Project description:Human T-cell leukemia virus type 1 (HTLV-1) is linked to the development of adult T-cell leukemia (ATL) and the neuroinflammatory disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 Tax oncoprotein regulates viral gene expression and the NF-kB pathway to promote the survival of HTLV-1 infected T cells. In thsi study, we utilize a kinome-wide shRNA screen to identify the tyrosine kinase KDR/VEGFR2 as an essential survival factor of HTLV-1-transformed T cells. Inhibition of KDR induces apoptosis of Tax expressing HTLV-1-transformed cell lines and CD4+ T cells from HAM/TSP patients. Phosphoproteomics analysis of HTLV-1 transformed cells treated with a KDR inhibitor revealed inhibition of the phosphorylation of multiple receptors/cell surface proteins, ubiquitin conjugating systems, proteases, phosphatases, apoptotic regulatory factors, adhesion/extracellular matrix proteins and viral proteins. This work suggests that HTLV-1 Tax has hijacked KDR kinase activity to promote Tax stability and the proliferation and survival of HTLV-1 infected cells.
Project description:Human T-cell leukemia virus type 1 (HTLV-1) encodes HTLV-1 bZIP factor (HBZ), which is thought to be crucial for neoplastic and inflammatory diseases caused by HTLV-1. So, we analyzed the transcriptional profile of HBZ expressing cells and how HBZ affect the expression of apoptosis-related genes. We used microarrays to detail the effect of HTLV-1 bZIP factor (HBZ), which is encoded in the minus strand of HTLV-1 genome on gene expression. Especially how HBZ affect the expression of apoptosis-related genes. Jurkat cells stably expressing HBZ were stimulated with or without PMA and ionomycin for 9hours. Then RNA extraction and hybridization on Affymetrix microarrays were performed.
Project description:Human T-cell leukemia virus type 1 (HTLV-1) encodes HTLV-1 bZIP factor (HBZ), which is thought to be crucial for neoplastic and inflammatory diseases caused by HTLV-1. So, we analyzed the transcriptional profile of HBZ expressing cells and how HBZ affect the expression of apoptosis-related genes. We used microarrays to detail the effect of HTLV-1 bZIP factor (HBZ), which is encoded in the minus strand of HTLV-1 genome on gene expression. Especially how HBZ affect the expression of apoptosis-related genes.
Project description:We previously reported that human T cell lymphotropic virus 1 (HTLV-1) Tax oncoprotein constitutively activates TAK1. Here, we established Tax-positive HuT-102 cells stably downregulated TAK1 expression by short-hairpin RNA (HuT-shTAK1 cells), and investigated the physiological function of TAK1. Microarray analysis demonstrated that several interferon (IFN)-inducible genes including chemokines such as CXCL10 and CCL5 were significantly downregulated in HuT-shTAK1 cells. In contrast, Tax-mediated constitutive activation of NF-kB was intact in HuT-shTAK1 cells. IRF3, a critical transcription factor in innate immunity to viral infection, was constitutively activated in a Tax-dependent manner. Activation of IRF3 and IRF3-dependent gene expression were dependent on TAK1 and TBK1. On the other hand, IRF4, another IRF family of transcription factor overexpressed in a Tax-independent manner, negatively regulated the TAK1-dependent IRF3 transcriptional activity. Together, HTLV-1 manipulates IFN signaling by regulating both positive and negative IRFs.
Project description:Human T cell leukemia virus type 1 (HTLV-1) Tax is potent activator of viral and cellular gene expression that interacts with a number of cellular proteins. In this study, a large-scale host cell signaling events related to cellular proliferation were used to identify genes involved in Tax-mediated cell signaling events related to cellular proliferation and apoptosis.
Project description:Human T-cell leukemia virus type 1 (HTLV-1) bZIP factor (HBZ) which is encoded in the minus strand of HTLV-1 provirus, possesses dual function as protein, and also as RNA. To know the effect of HBZ RNA and protein in primary T-cells, we introduced HBZ, or its mutant TTG (exclude protein activity), or SM (exclude RNA activity) with retrovirus vector into CD4 positive murine T cells, and analysed the transcriptome profiling. We found that HBZ RNA altered cell cycle progression, cell survival related genes, while HBZ protein altered immunology related genes. This microarray results demonstrated that HBZ RNA and protein possess distinct functions in primary cells.
Project description:Human T-cell leukemia virus type 1 (HTLV-1) bZIP factor (HBZ) which is encoded in the minus strand of HTLV-1 provirus, possesses dual function as protein, and also as RNA. To know the effect of HBZ RNA and protein in primary T-cells, we introduced HBZ, or its mutant TTG (exclude protein activity), or SM (exclude RNA activity) with retrovirus vector into CD4 positive murine T cells, and analysed the transcriptome profiling. We found that HBZ RNA altered cell cycle progression, cell survival related genes, while HBZ protein altered immunology related genes. This microarray results demonstrated that HBZ RNA and protein possess distinct functions in primary cells. CD4 positive cells were enriched from murine splenocyte, and cultured with irradiated antigen presenting cells (APC). HBZ, or its mutant were introduced with retroviral vector. Forty eight hours after introduction, cells were washed and cultured with recombinant human IL-2. Further 48 hours after culture, virus infected cells were sorted and analysed by agilent microarray.
Project description:The p65/RelA factor of NF-κB plays a pivotal role in coordinating gene expression in response to diverse stimuli, including viral infections. At the chromatin level, p65/RelA governs gene transcription and alternative splicing (AS) through promoter enrichment and genomic exon occupancy, respectively. However, the mechanisms underlying the coordination of these processes remain elusive. In this study, we employed the HTLV-1 Tax viral oncoprotein, a potent activator of NF-κB, to investigate the integrative relationship between 3D chromatin architecture and NF-κB-regulated AS. Our analysis revealed that Tax induces a significant reorganization of the 3D genome, resulting in the formation of multigene complexes that comprise genes co-regulated in transcription and in AS. Notably, we found that the Tax-induced gene-gene contact between the two master genes NFKBIA and RELA is associated with their differential regulation in gene expression and alternative splicing, respectively. Through dCas9-mediated approaches, we demonstrated that NFKBIA-RELA interaction is required for alternative splicing regulation and is caused by an intragenic enrichment of p65/RelA on RELA. Via this mechanism, Tax promotes the expression of the splice isoform RELAE6 that exhibits specific gene transactivation capacity at the protein level. Our findings shed light on new regulatory mechanisms upon HTLV-1 Tax and underscore the crucial role of p65/RelA in coordinated regulation of NF-κB-responsive genes at both transcriptional and alternative splicing levels in the context of the 3D genome.