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See detailComparative Interactome of HIV-1 Tat and Human T Lymphotropic Virus Type-1 Tax and the Cellular Transcriptional Machinery.
Vandermeulen, Charlotte; Hajingabo, Leon-Juvenal; Twizere, Jean-Claude ULiege

in AIDS Research and Human Retroviruses (2015), 31(12), 1204-5

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See detailMathematical modeling of HIV dynamics after antiretroviral therapy initiation: A clinical research study
Moog, Claude; Rivadeneira, Pablo; Stan, Guy-Bart et al

in AIDS Research and Human Retroviruses (2014), 30(9), 831-834

Immunological failure is identified from the estimation of certain parameters of a mathematical model of the HIV infection dynamics. This identification is supported by clinical research results from an ... [more ▼]

Immunological failure is identified from the estimation of certain parameters of a mathematical model of the HIV infection dynamics. This identification is supported by clinical research results from an original clinical trial. Standard clinical data were collected from infected patients starting Highly Active Anti-Retroviral Therapy (HAART), just after one month following therapy initiation and were used to carry out the model identification. The early diagnosis is shown to be consistent with the patients monitoring after six months. [less ▲]

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See detailHTLV-1 clonality during chronic infection and BLV clonality during primary infection
Gillet, N.; Hlela, C.; Verdonck, T. et al

in AIDS Research and Human Retroviruses (2011, June 06), 8(1), 185

HTLV-1 clonality during chronic infection and BLV clonality during primary infection Nicolas A Gillet1,2*, Carol Hlela1, Tine Verdonck3, Eduardo Gotuzzo3, Daniel Clark3, Sabrina Rodriguez2, Nirav Malani4 ... [more ▼]

HTLV-1 clonality during chronic infection and BLV clonality during primary infection Nicolas A Gillet1,2*, Carol Hlela1, Tine Verdonck3, Eduardo Gotuzzo3, Daniel Clark3, Sabrina Rodriguez2, Nirav Malani4, Anat Melamed1, Niall Gormley5, Richard Carter5, David Bentley5, Charles Berry6, Frederic D Bushman4, Graham P Taylor7, Luc Willems2, Charles R M Bangham1 1Department of Immunology, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. 2Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULg), Liège, 4000, Belgium. 3Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru. 4Department of Microbiology, University of Pennsylvania School of Medicine, Pennsylvania, Philadelphia, PA, 19104, USA. 5Illumina, Chesterford Research Park, Essex, Little Chesterford, CB10 1XL, UK. 6University of California, California, La Jolla San Diego, CA, 92093-0901, USA. 7Department of Genitourinary Medicine and Communicable Diseases, Wright-Fleming Institute, Imperial College London, London, W2 1PG, UK. HTLV-1 persists by driving clonal proliferation of infected T-lymphocytes. A high proviral load predisposes to the inflammatory and malignant diseases associated with HTLV-1. Yet the reasons for the remarkable variation within and between individuals in the abundance of HTLV-1-infected clones remain unknown. We demonstrate that negative selection dominates during chronic infection, favouring establishment of proviruses integrated in transcriptionally silenced DNA: this selection is significantly stronger in asymptomatic carriers. We postulated that this selection occurred mainly during the primary infection. We are testing this hypothesis in an animal model by studying the BLV clonality during the primary infection in cows. By measuring the proviral load, the anti-BLV immune response and the BLV clonality we aim to quantify the impact of the immune response on the rate of infectious spread and on the selection of proviruses inserted in a particular genomic environment. Co-infection with Strongyloides stercoralis or Staphylococcus appears to be another risk factor for the development of HTLV-1 associated diseases. We observed that HTLV-1 clonality is altered by co-infection with these pathogens with an increase of both the number and the abundance of the infected T-cell clones. The genomic characteristics of the proviral integration sites in the most abundant clones differ significantly between co-infected individuals and those with HTLV-1 alone, implying the existence of different selection forces in co-infected patients. The rate of appearance of new clones in patients co-infected with Strongyloides stercoralis is higher than in patients with HTLV-1 alone. By comparing skin lesions and blood samples from patients with Infective Dermatitis associated with HTLV-1 (IDH), we observed a significant proportion of distinct infected clones between the two compartments. The skin lesions seem to be a site for HTLV-1 infectious spread. [less ▲]

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See detailA life-attenuated BLV deletant as a candidate vaccine to inhibit viral transmission in bovine herds
Gutiérrez, G.; Rodriguez, Sabrina ULiege; Florins, A. et al

in AIDS Research and Human Retroviruses (2011, June 05), 8(1), 12

A life-attenuated BLV deletant as a candidate vaccine to inhibit viral transmission in bovine herds Gerónimo Gutiérrez2*, Sabrina M. Rodríguez1*†, Arnaud Florins3, Lucas Vagnoni2, Irene Alvarez2, Nicolas ... [more ▼]

A life-attenuated BLV deletant as a candidate vaccine to inhibit viral transmission in bovine herds Gerónimo Gutiérrez2*, Sabrina M. Rodríguez1*†, Arnaud Florins3, Lucas Vagnoni2, Irene Alvarez2, Nicolas Gillet3, Karina Trono2‡, Luc Willems1,3‡ *‡S.M. Rodríguez / G. Gutiérrez and K.Trono / L. Willems contributed equally to this work. 1 Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), University of Liège (ULg), Liège (4100), Belgium. 2 Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, (1712), Castelar, Argentina. 3 Molecular and Cellular Biology, Gembloux Agro-Bio Tech, University of Liège (ULg), Gembloux (5030), Belgium †E-mail: sabrina.rodriguez@ulg.ac.be There are different strategies to reduce BLV prevalence. Eradication by culling of infected animals is not economically sustainable in highly infected regions such as Argentina, US or Japan. Partition and confinement on BLV-infected cows is expensive due to duplication of facilities. Finally, several candidate vaccines based on recombinant viral proteins were unsuccessful to protect from challenge. Facing these failures, we propose a novel strategy based on the use of a live-attenuated BLV provirus. The rationale behind this strategy relies on the deletion of genes required to induce pathogenesis leaving those involved in infectivity, resulting in an attenuated mutant with impaired transmissibility. In a first set of experiments, we show that the mutant is infectious and elicits an efficient immune response in sheep (n=3) and in cows (n=9). Lack of spread to uninfected sentinels further supports the safety of the vaccine. Based on these promising results, a validation program in herd (n=105) is ongoing to evaluate the capacity of the candidate vaccine to protect from wild-type BLV infection. The following experiments are carried out: quantification of the proviral loads, assessment of immune response efficiency (antibody titers, CTL response and cytokine profiling), measure of viral expression in vivo (qRT-PCR) and ex vivo (expression of Tax and p24gag) and determination of provirus clonality during infection. This data will be instrumental for understanding the basic mechanisms undergoing during BLV infection and for elaborating of a novel vaccine. [less ▲]

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See detailEvidence for the existence of pathogenicity determinants in the Long Terminal Repeats (LTRs) of the Bovine Leukemia Virus (BLV) genome
Rodriguez, Sabrina ULiege; Trono, K.; Jones, L.R.

in AIDS Research and Human Retroviruses (2011), 8(1), 26

Evidence for the existence of pathogenicity determinants in the Long Terminal Repeats (LTRs) of the Bovine Leukemia Virus (BLV) genome Sabrina M. Rodríguez1*, Karina Trono2, Leandro R. Jones3 1 Molecular ... [more ▼]

Evidence for the existence of pathogenicity determinants in the Long Terminal Repeats (LTRs) of the Bovine Leukemia Virus (BLV) genome Sabrina M. Rodríguez1*, Karina Trono2, Leandro R. Jones3 1 Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) , University of Liège (ULg), Belgium. 2 Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria INTA-Castelar, CC 25 (1712), Castelar. 3 División de Biología Molecular, Estación de Fotobiología Playa Unión, CC 15, Rawson, Chubut 9103, Argentina. *E-mail: sabrina.rodriguez@ulg.ac.be The majority of BLV-infected animals are asymptomatic carriers (AL) while about 30% develop a benign persistent lymphocytosis (PL). Fatal lymphosarcoma (LS) occurs in 5% of infected animals. The genetic basis of these diverse outcomes of BLV infection is still unknown. Viral LTRs constitute a genetic determinant of pathogenesis for other retroviruses. However, this possibility has never been tested for BLV. Analyses to test correlation between clinical and genotypic traits across species must be corrected by including the group phylogeny. Otherwise, shared evolutionary history can jeopardize statistical independence. Thus, the influence of BLV LTR genetic variation on the clinical manifestation of the disease was investigated by employing Cladistic and Probabilistic, phylogenetic comparative methods. With this purpose, the 5´LTR region of 40 BLV proviruses from bovines with different clinical presentations (AL, PL, LS) was sequenced. Seven polymorphic positions showing an apparent association with the clinical presentation were identified. A provirus phylogeny was obtained using env gene sequences from 28 of the 40 provirus studied in this work. Both Cladistic and Probabilistic comparative analyses based on the empirical sequence alignment and the provirus phylogeny suggested that positions 41 and 56 might be correlated to the clinical presentation. The probabilistic analysis further indicated an association with the viral pathogenesis for positions 373, 450, 494 and 505, though the corresponding statistical supports were lower in comparison to the supports obtained for positions 41 and 56. These observations indicate that the BLV LTRs might contain pathogenicity determinants. [less ▲]

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See detailThe impact of HAART initiation on the selection and persistence of HIV-1 CTL-escape mutations
Dilernia, D.A.; Monaco, D.C.; Jones, L.R. et al

in AIDS Research and Human Retroviruses (2010, October), 26(10), 72

The impact of HAART initiation on the selection and persistence of HIV-1 CTL-escape mutations D.A. Dilernia,1 D.C. Monaco,1 L.R. Jones,2 G.D. Damilano,1 S. Rodriguez,3 H. Salomon1 1Argentinean Reference ... [more ▼]

The impact of HAART initiation on the selection and persistence of HIV-1 CTL-escape mutations D.A. Dilernia,1 D.C. Monaco,1 L.R. Jones,2 G.D. Damilano,1 S. Rodriguez,3 H. Salomon1 1Argentinean Reference Center for AIDS, Capital Federal, Argentina; 2División de Biología Molecular, Estación de Fotobiología, Playa Unión, Rawson, Chubut, Argentina; 3INTA, Castelar, Buenos Aires, Argentina Background: Immune response drives the selection of CTL escape mutations during the course of HIV infection. After initiation of HAART, antiviral drugs exert a strong selective force leading to an important limitation of viral replication. Our objective was to evaluate the impact of HAART initiation on the selection and persistence of CTL-escape mutations. Methods: Blood samples were collected from 113 newly HIV diagnosed individuals. A second sample was collected from 49 of them after 3 years. (12 of which were still drug-naı¨ve in the second sample). Dynamics of CTL-escape mutations identified in the gag gene by statistical analysis of HLA genes and viral sequences, including multiple comparison corrections (BH method) and phylogeny correction (Bayesian MCM method), were analyzed. Epitope-specific immune response was evaluated by ELISPOT against sequence-based designed peptides. Results: Immune response was evaluated on 113 individuals on an HLA-allele basis. Positive responses were detected against 6 of the 9 epitopes containing HLA-associated CTL-escape mutations.A03-restricted epitope RLRPGGKKK had the highest frequency of detection in allele-matched individuals (75%). Epitopes harboring the CTL-escape mutations identified through negative associations (i.e. escape is consensus) had lower frequency of detection: A02-restricted SLYNTVATL(25%) and A24-resctricted KYKLKHIVW(0%). Epitope sequences analysis over the second sample of 21 patients successfully sequenced showed that 38% of them did not have evidence of escape neither in the first sample nor in the second, 44% had the escape mutations in both samples and in 18%the escape mutations appeared in the second sample. Of the 7 individuals containing the epitopes of the last group, only 2 had initiated HAART (28.6%) while 64.3% (9/14) of individuals where no escape emerged, had initiated HAART. Conclusion: Accumulation of CTL-escape mutations at the population-level impaired recognition by individuals studied while initiation of HAART may prevent the selection of new escape mutations even in advanced stages of infection. [less ▲]

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See detailLong-term treatment with valproic acid does not alleviate the condition of HAM/TSP
Olindo, S.; Belrose, G.; Lezin, A. et al

in AIDS Research and Human Retroviruses (2009, July 01), 25(11), 21

Long-Term Treatment with Valproic Acid Does Not Alleviate the Condition of HAM/TSP Olindo, S.,1 Belrose, G.,2 Lezin, A.,2 Gillet, N.,3 Defoiche, J.,4 Rodriguez, S.,4 Signaté, A.,1 Verlaeten, O.,4 Smadja ... [more ▼]

Long-Term Treatment with Valproic Acid Does Not Alleviate the Condition of HAM/TSP Olindo, S.,1 Belrose, G.,2 Lezin, A.,2 Gillet, N.,3 Defoiche, J.,4 Rodriguez, S.,4 Signaté, A.,1 Verlaeten, O.,4 Smadja, D.,1 Césaire, R.,2 Willems, L.4 1Service de Neurologie and JE 2503, Centre Hospitalier Universitaire de Fort-de-France, 97200 Fort-de-France, Martinique, France; 2Laboratoire de Virologie-Immunologie and JE 2503, Centre Hospitalier Universitaire de Fort-de-France, 97200 Fort-de-France, Martinique, France; 3Department of Immunology, Imperial College, London, UK; 4Molecular and Cellular Biology, University Academia ‘‘Wallonie-Europe’’, 5030 Gembloux, Belgium. LW is Research Director of the FNRS. We previously proposed to interfere with proviral loads in HAM/TSP patients by modulating lysine deacetylase activity using valproic acid (VPA). The strategy aims at activating viral gene expression in order to expose virus-positive cells to the host immune response. We conducted a single-center, two-year open-label trial, with 19 HAM/TSP volunteers treated with oral doses of VPA (20mg/Kg/day). Objectives were to assess biological response and clinical safety to VPA treatment in HAM/TSP patients. By microarray analysis, we show that VPA treatment moderately stimulated expression of cyclinD2 and Rho GTPase activating protein 18 in CD4-T cells. CD8-mediated lysis efficiency of Tax-expressing cells was unaltered by VPA treatment. The CD4-T cell turnover rate was calculated by GC/MS analysis from quantitative incorporation of deuterium into DNA. Transient increase in proviral loads correlated with accelerated proliferation. After 2 years, the proviral loads reached levels similar to those before treatment. The main clinical side effects were drowsiness (52%), tremor (47%), digestive symptoms (37%), vertigo (26%), and alopecia (10%). The frequency of side symptoms tended to decrease over the trial course. The neurological status over the study constituted the primary clinical safety measures. Disability Status Scale, muscle testing score, Ashworth score, and urinary dysfunction score showed no significant changes. Walking Time Test (WTT) slightly varied over the study except in 3 patients in whom the WTT variation rates were>20%. These 3 patients experienced drowsiness and tremor and improved rapidly after treatment discontinuation. Together, these observations indicated that long term treatment with VPA is safe but does not alleviate the condition of HAM/TSP. [less ▲]

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See detailBovine Leukemia Virus (BLV) could be subdivided into up to seven groups based on phylogenetic and similarity analyses of sequences from the env gene
Rodriguez, Sabrina ULiege; Golemba, M.D.; Campos, R. et al

in AIDS Research and Human Retroviruses (2009, July 01), 25(11), 16

Bovine Leukemia Virus (BLV) Could be Subdivided into up to Seven Groups Based on Phylogenetic and Similarity Analyses of Sequences from the env Gene. Rodríguez, S.M., Trono, K., Jones, L.R., Golemba, M ... [more ▼]

Bovine Leukemia Virus (BLV) Could be Subdivided into up to Seven Groups Based on Phylogenetic and Similarity Analyses of Sequences from the env Gene. Rodríguez, S.M., Trono, K., Jones, L.R., Golemba, M., Campos, R. Instituto De Virología - Cicvya - Inta Castelar We sequenced the env gene from 28 BLV field strains from Argentina, and combined these sequences with 45 env sequences representing all the genetic groupings identified previously. These data were analyzed by phylogenetic analysis and similarity comparisons. Phylogenetic analyses showed the existence of five groups of sequences or genotypes. Four genotypes were supported by high bootstraps (89–100) and posterior probabilities (p=1.0), and the fifth one was supported by a high posterior probability (p=1.0) and moderate bootstrap (80–96) values. All these genotypes have one or more counterparts among the groupings identified previously, and thus many groups that were originally named differently correspond actually to the same genotype. Two sequences did not cluster with any other sequence, and were highly divergent when compared to the five groups mentioned above. This indicates that two extra genotypes could exist. The similarity comparisons were highly congruent with the phylogenetic analyses. The mean number of pair wise nucleotide substitutions between sequences from the same genotype was 11.1 (min. 6.5; max. 19), whereas it was 39.6 (min.36.8; max. 47.9) between sequences from different genotypes. Likewise, the mean number of amino acid substitutions in pair wise comparisons at the intra-genotype level was 3.3 (min. 0.4; max. 6.2), whereas it was 9.6 (min. 8.3; max. 13.5) at the inter-genotype level. Our analyses confirmed the existence of geographic clusters (p=6.838E-15, Chi2 test; p=4.583E-12, Fisher’s exact test). [less ▲]

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See detailCross-reactive T cell responses in HIV CRF01_AE and B'-infected intravenous drug users: implications for superinfection and vaccines.
Promadej-Lanier, Nattawan; Thielen, Caroline ULiege; Hu, Dale J et al

in AIDS Research and Human Retroviruses (2009), 25(1), 73-81

Abstract We previously observed limited cross-reactive T cell responses in two HIV-1-superinfected injection drug users (IDUs) before superinfection [Ramos A, et al.: J Virol 2002;76(15):7444-7452]. To ... [more ▼]

Abstract We previously observed limited cross-reactive T cell responses in two HIV-1-superinfected injection drug users (IDUs) before superinfection [Ramos A, et al.: J Virol 2002;76(15):7444-7452]. To elucidate the role of such responses in superinfection we examined cross-reactive T cell responses in IDUs infected with a single HIV-1 subtype. In this study, IFN-gamma ELISPOT assays were performed using recombinant vaccinia constructs and peripheral blood mononuclear cells (PBMCs) from 43 IDUs singly infected with CRF01_AE or B' from the same cohort as the superinfected IDUs. PBMCs were from time points corresponding to pre- (early) or post- (late) superinfection in the superinfected IDUs. We observed that most singly infected IDUs had cross-reactivity in samples from early (84% of CRF01_AE and 78% of B'-infected IDUs) and late (96% of CRF_01AE and 77% of B'-infected IDUs) time points. Frequent homologous reactivity at early (67% of CRF-01AE and 100% of B') and late (84% of CRF01_AE-infected and 100% of B'-infected IDUs) time points was also observed. Cross-reactive responses were predominantly to Pol and were broader and higher in CRF01_AE than in B'-infected IDUs (medians of 825 vs. 90 and 585 vs. 60 spot-forming units/10(6) PBMCs at early and late time points, respectively). Our results show that cross-reactive responses were more prevalent with greater height and breadth in singly infected IDUs than previously observed in corresponding collection time points of superinfected IDU. Thus, low or absent cross-reactivity may have contributed to the previously observed superinfections. These data are relevant for understanding superinfection and improving vaccine design. [less ▲]

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See detailEvidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load
Dilernia, D.; Lourtau, L.; Jones, L.R. et al

in AIDS Research and Human Retroviruses (2008, October 13), 4(1), 79

Evidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load. Dario A Dilernia, L Lourtau, L Jones, S Rodriguez, C Bautista, M Gomez ... [more ▼]

Evidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load. Dario A Dilernia, L Lourtau, L Jones, S Rodriguez, C Bautista, M Gomez-Carrillo, M Losso, and H Salomon. Immune response drives the selection of CTL-escape mutations during the course of HIV infection. After initiation of HAART, antiviral drugs exert a stronger selective force leading to a higher limitation of viral replication. Our objective was to evaluate the effectiveness of immune response as a selective force in a context of extremely reduced viral population size. Gag gene was sequenced and HLA-A and B genotyped over 108 samples from drug-naïve HIV-1 positive individuals. Associations between HLA alleles and viral polymorphisms were assessed by logistic regression. Multiple comparison corrections were addressed by the BH method (q-values). Phylogeny correction was performed by a Bayesian Markov-Chain Monte-Carlo method. Analysis of site-specific synonymous and non-synonymous substitution rate was assessed through the codon-based ML IFEL method. For four patients with viral load < 50 copies/ml (identified according to their HLA profile), RNA extraction was performed from 7 ml of plasma through an ultracentrifugation-based method and gag gene amplified through a Hi-Fi PCR. 20-40 clones were sequenced in samples obtained previously and during HAART. We found that HLA-B57 and A03 were the most efficient alleles in forcing CTL-escape, targeting mainly the previously characterized epitopes TSTLQEQIGW(p=0.0002) and RLRPGGKKK(p<10E-7), respectively. Sites under significant positive selection (p<0.05) during HAART were position 20 (within A03-restricted RLRPGGKK) for patient A02A3B35B39, position 385 (within A3-restricted RGNFRNQRK) for patient A3A31B7B45 and position 84 (within A2-restricted SLYNTVATL) for patient A2A3B39B57. Epitopes sequences of RLRPGGKKK and TSTLQEQIGWF were in the escape state for patients harboring the selective alleles. In spite of the low viral diversity achieved during HAART, we detected sites under positive selection. Our results show that during successful HAART, targeted CTL-epitopes are still forced to evolve adaptively, suggesting that CTL-mediated immune response would be able to keep driving the evolution of HIV variants even in viral population with a remarkable low replication rate. [less ▲]

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See detailPrevalence and epidemiology of HIV type 1 drug resistance among newly diagnosed therapy-naive patients in Belgium from 2003 to 2006.
Vercauteren, Jurgen; Derdelinckx, Inge; Sasse, Andre et al

in AIDS Research and Human Retroviruses (2008), 24(3), 355-62

This study is the first prospective study to assess the prevalence, epidemiology, and risk factors of HIV-1 drug resistance in newly diagnosed HIV-infected patients in Belgium. In January 2003 it was ... [more ▼]

This study is the first prospective study to assess the prevalence, epidemiology, and risk factors of HIV-1 drug resistance in newly diagnosed HIV-infected patients in Belgium. In January 2003 it was initiated as part of the pan-European SPREAD program, and continued thereafter for four inclusion rounds until December 2006. Epidemiological, clinical, and behavioral data were collected using a standardized questionnaire and genotypic resistance testing was done on a sample taken within 6 months of diagnosis. Two hundred and eighty-five patients were included. The overall prevalence of transmitted HIV-1 drug resistance in Belgium was 9.5% (27/285, 95% CI: 6.6-13.4). Being infected in Belgium, which largely coincided with harboring a subtype B virus, was found to be significantly associated with transmission of drug resistance. The relatively high rate of baseline resistance might jeopardize the success of first line treatment as more than 1 out of 10 (30/285, 10.5%) viruses did not score as fully susceptible to one of the recommended first-line regimens, i.e., zidovudine, lamivudine, and efavirenz. Our results support the implementation of genotypic resistance testing as a standard of care in all treatment-naive patients in Belgium. [less ▲]

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See detailDetection of BLV in frozen semen samples by PCR assay
Dus Santos, M.J.; Rodriguez, Sabrina ULiege; Wigdorovitz, A. et al

in AIDS Research and Human Retroviruses (2007, April 23), 23(4), 651

Detection of BLV in frozen semen samples by PCR assay Dus Santos Maria Jose; Rodriguez Sabrina; Wigdorovitz Andrés; Trono Karina Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires ... [more ▼]

Detection of BLV in frozen semen samples by PCR assay Dus Santos Maria Jose; Rodriguez Sabrina; Wigdorovitz Andrés; Trono Karina Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires, Argentina. Detection of BLV in frozen semen samples by PCR assay María José Dus Santos, Sabrina Rodriguez, Andrés Wigdorovitz and Karina Trono. Instituto de Virología, CICVyA, INTA-Castelar. CC 77. Buenos Aires, Argentina mdussantos@cnia.inta.gov.ar The sanitary and economic impact of BLV infection is associated with the interference in the international movement of cattle and their germ plasm. Although experimental data support the improbability that semen from BLV-positive bulls could infect recipient cows, restriction for commercialization of semen from infected animals is still present. The objective of this work was to standardize a PCR assay to diagnose the presence of BLV genome and to describe the pattern of BLV detection in frozen semen samples. The developed methodology involves the amplification of an internal fragment of gag gene and posses a limit of detection of 60 viral particles. Additionally, a biological test in susceptible sheep was performed in order to evaluate the transmission of BLV genome by semen from seropositive animals. This data strongly suggest that semen from seropositive bulls that resulted negative by PCR can be used for artificial insemination (AI), accompanied by proper collection protocols. Frozen semen samples from 30 seropositive bulls were analyzed. It was possible to detect proviral DNA in 118 out of 545 samples. It was important to note that BLV genome detection occurred in several collections but in an alternated way with non detection periods. On the other hand, in 4 seropositive bulls, it was not possible to detect BLV genome in all the samples analyzed. The development of this PCR assay constitutes a valuable diagnostic tool to determine the BLV-free status of semen used for AI. Moreover, the results suggest that BLV could present an intermittent pattern of excretion. [less ▲]

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See detailNaturally occurring BLV- LTR variants show differential binding with transcriptional regulator E2F-4
Rodriguez, Sabrina ULiege; Varone, C.; Cánepa, E. et al

in AIDS Research and Human Retroviruses (2007, April 23), 23(4), 657

Naturally occurring BLV- LTR variants show differential binding with transcriptional regulator E2F-4. Sabrina M. Rodríguez1, Cecilia Varone2, Eduardo Cánepa2, Karina Trono1. srodriguez@cnia.inta.gov.ar ... [more ▼]

Naturally occurring BLV- LTR variants show differential binding with transcriptional regulator E2F-4. Sabrina M. Rodríguez1, Cecilia Varone2, Eduardo Cánepa2, Karina Trono1. srodriguez@cnia.inta.gov.ar 1Instituto de Virología. CICVyA. INTA-Castelar. Castelar. Buenos Aires. Argentina 2Catedra de Biología Molecular. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Buenos Aires. Argentina The proviral Long Terminal Repeats (LTR) of retroviruses constitute a critical element involved in the regulation of viral and cellular gene expression. It is well known for some viruses within the Retroviridae family that minimal changes in this region can influence tropism, virulence and pathogenicity. The aim of this work was to elucidate if there is any association between the binding capacity of the Bovine Leukemia Virus (BLV) LTR region with cellular transcription factors and the pathogenic evolution of natural infection. The complete 5´LTR sequence amplified from mononuclear cells and tumour tissues of 40 naturally infected cattle was analyzed. Sequence analysis revealed the presence of two LTR variants associated with the different BLV pathogenic phenotypes: aleukemic (AL), persistent lymphocitosis (PL) and lymphosarcoma (LS). Analysis by EMSA showed a clearly weaker specific binding pattern when a LS-derived sequence was used as probe. Together with this finding, we also demonstrated by gel shift and supershift assays that the cellular transcription factor E2F-4 specifically interacts with a putative E2F binding motif within the U5 region of BLV 5`LTR unveiled by “in sillico” analysis. The results of this work demonstrates for the first time the presence of differential binding capacity of BLV natural derived variants to cellular nuclear proteins, together with physical characterization of an E2F-4 binding site in the U5 region of BLV-LTR that shows preferential binding to AL/PL derived sequences. These findings can contribute to the knowledge of LTR-driven regulation of viral and cellular gene expression. [less ▲]

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See detailVirulence genetic markers in the LTR of naturally occurring variants of Bovine Leukemia Virus from Argentina
Rodriguez, Sabrina ULiege; Trono, K.; Jones, L.R.

in AIDS Research and Human Retroviruses (2007, April 23), 23(4), 656

Virulence Genetic Markers in the LTR of Naturally Occurring Variants of Bovine Leukemia Virus from Argentina *Sabrina M Rodríguez1 Karina G Trono1 Leandro R Jones1 1Instituto de Virología, CICVyA, INTA ... [more ▼]

Virulence Genetic Markers in the LTR of Naturally Occurring Variants of Bovine Leukemia Virus from Argentina *Sabrina M Rodríguez1 Karina G Trono1 Leandro R Jones1 1Instituto de Virología, CICVyA, INTA-Castelar, Castelar, Buenos Aires, Argentina *Corresponding author, Sabrina Rodríguez, E-mail: srodriguez@cnia.inta.gov.ar Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis, is classified within the Deltaretrovirus genus. The outcome of infection is diverse. Almost 70% of the infected animals are asymptomatic (AL), while 25% develop a benign condition called persistent lymphocytosis (PL). In addition, between 1 and 5% of the infected cattle develop a B-lymphoproliferative neoplastic condition or lymphosarcoma (LS). The genetic basis of these various clinical manifestations is unknown. Long terminal repeats (LTR) are implicated in the regulation of viral and cellular gene expression. It is well documented for other retroviruses that even single point mutations in the nucleotidic sequence of the LTR can have a direct impact on tissue tropism, virulence, and pathogenicity. However, the influence of genetic variation in LTRs on clinical aspects has never been studied for BLV. In order to study the association between LTR genetic variations and the clinical presentation of BLV infection, sequencing of the complete 5 -LTR region from 28 naturally BLV-infected cattle was carried out. The relation of genetic variations to clinical evolution was analyzed for each variant position using comparative methods as implemented in Pagel’s correlation test of the Mesquite program. These analyses showed that two out of seven variant positions were highly correlated with pathogenesis (p value less than 10E-18). The results reported herein suggest an important role for certain positions of the LTR in the determination of the clinical evolution of BLV-infected cattle. These findings could contribute to gaining insight into the molecular grounds of BLV viral pathogenesis in cattle. [less ▲]

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See detailCell turnover in BLV-infected sheep.
Debacq, C.; Peremans, T.; Kerkhofs, P. et al

in AIDS Research and Human Retroviruses (2001), 17(1), 13

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See detailGenetic Determinants Of Bovine Leukemia Virus Pathogenesis
Willems, Luc ULiege; Burny, A.; Collete, Delphine et al

in AIDS Research and Human Retroviruses (2000), 16(16), 1787-95

The understanding of HTLV-induced disease is hampered by the lack of a suitable animal model allowing the study of both viral replication and leukemogenesis in vivo. Although valuable information has been ... [more ▼]

The understanding of HTLV-induced disease is hampered by the lack of a suitable animal model allowing the study of both viral replication and leukemogenesis in vivo. Although valuable information has been obtained in different species, such as rabbits, mice, rats, and monkeys, none of these systems was able to conciliate topics as different as viral infectivity, propagation within the host, and generation of leukemic cells. An alternate strategy is based on the understanding of diseases induced by viruses closely related to HTLV-1, like bovine leukemia virus (BLV). Both viruses indeed belong to the same subfamily of retroviruses, harbor a similar genomic organization, and infect and transform cells of the hematopoietic system. The main advantage of the BLV system is that it allows direct experimentation in two different species, cattle and sheep. [less ▲]

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See detailModulation Of Cd3-Gamma Gene Expression After Hiv Type 1 Infection Of The We17/10 T Cell Line Is Progressive And Occurs In Concert With Decreased Production Of Viral P24 Antigen
Willardgallo, Ke.; Delmellewibaut, C.; Segurazapata, I. et al

in AIDS Research and Human Retroviruses (1996), 12(8),

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See detailIron chelation decreases NF-kappaB and HIV-1 activation due to oxidative stress
Sappey, Christine; Boelaert, J. R.; Legrand-Poels, Sylvie ULiege et al

in AIDS Research and Human Retroviruses (1995)

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See detailStimulation of glutatione-peroxidase activity decreases HIV type-1 activation after oxidative stress
Sappey, C.; Legrand, Sylvie ULiege; Best-Belopmme, M. et al

in AIDS Research and Human Retroviruses (1994), 10(11), 1451-1461

Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this ... [more ▼]

Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this study, we demonstrate that selenium supplementation can effectively increase glutathione peroxidase (GPx) activity in latently infected T lymphocytes. The Se-supplemented cells exhibited an important protection against the cytotoxic and reactivating effects of hydrogen peroxide (H2O2). Concomitantly, NF-kappa B activation by H2O2 was also decreased in Se-supplemented cells. Selenium stimulation of GPx activity also induces a protective effect against cell activation by tumor necrosis factor alpha (TNF-alpha) but less significantly by phorbol esters such as PMA. These Se-mediated effects were specific because they were not found when AP-1 DNA-binding activity was studied after H2O2-induced stress. Hyperthermia was also studied because it could promote intracellular electron leakage in electron transport chains. Elevating the temperature to 42 degrees C did not induce NF-kappa B directly. Rather, it sensitized infected cells to subsequent oxidative stress by H2O2, demonstrating the importance of hyperthermia, often associated with opportunistic infections in the development of immunodeficiency. In this case, Se induced partial protection against the sensitizing effect of hyperthermia. [less ▲]

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See detailThe interaction between Bovine Leukemia Virus and its target cell.
Burny, Arsène; Kettmann, Richard ULiege; Willems, Luc ULiege et al

in AIDS Research and Human Retroviruses (1992), 8

Previous results indicate that the external glycoprotein gp51 of bovine leukemia virus plays an important role in the process of cell fusion induced by bovine leukemia virus (Bruck, C., Mathot, S ... [more ▼]

Previous results indicate that the external glycoprotein gp51 of bovine leukemia virus plays an important role in the process of cell fusion induced by bovine leukemia virus (Bruck, C., Mathot, S., Portetelle, D., Berte, C., Franssen, J. D., Herion, P., and Burny, A. (1982) Virology 122, 342-352; Voneche, V., Portetelle., D., Kettmann, R., Willems, L., Limbach, K., Paoletti, E., Ruysschaert, J. M., Burny, A., and Brasseur, R. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 3810-3814) and suggest that a region encompassing residues 23 and 25 of gp51 is involved in this process (Portetelle, D., Couez, D., Bruck, C., Kettmann, R., Mammerickx, M., Van der Maaten, M., Brasseur, R., and Burny, A. (1989) Virology 169, 27-33; Mamoun, R., Morisson, M., Rebeyrotte, N., Busetta, B., Couez, D., Kettmann, R., Hospital, M., and Guillemain, B. (1990) J. Virol. 64, 4180-4188). X-ray diffraction studies performed on envelope glycoproteins of influenza virus indicate that the NH2-terminal part of the external glycoprotein lies very close to the fusion peptide. The same overall structure seems to exist in human immunodeficiency virus as suggested by site-directed mutagenesis followed by syncytia induction assays. Our theoretical studies indicate that a segment expanding between residues 19 and 27 of gp51 probably adopts an amphipathic beta-strand structure. We hypothesize that the amphipathic 19-27 structure of gp51 plays an important role in the process of membrane fusion by interacting with the fusion peptide or with another region of gp30. Mutational analysis disrupting the amphipathy of the 19-27 region strongly altered the fusogenic capacity of the gp51-gp30 complex. [less ▲]

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