Project description:Tissue mononuclear phagocytes (MNP) are specialised in pathogen detection and antigen presentation. They are the first cells of the immune system to encounter HIV and play a key role in transmission as they deliver the virus to CD4 T cells, which are the primary HIV target cell in which the virus undergoes replication. Most studies have investigated the role that epithelial MNPs play in HIV transmission but, as mucosal trauma and inflammation are strongly associated with HIV transmission, it is also important to examine the role that sub-epithelial MNPs play. Sub-epithelial MNPs are present in a diverse array of subsets which differ in their function and the pathogens they detect. Understanding how specific subsets interact with HIV and deliver the virus to CD4 T cells is therefore of key importance to vaccine and microbicide development. In this study we have shown that, after topical application, HIV can penetrate to interact with sub-epithelial resident myeloid cells in anogenital explants and defined the full array of MNP subsets that are present in all the human anogenital and colorectal sub-epithelial tissues that HIV may encounter during sexual transmission. In doing so we have identified two subsets that preferentially take up HIV, become infected and transmit the virus to CD4 T cells; CD14+CD1c+CD11c+ monocyte-derived dendritic cells and langerin-expressing conventional dendritic cells 2 (cDC2).
Project description:The role of the human type I interferon (IFN-I) system in restricting Zika virus (ZIKV) is uncertain. Here, genetic and pharmacological ablation of IFN-I signalling enhanced ZIKV replication and cytopathicity in macrophages and microglia, key cells in ZIKV transmission and pathogenesis. Thus, despite the extensive IFN-I countermeasures employed by ZIKV, IFN-I dictates the outcome of infection in macrophages. Therapeutic manipulation of the IFN-I system may bring clinical benefit in ZIKV.
Project description:To unravel the molecular mechanisms potentially associated with the pathogenesis of the EDS-HT/JHS. Transcriptome-wide expression profiling using the Affymetrix Gene 1.0 ST platform comparing the gene expression patterns of skin fibroblasts of five EDS-HT/JHS patients with those of six healthy individuals Comparison between five EDS-HT/JHS human fibroblasts and six healthy individuals
Project description:To unravel the molecular mechanisms potentially associated with the pathogenesis of the EDS-HT/JHS. Transcriptome-wide expression profiling using the Affymetrix Gene 1.0 ST platform comparing the gene expression patterns of skin fibroblasts of five EDS-HT/JHS patients with those of six healthy individuals
Project description:Environmental enrichment (EE) conditions have profound beneficial effects for reinstating cognitive ability in neuropathological disorders like Alzheimerâs disease (AD). While EE benefits involve epigenetic gene control mechanisms that comprise histone acetylation, the histone acetyltransferases (HATs) involved remain largely unknown. Here, we examine a role for Tip60 HAT action in mediating activity- dependent beneficial neuroadaptations to EE using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that flies raised under EE conditions display enhanced MB axonal outgrowth, synapse protein production, histone acetylation induction and transcriptional activation of cognition linked genes when compared to their genotypically identical siblings raised under isolated conditions. Further, these beneficial changes are impaired in both Tip60 HAT mutant flies and APP neurodegenerative flies. While EE conditions provide only slight beneficial neuroadaptive changes in the APP neurodegenerative fly MB, such positive changes are significantly enhanced by increasing MB Tip60 HAT levels. Our results implicate Tip60 as a critical mediator of EE-induced benefits, and provide insight into synergistic behavioral and epigenetic based approaches for treatment of cognitive disorders. EE has been shown to positively impact gene expression profiles in the mouse brain that are enriched in functions such as neuronal structure, synaptic plasticity and neurotransmission. Thus, we asked whether the EE induced beneficial MB structural and synaptic changes we observe are accompanied by neuroadaptive transcriptional benefits in the Drosophila MB, and if so, is Tip60 HAT action required for this process. To address this question, we accessed EE induced beneficial transcriptional changes using microarray. We crossed our UAS-mCD8-GFP;Tip60E431Q flies or control UAS-mCD8-GFP flies to MB GAL4 OK-107 to simultaneously induce Tip60 HAT loss in the MB while tagging MB cells with GFP. Adult progeny were exposed to EE or ISO conditions. After conditioning, the GFP tagged MB Kenyon neurons were FACs purified from conditioned fly brains from each genotype to enrich for detection of an EE induced MB transcriptional response. RNA was isolated from the purified Kenyon MB neurons and transcriptional changes for each genotype were assessed using microarray analysis
Project description:To screen for potential miRNA that may contribute to the etiopathogenesis of EDS-HT/JHS miRNA expression profiling was performed using the Affymetrix GeneChip® miRNA 3.0 Array and comparing the miRNA expression changes of skin fibroblasts of five EDS-HT/JHS patients with those of six healthy individuals
Project description:Tip60 is a key histone acetyltransferase (HAT) enzyme that plays a central role in diverse biological processes critical for general cell function, however the chromatin-mediated cell-type specific developmental pathways that are dependent exclusively upon the HAT activity of Tip60 remain to be explored. Here, we investigate the role of Tip60 HAT activity in transcriptional control during multicellular development, in vivo by examining genome-wide changes in gene expression in a Drosophila model system specifically depleted for endogenous dTip60 HAT function. We show that amino acid residue E431 in the catalytic HAT domain of dTip60 is critical for the acetylation of endogenous histone H4 in our fly model in vivo, and demonstrate that dTip60 HAT activity is essential for multicellular development. Moreover, our results uncover a novel role for Tip60 HAT activity in controlling neuronal specific gene expression profiles essential for nervous system function as well as a central regulatory role for Tip60 HAT function in general metabolism. Drosophila larvae ubiquitously expressing either our dTIP60 HAT specific mutant or an additional copy of wild type dTIP60 were selected along with age-matched wild type controls for RNA extraction. Two samples, each containing a pool of thirty-five staged whole larvae, were collected from each respective genotypic cross, and were used for hybridization on a separate Affymetrix microarray.
Project description:Histone acetyltransferases (HAT) assemble into multisubunit complexes in order to target distinct lysine residues on nucleosomal histones. Here, we characterize native HAT complexes assembled by the BRPF-family of scaffold proteins. Their PHD-ZnKnuckle-PHD domain is essential for binding chromatin and restricted to unmethylated H3K4, a specificity that is reversed by the associated ING subunit. Native BRPF1 complexes can contain either MOZ/MORF or HBO1 as catalytic acetyltransferase subunit. Interestingly, while the previously reported HBO1 complexes containing JADE scaffold proteins target histone H4, the HBO1-BRPF1 complex acetylates only H3 in chromatin. We mapped a small region at the N-terminus of scaffold proteins responsible for histone tail selection on chromatin. Thus, alternate choice of subunits associated with HBO1 can switch its specificity from H4 to H3 tails, highlighting a crucial new role of associated subunits within HAT complexes, previously thought to be intrinsic to the catalytic subunit. Genome-wide mapping of MYST acetyltransferases subunits and H3K4me3 histone mark in RKO cells.