Project description:Listeria monocytogenes is a foodborne intracellular bacterial pathogen leading to human listeriosis. Despite a high mortality rate and increasing antibiotic resistance no clinically approved vaccine against Listeria is available. To identify antigens for this bacterial pathogen that can be encoded in mRNA vaccine formulations, we screened for Listeria epitopes presented on the surface of infected human cell lines by mass spectrometry-based immunopeptidomics. In between more than 15,000 human self-peptides, we detected 68 Listeria epitopes from 42 different bacterial proteins, including several known antigens. Peptide epitopes presented on different cell lines were often derived from the same bacterial surface proteins, classifying these antigens as potential vaccine candidates. Encoding these highly presented antigens in lipid nanoparticle mRNA vaccine formulations resulted in high levels of protection in vaccination challenge experiments in mice. Our results pave the way for the development of a clinical mRNA vaccine against Listeria and demonstrate the power of immunopeptidomics for next-generation bacterial vaccine development.
Project description:B6 mice were immunized with either 2000 cfu of ova expressing Listeria monocytogenes (LM-ova) or 100ug whle ovalbumin adjuvanted with 50ug polyIC + 50ug anti-CD40 (FGK45). 7 days later, tetramer staining CD8+ T cells from the spleen were flow sorted to purity (~98%), the RNA isolated, reverse transcribed and the resulting cDNA analyzed by gene array MoGene-1_0-st-v1 gene expression determined in naïve (CD44lo) and day 7 post Listeria chalelneg or combined adjuvant vaccine immunization (internally referred to as "synergy").
Project description:Mucosal-associated invariant T (MAIT) cells are innate sensors of viruses, which can augment early immune responses and contribute to protection from lethal infection. Thus, we reasoned MAIT cells may have an adjuvating role in the immunogenicity of replication-incompetent adenovirus vectors, which are novel vaccine platforms for pandemic pathogens such as Ebola virus and SARS-CoV-2. In both mice and human volunteers, immunization with ChAdOx1 (Chimpanzee Adenovirus Ox1) robustly activated MAIT cells. Activation required transduction of plasmacytoid dendritic cells and monocytes to produce IFN- and IL-18, respectively. IFN--induced monocyte-derived TNF was identified as a novel intermediate in this activation pathway, and activation required combinatorial signaling of all three cytokines both in vitro and in vivo. Strikingly, vaccine-induced activation of MAIT cells positively correlated with vaccine-induced T cell responses in human volunteers. Supporting a causal relationship, MAIT cell-deficient mice displayed impaired CD8+ T cell responses to multiple vaccine-encoded antigens. These findings define a novel role for MAIT cells in the immunogenicity of adenovirus vector vaccines, with potential implications for vaccine design.
Project description:The goal was to examine gene expression after in vivo activation by different vaccine strains of Listeria monocytogenes. Heat killed LM, irradiated LM and live actA- LM were used to immunize mice after transfer of OT-I cells
Project description:This study will evaluate the safety and tolerability of a personalized live, attenuated, double-deleted Listeria monocytogenes (pLADD) treatment in adults with metastatic colorectal cancer.
Project description:Several Toll-like receptors are activated by Listeria monocytogenes infection, resulting in the activation of MyD88 dependent signaling pathway. However, the negative role of MyD88 in gene expresson is unclear. To address this, we performed microarray analysis of mRNAs from WT or MyD88-/- peritoneal macrophages infected with Listeria monocytogenes.
Project description:Laying hens Rosa 1 were immunized with two doses of DNA vaccine, based on the hemagglutinin (HA) DNA from H5N1 virus, in comparison to the control group, which was administered an empty vector (pCI). Additional groups of Rosa 1 hens were treated with one dose of above described vaccine or empty vector. Gene expression changes in the spleens of chickens were investigated at 7 day post last vaccination dose.
Project description:Transcriptional profling of a Listeria monocytogenes under nisin treatment comparing ctsR mutant and wild type one condition (nisin treament 20ug/ml, 24 hours) experiment, ctsR mutant vs. wild type Listeria monocytogenes Scott A, 2 biological replicates, 4 technical replicates
