Engineering well-expressed, V2-immunofocusing HIV-1 envelope glycoprotein membrane trimers for use in heterologous prime-boost vaccine regimens
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Eclipse
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: 
Max Crispin
PROVIDER: MSV000088108 | MassIVE |
REPOSITORIES: MassIVE
Similar Datasets
Project description:HIV-1 vaccine immunofocusing strategies may be able to induce broadly-reactive neutralizing antibodies (NAbs). Here, we engineered a panel of diverse, membrane-resident native HIV-1 trimers vulnerable to two broad targets-the V2 apex and fusion peptide (FP). Selection criteria included i) high expression and ii) infectious function, so that trimer neutralization sensitivity can be profiled in pseudovirus (PV) assays. Initially, we boosted the expression of 17 candidate trimers by truncating gp41 and introducing a gp120-gp41 SOS disulfide to prevent gp120 shedding. "Repairs" were made to fill glycan holes and eliminate other strain-specific aberrations. A new neutralization assay allowed PV infection when our standard assay was insufficient. Trimers with exposed V3 loops, a target of non-NAbs, were discarded. To try to increase V2-sensitivity, we removed clashing glycans and modified the C-strand. Notably, a D167N mutation improved V2-sensitivity in several cases. Glycopeptide analysis of JR-FL trimers revealed near complete sequon occupation and that filling the N197 glycan hole was well-tolerated. In contrast, sequon optimization and inserting/removing glycans at other positions frequently had global "ripple" effects on glycan maturation and sequon occupation throughout the gp120 outer domain and gp41. V2 MAb CH01 selectively bound to trimers with small high mannose glycans near the base of the V1 loop, thereby avoiding clashes. Knocking in a rare N49 glycan was found to perturb gp41 glycans, increasing FP NAb sensitivity-and sometimes improving expression. Finally, a biophysical analysis of VLPs revealed that i) ~25% of particles bear Env spikes, ii) spontaneous particle budding is high and only increases 4-fold upon Gag transfection, and iii) Env+ particles express ~30-40 spikes. Taken together, we identified 7 diverse trimers with a range of sensitivities to two targets to allow rigorous testing of immunofocusing vaccine concepts.
| S-EPMC8565784 | biostudies-literature
Project description:Broadly neutralizing antibodies (bnAbs) to the HIV envelope (Env) V2-apex region are important leads for HIV vaccine design. Most V2-apex bnAbs engage Env with an uncommonly long heavy chain complementarity-determining region 3 (HCDR3), suggesting that rarity of bnAb precursors poses a challenge for vaccine priming. We created precursor sequence definitions for V2-apex HCDR3-dependent bnAbs and searched for related precursors in human antibody heavy chain ultradeep sequencing data from 14 HIV-unexposed donors. We found potential precursors in a majority of donors for only two long-HCDR3 V2-apex bnAbs, PCT64 and PG9, identifying these bnAbs as priority vaccine targets. We then engineered ApexGT Env trimers that bind inferred germlines for PCT64 and PG9 and have higher affinities for bnAbs; determined cryo-EM structures of ApexGT trimers bound to inferred germline and bnAb forms of PCT64 and PG9; and developed an mRNA-encoded cell-surface trimer for our lead ApexGT candidate. The methods and immunogens developed here have promise to assist the development of an HIV vaccine.
2023-03-11 | PXD033766 | Pride
Project description:HIV-related fatigue is multi-causal in origin and potentially related to mitochondrial dysfunction caused by toxicity from nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral therapy. CD14+ cells are undifferentiated macrophages, vulnerable to HIV infection, and easily accessible for gene expression experiments in a purified cell population. We utilized a novel mitochondrially-specific gene expression microarray to assess mitochondrial and nuclear genes in CD14+ cells of low- and high-fatigued, NRTI-treated HIV/AIDS patients (n=5 each). Novel Bayesian and liquid association network methods identified 33 genes predictive of low versus high fatigue and 32 genes predictive of healthy versus HIV infection. Sulfotransferase 2B1 (SULT2B1) is relevant to both the cholesterol and testosterone pathway, and like several inner mitochondrial membrane genes also identified, predictive of fatigue status, while outer mitochondrial membrane genes were predictive of HIV status. A surprising finding was that adenylate cyclase 2 (ADCY2) was a predictor of both HIV and fatigue; it had the highest Kendallâs Tau association value in the HIV group, but in reverse, the lowest Tau value in the fatigue group. Assaying CD14+ cells may provide an alternative to muscle biopsy and a minimally invasive procedure to evaluate patient mitochondrial function, and Bayesian and network tools are useful to identify the link between subjective symptom perceptions and underlying biologically pathways. Fatigue status in HIV patients treated with NRTIs was found to be linked to RNA expression differences related to mitochondrial function. Additional studies are needed to confirm the relevance of our findings in CD14+ cells in other tissues (e. g. skeletal muscle) and to understand the significance of key genes such as SULT2B and ADCY2 in fatigue and HIV disease. The design was a comparison of HIV high fatigue to HIV low fatigue. Low fatigue was determined as 3-7 on the Revised Piper Fatigue Score and High fatigue was a score of 7 or greater. Five HIV negative control samples were used to compare normal fatigue and non-disease status.
2010-06-21 | E-GEOD-18468 | biostudies-arrayexpress
Project description:Impact of Common Modifications on the Antigenic Profile and Glycosylation of Membrane-Expressed HIV-1 Envelope Glycoprotein
Recent HIV-1 vaccine development has centered on near native soluble envelope glycoprotein (Env) trimers. These trimers are artificially stabilized laterally (between protomers) and apically (between gp120 and gp41). These same stabilizing mutations have been leveraged for use in membrane-expressed Env mRNA vaccines, although their precise effects in this context are unclear. To address this question, we investigated the effects of Env mutations expressed on virus-like particle (VLP) in 293T cells. Uncleaved (UNC) trimers were laterally unstable upon gentle lysis from membranes. However, gp120/gp41 processing improved lateral stability. Due to inefficient gp120/gp41 processing, UNC is incorporated into VLPs. A linker between gp120 and gp41 (NFL) neither improved trimer stability nor its antigenic profile. An artificially introduced enterokinase cleavage site allowed processing post-expression, resulting in increased trimer stability. Gp41 N-helix mutations I559P and NT1-5 both imparted lateral trimer stability, but concomitantly reduced gp120/gp41 processing and/or impacted V2 apex and interface NAb binding. I559P consistently reduced recognition by HIV+ donor plasmas, further supporting antigenic differences. Mutations in the gp120 bridging sheet failed to stabilize membrane trimers in a pre-fusion conformation, reduced gp120/gp41 processing and exposed non-neutralizing epitopes. Reduced glycan maturation and increased sequon skipping were common effect of mutations. In some cases, this may be due to increased rigidity which limits access to glycan processing enzymes. In contrast, viral gp120 did not show glycan skipping. We observed a minor species of high mannose glycan only gp160 in particle preparations. This was unaffected by any mutations and instead bypasses normal folding and glycan maturation processes. Including the full gp41 cytoplasmic tail led to markedly reduced gp120/gp41 processing and increased the proportion of high mannose gp160. Remarkably, NAbs were unable to bind to full-length Env trimers. Overall, our findings suggest caution in leveraging mutations to ensure they impart valuable membrane trimer phenotypes for vaccine use.
The files enclosed are labelled according to the enzyme used in the digest. T = Trypsin, C = Chymotrypsin, A = Alpha-lytic protease
2023-07-12 | MSV000092416 | MassIVE
Project description:Membrane-associated, integral membrane and secreted proteins are of key importance in many cellular processes. For most of the 28 952 predicted proteins in Arabidopsis, the actual subcellular localisation has not been demonstrated experimentally. So far, their potential membrane-association has been deduced from algorithms that predict transmembrane domains and signal peptides. However, the comprehensiveness and accuracy of these algorithms is still limited. The majority of membrane-associated and secreted proteins is synthesised on membrane-bound polysomes. Therefore, the isolation and characterisation of mRNA associated with membrane-bound polysomes offers an experimental tool for the genome-wide identification of these proteins. Here we describe an efficient method to isolate mRNA from membrane-bound polysomes and report on the validation of the method to enrich for transcripts encoding membrane-associated and secreted proteins. The sensitivity and reproducibility of the isolation method was investigated by DNA microarray analysis. Pearson correlations between transcript levels obtained from three replicate isolations showed that the method is highly reproducible. A significant enrichment for mRNAs encoding proteins containing predicted transmembrane domains and signal peptides was observed in the membrane-bound polysomal fraction. In this fraction, 301 transcripts were classified by gene ontologies as âcellular component unknownâ, and potentially encode previously unrecognised secreted or membrane-associated proteins. Membrane-bound (MBP) and free polysomes (FP) were isolated in triplicate from one batch of two weeks old aboveground parts of Arabidopsis seedlings. Each combination of isolated MBP and FP was applied to 4 microarrays, of which two were dyeswapped, giving a total of 12 arrays.
2010-07-01 | E-GEOD-4023 | biostudies-arrayexpress
Project description:HIV-related fatigue is multi-causal in origin and potentially related to mitochondrial dysfunction caused by toxicity from nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral therapy. CD14+ cells are undifferentiated macrophages, vulnerable to HIV infection, and easily accessible for gene expression experiments in a purified cell population. We utilized a novel mitochondrially-specific gene expression microarray to assess mitochondrial and nuclear genes in CD14+ cells of low- and high-fatigued, NRTI-treated HIV/AIDS patients (n=5 each). Novel Bayesian and liquid association network methods identified 33 genes predictive of low versus high fatigue and 32 genes predictive of healthy versus HIV infection. Sulfotransferase 2B1 (SULT2B1) is relevant to both the cholesterol and testosterone pathway, and like several inner mitochondrial membrane genes also identified, predictive of fatigue status, while outer mitochondrial membrane genes were predictive of HIV status. A surprising finding was that adenylate cyclase 2 (ADCY2) was a predictor of both HIV and fatigue; it had the highest Kendall’s Tau association value in the HIV group, but in reverse, the lowest Tau value in the fatigue group. Assaying CD14+ cells may provide an alternative to muscle biopsy and a minimally invasive procedure to evaluate patient mitochondrial function, and Bayesian and network tools are useful to identify the link between subjective symptom perceptions and underlying biologically pathways. Fatigue status in HIV patients treated with NRTIs was found to be linked to RNA expression differences related to mitochondrial function. Additional studies are needed to confirm the relevance of our findings in CD14+ cells in other tissues (e. g. skeletal muscle) and to understand the significance of key genes such as SULT2B and ADCY2 in fatigue and HIV disease.
2009-10-08 | GSE18468 | GEO
Project description:Buffering of deleterious mutations by molecular chaperones and degradation of aberrant proteins by quality control systems are both major factors that can impact the mutational landscape available to a client protein. The impacts of the proteostasis network on protein evolution are not limited to just endogenous clients, but can also shape the mutational landscapes accessible to rapidly evolving viral proteins. Here, we test the hypothesis that the composition of the host cell’s endoplasmic reticulum (ER) proteostasis network shapes the evolution of RNA viruses by focusing on human immunodeficiency virus-1 envelope (Env), a membrane glycoprotein that folds and matures in the host cell’s secretory pathway. We apply chemical genetic methods to activate the IRE1-XBP1s and/or the ATF6 transcriptional arms of the unfolded protein response in a stress-independent manner. We then quantitatively assess the impact of the resulting altered host cell ER proteostasis environments on the relative enrichment of all Env single amino acid substitutions using deep mutational scanning. We find that upregulation of host ER proteostasis factors globally reduces the mutational tolerance of HIV-1 Env, particularly upon induction of the IRE1-XBP1s transcriptional arm of the UPR. The effects of ATF6 activation are less global, but still significant at particular Env sites. The impact of the XBP1s-induced ER proteostasis environment is disparate for diverse structural elements of Env. Conserved, functionally important regions generally exhibit the largest decreases in mutational tolerance upon XBP1s activation. In contrast, specific regions of Env, including regions targeted by broadly neutralizing antibodies, display greatly enhanced mutational tolerance when XBP1s is activated. Altogether, these data reveal a new set of host factors that specifically shape the mutational space accessible to HIV Env and, more generally, provide compelling evidence that UPR-regulated proteostasis mechanisms play critical roles in membrane protein evolution.
2022-01-30 | GSE171356 | GEO
Project description:Bacterial microcompartments (BMCs) are intracellular proteinaceous organelles devoid of a lipid membrane that encapsulates enzymes of metabolic pathways. Salmonella enterica synthesizes propanediol-utilization BMCs containing enzymes involved in the degradation of 1,2-propanediol. BMCs can be designed to enclose heterologous proteins, paving the way to engineered catalytic microreactors. Here, we investigate broader applicability of this design principle by directing three different enzymes to the BMC. We demonstrate that ?-galactosidase, esterase Est5, and cofactor-dependent glycerol dehydrogenase can be directed to the BMC and copurified with the microcompartment shell in a catalytically active form. We show that the BMC shell protects enzymes from pH-dependent but not from temperature stress. Moreover, we provide evidence that the heterologously expressed BMCs act as a moderately selective diffusion barrier for lipophilic small molecules.
| S-EPMC6999380 | biostudies-literature
Project description:BackgroundEukaryotic cells are often preferred for the production of complex enzymes and biopharmaceuticals due to their ability to form post-translational modifications and inherent quality control system within the endoplasmic reticulum (ER). A non-conventional yeast species, Yarrowia lipolytica, has attracted attention due to its high protein secretion capacity and advanced secretory pathway. Common means of improving protein secretion in Y. lipolytica include codon optimization, increased gene copy number, inducible expression, and secretory tag engineering. In this study, we develop effective strategies to enhance protein secretion using the model heterologous enzyme T4 lysozyme.ResultsBy engineering the commonly used native lip2prepro secretion signal, we have successfully improved secreted T4 lysozyme titer by 17-fold. Similar improvements were measured for other heterologous proteins, including hrGFP and [Formula: see text]-amylase. In addition to secretion tag engineering, we engineered the secretory pathway by expanding the ER and co-expressing heterologous enzymes in the secretion tag processing pathway, resulting in combined 50-fold improvement in T4 lysozyme secretion.ConclusionsOverall, our combined strategies not only proved effective in improving the protein production in Yarrowia lipolytica, but also hint the possible existence of a different mechanism of secretion regulation in ER and Golgi body in this non-conventional yeast.
| S-EPMC9252082 | biostudies-literature
Project description:Because a strategy to elicit broadly neutralizing anti-human immunodeficiency virus type 1 (HIV-1) antibodies has not yet been found, the role of an Env immunogen in HIV-1 vaccine candidates remains undefined. We sought to determine whether an HIV-1 Env immunogen genetically disparate from the Env of the challenge virus can contribute to protective immunity. We vaccinated Indian-origin rhesus monkeys with Gag-Pol-Nef immunogens, alone or in combination with Env immunogens that were either matched or mismatched with the challenge virus. These animals were then challenged with a pathogenic simian-human immunodeficiency virus. The vaccine regimen included a plasmid DNA prime and replication-defective adenoviral vector boost. Vaccine regimens that included the matched or mismatched Env immunogens conferred better protection against CD4(+) T-lymphocyte loss than that seen with comparable regimens that did not include Env immunogens. This increment in protective immunity was associated with anamnestic Env-specific cellular immunity that developed in the early days following viral challenge. These data suggest that T-lymphocyte immunity to Env can broaden the protective cellular immune response to HIV despite significant sequence diversity of the strains of the Env immunogens and can contribute to immune protection in this AIDS vaccine model.
| S-EPMC434100 | biostudies-literature