Comparative analysis of cellular mRNA incorporation into MLV and HIV1 virus-like particles
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE7213 | GEO | 2007/03/08
SECONDARY ACCESSION(S): PRJNA98295
REPOSITORIES: GEO
Similar Datasets
Project description:We hypothesize that cellular mRNAs are incorporated nonselectively into retrovirus particles Experiment Overall Design: This study utilizes microarray analysis to test these hypotheses. Transfected cells were grown, RNA was isolated and used for global gene expression profiling (Affymetrix Human U133 Plus 2.0 array). Statistically significant gene expression was determined as a minimum 6 counts of 9 pairwise comparisons, minimum 1.5-fold change, and p < 0.05. Further, Absolute | FC - FC SEM | >= 1.5.
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2021-06-08 | GSE164270 | GEO
Project description:The broadly neutralizing antibody against HIV-1, b12, binds to the CD4 binding site (CD4bs) on the outer domain (OD) of the gp120 subunit of HIV-1 Env. We have previously reported the design of an E. coli expressed fragment of HIV-1 gp120, b122a, containing about 70% of the b12 epitope with the idea of focusing the immune response to this structure. Since the b122a structure was found to be only partially folded, as assessed by circular dichroism and protease resistance, we attempted to stabilize it by the introduction of additional disulfide bonds. One such mutant, b122a1-b showed increased stability and bound b12 with 30-fold greater affinity as compared to b122a. Various b122a and OD fragment proteins were displayed on the surface of Qβ virus-like particles. Sera raised against these particles in six-month long rabbit immunization studies could neutralize Tier1 viruses across different subtypes with the best results observed with b122a1-b displayed particles. Significantly higher amounts of antibodies directed towards the CD4bs were also elicited by particles displaying b122a1-b. This study highlights the ability of fragment immunogens to focus the antibody response to the conserved CD4bs of HIV-1.
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Project description:RNA delivery is a method of choice to achieve transient gene expression for research and in cell- or gene-based therapies. To improve retroviral transfer, we designed a dimerization-independent MS2-driven packaging system using MS2-retrovirus chimeras. We delivered RUNX2- or DLX5-mRNA into primary human bone-marrow mesenchymal-stem-cells. We used microarrays to detail the global programme of gene expression confirming the effects of pro-osteogenic genes transduced by MS2 chimeric lentiviral particles.
2015-03-11 | GSE66723 | GEO
Project description:Virions are thought to contain all the essential proteins that govern virus egress from the host cell and initiation of replication in the target cell. It has been known for some time that influenza virions contain nine viral proteins; however, analyses of other enveloped viruses have revealed that proteins from the host cell can also be detected in virions. To address whether the same is true for influenza virus, we used two complementary mass spectrometry approaches to perform a comprehensive proteomic analysis of purified influenza virus particles. In addition to the aforementioned nine virus-encoded proteins, we detected the presence of 36 host-encoded proteins. These include both cytoplasmic and membrane-bound proteins that can be grouped into several functional categories, such as cytoskeletal proteins, annexins, glycolytic enzymes, and tetraspanins. Interestingly, a significant number of these have also been reported to be present in virions of other virus families. Protease treatment of virions combined with immunoblot analysis was used to verify the presence of the cellular protein and also to determine whether it is located in the core of the influenza virus particle. Immunogold labeling confirmed the presence of membrane-bound host proteins on the influenza virus envelope. The identification of cellular constituents of influenza virions has important implications for understanding the interactions of influenza virus with its host and brings us a step closer to defining the cellular requirements for influenza virus replication. While not all of the host proteins are necessarily incorporated specifically, those that are and are found to have an essential role represent novel targets for antiviral drugs and for attenuation of viruses for vaccine purposes.
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Project description:Viral infections involve packaging of the viral genome and proteins into virions. Knowing virion composition and structure is critical to understand viral pathogenesis. However, an integrated picture of virion proteome organization of large viruses, such as Herpesviruses, is lacking. Here we use cross-linking mass spectrometry to derive a spatially resolved structural interactome of intact human cytomegalovirus virions. We capture interactions of 82 host and 33 viral proteins, allowing us to de novo allocate them into distinct virion-layers and identify several host proteins as constitutive virion components recruited via specific protein interactions. The abundant viral protein pp150 forms domain-specific interactions with all virion layers and scaffolds numerous viral and host proteins such as PP1 phosphatase and 14-3-3 proteins, which are incorporated via nearby short linear motifs in pp150’s C-terminus. PP1 recruitment antagonizes 14-3-3 proteins and is pivotal during early and late viral replication steps. Collectively, this study gives a spatial and quantitative inventory of the system-wide organization and functional relevance of protein interactions inside native herpesvirus particles.
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Project description:Viral antigens can activate phagocytes inducing inflammation but the mechanisms are barely explored. This study aimed to investigate the capability of viral oligomeric proteins of different structure to induce inflammatory response in macrophages. Human THP-1 cell line was used to prepare macrophages which were treated with filamentous nucleocapsid-like particles (NLPs) of paramyxoviruses and spherical virus-like particles (VLPs) of human polyomaviruses. The effects of viral proteins on cell viability, pro-inflammatory cytokines’ production and formation of NLRP3 inflammasome components, ASC specks, were investigated. Filamentous NLPs did not induce inflammation markers while spherical VLPs mediated inflammatory response followed by NLRP3 inflammasome activation. Inhibitors of cathepsins and K+ efflux decreased IL-1β levels and cell death indicating a complex inflammasome activation process. Similar activation pattern was observed in primary human macrophages treated with VLPs. Single cell RNAseq analysis of THP-1 cells revealed several cell activation states characterized by high expression of inflammation-related genes. This study provides new insights into interaction of viral proteins with innate immune cells and suggests that structural properties of oligomeric proteins may define cell activation pathways.
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Project description:During virus particle assembly, the arenavirus nucleoprotein (NP) associates with the viral genome to form nucleocapsids, which ultimately become incorporated into new virions at the cell membrane. Virion release is facilitated by the viral matrix Z protein through its interaction with the cellular endosomal sorting complex required for transport (ESCRT) machinery. However, the mechanism of nucleocapsid incorporation into virions is not well understood. Here, we demonstrate that ALIX/AIP1, an ESCRT-associated host protein, is required for the incorporation of the NP of Mopeia virus, a close relative of Lassa virus, into Z-induced virus-like particles (VLPs). Furthermore, we show that the Bro1 domain of ALIX/AIP1 interacts with the NP and Z proteins simultaneously, facilitating their interaction, and we identify residues 342 to 399 of NP as being necessary for its interaction with ALIX/AIP1. Our observations suggest a potential role for ALIX/AIP1 in linking Mopeia virus NP to Z and the budding apparatus, thereby promoting NP incorporation into virions.
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Project description:The human immunodeficiency virus (HIV) envelope (Env) protein is incorporated into HIV virions or virus-like particles (VLPs) at very low levels compared to the glycoproteins of most other enveloped viruses. To test factors that influence HIV Env particle incorporation, we generated a series of chimeric gene constructs in which the coding sequences for the signal peptide (SP), transmembrane (TM), and cytoplasmic tail (CT) domains of HIV-1 Env were replaced with those of other viral or cellular proteins individually or in combination. All constructs tested were derived from HIV type 1 (HIV-1) Con-S DeltaCFI gp145, which itself was found to be incorporated into VLPs much more efficiently than full-length Con-S Env. Substitution of the SP from the honeybee protein mellitin resulted in threefold-higher chimeric HIV-1 Env expression levels on insect cell surfaces and an increase of Env incorporation into VLPs. Substitution of the HIV TM-CT with sequences derived from the mouse mammary tumor virus (MMTV) envelope glycoprotein, influenza virus hemagglutinin, or baculovirus (BV) gp64, but not from Lassa fever virus glycoprotein, was found to enhance Env incorporation into VLPs. The highest level of Env incorporation into VLPs was observed in chimeric constructs containing the MMTV and BV gp64 TM-CT domains in which the Gag/Env molar ratios were estimated to be 4:1 and 5:1, respectively, compared to a 56:1 ratio for full-length Con-S gp160. Electron microscopy revealed that VLPs with chimeric HIV Env were similar to HIV-1 virions in morphology and size and contained a prominent layer of Env spikes on their surfaces. HIV Env specific monoclonal antibody binding results showed that chimeric Env-containing VLPs retained conserved epitopes and underwent conformational changes upon CD4 binding.
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