Search results for "Retrovirus"

2018

The murine Friend virus (FV) retrovirus model has been widely used to study anti-viral immune responses, and virus-induced cancer. Here we analyzed FV immune evasion mechanisms on the level of dendritic cells (DC) essential for the induction of primary adaptive immune responses. Comparative quantitative proteome analysis of FV-infected DC (FV-DC) of different genotypes (BALB/c, C57BL/6) and non-infected DC revealed numerous genotype-independently regulated proteins rergulating metabolic activity, cytoskeletal rearrangements, and antigen processing/presentation. These alterations may promote virion production in FV-DC. Stimulation of FV-DC with LPS resulted in strongly enhanced IL-10 product…

Evolution of gypsy Endogenous Retrovirus in the Drosophila obscura Species Group

2000

The Ty3/gypsy family of retroelements is closely related to retroviruses, and some of their members have an open reading frame resembling the retroviral gene env. Sequences homologous to the gypsy element from Drosophila melanogaster are widely distributed among Drosophila species. In this work, we report a phylogenetic study based mainly on the analysis of the 5' region of the env gene from several species of the obscura group, and also from sequences already reported of D. melanogaster, Drosophila virilis, and Drosophila hydei. Our results indicate that the gypsy elements from species of the obscura group constitute a monophyletic group which has strongly diverged from the prototypic D. m…

Impact of probiotic Saccharomyces boulardii on the gut microbiome composition in HIV-treated patients: A double-blind, randomised, placebo-controlled…

2017

Dysbalance in gut microbiota has been linked to increased microbial translocation, leading to chronic inflammation in HIV-patients, even under effective HAART. Moreover, microbial translocation is associated with insufficient reconstitution of CD4+T cells, and contributes to the pathogenesis of immunologic non-response. In a double-blind, randomised, placebo-controlled trial, we recently showed that, compared to placebo, 12 weeks treatment with probiotic Saccharomyces boulardii significantly reduced plasma levels of bacterial translocation (Lipopolysaccharide-binding protein or LBP) and systemic inflammation (IL-6) in 44 HIV virologically suppressed patients, half of whom (n = 22) had immun…

Strong immunogenic potential of a B7 retroviral expression vector: generation of HLA-B7-restricted CTL response against selectable marker genes.

1998

The stimulation of a specific immune response is an attractive goal in cancer therapy. Gene transfer of co-stimulatory molecules and/or cytokine genes into tumor cells and the injection of these genetically modified cells leads to tumor rejection by syngeneic hosts and the induction of tumor immunity. However, the development of host immune response could be either due to the introduced immunomodulatory genes or due to vector components. In this study, human renal cell carcinoma cell lines were modified by a retrovirus to express the co-stimulatory molecule B7-1 together with the hygromycin/thymidine kinase fusion protein (HygTk) as positive and negative selection markers. These B7-1-transd…

Sequential Cross-Sectional Surveys in Orange Farm, a Township of South Africa, Revealed a Constant Low Voluntary Medical Male Circumcision Uptake amo…

2016

Background WHO recommends a male circumcision (MC) prevalence rate higher than 80% to have a substantial impact on the HIV-AIDS epidemic in Eastern and Southern Africa. Orange Farm, a township in South Africa, has a free-for-service voluntary medical male circumcision (VMMC) clinic in operation since 2008. Following an intense campaign from 2008 to 2010, MC prevalence rate increased to 55.4% (ANRS-12126). Ongoing and past VMMC campaigns focused on youths, through school talks, and adults at a community level. The main objective of the study was to assess the change in MC prevalence rate among adults aged 18–19 and 18–49 years in the past 5 years. Methods A cross-sectional survey (ANRS-12285…

The effectiveness of peer-support for people living with HIV: A systematic review and meta-analysis

2021

Background The practice of involving people living with HIV in the development and provision of healthcare has gained increasing traction. Peer-support for people living with HIV is assistance and encouragement by an individual considered equal, in taking an active role in self-management of their chronic health condition. The objective of this systematic review was to assess the effects of peer-support for people living with HIV. Methods We conducted a systematic review in accordance with international guidelines. Following systematic searches of eight databases until May 2020, two reviewers performed independent screening of studies according to preset inclusion criteria. We conducted ri…

Regulation of the tumor marker Fascin by the viral oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) depends on promoter activation and …

2015

AbstractAdult T-cell leukemia/lymphoma is a highly infiltrative neoplasia of CD4+ T-lymphocytes that occurs in about 5% of carriers infected with the deltaretrovirus human T-cell leukemia virus type 1 (HTLV-1). The viral oncoprotein Tax perturbs cellular signaling pathways leading to upregulation of host cell factors, amongst them the actin-bundling protein Fascin, an invasion marker of several types of cancer. However, transcriptional regulation of Fascin by Tax is poorly understood. In this study, we identified a triple mode of transcriptional induction of Fascin by Tax, which requires (1) NF-κB-dependent promoter activation, (2) a Tax-responsive region in the Fascin promoter, and (3) a p…

Rapid Detection of the ERV-K(C4) Retroviral Insertion Reveals Further Structural Polymorphism of the Complement C4 Genes in Old World Primates

2001

The fourth component of complement (C4) is coded for by two tandem-duplicated genes located in the class III region of the MHC of humans as well as a number of primates. A C4 gene size polymorphism giving rise to two gene variants of 16 and 22.3 kb length can be attributed to a complete endogenous retroviral insertion of 6.3 kb termed ERV-K(C4) in intron 9 of the long C4 genes. We developed a simple PCR-based screening assay to detect the presence of this insertion, and tested a number of unrelated animals from old world primate species. The presence of the ERV insertion in the orangutan, rhesus macaque and green monkey as well as its absence in gorillas and chimpanzees could be confirmed. …

Human endogenous retrovirus rec interferes with germ cell development in mice and may cause carcinoma in situ, the predecessor lesion of germ cell tu…

2005

Germ cell tumors (GCTs) are among the most common malignancies in young men. We have previously documented that patients with GCT frequently produce serum antibodies directed against proteins encoded by human endogenous retrovirus (HERV) type K sequences. Transcripts originating from the env gene of HERV-K, including the rec-relative of human immunodeficiency virus rev, are highly expressed in GCTs. We report here that mice that inducibly express HERV-K rec show a disturbed germ cell development and may exhibit, by 19 months of age, changes reminiscent of carcinoma in situ, the predecessor lesion of classic seminoma in humans. This provides the first direct evidence that the expression of a…

Gypsy endogenous retrovirus maintains potential infectivity in several species of Drosophilids.

2008

Abstract Background Sequences homologous to the gypsy retroelement from Drosophila melanogaster are widely distributed among drosophilids. The structure of gypsy includes an open reading frame resembling the retroviral gene env, which is responsible for the infectious properties of retroviruses. Results In this study we report molecular and phylogeny analysis of the complete env gene from ten species of the obscura group of the genus Drosophila and one species from the genus Scaptomyza. Conclusion The results indicate that in most cases env sequences could produce a functional Env protein and therefore maintain the infectious capability of gypsy in these species.