scholarly journals Human anelloviruses: diverse, omnipresent and commensal members of the virome

2020 ◽  
Vol 44 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Joanna Kaczorowska ◽  
Lia van der Hoek
Keyword(s):  
Beneficial Effect ◽  
Culture System ◽  
Human Population ◽  
Human Life ◽  
Disease Association ◽  
Viral Clearance ◽  
Early Age ◽  
Dna Viruses ◽  
Circular Dna ◽  
Host Interactions

ABSTRACT Anelloviruses are small, single stranded circular DNA viruses. They are extremely diverse and have not been associated with any disease so far. Strikingly, these small entities infect most probably the complete human population, and there are no convincing examples demonstrating viral clearance from infected individuals. The main transmission could be via fecal-oral or airway route, as infections occur at an early age. However, due to the lack of an appropriate culture system, the virus–host interactions remain enigmatic. Anelloviruses are obviously mysterious viruses, and their impact on human life is not yet known, but, with no evidence of a disease association, a potential beneficial effect on human health should also be investigated.

scholarly journals Viruses go modular

2020 ◽  
Vol 295 (14) ◽  
pp. 4604-4616 ◽  
Author(s):  
Ariel Shepley-McTaggart ◽  
Hao Fan ◽  
Marius Sudol ◽  
Ronald N. Harty
Keyword(s):  
Hippo Pathway ◽  
Host Proteins ◽  
Dna Viruses ◽  
Ww Domain ◽  
Ww Domains ◽  
Host Interactions ◽  
New Class ◽  
Domain Interactions ◽  
Molecular Aspects ◽  
The Hippo Pathway

The WW domain is a modular protein structure that recognizes the proline-rich Pro-Pro-x-Tyr (PPxY) motif contained in specific target proteins. The compact modular nature of the WW domain makes it ideal for mediating interactions between proteins in complex networks and signaling pathways of the cell (e.g. the Hippo pathway). As a result, WW domains play key roles in a plethora of both normal and disease processes. Intriguingly, RNA and DNA viruses have evolved strategies to hijack cellular WW domain–containing proteins and thereby exploit the modular functions of these host proteins for various steps of the virus life cycle, including entry, replication, and egress. In this review, we summarize key findings in this rapidly expanding field, in which new virus-host interactions continue to be identified. Further unraveling of the molecular aspects of these crucial virus-host interactions will continue to enhance our fundamental understanding of the biology and pathogenesis of these viruses. We anticipate that additional insights into these interactions will help support strategies to develop a new class of small-molecule inhibitors of viral PPxY-host WW-domain interactions that could be used as antiviral therapeutics.

Novel circular DNA virus identified in Opuntia discolor (Cactaceae) that codes for proteins with similarity to those of geminiviruses

2021 ◽  
Vol 102 (11) ◽  
Author(s):  
Rafaela S. Fontenele ◽  
Matias Köhler ◽  
Lucas C. Majure ◽  
Jesús A. Avalos-Calleros ◽  
Gerardo R. Argüello-Astorga ◽  
...  
Keyword(s):  
South America ◽  
Rolling Circle Replication ◽  
Dna Virus ◽  
Single Stranded Dna ◽  
Dna Viruses ◽  
Circular Dna ◽  
Rolling Circle ◽  
Rep Protein ◽  
Molecular Features ◽  
Viral Components

Viral metagenomic studies have enabled the discovery of many unknown viruses and revealed that viral communities are much more diverse and ubiquitous than previously thought. Some viruses have multiple genome components that are encapsidated either in separate virions (multipartite viruses) or in the same virion (segmented viruses). In this study, we identify what is possibly a novel bipartite plant-associated circular single-stranded DNA virus in a wild prickly pear cactus, Opuntia discolor, that is endemic to the Chaco ecoregion in South America. Two ~1.8 kb virus-like circular DNA components were recovered, one encoding a replication-associated protein (Rep) and the other a capsid protein (CP). Both of the inferred protein sequences of the Rep and CP are homologous to those encoded by members of the family Geminiviridae. These two putatively cognate components each have a nonanucleotide sequence within a likely hairpin structure that is homologous to the origins of rolling-circle replication (RCR), found in diverse circular single-stranded DNA viruses. In addition, the two components share similar putative replication-associated iterative sequences (iterons), which in circular single-stranded DNA viruses are important for Rep binding during the initiation of RCR. Such molecular features provide support for the possible bipartite nature of this virus, which we named utkilio virus (common name of the Opuntia discolor in South America) components A and B. In the infectivity assays conducted in Nicotiana benthamiana plants, only the A component of utkilio virus, which encodes the Rep protein, was found to move and replicate systemically in N. benthamiana. This was not true for component B, for which we did not detect replication, which may have been due to this being a defective molecule or because of the model plants (N. benthamiana) used for the infection assays. Future experiments need to be conducted with other plants, including O. discolor, to understand more about the biology of these viral components.

scholarly journals Effect of Lactobacillus acidophilus Fermented Broths Enriched with Eruca sativa Seed Extracts on Intestinal Barrier and Inflammation in a Co-Culture System of an Enterohemorrhagic Escherichia coli and Human Intestinal Cells

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3064
Author(s):  
Francesca Bonvicini ◽  
Eleonora Pagnotta ◽  
Angela Punzo ◽  
Donato Calabria ◽  
Patrizia Simoni ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Beneficial Effect ◽  
Culture System ◽  
Intestinal Inflammation ◽  
Enterohemorrhagic Escherichia Coli ◽  
Eruca Sativa ◽  
Intestinal Function ◽  
Barrier Dysfunction ◽  
Gut Barrier ◽  
Seed Extracts

Lactic acid bacteria (LAB) “fermentates” confer a beneficial effect on intestinal function. However, the ability of new fermentations to improve LAB broth activity in preventing pathogen-induced intestinal inflammation and barrier dysfunction has not yet been studied. The objective of this study was to determine if broths of LAB fermented with Eruca sativa or Barbarea verna seed extracts prevent gut barrier dysfunction and interleukin-8 (CXCL8) release in vitro in human intestinal Caco-2 cells infected with enterohemorrhagic Escherichia coli (EHEC) O157:H7. LAB broths were assayed for their effects on EHEC growth and on Caco-2 viability; thereafter, their biological properties were analysed in a co-culture system consisting of EHEC and Caco-2 cells. Caco-2 cells infected with EHEC significantly increased CXCL8 release, and decreased Trans-Epithelial Electrical Resistance (TEER), a barrier-integrity marker. Notably, when Caco-2 cells were treated with LAB broth enriched with E. sativa seed extract and thereafter infected, both CXCL8 expression and epithelial dysfunction reduced compared to in untreated cells. These results underline the beneficial effect of broths from LAB fermented with E. sativa seed extracts in gut barrier and inflammation after EHEC infection and reveal that these LAB broths can be used as functional bioactive compounds to regulate intestinal function.

scholarly journals Unique structure and function of viral rhodopsins

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Dmitry Bratanov ◽  
Kirill Kovalev ◽  
Jan-Philipp Machtens ◽  
Roman Astashkin ◽  
Igor Chizhov ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Structure And Function ◽  
Proton Donor ◽  
Dna Viruses ◽  
Host Interactions ◽  
Hydrophobic Barrier ◽  
High Resolution Structure ◽  
Group 2 ◽  
Marine Protists ◽  
And Function

Abstract Recently, two groups of rhodopsin genes were identified in large double-stranded DNA viruses. The structure and function of viral rhodopsins are unknown. We present functional characterization and high-resolution structure of an Organic Lake Phycodnavirus rhodopsin II (OLPVRII) of group 2. It forms a pentamer, with a symmetrical, bottle-like central channel with the narrow vestibule in the cytoplasmic part covered by a ring of 5 arginines, whereas 5 phenylalanines form a hydrophobic barrier in its exit. The proton donor E42 is placed in the helix B. The structure is unique among the known rhodopsins. Structural and functional data and molecular dynamics suggest that OLPVRII might be a light-gated pentameric ion channel analogous to pentameric ligand-gated ion channels, however, future patch clamp experiments should prove this directly. The data shed light on a fundamentally distinct branch of rhodopsins and may contribute to the understanding of virus-host interactions in ecologically important marine protists.

Novel circular DNA viruses associated with Apiaceae and Poaceae from South Africa and New Zealand

2018 ◽  
Vol 164 (1) ◽  
pp. 237-242 ◽  
Author(s):  
Cécile Richet ◽  
Simona Kraberger ◽  
Denis Filloux ◽  
Pauline Bernardo ◽  
Gordon W. Harkins ◽  
...  
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Dna Viruses ◽  
Circular Dna

scholarly journals Review on the Relationship between Human Polyomaviruses-Associated Tumors and Host Immune System

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Serena Delbue ◽  
Manola Comar ◽  
Pasquale Ferrante
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Human Population ◽  
Host Immune System ◽  
Dna Viruses ◽  
Human Host ◽  
Immunosuppressed Patients ◽  
The Relationship ◽  
Associated Tumors ◽  
Human Polyomaviruses

The polyomaviruses are small DNA viruses that can establish latency in the human host. The name polyomavirus is derived from the Greek rootspoly-, which means “many,” and -oma, which means “tumours.” These viruses were originally isolated in mouse (mPyV) and in monkey (SV40). In 1971, the first human polyomaviruses BK and JC were isolated and subsequently demonstrated to be ubiquitous in the human population. To date, at least nine members of thePolyomaviridaefamily have been identified, some of them playing an etiological role in malignancies in immunosuppressed patients. Here, we describe the biology of human polyomaviruses, their nonmalignant and malignant potentials ability, and their relationship with the host immune response.

scholarly journals Swine torque teno virus detection in pig commercial vaccines, enzymes for laboratory use and human drugs containing components of porcine origin

2009 ◽  
Vol 90 (3) ◽  
pp. 648-653 ◽  
Author(s):  
Tuija Kekarainen ◽  
Laura Martínez-Guinó ◽  
Joaquim Segalés
Keyword(s):  
Virus Detection ◽  
Mycoplasma Hyopneumoniae ◽  
The Other ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Dna Viruses ◽  
Circular Dna ◽  
Wasting Syndrome ◽  
High Prevalence ◽  
Porcine Origin

Torque teno viruses (TTVs) are vertebrate infecting, single-stranded circular DNA viruses. Two genetically distinct TTV genogroups (TTV1 and TTV2) infect swine worldwide with high prevalence. Currently, swine TTVs are considered non-pathogenic, although TTV2 has been linked to post-weaning multisystemic wasting syndrome, a porcine circovirus disease. On the other hand, pig materials are an important source of components used in porcine vaccine manufacturing, human drugs and commercial enzyme products. However, there is little information about the possible existence of extraneous viruses in products containing porcine-derived components. In the present study, 26 commercial swine vaccines, seven human drugs and three enzyme products from porcine origin were tested for the presence of TTV1 and TTV2 genomes by PCR. Four vaccines against Mycoplasma hyopneumoniae were positive for TTV2 by PCR. Three M. hyopneumoniae, one porcine parvovirus and one porcine reproductive and respiratory syndrome virus vaccines were PCR positive for TTV1. One human drug contained TTV1 DNA as well as a trypsin enzyme; a porcine-derived elastase product was positive for both TTV genogroups. These results show that swine TTVs are contaminants not only of swine vaccines but also of human drugs containing porcine components and enzymes for laboratory use.

scholarly journals A new full-length virus genome sequencing method reveals that antiviral RNAi changes geminivirus populations in field-grown cassava

2017 ◽  
Author(s):  
Devang Mehta ◽  
Matthias Hirsch-Hoffmann ◽  
Mariam Were ◽  
Andrea Patrignani ◽  
Hassan Were ◽  
...  
Keyword(s):  
Single Molecule ◽  
Deep Sequencing ◽  
Cost Effective ◽  
Virus Genome ◽  
Full Length ◽  
Dna Viruses ◽  
Circular Dna ◽  
Sequencing Technologies ◽  
Virus Genomes ◽  
And Control

ABSTRACTDeep-sequencing of virus isolates using short-read sequencing technologies is problematic since viruses are often present in complexes sharing a high-degree of sequence identity. The full-length genomes of such highly-similar viruses cannot be assembled accurately from short sequencing reads. We present a new method, CIDER-Seq (Circular DNA Enrichment Sequencing) which successfully generates accurate full-length virus genomes from individual sequencing reads with no sequence assembly required. CIDER-Seq operates by combining a PCR-free, circular DNA enrichment protocol with Single Molecule Real Time sequencing and a new sequence deconcatenation algorithm. We apply our technique to produce more than 1,200 full-length, highly accurate geminivirus genomes from RNAi-transgenic and control plants in a field trial in Kenya. Using CIDER-Seq we can demonstrate for the first time that the expression of antiviral doublestranded RNA (dsRNA) in transgenic plants causes a consistent shift in virus populations towards species sharing low homology to the transgene derived dsRNA. Our results show that CIDER-seq is a powerful, cost-effective tool for accurately sequencing circular DNA viruses, with future applications in deep-sequencing other forms of circular DNA such as transposons and plasmids.

scholarly journals The Enhancement of Phytochemical Compounds in Fresh Produces by Abiotic Stress Application at Postharvest Handling Stage

2021 ◽  
Vol 2 (01) ◽  
pp. 1-18
Author(s):  
Daimon Syukri ◽  
Arisvan Chamel
Keyword(s):  
Abiotic Stress ◽  
Beneficial Effect ◽  
Functional Food ◽  
Human Life ◽  
External Quality ◽  
Handling System ◽  
Postharvest Handling ◽  
Phytochemical Compounds ◽  
Stress Application ◽  
Phytochemical Contents

Fresh produces is one of functional food based on its phytochemical contents. The great amounts of the phytochemical compounds in fresh produces become the main core of quality jugdement from fresh produses as  a functional food. The use of proper postharvest handling system of fresh produces can be as a tool to protect the loss of the external quality and also can be used to enhance the levels of phytochemical compounds therein at the same time. A  good management of plant stresses in respect to key enzymes activation of phytocemicals pathway during postharvest handling treatments of fresh produces can trigger distinct change of contained phytochemicals that can promote their healthy beneficial effect for human life.

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