scholarly journals Identification and Characterization of Two Closely Related Unclassifiable Endogenous Retroviruses in Pythons (Python molurus and Python curtus)

2002 ◽  
Vol 76 (15) ◽  
pp. 7607-7615 ◽  
Author(s):  
Jon B. Huder ◽  
Jürg Böni ◽  
Jean-Michel Hatt ◽  
Guido Soldati ◽  
Hans Lutz ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Peripheral Blood Mononuclear ◽  
Python Regius ◽  
Boa Constrictor ◽  
Inclusion Body Disease ◽  
Python Molurus

ABSTRACT Boid inclusion body disease (BIBD) is a fatal disorder of boid snakes that is suspected to be caused by a retrovirus. In order to identify this agent, leukocyte cultures (established from Python molurus specimens with symptoms of BIBD or kept together with such diseased animals) were assessed for reverse transcriptase (RT) activity. Virus from cultures exhibiting high RT activity was banded on sucrose density gradients, and the RT peak fraction was subjected to highly efficient procedures for the identification of unknown particle-associated retroviral RNA. A 7-kb full retroviral sequence was identified, cloned, and sequenced. This virus contained intact open reading frames (ORFs) for gag, pro, pol, and env, as well as another ORF of unknown function within pol. Phylogenetic analysis showed that the virus is distantly related to viruses from both the B and D types and the mammalian C type but cannot be classified. It is present as a highly expressed endogenous retrovirus in all P. molurus individuals; a closely related, but much less expressed virus was found in all tested Python curtus individuals. All other boid snakes tested, including Python regius, Python reticulatus, Boa constrictor, Eunectes notaeus, and Morelia spilota, were virus negative, independent of whether they had BIBD or not. Virus isolated from P. molurus could not be transmitted to the peripheral blood mononuclear cells of B. constrictor or P. regius. Thus, there is no indication that this novel virus, which we propose to name python endogenous retrovirus (PyERV), is causally linked with BIBD.

scholarly journals Characterization of Endogenous Retroviruses in Sheep

2003 ◽  
Vol 77 (20) ◽  
pp. 11268-11273 ◽  
Author(s):  
Nikolai Klymiuk ◽  
Mathias Müller ◽  
Gottfried Brem ◽  
Bernhard Aigner
Keyword(s):  
Endogenous Retrovirus ◽  
Ovis Aries ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
In Vivo Experiments ◽  
Pregnant Sheep ◽  
Reading Frames

ABSTRACT Endogenous retrovirus (ERV) sequences have been found in all mammals. In vitro and in vivo experiments revealed ERV activation and cross-species infection in several species. Sheep (Ovis aries) are used for various biotechnological purposes; however, they have not yet been comprehensively screened for ERV sequences. Therefore, the aim of the study was to classify the ERV sequences in the ovine genome (OERV) by analyzing the retroviral pro-pol sequences. Three OERV β families and nine OERV γ families were revealed. Novel open reading frames (ORF) in the amplified proviral fragment were found in one OERV β family and two OERV γ families. Hybrid OERV produced by putative recombination events were not detected. Quantitative analysis of the OERV sequences in the ovine genome revealed no relevant variations in the endogenous retroviral loads of different breeds. Expression analysis of different tissues from fetal and pregnant sheep detected mRNA from both gammaretrovirus families, showing ORF fragments. Thus, the release of retroviruses from sheep cells cannot be excluded.

scholarly journals Detection and Characterization of Porcine Endogenous Retrovirus in Porcine Plasma and Porcine Factor VIII

2001 ◽  
Vol 75 (10) ◽  
pp. 4551-4557 ◽  
Author(s):  
Daniel M. Takefman ◽  
Susan Wong ◽  
Thomas Maudru ◽  
Keith Peden ◽  
Carolyn A. Wilson
Keyword(s):  
Factor Viii ◽  
Mononuclear Cells ◽  
Infectious Virus ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Peripheral Blood Mononuclear ◽  
Porcine Endogenous Retrovirus ◽  
Pig Genome

ABSTRACT The pig genome contains porcine endogenous retroviruses (PERVs) capable of infecting human cells. Detection of infectious retrovirus in porcine peripheral blood mononuclear cells and endothelial cells suggested to us that pig plasma is likely to contain PERV. Both PERV env sequences and viral reverse transcriptase (RT) activity were detected in all plasma samples isolated from four NIH minipigs. To detect infectious virus from plasma, we performed a culture assay using three cell lines of feline, swine, and human origin that had previously been shown to be permissive for PERV. Infectious virus was successfully cultured from all four NIH minipig plasmas on the swine cell line ST-IOWA. Using RT-PCR with env-specific primers, we could detect expression of PERV class C envelope in the supernatant of ST-IOWA cells that had been exposed to each pig plasma. We next examined a pig plasma derivative, Hyate:C (porcine factor VIII), and found evidence of PERV particles, since all six lots examined were positive for PERV RNA and RT activity. However, infectious virus could not be detected in clinical lots of Hyate:C, suggesting that the manufacturing process might reduce the load of infectious virus to levels below detectable limits of the assay. Detection of infectious virus in porcine plasma confirms and extends the previous findings that certain porcine cells express PERV when manipulated in vitro and clearly demonstrates that there are porcine cells that express infectious PERV constitutively in vivo.

scholarly journals The Decrease in Human Endogenous Retrovirus-H Activity Runs in Parallel with Improvement in ADHD Symptoms in Patients Undergoing Methylphenidate Therapy

2018 ◽  
Vol 19 (11) ◽  
pp. 3286 ◽  
Author(s):  
Cipriani Chiara ◽  
Pitzianti Bernanda ◽  
Matteucci Claudia ◽  
D’Agati Elisa ◽  
Miele Tony ◽  
...  
Keyword(s):  
Time Course ◽  
Mononuclear Cells ◽  
Clinical Symptoms ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Peripheral Blood Mononuclear ◽  
Dynamic Regulation ◽  
Expression Levels

Increasing scientific evidence demonstrated the deregulation of human endogenous retroviruses (HERVs) expression in complex diseases, such as cancer, autoimmune, psychiatric, and neurological disorders. The dynamic regulation of HERV activity and their responsiveness to a variety of environmental stimuli designate HERVs as genetic elements that could be modulated by drugs. Methylphenidate (MPH) is widely used in the treatment of attention deficit hyperactivity disorder (ADHD). The aim of this study was to evaluate the time course of human endogenous retrovirus H (HERV-H) expression in peripheral blood mononuclear cells (PBMCs) with respect to clinical response in ADHD patients undergoing MPH therapy. A fast reduction in HERV-H activity in ADHD patients undergoing MPH therapy was observed in parallel with an improvement in clinical symptoms. Moreover, when PBMCs from drug-naïve patients were cultured in vitro, HERV-H expression increased, while no changes in the expression levels were found in ADHD patients undergoing therapy. This suggests that MPH could affect the HERV-H activity and supports the hypothesis that high expression levels of HERV-H could be considered a distinctive trait of ADHD patients.

scholarly journals Endogenous retrovirus-encoded Syncytin-2 contributes to exosome-mediated immunosuppression of T cells†

2019 ◽  
Author(s):  
Adjimon G Lokossou ◽  
Caroline Toudic ◽  
Phuong Trang Nguyen ◽  
Xavier Elisseeff ◽  
Amandine Vargas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Map Kinases ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Endogenous Retrovirus ◽  
Jurkat Cells ◽  
Peripheral Blood Mononuclear ◽  
Interfering Rna

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.

Distinctive patterns of age-dependent hypomethylation in interspersed repetitive sequences

2010 ◽  
Vol 41 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Pornrutsami Jintaridth ◽  
Apiwat Mutirangura
Keyword(s):  
Mononuclear Cells ◽  
Repetitive Sequences ◽  
Endogenous Retrovirus ◽  
Human Endogenous Retrovirus ◽  
Cellular Functions ◽  
Peripheral Blood Mononuclear ◽  
Global Methylation ◽  
Short Interspersed Elements ◽  
Genome Wide ◽  
Age Dependent

Interspersed repetitive sequences (IRSs) are a major contributor to genome size and may contribute to cellular functions. IRSs are subdivided according to size and functionally related structures into short interspersed elements, long interspersed elements (LINEs), DNA transposons, and LTR-retrotransposons. Many IRSs may produce RNA and regulate genes by a variety of mechanisms. The majority of DNA methylation occurs in IRSs and is believed to suppress IRS activities. Global hypomethylation, or the loss of genome-wide methylation, is a common epigenetic event not only in senescent cells but also in cancer cells. Loss of LINE-1 methylation has been characterized in many cancers. Here, we evaluated the methylation levels of peripheral blood mononuclear cells of LINE-1, Alu, and human endogenous retrovirus K (HERV-K) in 177 samples obtained from volunteers between 20 and 88 yr of age. Age was negatively associated with methylation levels of Alu (r = −0.452, P < 10−3) and HERV-K (r = −0.326, P < 10−3) but not LINE-1 (r = 0.145, P = 0.055). Loss of methylation of Alu occurred during ages 34–68 yr, and loss of methylation of HERV-K occurred during ages 40–63 yr and again during ages 64–83 yr. Interestingly, methylation of Alu and LINE-1 are directly associated, particularly at ages 49 yr and older (r = 0.49, P < 10−3). Therefore, only some types of IRSs lose methylation at certain ages. Moreover, Alu and HERV-K become hypomethylated differently. Finally, there may be several mechanisms of global methylation. However, not all of these mechanisms are age-dependent. This finding may lead to a better understanding of not only the biological causes and consequences of genome-wide hypomethylation but also the role of IRSs in the aging process.

scholarly journals Virological and Parasitological Characterization of Mini-LEWE Minipigs Using Improved Screening Methods and an Overview of Data on Various Minipig Breeds

2021 ◽  
Vol 9 (12) ◽  
pp. 2617
Author(s):  
Sabrina Halecker ◽  
Julia Metzger ◽  
Christina Strube ◽  
Ludwig Krabben ◽  
Benedikt Kaufer ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Massachusetts General Hospital ◽  
Hepatitis E ◽  
Human Cells ◽  
Gastrointestinal Parasites ◽  
Endogenous Retroviruses ◽  
Detection Methods ◽  
Screening Methods ◽  
Rt Pcr ◽  
Peripheral Blood Mononuclear

Minipigs play an important role in biomedical research and have also been used as donor animals in xenotransplantation. To serve as a donor in xenotransplantation, the animals must be free of potential zoonotic viruses, bacteria and parasites. Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pigs and cannot be eliminated as most of the other pig viruses can. PERV-A and PERV-B infect human cells in cell culture and are integrated in all pigs, whereas PERV-C infects only pig cells and it is found in many, but not all pigs. Minipigs are known for a high prevalence of recombinant PERV-A/C viruses able to infect human cells (Denner and Schuurman, Viruses, 2021;13:1869). Here, Mini-LEWE minipigs are screened for the first time for pig viruses including PERV. Peripheral blood mononuclear cells (PBMCs) from 10 animals were screened using PCR-based methods (PCR, RT-PCR, and real-time PCR). In comparison with our previous screening assays, numerous improvements were introduced, e.g., the usage of gene blocks as a PCR standard and foreign RNA to control reverse transcription in RT-PCR. Using these improved detection methods, Mini-LEWE pigs were found to be negative for porcine cytomegalovirus (PCMV), porcine lymphotropic herpesviruses (PLHV-1, -2 and -3), porcine circoviruses (PCV1, 2, 3 and 4), porcine parvovirus (PPV) and hepatitis E virus (HEV). All animals carried PERV-A, PERV-B and PERV-C in their genome. PERV-A/C was not found. In contrast to all other minipig breeds (Göttingen minipigs, Aachen minipigs, Yucatan micropig, Massachusetts General Hospital miniature pigs), Mini-LEWE minipigs have less viruses and no PERV-A/C. Parasitological screening showed that none of the Mini-LEWE minipigs harbored ecto- and gastrointestinal parasites, but at least one animal tested positive for anti-Toxoplasma gondii antibodies.

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