Viral metagenomic identification of a novel anellovirus in blood sample of a child with atopic dermatitis.

Here, using viral metagenomics, a novel anellovirus with strain name HuAV-zj-ad1 was detected in blood sample from a child with atopic dermatitis. The complete genome sequence of HuAV-zj-ad1 was determined and fully characterized. The circular genome of HuAV-zj-ad1 is 2841 nt in length and includes four polyprotein ORFs. Phylogenetic analysis and pairwise sequence comparisons based on the amino acid sequences of ORF1, ORF2, ORF3, ORF4 indicated that HuAV-zj-ad1 belonged to a novel species within the genus Betatorquevirus. Polymerase chain reaction screening results showed this anellovirus was not present 50 blood samples from normal children. Whether this novel species of anellovirus has association with a certain disease needs further study.

Diversity and dynamic changes of anelloviruses in plasma following allogeneic hematopoietic stem cell transplantation.

Monitoring of alphatorquevirus (torque teno virus [TTV]) DNA in plasma may prove to be useful to assess the net state of immune competence following allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are scarce data published on the prevalence of beta (torque teno mini virus [TTMV]) and gammatorqueviruses (torque teno midi virus [TTMDV]) and, in particular, on the dynamics of anelloviruses in allo-HSCT patients. Twenty-five allo-HSCT recipients with available plasma specimens obtained before conditioning and after engraftment were included. Degenerated primers targeting a highly conserved genomic sequence across all anelloviruses were designed for genomic amplification and high-throughput sequencing. Co-detection of TTV, TTMV, and TTMDV both in pre-transplant and post-engraftment plasma specimens was documented in more than two-thirds of patients. The use of quantitative real-time polymerase chain reaction (PCR) assays targeting TTMV and TTMDV in addition to TTV may add value to TTV-specific PCR assays in the inference of the net state of immunosuppresion or immune competence in this clinical setting.

Complex Virome in a Mesenteric Lymph Node from a Californian Sea Lion (Zalophus Californianus) with Polyserositis and Steatitis.

An emaciated subadult free-ranging California sea lion (Csl or Zalophus californianus) died following stranding with lesions similar to 11 other stranded animals characterized by chronic disseminated granulomatous inflammation with necrotizing steatitis and vasculitis, involving visceral adipose tissues in the thoracic and peritoneal cavities. Histologically, affected tissues had extensive accumulations of macrophages with perivascular lymphocytes, plasma cells, and fewer neutrophils. Using viral metagenomics on a mesenteric lymph node six mammalian viruses were identified consisting of novel parvovirus, polyomavirus, rotavirus, anellovirus, and previously described Csl adenovirus 1 and Csl bocavirus 4. The causal or contributory role of these viruses to the gross and histologic lesions of this sea lion remains to be determined.

Metagenomic Next-Generation Sequencing Reveals Individual Composition and Dynamics of Anelloviruses during Autologous Stem Cell Transplant Recipient Management.

Over recent years, there has been increasing interest in the use of the anelloviruses, the major component of the human virome, for the prediction of post-transplant complications such as severe infections. Due to an important diversity, the comprehensive characterization of this viral family over time has been poorly studied. To overcome this challenge, we used a metagenomic next-generation sequencing (mNGS) approach with the aim of determining the individual anellovirus profile of autologous stem cell transplant (ASCT) patients. We conducted a prospective pilot study on a homogeneous patient cohort regarding the chemotherapy regimens that included 10 ASCT recipients. A validated viral mNGS workflow was used on 108 plasma samples collected at 11 time points from diagnosis to 90 days post-transplantation. A complex interindividual variability in terms of abundance and composition was noticed. In particular, a strong sex effect was found and confirmed using quantitative PCR targeting torque teno virus, the most abundant anellovirus. Interestingly, an important turnover in the anellovirus composition was observed during the course of the disease revealing a strong intra-individual variability. Although more studies are needed to better understand anellovirus dynamics, these findings are of prime importance for their future use as biomarkers of immune competence.

Viral nucleic acids in human plasma pools.

BACKGROUND: The identification of viruses in human blood is required for epidemiologic surveillance and to detect potentially emerging threats to blood transfusion safety. STUDY DESIGN AND METHODS: Viral nucleic acids in plasma fractionation pools assembled from blood donors in the United States and Europe were analyzed by viral metagenomics. RESULTS: Anelloviruses were detected in each of the 10 plasma pools. Human pegivirus A (HPgV; GB virus type C) sequences were identified in eight of the 10 pools, more than 90% of which belong to Genotype 2. The recently described human HPgV2 in Flaviviridae was not detected. A small number of sequence reads of human papillomavirus were also detected in three pools. In one pool, two different gemycircularvirus genomes were identified and fully sequenced. The capsid protein of one gemycircularvirus shared 83% to 84% identity to those of genomes from human serum and sewage. The presence of the gemycircularvirus genomes in the plasma pool was independently confirmed and the viral concentration estimated by digital PCR at more than 10(6) copies/mL assuming their origin from single donors. CONCLUSION: Further research is required to elucidate whether gemycircularviruses can infect humans or are indicative of contamination occurring during phlebotomy, plasma pool processing, or ongoing donor fungal infections.

Human anelloviruses: an update of molecular, epidemiological and clinical aspects.

Human torque teno viruses (TTVs) are new, emerging infectious agents, recently assigned to the family Anelloviridae. The first representative of the genus, torque teno virus (TTV), was discovered in 1997, followed by torque teno mini virus (TTMV) in 2000, and torque teno midi virus (TTMDV) in 2007. These viruses are characterized by an extremely high prevalence, with relatively uniform distribution worldwide and a high level of genomic heterogeneity, as well as an apparent pan-tropism at the host level. Although these viruses have a very high prevalence in the general population across the globe, neither their interaction with their hosts nor their direct involvement in the etiology of specific diseases are fully understood. Since their discovery, human anelloviruses, and especially TTV, have been suggested to be associated with various diseases, such as hepatitis, respiratory diseases, cancer, hematological and autoimmune disorders, with few arguments for their direct involvement. Recent studies have started to reveal interactions between TTVs and the host's immune system, leading to new hypotheses for potential pathological mechanisms of these viruses. In this review article, we discuss the most important aspects and current status of human TTVs in order to guide future studies.

[GENUS ANELLOVIRIDAE VIRUSES IN CHRONIC LIVER DISEASE].

AIM: Viruses from genus Anelloviridae (TTV, TTMDV and TTMV) are small DNA viruses that are widespread in human popu- lation. Data on tissue tropism, cell localization and morphometry of anelloviruses are scarce. The purpose of this study was to determine the prevalence of TTV, TTMDV and TTMV in persons with liver disease and in healthy individuals, as well as electron-microscopic verification of Anelloviridae species. METHODS: Detection of anelloviral DNA was performed in serum samples from 203 patients with liver diseases of various etiology and 115 voluntary blood donors using PCR with primers allowing to differentiate TTV, TTMDV TTMV based on the length of amplified fragment. Histopathological and electron microscopic studies were performed for liver biopsy specimens from 203 patients with liver disease. RESULTS: High prevalence (70-90%) of all three anelloviruses in healthy individuals and patients with liver disease was demonstrated, with high frequency of triple TTV, TTMDV and TTMV infection (52.2-55.7%). Electron-microscopic study of liver biopsy specimens from TTMDV monoinfected patients gave a submicroscopic image of TTMDV virions with diameter 35.86 ± 2.04 nm. Electron microscopic studies confirmed the nature of liver damage in TTMDV monoinfection: accumulation of virus in the hepatocytes, significant cyropathy with enlightenment matrix of the cytoplasm and reduction of intracellula organelles involved in protein synthesis, portal and perivascular perisinusoidal fibrosis. TTV, TTMDV and TTMV virions were dentified in hepatocytes, confirming these viruses to be hepatotropic. CONCLUSION: Our results demonstrate that anelloviruses are lymphotropic viruses, individual genotypes of those might be hepatotropic and pathogenic to liver.