ABSTRACT: The soaring global monkeypox cases lead to a surge in demand for monkeypox vaccine, which far exceeds the supply. mRNA vaccine has achieved great success in prevention of coronavirus disease and holds promise against diverse pathogens. In this study, we generate a polyvalent lipid nanoparticle (LNP) mRNA vaccine candidate for monkeypox virus (MPXV) and evaluate its immunogenicity in animal models. This polyvalent MPXV mRNA vaccine candidate, MPXVac-097, encodes five 2022 MPXV targets that are important surface antigens. Three-dose (prime-boost-booster) MPXVac-097 vaccination elicits strong antibody response to A35R and E8L antigens, moderate response to M1R, but not B6R or A29, highlighting the differences in immunogenicity. Bulk T cell receptor (TCR) sequencing reveals preferential usage of VJ combinations and clonal expansion of peripheral T cells after MPXVac-097 vaccination. These data demonstrate initial feasibility of developing MPXV mRNA vaccine and pave the way for its future optimization.
Project description:We developed two multivalent mRNA vaccines that induced strong immune responses and provided protection against monkeypox virus in mice. Additionally, we used single-cell RNA sequencing and V(D)J sequencing to explore the postvaccination immune landscape at the single-cell level and revealed B-cell receptor and T-cell receptor diversity, gene rearrangement, and predicted CDR3 motifs, systematically exploring the post-vaccination immune landscape at the single-cell level. These findings are poised to guide future vaccine design and present an innovative clinical strategy against monkeypox and orthopoxvirus outbreaks.
Project description:Heterologous vaccination regimens are increasingly recommended for their potential benefits, including reduced side effects and enhanced immunogenicity. In this study, we investigated the innate and adaptive immune responses elicited by heterologous prime-boost vaccination using adenoviral vector and mRNA vaccines against SARS-CoV-2 in a mouse model. Our findings show that heterologous vaccination induced superior serum neutralizing and binding antibody titers, as well as enhanced cellular immune responses against the Delta and Omicron (BA.5) variants, compared to homologous vaccination. Single-cell transcriptomic analysis at the injection site, conducted 16 hours post-vaccination, revealed that the lipid nanoparticle (LNP)-based mRNA vaccine—and even empty LNP injection—triggered significant immune cell infiltration, while adenoviral vector vaccination caused minimal changes in injection-site cell composition following the first dose. Notably, spike mRNA was predominantly expressed in fibroblasts and macrophages across both vaccine platforms, suggesting these cells’ role in local immune responses. Further analysis demonstrated that the adenoviral vector booster induced amplified immune responses, marked by increased transcriptional changes, particularly in stromal pro-inflammatory pathways. Heterologous vaccination (adenoviral prime, mRNA boost) further intensified these responses compared to homologous mRNA vaccination, indicating that adenoviral priming enhances inflammatory responses when followed by an mRNA boost. In summary, our results demonstrate that heterologous vaccination strategies elicit stronger innate and adaptive immune responses compared to homologous regimens, supporting their use as an effective approach for enhanced protection against variants.
Project description:Crimean-Congo hemorrhagic fever (CCHF), caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is on the World Health Organizations list over emerging pathogens and prioritized diseases. With global distribution, high fatality rate and no approved treatment or vaccine, CCHF constitute a treat against the global health. In the current study we show full protection of mice against lethal CCHFV infection due to mRNA-LNP vaccination. IFNAR-/- mice received two immunizations with either mRNA-LNP encoding for the CCHFV nucleoprotein, glycoproteins or a combination of both. While unvaccinated mice showed clear signs of severe disease, vaccinated mice was significantly protected. Vaccine induced immune responses due to vaccination was evaluated both in IFNAR-/- and immunocompetent mice and a strong humoral and cellular immune response was observed in both mouse models with high titers of neutralizing antibodies and primed T-cells. In addition, we conducted a proteomic analysis on liver samples from vaccinated and unvaccinated mice after CCHFV infection to determine the effect of vaccination on the protein profile. Similar to what has been observed in humans due to vaccination, there was an effect on metabolic pathways. In conclusion, this study shows very promising results regarding development of a vaccine against CCHFV.
Project description:Lipid nanoparticles (LNPs) for mRNA delivery have advanced significantly, but LNP-mediated DNA delivery still faces clinical challenges. This study compared various LNP formulations for delivering DNA-encoded biologics, assessing their expression efficacy and the protective immunity generated by LNP-encapsulated DNA in different models. The LNP formulation used in Moderna’s Spikevax mRNA vaccine (LNP-M) demonstrated a stable nanoparticle structure, high expression efficiency, and low toxicity. Notably, a DNA vaccine encoding the spike protein, delivered via LNP-M, induced stronger antigen-specific antibody and T cell immune responses compared to electroporation. Single-cell RNA sequencing (scRNA-seq) analysis revealed that the LNP-M/pSpike vaccine enhanced CD80 activation signaling in CD8+ T cells, NK cells, macrophages, and DCs, while reducing the immunosuppressive signals. The enrichment of TCR and BCR by LNP-M/pSpike suggested an increase in immune response specificity and diversity. Additionally, LNP-M effectively delivered DNA-encoded antigens, such as mouse PD-L1 and p53R172H, or monoclonal antibodies targeting mouse PD-1 and human p53R282W. This approach inhibited tumor growth or metastasis in several mouse models. The long-term anti-tumor effects of LNP-M-delivered anti-p53R282W antibody relied on memory CD8+ T cell responses and enhanced MHC-I signaling from APCs to CD8+ T cells. These results highlight LNP-M as a promising and effective platform for delivering DNA-based vaccines and cancer immunotherapies.
Project description:Successful development of HIV-vaccination strategies will also depend on the ability to use novel approaches to analyse and integrate immunogenicity data generated in vaccine trials. The ANRS VAC 18 trial evaluated the immunogenicity of HIV-LIPO-5 vaccine (5 HIV peptides coupled to a palmytoil tail) administered at W0, 4, 12 and 24 in healthy volunteers. 62-69% of vaccinees developed HIV-specific ELISpot responses by W26. Here we present extensive immunogenicity assessments in a subset of vaccinees using ELISpot, lymphoproliferation, intracellular cytokine staining (ICS), cytokine multiplex and transcriptomic analyses. Peripheral blood mononuclear cells from volunteers collected before and following vaccinations were stimulated with HIV LIPO 5 vaccine, Gag peptides contained or not in the vaccine as controls. Different time points and stimulation conditions were compared, using false discovery rate to control for test multiplicity. 74% and 30% of vaccinees had cultured ELISpot and lymphoproliferation responses at W14, respectively. Ex-vivo ICS showed mainly single IL-2 producing cells. Secretion of IFN-γ, TNF-α, IL-5, and IL-13 increased significantly in response to Gag stimulation after culture at W14 compared to W0. An induction of metallothionein genes was consistently detected after HIV-LIPO-5 stimulation at W0 and W14 related to the adjuvant effect of the lipid tail. After vaccination (W14), significant probes increased substantially (>1200 probes) including IFN-γ, CXCL9, IL2RA, TNFAIP6, CCL3L1 and IL-6 W14 (fold change > 100%). In conclusion, HIV LIPO-5 vaccination elicited memory precursor responses with a Th1 and Th2 profile. The signature profile before vaccination provides information about the adjuvant effect of the lipid tail. Consistently with cytokine responses, vaccination is associated with a modulation in gene expression. This combined approach allowed to identify new signatures of HIV vaccine response and indicates that HIV-LIPO-5 could be further developed as a prime component of heterologous prime boost strategies. PBMC mRNA of 12 healthy volunteers, stimulate in four different conditions (HIV-LIPO-5, Gag+, Gag-, NS) during 6 and 24 hours before and after vaccination (week 0 and week 14)
Project description:Orthopox viruses, including monkeypox, multiply intracellularly and induce numerous changes in host genes expression. The virus target mainly humoral host response, and simultaneously, exploits other genes and functions to reproduce effectively. The goal of this experiment is to identify those host genes and functions that are essential for monkeypox virus replication. Mock infected control cells were treated and incubated identically to time point arms, except for virus exposure. Two time points of cells infected with monkeypox virus were harvested at 3, 7 hours post infection, and gene expression was assessed using microarray in all arms. The experiment was done in triplicate.
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:Orthopox viruses, including monkeypox, multiply intracellularly and induce numerous changes in host genes expression. The virus target mainly humoral host response, and simultaneously, exploits other genes and functions to reproduce effectively. The goal of this experiment is to identify those host genes and functions that are essential for monkeypox virus replication.
Project description:In this exploratory post-hoc analysis of clinical trial samples (clinicalTrials.gov: NCT01424501), we compared gene expression patterns elicited by two immunizations with the candidate tuberculosis (TB) vaccine M72/AS01, between three groups of individuals with different levels of memory responses to TB antigens before vaccination