Understanding off-target growth defects introduced to influenza A virus by synonymous recoding.

CpG dinucleotides are under-represented in the genomes of most RNA viruses. Synonymously increasing CpG content of a range of RNA virus genomes reliably causes replication defects due to the recognition of CpG motifs in RNA by cellular Zinc-finger Antiviral Protein (ZAP). Prior to the discovery of ZAP as a CpG sensor, we described an engineered influenza A virus (IAV) enriched for CpGs in segment 5 that displays the expected replication defects.

Towards the Development of a Minigenome Assay for Species A Rotaviruses.

RNA virus polymerases carry out multiple functions necessary for successful genome replication and transcription. A key tool for molecular studies of viral RNA-dependent RNA polymerases (RdRps) is a 'minigenome' or 'minireplicon' assay, in which viral RdRps are reconstituted in cells in the absence of full virus infection. Typically, plasmids expressing the viral polymerase protein(s) and other co-factors are co-transfected, along with a plasmid expressing an RNA encoding a fluorescent or luminescent reporter gene flanked by viral untranslated regions containing -acting elements required for viral RdRp recognition.

CpG dinucleotide enrichment in the influenza A virus genome as a live attenuated vaccine development strategy.

Synonymous recoding of RNA virus genomes is a promising approach for generating attenuated viruses to use as vaccines. Problematically, recoding typically hinders virus growth, but this may be rectified using CpG dinucleotide enrichment. CpGs are recognised by cellular zinc-finger antiviral protein (ZAP), and so in principle, removing ZAP sensing from a virus propagation system will reverse attenuation of a CpG-enriched virus, enabling high titre yield of a vaccine virus.

1 Cellular protein TTC4 and its cofactor HSP90 are pro-viral for bovine herpesvirus 1.

Bovine Herpesvirus Type 1 (BoHV-1) infection causes infectious bovine rhinotracheitis and genital disease in cattle, with significant economic and welfare impacts. However, the role of cellular host factors during viral replication remains poorly characterised. A previously performed genome-wide CRISPR knockout screen identified pro- and antiviral host factors acting during BoHV-1 replication.

Novel adenoviruses detected in British mustelids, including a unique in the tissues of pine martens ().

Several adenoviruses are known to cause severe disease in veterinary species. Recent evidence suggests that canine adenovirus type 1 (CAV-1) persists in the tissues of healthy red foxes (), which may be a source of infection for susceptible species. It was hypothesized that mustelids native to the UK, including pine martens () and Eurasian otters (), may also be persistently infected with adenoviruses.

PARV4 prevalence, phylogeny, immunology and coinfection with HIV, HBV and HCV in a multicentre African cohort.

The seroprevalence of human parvovirus-4 (PARV4) varies considerably by region. In sub-Saharan Africa, seroprevalence is high in the general population, but little is known about the transmission routes or the prevalence of coinfection with blood-borne viruses, HBV, HCV and HIV.  To further explore the characteristics of PARV4 in this setting, with a particular focus on the prevalence and significance of coinfection, we screened a cohort of 695 individuals recruited from Durban and Kimberley (South Africa) and Gaborone (Botswana) for PARV4 IgG and DNA, as well as documenting HIV, HBV and HCV status.

Serological and molecular epidemiology of canine adenovirus type 1 in red foxes (Vulpes vulpes) in the United Kingdom.

Canine adenovirus type 1 (CAV-1) causes infectious canine hepatitis (ICH), a frequently fatal disease which primarily affects canids. In this study, serology (ELISA) and molecular techniques (PCR/qPCR) were utilised to investigate the exposure of free-ranging red foxes (Vulpes vulpes) to CAV-1 in the United Kingdom (UK) and to examine their role as a wildlife reservoir of infection for susceptible species. The role of canine adenovirus type 2 (CAV-2), primarily a respiratory pathogen, was also explored.

Evaluation of Viremia Frequencies of a Novel Human Pegivirus by Using Bioinformatic Screening and PCR.

Next-generation sequencing has critical applications in virus discovery, diagnostics, and environmental surveillance. We used metagenomic sequence libraries for retrospective screening of plasma samples for the recently discovered human hepegivirus 1 (HHpgV-1). From a cohort of 150 hepatitis C virus (HCV)-positive case-patients, we identified 2 persons with HHpgV-1 viremia and a high frequency of human pegivirus (HPgV) viremia (14%).

High prevalence and diversity of bovine astroviruses in the faeces of healthy and diarrhoeic calves in South West Scotland.

Astroviruses (AstV) are single-stranded, positive-sense RNA viruses and one of the major causes of infant diarrhoea worldwide. Diarrhoea is a common and important cause of morbidity and mortality in calves; therefore, we investigated whether the presence of AstV is associated with calf diarrhoea. We identified diverse AstV lineages from faecal samples of both healthy and diarrhoeic calves and healthy adult cattle in South West Scotland.

Complete genome sequences of novel anelloviruses from laboratory rats.

Anelloviruses are nonenveloped single-stranded DNA viruses infecting a wide range of mammals. We report three complete genomes of novel anelloviruses detected in laboratory rats. Phylogenetic analysis demonstrates that these viruses are related to but distinct from recently described rodent Torque teno viruses (RoTTVs) found in wild rodent species.

Identification of novel anelloviruses with broad diversity in UK rodents.

Anelloviruses are a family of small circular ssDNA viruses with a vast genetic diversity. Human infections with the prototype anellovirus, torque teno virus (TTV), are ubiquitous and related viruses have been described in a number of other mammalian hosts. Despite over 15 years of investigation, there is still little known about the pathogenesis and possible disease associations of anellovirus infections, arising in part due to the lack of a robust cell culture system for viral replication or tractable small-animal model.

Human parvovirus 4 infection, Cameroon.

In a post hoc analysis of samples collected in 2009, we determined seroprevalence of parvovirus 4 (PARV4) among elderly Cameroonians. PARV4 seropositivity was associated with receipt of intravenous antimalarial drugs, intramuscular streptomycin, or an intramuscular contraceptive, but not hepatitis C virus seropositivity. Findings suggest parenteral acquisition of some PARV4 infections.

Virologic and clinical features of primary infection with human parvovirus 4 in subjects with hemophilia: frequent transmission by virally inactivated clotting factor concentrates.

Background: Human parvovirus 4 (PARV4) is a newly discovered parvovirus prevalent in injecting drug users and other groups with histories of parenteral exposure including persons with hemophilia exposed to non-virally inactivated clotting factor concentrates. To investigate its potential ongoing transmission to persons with hemophilia treated with plasma-derived, virally inactivated clotting factors, we screened a large cohort of persons with hemophilia for antibody seroconversion to PARV4 over a 5-year observation period.

Study Design And Methods: Samples from 195 persons with hemophilia enrolled in the Hemophilia Growth and Development Study cohort were screened for PARV4 antibodies at the start and end of a 5-year period of treatment with exclusively virally inactivated clotting factor concentrates.

Detection and genetic characterization of enteroviruses circulating among wild populations of chimpanzees in Cameroon: relationship with human and simian enteroviruses.

Enteroviruses (EVs), members of the family Picornaviridae, are a genetically and antigenically diverse range of viruses causing acute infections in humans and several Old World monkey (OWM) species. Despite their known wide distribution in primates, nothing is currently known about the occurrence, frequency, and genetic diversity of enteroviruses infecting apes. To investigate this, 27 chimpanzee and 27 gorilla fecal samples collected from undisturbed jungle areas with minimal human contact in Cameroon were screened for EVs.

Changing epidemiology of human parvovirus 4 infection in sub-Saharan Africa.

Human parvovirus 4 infections are primarily associated with parenteral exposure in western countries. By ELISA, we demonstrate frequent seropositivity for antibody to parvovirus 4 viral protein 2 among adult populations throughout sub-Saharan Africa (Burkina Faso, 37%; Cameroon, 25%; Democratic Republic of the Congo, 35%; South Africa, 20%), which implies existence of alternative transmission routes.

Widespread infection with homologues of human parvoviruses B19, PARV4, and human bocavirus of chimpanzees and gorillas in the wild.

Infections with human parvoviruses B19 and recently discovered human bocaviruses (HBoVs) are widespread, while PARV4 infections are transmitted parenterally and prevalent specifically in injecting drug users and hemophiliacs. To investigate the exposure and circulation of parvoviruses related to B19 virus, PARV4, and HBoV in nonhuman primates, plasma samples collected from 73 Cameroonian wild-caught chimpanzees and gorillas and 91 Old World monkey (OWM) species were screened for antibodies to recombinant B19 virus, PARV4, and HBoV VP2 antigens by enzyme-linked immunosorbent assay (ELISA). Moderate to high frequencies of seroreactivity to PARV4 (63% and 18% in chimpanzees and gorillas, respectively), HBoV (73% and 36%), and B19 virus (8% and 27%) were recorded for apes, while OWMs were uniformly negative (for PARV4 and B19 virus) or infrequently reactive (3% for HBoV).

High frequencies of exposure to the novel human parvovirus PARV4 in hemophiliacs and injection drug users, as detected by a serological assay for PARV4 antibodies.

Background: PARV4 is a human parvovirus that was first detected in and cloned from an individual with a human immunodeficiency virus (HIV) seroconversion-like illness and that subsequently persisted in the lymphoid tissue and bone marrow. In contrast to human parvovirus B19 infections, PARV4 infections are most frequently detected in injection drug users (IDUs), particularly those who are coinfected with HIV type 1 (HIV-1). To investigate the routes of transmission of PARV4 and to ascertain whether infections are acquired through plasma-derived blood products, we developed a novel anti-PARV4 enzyme-linked immunosorbent assay (ELISA) to determine its seroprevalence in subjects with parenteral exposure.

Atypical progressive multifocal leukoencephalopathy associated with an unusual JC polyomavirus mutation.

Objective: To report the clinical and radiologic features in a patient with myelofibrosis who developed atypical progressive multifocal leukoencephalopathy.

Design: Case report.

Setting: Tertiary referral center.

Reactivation and mutation of newly discovered WU, KI, and Merkel cell carcinoma polyomaviruses in immunosuppressed individuals.

Background: Infection with the human polyomaviruses BK (BKV) and JC (JCV) is almost ubiquitous, asymptomatic, and lifelong. However, reactivation during immunosuppression, associated with mutations in the transcriptional control region (TCR) that up-regulates viral replication, can cause life-threatening disease. In this study, we investigated whether the recently discovered WU and KI polyomaviruses (WUPyV and KIPyV) and Merkel cell polyomavirus (MCPyV) could, like BKV and JCV, persist, mutate, and reactivate in immunodeficient subjects.

Continuous control of autoimmune disease by antigen-dependent polyclonal CD4+CD25+ regulatory T cells in the regional lymph node.

This study investigated the unresolved issue of antigen-dependency and antigen-specificity of autoimmune disease suppression by CD4+CD25+ T cells (T regs). Based on autoimmune ovarian disease (AOD) in day 3 thymectomized (d3tx) mice and polyclonal T regs expressing the Thy1.1 marker, we determined: (a) the location of recipient T cell suppression, (b) the distribution of AOD-suppressing T regs, and (c) the relative efficacy of male versus female T regs.