Laurent Houzet

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Short interfering RNAs (siRNAs) have been used to inhibit HIV-1 replication. The durable inhibition of HIV-1 replication by RNA interference has been impeded, however, by a high mutation rate when viral sequences are targeted and by cytotoxicity when cellular genes are knocked down. To identify cellular proteins that contribute to HIV-1 replication that can(More)
MicroRNAs (miRNAs) play diverse roles in regulating cellular and developmental functions. We have profiled the miRNA expression in peripheral blood mononuclear cells from 36 HIV-1 seropositive individuals and 12 normal controls. The HIV-1-positive individuals were categorized operationally into four classes based on their CD4+ T-cell counts and their viral(More)
Small non-coding RNAs of 18-25 nt in length can regulate gene expression through the RNA interference (RNAi) pathway. To characterize small RNAs in HIV-1-infected cells, we performed linker-ligated cloning followed by high-throughput pyrosequencing. Here, we report the composition of small RNAs in HIV-1 productively infected MT4 T-cells. We identified(More)
In addition to genomic RNA, HIV-1 particles package cellular and spliced viral RNAs. In order to determine the encapsidation mechanisms of these RNAs, we determined the packaging efficiencies and specificities of genomic RNA, singly and fully spliced HIV mRNAs and different host RNAs species: 7SL RNA, U6 snRNA and GAPDH mRNA using RT-QPCR. Except GAPDH(More)
MicroRNAs (miRNAs) are small non-coding RNAs that control a multitude of critical processes in mammalian cells. Increasing evidence has emerged that host miRNAs serve in animal cells to restrict viral infections. In turn, many viruses encode RNA silencing suppressors (RSS) which are employed to moderate the potency of the cell's miRNA selection against(More)
HIV-1 particles contain RNA species other than the unspliced viral RNA genome. For instance, viral spliced RNAs and host 7SL and U6 RNAs are natural components that are non-randomly incorporated. To understand the mechanism of packaging selectivity, we analyzed the content of a large panel of HIV-1 variants mutated either in the 5'UTR structures of the(More)
BACKGROUND Tumor necrosis factor (TNF) production by macrophages plays an important role in the host response to infection. TNF-alpha gene expression in RAW 264.7 macrophages is predominantly regulated at the translational level. A key element in this regulation is an AU-rich (AUR) sequence located in the 3' untranslated region (UTR) of TNF mRNA. In(More)
TNF-alpha gene expression is regulated at transcriptional and post-transcriptional levels in mouse macrophages. The post-transcriptional regulation is mediated by the AU-rich element (ARE) located in the TNF-alpha mRNA 3' untranslated region (UTR), which controls its translation and stability. In resting macrophages, the ARE represses TNF-alpha mRNA(More)
Although semen is the principal vector of human immunodeficiency virus (HIV) dissemination worldwide, the origin of the infected leukocytes and free viral particles in this body fluid remain elusive. Here we review the accumulated evidence of the genital origin of HIV in semen from therapy naive individuals and men receiving suppressive highly active(More)
With the recent development of short interfering RNA and short hairpin RNA expression libraries, RNA interference (RNAi) technology has been extensively employed to identify genes involved in diverse cellular processes, such as signal transduction, cell cycle, cancer biology and host-pathogen interactions. In the field of viral infection, this approach has(More)