8,104 results match your criteria simian retrovirus


Oncolytic Foamy Virus - generation and properties of a nonpathogenic replicating retroviral vector system that targets chronically proliferating cancer cells.

J Virol 2021 Mar 10. Epub 2021 Mar 10.

Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA

Nonpathogenic retroviruses of the subfamily can persist long-term in the cytoplasm of infected cells, completing their lifecycle only after the nuclear membrane dissolves at the time of cell division. Since the targeting of slowly dividing cancer cells remains an unmet need in oncolytic virotherapy we constructed a replication competent Foamy Virus vector (oFV) from the genomes of two chimpanzee Simian Foamy Viruses (PAN1 and PAN2) and inserted a GFP transgene in place of the open reading frame. oFV-GFP infected and propagated with slow kinetics in multiple human tumor cell lines, inducing a syncytial cytopathic effect. Read More

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Persistence of viral RNA in lymph nodes in ART-suppressed SIV/SHIV-infected Rhesus Macaques.

Nat Commun 2021 03 5;12(1):1474. Epub 2021 Mar 5.

Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA.

The establishment of a long-lived viral reservoir is the key obstacle for achieving an HIV-1 cure. However, the anatomic, virologic, and immunologic features of the viral reservoir in tissues during antiretroviral therapy (ART) remain poorly understood. Here we present a comprehensive necroscopic analysis of the SIV/SHIV viral reservoir in multiple lymphoid and non-lymphoid tissues from SIV/SHIV-infected rhesus macaques suppressed with ART for one year. Read More

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Endogenization of a Prosimian Retrovirus during Lemur Evolution.

Viruses 2021 02 27;13(3). Epub 2021 Feb 27.

Center for Fundamental and Applied Microbiomes, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA.

Studies of viruses that coevolved with lemurs provide an opportunity to understand the basal traits of primate viruses and provide an evolutionary context for host-virus interactions. Germline integration of endogenous retroviruses (ERVs) are fossil evidence of past infections. Hence, characterization of novel ERVs provides insight into the ancient precursors of extant viruses and the evolutionary history of their hosts. Read More

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February 2021

SIV-induced terminally differentiated adaptive NK cells in lymph nodes associated with enhanced MHC-E restricted activity.

Nat Commun 2021 02 24;12(1):1282. Epub 2021 Feb 24.

Institut Pasteur, Unité HIV, Inflammation et Persistance, Paris, France.

Natural killer (NK) cells play a critical understudied role during HIV infection in tissues. In a natural host of SIV, the African green monkey (AGM), NK cells mediate a strong control of SIVagm infection in secondary lymphoid tissues. We demonstrate that SIVagm infection induces the expansion of terminally differentiated NKG2a NK cells in secondary lymphoid organs displaying an adaptive transcriptional profile and increased MHC-E-restricted cytotoxicity in response to SIV Env peptides while expressing little IFN-γ. Read More

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February 2021

Distinct Features of Germinal Center Reactions in Macaques Infected by SIV or Vaccinated with a T-Dependent Model Antigen.

Viruses 2021 02 9;13(2). Epub 2021 Feb 9.

Institut Cochin, Université de Paris, INSERM, CNRS, 75014 Paris, France.

B-cell follicles constitute large reservoirs of infectious HIV/SIV associated to follicular dendritic cells and infecting follicular helper (T) and regulatory (T) T-cells in germinal centers (GCs). Thus, follicular and GC B-cells are persistently exposed to viral antigens. Despite recent development of potent HIV immunogens, numerous questions are still open regarding GC reaction during early HIV/SIV infection. Read More

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February 2021

Human T-cell lymphotropic virus type 1 transmission dynamics in rural villages in the Democratic Republic of the Congo with high nonhuman primate exposure.

PLoS Negl Trop Dis 2021 Jan 28;15(1):e0008923. Epub 2021 Jan 28.

Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.

The Democratic Republic of the Congo (DRC) has a history of nonhuman primate (NHP) consumption and exposure to simian retroviruses yet little is known about the extent of zoonotic simian retroviral infections in DRC. We examined the prevalence of human T-lymphotropic viruses (HTLV), a retrovirus group of simian origin, in a large population of persons with frequent NHP exposures and a history of simian foamy virus infection. We screened plasma from 3,051 persons living in rural villages in central DRC using HTLV EIA and western blot (WB). Read More

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January 2021

A Potent anti-Simian Immunodeficiency Virus Neutralizing Antibody Induction Associated with a Germline Immunoglobulin Gene Polymorphism in Rhesus Macaques.

J Virol 2021 Jan 13. Epub 2021 Jan 13.

AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan

Virus infection induces B cells with a wide variety of B cell receptor (BCR) repertoires. Patterns of induced BCR repertoires are different in individuals, while the underlying mechanism causing this difference remains largely unclear. In particular, the impact of germ line BCR immunoglobulin (Ig) gene polymorphism on B cell/antibody induction has not fully been determined. Read More

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January 2021

Identification of an Intermediate Step in Foamy Virus Fusion.

Viruses 2020 12 21;12(12). Epub 2020 Dec 21.

Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany.

Viral glycoprotein-mediated membrane fusion is an essential step for productive infection of host cells by enveloped viruses; however, due to its rarity and challenges in detection, little is known about the details of fusion events at the single particle level. Here, we have developed dual-color foamy viruses (FVs) composed of eGFP-tagged prototype FV (PFV) Gag and mCherry-tagged Env of either PFV or macaque simian FV (SFVmac) origin that have been optimized for detection of the fusion process. Using our recently developed tracking imaging correlation (TrIC) analysis, we were able to detect the fusion process for both PFV and SFVmac Env containing virions. Read More

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December 2020

Recrudescence of Natural Coccidioidomycosis During Combination Antiretroviral Therapy in a Pigtail Macaque Experimentally Infected with Simian Immunodeficiency Virus.

AIDS Res Hum Retroviruses 2021 Feb 23. Epub 2021 Feb 23.

Washington National Primate Research Center, Seattle, Washington, USA.

Coccidioidomycosis is a common fungal infection in people living with HIV-1, particularly in southwest regions of the United States where the sp. is endemic, but rates of infection have significantly declined in the era of potent combination antiretroviral therapy (cART). Natural coccidioidomycosis also occurs in outdoor-housed macaques residing in the southwestern states that are utilized in biomedical research. Read More

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February 2021

The V2 loop of HIV gp120 delivers costimulatory signals to CD4 T cells through Integrin αβ and promotes cellular activation and infection.

Proc Natl Acad Sci U S A 2020 12 7;117(51):32566-32573. Epub 2020 Dec 7.

Laboratory of Immunoregulation, National Institutes of Health, Bethesda, MD 20814.

Acute HIV infection is characterized by rapid viral seeding of immunologic inductive sites in the gut followed by the severe depletion of gut CD4 T cells. Trafficking of αβ-expressing lymphocytes to the gut is mediated by MAdCAM, the natural ligand of αβ that is expressed on gut endothelial cells. MAdCAM signaling through αβ costimulates CD4 T cells and promotes HIV replication. Read More

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December 2020

CRISPR based editing of SIV proviral DNA in ART treated non-human primates.

Nat Commun 2020 11 27;11(1):6065. Epub 2020 Nov 27.

Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA.

Elimination of HIV DNA from infected individuals remains a challenge in medicine. Here, we demonstrate that intravenous inoculation of SIV-infected macaques, a well-accepted non-human primate model of HIV infection, with adeno-associated virus 9 (AAV9)-CRISPR/Cas9 gene editing construct designed for eliminating proviral SIV DNA, leads to broad distribution of editing molecules and precise cleavage and removal of fragments of the integrated proviral DNA from the genome of infected blood cells and tissues known to be viral reservoirs including lymph nodes, spleen, bone marrow, and brain among others. Accordingly, AAV9-CRISPR treatment results in a reduction in the percent of proviral DNA in blood and tissues. Read More

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November 2020

Construction of A Preliminary Three-Dimensional Structure Serotype-2 (SRV-2) Reverse Transcriptase Isolated from Indonesian Cynomolgus Monkey.

Trop Life Sci Res 2020 Oct 15;31(3):47-61. Epub 2020 Oct 15.

Primate Research Centre, Bogor Agricultural University (PSSP LPPM IPB), Jalan Lodaya II/5 Bogor 16151, Indonesia.

serotype-2 (SRV-2) is an important pathogenic agent in Asian macaques. It is a potential confounding variable in biomedical research. SRV-2 also provides a valuable viral model compared to other retroviruses which can be used for understanding many aspects of retroviral-host interactions and immunosuppression, infection mechanism, retroviral structure, antiretroviral and vaccine development. Read More

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October 2020

Recapitulation of HIV-1 Env-antibody coevolution in macaques leading to neutralization breadth.

Science 2021 01 19;371(6525). Epub 2020 Nov 19.

Departments of Medicine and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.

Neutralizing antibodies elicited by HIV-1 coevolve with viral envelope proteins (Env) in distinctive patterns, in some cases acquiring substantial breadth. We report that primary HIV-1 envelope proteins-when expressed by simian-human immunodeficiency viruses in rhesus macaques-elicited patterns of Env-antibody coevolution very similar to those in humans, including conserved immunogenetic, structural, and chemical solutions to epitope recognition and precise Env-amino acid substitutions, insertions, and deletions leading to virus persistence. The structure of one rhesus antibody, capable of neutralizing 49% of a 208-strain panel, revealed a V2 apex mode of recognition like that of human broadly neutralizing antibodies (bNAbs) PGT145 and PCT64-35S. Read More

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January 2021

Site-Specific Evolutionary Rate Shifts in HIV-1 and SIV.

Viruses 2020 11 16;12(11). Epub 2020 Nov 16.

The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.

Site-specific evolutionary rate shifts are defined as protein sites, where the rate of substitution has changed dramatically across the phylogeny. With respect to a given clade, sites may either undergo a rate acceleration or a rate deceleration, reflecting a site that was conserved and became variable, or vice-versa, respectively. Sites displaying such a dramatic evolutionary change may point to a loss or gain of function at the protein site, reflecting adaptation, or they may indicate epistatic interactions among sites. Read More

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November 2020

Methamphetamine Increases the Proportion of SIV-Infected Microglia/Macrophages, Alters Metabolic Pathways, and Elevates Cell Death Pathways: A Single-Cell Analysis.

Viruses 2020 11 12;12(11). Epub 2020 Nov 12.

Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.

Both substance use disorder and HIV infection continue to affect many individuals. Both have untoward effects on the brain, and the two conditions often co-exist. In the brain, macrophages and microglia are infectable by HIV, and these cells are also targets for the effects of drugs of abuse, such as the psychostimulant methamphetamine. Read More

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November 2020

Systematic Assessment of Antiviral Potency, Breadth, and Synergy of Triple Broadly Neutralizing Antibody Combinations against Simian-Human Immunodeficiency Viruses.

J Virol 2021 01 13;95(3). Epub 2021 Jan 13.

Duke Human Vaccine Institute, Duke University, Durham, North Carolina, USA

Daily burden and clinical toxicities associated with antiretroviral therapy (ART) emphasize the need for alternative strategies to induce long-term human immunodeficiency virus (HIV) remission upon ART cessation. Broadly neutralizing antibodies (bNAbs) can both neutralize free virions and mediate effector functions against infected cells and therefore represent a leading immunotherapeutic approach. To increase potency and breadth, as well as to limit the development of resistant virus strains, it is likely that bNAbs will need to be administered in combination. Read More

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January 2021

Equine lentivirus counteracts SAMHD1 restriction by Rev-mediated degradation of SAMHD1 via the BECN1-dependent lysosomal pathway.

Autophagy 2020 Nov 24:1-18. Epub 2020 Nov 24.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences , Harbin, China.

The innate immune restriction factor SAMHD1 can inhibit diverse viruses in myeloid cells. Mechanistically, SAMHD1 inhibits lentiviral replication including HIV-1 by depleting the nucleotide pool to interfere with their reverse transcription. Equine infectious anemia virus (EIAV) is an ancient lentivirus that preferentially attacks macrophages. Read More

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November 2020

Tertiary Base Triple Formation in the SRV-1 Frameshifting Pseudoknot Stabilizes Secondary Structure Components.

Biochemistry 2020 11 9;59(46):4429-4438. Epub 2020 Nov 9.

School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), No. 2001 Longxiang Boulevard, Longgang District, Shenzhen, Guangdong 518172, P. R. China.

Minor-groove base triples formed between stem 1 and loop 2 of the simian retrovirus type 1 (SRV-1) mRNA frameshifting pseudoknot are essential in stimulating -1 ribosomal frameshifting. How tertiary base triple formation affects the local stabilities of secondary structures (stem 1 and stem 2) and thus ribosomal frameshifting efficiency is not well understood. We made a short peptide nucleic acid (PNA) that is expected to invade stem 1 of the SRV-1 pseudoknot by PNA-RNA duplex formation to mimic the stem 1 unwinding process by a translating ribosome. Read More

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November 2020

Shifts in microbial diversity, composition, and functionality in the gut and genital microbiome during a natural SIV infection in vervet monkeys.

Microbiome 2020 11 6;8(1):154. Epub 2020 Nov 6.

Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.

Background: The microbiota plays an important role in HIV pathogenesis in humans. Microbiota can impact health through several pathways such as increasing inflammation in the gut, metabolites of bacterial origin, and microbial translocation from the gut to the periphery which contributes to systemic chronic inflammation and immune activation and the development of AIDS. Unlike HIV-infected humans, SIV-infected vervet monkeys do not experience gut dysfunction, microbial translocation, and chronic immune activation and do not progress to immunodeficiency. Read More

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November 2020

Alterations of the gut bacterial microbiota in rhesus macaques with SIV infection and on short- or long-term antiretroviral therapy.

Sci Rep 2020 11 4;10(1):19056. Epub 2020 Nov 4.

Tulane National Primate Research Center, Covington, LA, 70433, USA.

Gut dysbiosis and microbial translocation are associated with chronic systemic immune activation and inflammation in HIV-1 infection. However, the extent of restoration of gut microbiota in HIV-1 patients with short or long-term antiretroviral therapy (ART) is unclear. To understand the impact of ART on the gut microbiota, we used the rhesus macaque model of SIV infection to characterize and compare the gut microbial community upon SIV infection and during ART. Read More

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November 2020

Functional Analyses of Bovine Foamy Virus-Encoded miRNAs Reveal the Importance of a Defined miRNA for Virus Replication and Host-Virus Interaction.

Viruses 2020 11 2;12(11). Epub 2020 Nov 2.

Division Viral Transformation Mechanisms, Research Focus Infection, Inflammation and Cancer, German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), 69120 Heidelberg, Germany.

In addition to regulatory or accessory proteins, some complex retroviruses gain a repertoire of micro-RNAs (miRNAs) to regulate and control virus-host interactions for efficient replication and spread. In particular, bovine and simian foamy viruses (BFV and SFV) have recently been shown to express a diverse set of RNA polymerase III-directed miRNAs, some with a unique primary miRNA double-hairpin, dumbbell-shaped structure not known in other viruses or organisms. While the mechanisms of expression and structural requirements have been studied, the functional importance of these miRNAs is still far from understood. Read More

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November 2020

Characterization of Nef expression in different brain regions of SIV-infected macaques.

PLoS One 2020 2;15(11):e0241667. Epub 2020 Nov 2.

Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States of America.

Objective: HIV-associated CNS dysfunction is a significant problem among people with HIV (PWH), who now live longer due to viral suppression from combined anti-retroviral therapy (ART). Over the course of infection, HIV generates toxic viral proteins and induces inflammatory cytokines that have toxic effects on neurons in the CNS. Among these viral proteins, HIV Nef has been found in neurons of postmortem brain specimens from PWH. Read More

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December 2020

Origin of rebound virus in chronically SIV-infected Rhesus monkeys following treatment discontinuation.

Nat Commun 2020 10 27;11(1):5412. Epub 2020 Oct 27.

Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

Viral rebound following antiretroviral therapy (ART) discontinuation in HIV-1-infected individuals is believed to originate from a small pool of CD4+ T cells harboring replication-competent provirus. However, the origin and nature of the rebound virus has remained unclear. Recent studies have suggested that rebound virus does not originate directly from individual latent proviruses but rather from recombination events involving multiple proviruses. Read More

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October 2020

Therapeutic vaccination of SIV-infected, ART-treated infant rhesus macaques using Ad48/MVA in combination with TLR-7 stimulation.

PLoS Pathog 2020 10 26;16(10):e1008954. Epub 2020 Oct 26.

Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States of America.

Globally, 1.8 million children are living with HIV-1. While antiretroviral therapy (ART) has improved disease outcomes, it does not eliminate the latent HIV-1 reservoir. Read More

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October 2020

Simian-Human Immunodeficiency Virus SHIV.C.CH505 Persistence in ART-Suppressed Infant Macaques Is Characterized by Elevated SHIV RNA in the Gut and a High Abundance of Intact SHIV DNA in Naive CD4 T Cells.

J Virol 2020 12 22;95(2). Epub 2020 Dec 22.

Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA

Mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) continues to cause new pediatric cases of infection through breastfeeding, a setting where it is not always possible to initiate early antiretroviral therapy (ART). Without novel interventions that do not rely on daily ART, HIV-1-infected children face lifelong medications to control infection. A detailed analysis of virus persistence following breast milk transmission of HIV-1 and ART has not been performed. Read More

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December 2020

Development and optimization of a simian immunodeficiency virus (SIV) droplet digital PCR (ddPCR) assay.

PLoS One 2020 9;15(10):e0240447. Epub 2020 Oct 9.

AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America.

Accurate and sensitive quantification of rebound competent HIV that persists despite combination antiretroviral treatment (cART), including in latently infected cells (i.e., viral reservoir), is critical for evaluating cure strategies for decreasing or eliminating this reservoir. Read More

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December 2020

Cryo-EM structure of the deltaretroviral intasome in complex with the PP2A regulatory subunit B56γ.

Nat Commun 2020 10 7;11(1):5043. Epub 2020 Oct 7.

Imperial College London, St Mary's Hospital, Department of Infectious Disease, Section of Virology, Norfolk Place, London, W2 1PG, UK.

Human T-cell lymphotropic virus type 1 (HTLV-1) is a deltaretrovirus and the most oncogenic pathogen. Many of the ~20 million HTLV-1 infected people will develop severe leukaemia or an ALS-like motor disease, unless a therapy becomes available. A key step in the establishment of infection is the integration of viral genetic material into the host genome, catalysed by the retroviral integrase (IN) enzyme. Read More

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October 2020

Rectal Acquisition of Simian Immunodeficiency Virus (SIV) SIVmac239 Infection despite Vaccine-Induced Immune Responses against the Entire SIV Proteome.

J Virol 2020 11 23;94(24). Epub 2020 Nov 23.

Department of Pathology, University of Miami, Miami, Florida, USA.

Given the complex biology of human immunodeficiency virus (HIV) and its remarkable capacity to evade host immune responses, HIV vaccine efficacy may benefit from the induction of both humoral and cellular immune responses of maximal breadth, potency, and longevity. Guided by this rationale, we set out to develop an immunization protocol aimed at maximizing the induction of anti-Envelope (anti-Env) antibodies and CD8 T cells targeting non-Env epitopes in rhesus macaques (RMs). Our approach was to deliver the entire simian immunodeficiency virus (SIV) proteome by serial vaccinations. Read More

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November 2020

miRNA profiling of primate cervicovaginal lavage and extracellular vesicles reveals miR-186-5p as a potential antiretroviral factor in macrophages.

FEBS Open Bio 2020 Oct 11;10(10):2021-2039. Epub 2020 Sep 11.

Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Cervicovaginal secretions, or their components collected, are referred to as cervicovaginal lavage (CVL). CVL constituents have utility as biomarkers and play protective roles in wound healing and against HIV-1 infection. However, several components of cervicovaginal fluids are less well understood, such as extracellular RNAs and their carriers, for example, extracellular vesicles (EVs). Read More

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October 2020

Enhanced enzyme kinetics of reverse transcriptase variants cloned from animals infected with SIVmac239 lacking viral protein X.

J Biol Chem 2020 12 2;295(50):16975-16986. Epub 2020 Oct 2.

Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA; Children's Healthcare of Atlanta, Atlanta, Georgia, USA. Electronic address:

HIV Type 1 (HIV-1) and simian immunodeficiency virus (SIV) display differential replication kinetics in macrophages. This is because high expression levels of the active host deoxynucleotide triphosphohydrolase sterile α motif domain and histidine-aspartate domain-containing protein 1 (SAMHD1) deplete intracellular dNTPs, which restrict HIV-1 reverse transcription, and result in a restrictive infection in this myeloid cell type. Some SIVs overcome SAMHD1 restriction using viral protein X (Vpx), a viral accessory protein that induces proteasomal degradation of SAMHD1, increasing cellular dNTP concentrations and enabling efficient proviral DNA synthesis. Read More

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December 2020