Project description:Resting CD4+ T cells are infected by HIV-1 in vivo, however are refractory to cell-free HIV-1 infection in vitro. We show that they are efficiently infected by cell-to-cell spread. To allow resting T cell infection, uninfected resting target cells were co-cultured with infected donor T cells. Cells were infected with HIV-1 WT, dVpr or left mock treated and cultures with or without IL7. After 72h of co-culture, resting target cells were recovered by flow cytometry sorting and total RNA was extracted. RNASequencing revealed global transcriptomic reprogramming of resting memory T cells by HIV-1 Vpr.
Project description:Viruses target host proteins for degradation to enhance their replication and transmission, and identifying these targets has provided key insights into the host-pathogen interaction1-3. Here, we use complementary unbiased mass spectrometry-based approaches to dissect the widespread proteomeic remodelling seen in HIV-1 infected T-cells. Remarkably, the HIV accessory protein Vpr is both necessary and sufficient to cause the vast majority of these changes. Protein regulation requires recruitment of the DCAF1/DDB1/CUL4 E3 ubiquitin ligase complex, and pulsed-Stable Isotope Labelling with Amino Acids in Cell Culture (SILAC) and immunoprecipitation-mass spectrometry (IP-MS) identified at least 38 cellular proteins directly targeted for degradation by Vpr. Whilst other HIV-1 accessory proteins downregulate a small number of specific host factors, Vpr depletes multiple protein targets, causing systems-level changes to the cellular proteome. A subset of the novel cellular targets identified in this study are depleted by Vpr variants from across HIV-1/SIVcpz and other primate lentiviral lineages, confirming their biological importance in vivo.
Project description:HIV-1 accessory protein, Vpr, is required for efficient HIV-1 infection of macrophages. Here we show that Vpr reprograms macrophage gene expression by altering the activity of master transcriptional regulator, PU.1, which is responsible for regulating the expression of host immune response genes and is necessary for normal hematopoiesis. In HIV-infected primary macrophages, Vpr-dependent changes in PU.1 levels result in suppression of known anti-viral targets of Vpr including IFITM3 and MRC1. Moreover, we find that PU.1 and its co-factor TET2 are co-recruited to DCAF1 by Vpr and targeted for accelerated degradation. Downmodulation of PU.1 is a highly conserved function of Vpr that is maintained across primate lentiviruses including HIV-2 and several SIVs. In contrast, this activity is not shared by the evolutionarily related accessory protein Vpx. Our findings demonstrate how Vpr dramatically enhances HIV spread in macrophages by targeting a myeloid-specific transcription factor needed for expression of multiple viral restriction factors.
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune respone and cell signaling pathways. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human macrophages infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) and chemokines in human macrophages. Human monocytes-derived macrophages (MDMs) were isolated from peripheral blood mononuclear cells (PBMCs) from two healthy donors and were infected with recombinant adenoviruses either expressing HIV-1 Vpr or ZsGreen1 as a control. At 48 hours post-infection, RNA was isolated and subjected to microarray analysis.
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune responses. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human dendritic cells infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) in human monocyte derived dendritic cells. Human monocytes-derived dendritic cells (MDDCs) were isolated from peripheral blood mononuclear cells (PBMCs) from two healthy donors and were infected with recombinant adenoviruses either expressing HIV-1 Vpr or ZsGreen1 as a control. At 48 hours post-infection, RNA was isolated and subjected to microarray analysis.
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune respone and cell signaling pathways. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human macrophages infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) and chemokines in human macrophages.
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune responses. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human dendritic cells infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) in human monocyte derived dendritic cells.
Project description:Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders. Human fetal neurons were chosen to examine the impact of HIV-1 Vpr protein on gene expression
Project description:Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders. Using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Vpr) on the expression of miRNAs and mRNAs.
Project description:Recently, several neutralizing anti-HIV antibodies have been isolated from memory B cells of HIV-infected individuals. However, despite extensive evidence of B-cell dysfunction in HIV disease, little is known about the cells from which these rare HIV-specific antibodies originate. Accordingly, HIV envelope gp140 and CD4 or co-receptor (CoR) binding site (bs) mutant probes were used to evaluate HIV-specific responses in the peripheral blood B cells of individuals at various stages of infection. In contrast to non-HIV responses, HIV-specific responses against gp140 were enriched within abnormal B cells, namely activated and exhausted memory subsets, which are largely absent in the blood of uninfected individuals. Responses against the CoRbs (a poorly-neutralizing epitope) arose early whereas those against the CD4bs (a well-characterized neutralizing epitope) were delayed and infrequent. Enrichment of the HIV-specific response within resting memory B cells, the predominant subset in uninfected individuals, did occur in certain infected individuals who maintained low levels of plasma viremia and immune activation with or without antiretroviral therapy. These findings were corroborated by transcriptional profiles. Taken together, our findings provide valuable insight into virus-specific B-cell responses in HIV infection and demonstrate that memory B-cell abnormalities may contribute to the ineffectiveness of the antibody response in infected individuals. HIV-specific responses against gp140 were enriched within abnormal B cells, namely activated (AM) and exhausted (tissue-like; TLM) memory subsets, which are largely absent in the blood of uninfected individuals. These responses are highest during the early stage of HIV infection, significantly decreased following the initiation of antiretroviral therapy (ART), and most importantly, enriched in normal resting memory B cells (RM) when HIV viremia and immune activation are controlled either naturally or as a result of ART. These HIV-specific B cells (AM and TLM) and resting memory B cells (RM) were sorted from peripheral blood mononuclear cells (PBMCs) of 6 HIV infected individuals. In addition, gp140-specific IgG+ B cells were sorted from individuals with either a strong (n= 6) or weak (n= 6) pro-resting memory profile. TaqMan gene expression assay was performed on these HIV-specific B cells and B cell subset. The array consisted of 29 genes.