed E1B-55K nuclear localization. The failure of RUNX1c to allow nuclear colocalization was relieved by the deletion of amino-terminal residues of this protein. In the adenovirus-infected mouse cell, RUNX1 proteins were localized to discrete structures about the periphery of viral replication centers. These sites are enriched in viral RNA and RNA-processing factors. RUNX1b and RUNX1a proteins displaced E4orf6 from these sites. The association of E1B-55K at viral replication centers was enhanced by the RUNX1a and RUNX1b proteins, but only in the absence of E4orf6. In the presence of E4orf6, E1B-55K occurred in a perinuclear cytoplasmic body resembling the aggresome and was excluded from the nucleus of the infected mouse cell. We interpret these findings to mean that a dynamic relationship exists between the E4orf6, E1B-55K, and RUNX1 proteins. In cooperation with E4orf6, RUNX1 proteins are able to modulate the localization of E1B-55K and even remodel virus-specific structures that form at late times of infection. Subsequent studies will need to determine a functional consequence of the interaction between E4orf6, E1B-55K, and RUNX1.

Human Obesity Associated with an Intronic SNP in the Brain-Derived Neurotrophic Factor Locus.

Brain-derived neurotrophic factor (BDNF) plays a key role in energy balance. In population studies, SNPs of the BDNF locus have been linked to obesity, but the mechanism by which these variants cause weight gain is unknown. Here, we examined human hypothalamic BDNF expression in association with 44 BDNF SNPs. We observed that the minor C allele of rs12291063 is associated with lower human ventromedial hypothalamic BDNF expression (p < 0.001) and greater adiposity in both adult and pediatric cohorts (p values < 0.05). We further demonstrated that the major T allele for rs12291063 possesses a binding capacity for the transcriptional regulator, heterogeneous nuclear ribonucleoprotein D0B, knockdown of which disrupts transactivation by the T allele. Binding and transactivation functions are both disrupted by substituting C for T. These findings provide a rationale for BDNF augmentation as a targeted treatment for obesity in individuals who have the rs12291063 CC genotype.

Case of duodenal haematoma treated with ultrasound guided drainage.

Duodenal haematoma usually occurs secondary to blunt abdominal trauma(1), although more recently it has been recognized as a complication of endoscopic duodenal biopsy(2). The two established management strategies are to treat conservatively until resolution of the haematoma occurs or to surgically evacuate the haematoma. We present a case of duodenal haematoma that was successfully treated by ultrasound guided drainage when no improvement occurred with conservative treatment.

Clonal immortalized human glial cell lines support varying levels of JC virus infection due to differences in cellular gene expression.

JC virus (JCV) is a ubiquitous human polyomavirus that causes the demyelinating disease Progressive Multifocal Leukoencephalopathy (PML). JCV replicates in limited cell types in culture, predominantly in human glial cells. Following introduction of a replication defective SV40 mutant that expressed large T protein into a heterogeneous culture of human fetal brain cells, multiple phenotypes became immortalized (SVG cells). A subset of SVG cells could support JCV replication. In the current study, clonal cell lines were selected from the original SVG cell culture. The 5F4 clone showed low levels of viral growth. The 10B1 clone was highly permissive for JCV DNA replication and gene expression and supported persistent and stable JCV infection over months in culture. Microarray analysis revealed that viral infection did not significantly change gene expression in these cells. More resistant 5F4 cells expressed high levels of transcription factors known to inhibit JCV transcription. Interestingly, 5F4 cells expressed high levels of RNA of markers of radial glia and 10B1 cells had high expression of markers of immature glial cells and activation of transcription regulators important for stem/progenitor cell self-renewal. These SVG-derived clonal cell lines provide a biologically relevant model to investigate cell type differences in JCV host range and pathogenesis, as well as neural development. Several transcription regulators were identified which may be targets for therapeutic modulation of expression to abrogate JCV replication in PML patients. Additionally, these clonal cell lines can provide a consistent culture platform for testing therapies against JCV infection of the central nervous system.

Molecular regulation of JC virus tropism: insights into potential therapeutic targets for progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a growing concern for patients undergoing immune modulatory therapies for treatment of autoimmune diseases such as multiple sclerosis. Currently, there are no drugs approved for the treatment of PML that have been demonstrated in the patient to effectively and reproducibly alter the course of disease progression. The human polyoma virus JC is the causative agent of PML. JC virus (JCV) dissemination is tightly controlled by regulation of viral gene expression from the promoter by cellular transcription factors expressed in cells permissive for infection. JCV infection likely occurs during childhood, and latent virus containing PML-associated promoter sequences is maintained in lymphoid cells within the bone marrow. Because development of PML is tightly linked to suppression and or modulation of the immune system as in development of hematological malignancies, AIDS, and monoclonal antibody treatments, further scrutiny of the course of JCV infection in immune cells will be essential to our understanding of development of PML and identification of new therapeutic targets.