Project description:Next-generation T-cell-directed vaccines for COVID-19 aim to induce durable T-cell immunity against circulating and future hypermutated SARS-CoV-2 variants. Mass Spectrometry (MS)based immunopeptidomics holds promise for guiding vaccine design, but computational challenges impede the precise and unbiased identification of conserved T-cell epitopes crucial for vaccines against rapidly mutating viruses. We introduce a computational framework and analysis platform integrating a novel machine learning algorithm, immunopeptidomics, intra-host data, epitope immunogenicity, and geo-temporal CD8+ T-cell epitope conservation analyses. Central to our approach is MHCvalidator, a novel artificial neural network algorithm enhancing MS-based immunopeptidomics sensitivity by modeling antigen presentation and sequence features. MHCvalidator identified a novel nonconventional SARS-CoV-2 T-cell epitope presented by B7 supertype molecules, originating from a +1-frameshift in a truncated Spike (S) antigen, supported by ribo-seq data. Intra-host analysis of SARS-CoV-2 proteomes from ~100,000 COVID-19 patients revealed a prevalent S antigen truncation in ~51% of cases, exposing a rich source of frameshifted viral antigens. Our framework includes EpiTrack, a new computational pipeline tracking global mutational dynamics of MHCvalidator-identified SARS-CoV-2 CD8+ epitopes from vaccine BNT162b4. While most vaccine-encoded CD8+ epitopes exhibit global conservation from January 2020 to October 2023, a highly immunodominant A*01-associated epitope, especially in hospitalized patients, undergoes substantial mutations in Delta and Omicron variants. Our approach unveils unprecedented SARS-CoV-2 T-cell epitopes, elucidates novel antigenic features, and underscores mutational dynamics of vaccine-relevant epitopes. The analysis platform is applicable to any viruses, and underscores the need for continual vigilance in T-cell vaccine development against the evolving landscape of hypermutating SARS-CoV-2 variants.
Project description:The identification of protective epitopes in bacterial pathogens using mass spectrometry proteomics is essential for advancing vaccine design, especially against the backdrop of increasing antibiotic resistance. Our study introduces an innovative strategy, leveraging multi-modal mass spectrometry techniques, to decode the interaction between a neutralizing monoclonal antibody (nAb) and the Streptolysin O (SLO) toxin from Streptococcus pyogenes. By integrating XL-MS, HDX-MS, and computational modeling, we successfully identified and characterized a conserved protective epitope within SLO, providing critical insights for vaccine development. Utilizing a novel nAb sequenced through de novo bottom-up shotgun MS, we explored its binding mechanism and interaction with the SLO antigen with structural proteomics such as XL-MS and HDX-MS. This study not only clarifies the conformational epitope structure but also illuminated the antibody's unique protective mechanism mode. The epitope's high conservation (near 100%) across various S. pyogenes strains underscores its potential as a universal target for vaccine strategies. Additionally, our approach overcomes traditional limitations in epitope mapping, showcasing the power of mass spectrometry in resolving challenging antibody-antigen interfaces. Our findings represent a significant leap in understanding bacterial pathogenesis and immune defense, laying the groundwork for designing next-generation vaccines. The data generated from this study can guide the development of targeted therapies and vaccines, offering new solutions to combat severe streptococcal infections.
Project description:Mechanisms of poor responses to vaccines remain unknown. Hepatitis B virus-naïve elderly subjects received three vaccines, including a vaccine against hepatitis B virus (HBV). Transcriptomic profilling of blood collected pre-vaccination and post-vaccination was performed in order to identify candidate biomarkers of antibody response to the different vaccines.
Project description:A human embryonic fibroblast cell line was synchronously infected with poliovirus in the absence or presence of interferon-α, or with vacciniavirus, a virus that is not inhibited by interferon. The titers were sufficient to yield productive infection in a majority of the cells. The cells were harvested in triplicate at various time-points, and the transcriptosome compared with mock infected cells using oligo-based 35 k microarrays. The project had two purposes: to characterize the cellular response and to look for candidate genes involved in viral defense. The changes in gene expression due to vaccinia virus did not correspond to those caused by poliovirus. More surprisingly, neither did the changes when comparing 8 h and 16 h of poliovirus infection. However, a large proportion of the genes up-regulated by interferon-α were also up-regulated by poliovirus, both at 8 h and 16 h. Interferon-α inhibited poliovirus replication, thus the observations suggest that the cells do launch an antiviral response to poliovirus. Moreover, as interferon genes were not induced, the data indicate that several of the relevant genes can be activated in an interferon independent manner. Further analyses of the data led to a list of candidate antiviral genes. Functional information was limited, or absent, for most of these genes. Keywords: Poliovirus; Vacciniavirus; Interferon; Microarray; Gene expression; Defense genes
2006-10-16 | GSE5549 | GEO
Project description:Studies of genetic stability of a novel engineered poliovirus, type 2 vaccine candidate
Project description:Laboratory strain poliovirus was hybridized to the array as a control run and a proof of concept. Degree of cross hybridization between polio nucleic acid and non-polio probes was evaluated. Specificity of the probe design was determined. Keywords: control study: target detection and specificity
Project description:Vaccine development involves time-consuming and expensive evaluation of candidate vaccines in animal models. As mediators of both innate and adaptive immune responses dendritic cells (DCs) are considered to be highly important for vaccine performance. Here we evaluated in how far the response of DCs to a vaccine in vitro is in line with the immune response the vaccine evokes in vivo. To this end, we investigated the response of murine bone marrow-derived DCs to whole inactivated virus (WIV) and subunit (SU) influenza vaccine preparations. These vaccine preparations were chosen because they differ in the immune response they evoke in mice with WIV being superior to SU vaccine through induction of higher virus-neutralizing antibody titers and a more favorable Th1-skewed response phenotype. To evaluate if in vivo immunogenicity is reflected by DC reactions in vitro we studied the gene expression signature of murine bone-marrow-derived conventional DCs (cDCs) upon stimulation with WIV or SU influenza vaccine or, for reasons of comparison, with live influenza virus. Dendritic cells stimulated with PBS served as a control. Gene expression analysis was performed on samples 4, 12 and 24 hours after the start of stimulation.
Project description:Visceral leishmaniasis (VL), caused by Leishmania spp protozoan parasites, can provoke overwhelming and protracted epidemics, with high case–fatality rates. Despite extensive efforts towards the development of an effective prophylactic vaccine, no promising vaccine is available yet for humans. Multi-epitope peptide based vaccine development is manifesting as the new era of vaccination strategies against VL. Aim of the study was the design of chimeric peptides from immunogenic L. infantum proteins for encapsulation in PLGA nanoparticles (NPs) alone or in combination with MPLA adjuvant, or in PLGA NPs surface modified with an octapeptide mimicking TNF-alpha for DCs targeting, in order to construct a peptide-based nanovaccine. The in vitro evaluation of the above nanoformulations was performed in DCs isolated from HLA-A2.1 transgenic mice. Characterization of DCs transcriptional responses to these vaccine candidates via microarrays could improve our understanding of their mechanisms of action on DCs' functional differentiation and the type of adaptive immunity subsequently induced.
Project description:The natural history of chronic hepatitis B virus (HBV) infection could be divided in different phases by transaminase and HBV replication levels. However, it remains unknown how the intrahepatic transcriptomes in patients are correlated with the clinical phases. Here, we determined the intrahepatic transcriptomes of chronic hepatitis B patients and examined the role of specific groups of genes, including immune-related genes, in the control of hepatitis B virus infection. The transcriptomes of 83 chronic hepatitis B patients (22 immune tolerant, 50 immune clearance, and 11 inactive carrier state) were analyzed by performing microarray analysis of liver biopsies.KEGG pathway analysis showed that immune response genes and interferon-stimulated genes were up-regulated in the immune clearance phase. Although immune tolerant patients and inactive state carriers had significantly different serum viral loads, the hepatic transcriptomes of the two groups were largely similar and only significantly differed in the expression of 109 genes (p < 0.01). Thus, we hypothesized that some of the 109 genes may be involved in HBV control and identified genes of interest by performing systematic screening using specific siRNAs. We showed that silencing candidate genes such as EVA1A resulted in significantly increased viral replication. Conversely, overexpression of candidate genes suppressed virus replication. Conclusions: The immune related pathways were up-regulated in the immune clearance phase but not in the inactive carrier phase. A number of host genes unrelated to immune pathways were expressed in the inactive carrier phase and these may participate in the control of hepatitis B virus replication, resulting in low viral replication. This dataset is part of the TransQST collection.
Project description:Since the genome of herpes simplex virus 1 (HSV-1) was first sequenced more than 30 years ago, the 84 genes it was thought to encode have been intensively studied. Here, we unravel the full complement of viral transcription and translation during lytic infection with base-pair resolution by computational integration of multi-omics data. This includes a total of 201 viral transcripts and 296 open reading frames (ORFs), comprising all known large ORFs, 55 large novel ORFs including a novel spliced ORF in the ICP0 locus that initiates from a non-AUG start codon and a novel strongly translated ORF in the ICP34.5 locus as well as multiple short ORFs. By defining viral gene modules, we link translation of ORFs to the expression of transcript isoforms. This explained translation of the vast majority of viral ORFs as well as N-terminal extensions and truncations thereof. We show that N-terminal extensions initiating from non-AUG start codons govern subcellular protein localization and packaging of key viral regulators and structural proteins. This work has great implications for future functional studies, vaccine design and novel oncolytic therapies.