| 1. |
- Bernasconi, Valentina, 1989, et al.
(författare)
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A vaccine combination of lipid nanoparticles and a cholera toxin adjuvant derivative greatly improves lung protection against influenza virus infection
- 2021
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Ingår i: Mucosal Immunology. - : Elsevier BV. - 1933-0219 .- 1935-3456. ; 14:2, s. 523-536
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Tidskriftsartikel (refereegranskat)abstract
- This is a proof-of-principle study demonstrating that the combination of a cholera toxin derived adjuvant, CTA1-DD, and lipid nanoparticles (LNP) can significantly improve the immunogenicity and protective capacity of an intranasal vaccine. We explored the self-adjuvanted universal influenza vaccine candidate, CTA1-3M2e-DD (FPM2e), linked to LNPs. We found that the combined vector greatly enhanced survival against a highly virulent PR8 strain of influenza virus as compared to when mice were immunized with FPM2e alone. The combined vaccine vector enhanced early endosomal processing and peptide presentation in dendritic cells and upregulated co-stimulation. The augmenting effect was CTA1-enzyme dependent. Whereas systemic anti-M2e antibody and CD4(+)T-cell responses were comparable to those of the soluble protein, the local respiratory tract IgA and the specific Th1 and Th17 responses were strongly enhanced. Surprisingly, the lung tissue did not exhibit gross pathology upon recovery from infection and M2e-specific lung resident CD4(+)T cells were threefold higher than in FPM2e-immunized mice. This study conveys optimism as to the protective ability of a combination vaccine based on LNPs and various forms of the CTA1-DD adjuvant platform, in general, and, more specifically, an important way forward to develop a universal vaccine against influenza.
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| 2. |
- Bhide, Yoshita, et al.
(författare)
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Cross-Protective Potential and Protection-Relevant Immune Mechanisms of Whole Inactivated Influenza Virus Vaccines Are Determined by Adjuvants and Route of Immunization.
- 2019
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Ingår i: Frontiers in immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Adjuvanted whole inactivated virus (WIV) influenza vaccines show promise as broadly protective influenza vaccine candidates. Using WIV as basis we assessed the relative efficacy of different adjuvants by carrying out a head-to-head comparison of the liposome-based adjuvants CAF01 and CAF09 and the protein-based adjuvants CTA1-DD and CTA1-3M2e-DD and evaluated whether one or more of the adjuvants could induce broadly protective immunity. Mice were immunized with WIV prepared from A/Puerto Rico/8/34 (H1N1) virus intramuscularly with or without CAF01 or intranasally with or without CAF09, CTA1-DD, or CTA1-3M2e-DD, followed by challenge with homologous, heterologous or heterosubtypic virus. In general, intranasal immunizations were significantly more effective than intramuscular immunizations in inducing virus-specific serum-IgG, mucosal-IgA, and splenic IFNγ-producing CD4 T cells. Intranasal immunizations with adjuvanted vaccines afforded strong cross-protection with milder clinical symptoms and better control of virus load in lungs. Mechanistic studies indicated that non-neutralizing IgG antibodies and CD4 T cells were responsible for the improved cross-protection while IgA antibodies were dispensable. The role of CD4 T cells was particularly pronounced for CTA1-3M2e-DD adjuvanted vaccine as evidenced by CD4 T cell-dependent reduction of lung virus titers and clinical symptoms. Thus, intranasally administered WIV in combination with effective mucosal adjuvants appears to be a promising broadly protective influenza vaccine candidate.
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| 3. |
- Gribonika, Inta, et al.
(författare)
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Class-switch recombination to IgA in the Peyer's patches requires natural thymus-derived Tregs and appears to be antigen independent.
- 2019
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Ingår i: Mucosal immunology. - : Elsevier BV. - 1935-3456 .- 1933-0219. ; 12:6, s. 1268-1279
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of how class-switch recombination (CSR) to IgA occurs in the gut is still incomplete. Earlier studies have indicated that Tregs are important for IgA CSR and these cells were thought to transform into follicular helper T cells (Tfh), responsible for germinal center formation in the Peyer's patches (PP). Following adoptive transfer of T-cell receptor-transgenic (TCR-Tg) CD4 T cells into nude mice, we unexpectedly found that oral immunization did not require an adjuvant to induce strong gut IgA and systemic IgG responses, suggesting an altered regulatory environment in the PP. After sorting of splenic TCR-Tg CD4 T cells into CD25+ or CD25- cells we observed that none of these fractions supported a gut IgA response, while IgG responses were unperturbed in mice receiving the CD25- cell fraction. Hence, while Tfh functions resided in the CD25- fraction the IgA CSR function in the PP was dependent on CD25+ Foxp3+ Tregs, which were found to be Helios+ neuropilin-1+ thymus-derived Tregs. This is the first study to demonstrate that Tfh and IgA CSR functions are indeed, unique, and separate functions in the PP with the former being TCR-dependent while the latter appeared to be antigen independent.
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| 4. |
- Gribonika, Inta, et al.
(författare)
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Migratory CD103+CD11b+ cDC2 cells in Peyer's patches are critical for gut IgA responses following oral immunization.
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Ingår i: Mucosal Immunology. - 1933-0219.
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Tidskriftsartikel (refereegranskat)abstract
- Induction and regulation of specific intestinal IgA responses critically depend on dendritic cell subsets and the T cells they activate in the Peyer's patches (PP). We found that oral immunization with cholera toxin (CT) as an adjuvant resulted in migration-dependent changes in the composition and localization of PP DC subsets with increased numbers of CD103 - cDC2s and LysoDCs in the subepithelial dome and of CD103 + cDC2s that expressed CD101 in the T cell zones (TZ), while oral OVA tolerization was instead associated with larger quantities of TZ cDC1s and pTregs. Decreased IgA responses were observed after CT adjuvanted immunization in huCD207DTA mice lacking CD103 + cDC2s, while oral OVA tolerization was inefficient in cDC1-deficient Batf3 -/- mice. Using Ovalbumin (OVA) TCR transgenic CD4 T cell adoptive transfer models, we found that co-transferred endogenous WT CD4 T cells can hinder the induction of OVA-specific IgA responses through secretion of IL-10. CT could overcome this blocking effect, apparently through a modulating effect on peripherally induced Tregs (pTreg) while promoting an expansion of follicular helper T cells (Tfh). The data support a model where cDC1-induced pTreg normally supress PP responses for any given antigen and where CT's oral adjuvanticity effect is dependent on promoting Tfh responses through induction of CD103 + cDC2s.
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| 5. |
- Gribonika, Inta, et al.
(författare)
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Peyer's patch TH17 cells are dispensable for gut IgA responses to oral immunization.
- 2022
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Ingår i: Science immunology. - : American Association for the Advancement of Science (AAAS). - 2470-9468. ; 7:73
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Tidskriftsartikel (refereegranskat)abstract
- T helper 17 (TH17) cells located at the Peyer's patch (PP) inductive site and at the lamina propria effector site of the intestinal immune system are responsive to both pathogenic and commensal bacteria. Their plasticity to convert into follicular helper T (TFH) cells has been proposed to be central to gut immunoglobulin A (IgA) responses. Here, we used an IL-17A fate reporter mouse and an MHC-II tetramer to analyze antigen-specific CD4+ T cell subsets and isolate them for single-cell RNA sequencing after oral immunization with cholera toxin and ovalbumin. We found a TFH-dominated response with only rare antigen-specific TH17 cells (<8%) in the PP. A clonotypic analysis provided little support that clonotypes were shared between TFH and TH17 cells, arguing against TH17 plasticity as a major contributor to TFH differentiation. Two mouse models of TH17 deficiency confirmed that gut IgA responses to oral immunization do not require TH17 cells, with CD4CreRorcfl/fl mice exhibiting normal germinal centers in PP and unperturbed total IgA production in the intestine.
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| 6. |
- Gribonika, Inta
(författare)
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Regulation of gut IgA induction by helper T cells
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The gut is the largest lymphoid organ in the body. Due to intense and constant exposure to the outside world, it also functions as the most important portal of entry for many pathogens. T cell-dependent secretory immunoglobulin A (IgA) prevents pathogens from spreading to systemic tissues and, hence, oral immunization represents the most effective route for vaccination against these pathogens. The detailed mechanism of oral vaccination-induced protective IgA immunity is not fully understood. The main aim of this thesis was to investigate the role of the gut CD4 T subsets for the induction of IgA responses. By using Ovalbumin-specific TCR-Tg CD4 T cells in an adoptive transfer system and mucosal immunization with or without cholera toxin (CT) adjuvant I show that IgA induction in the Peyer's patch (PP) is regulated in a distinct two-step process, where T follicular helper cells (TFH) and thymus-derived T regulatory cells (tTreg) orchestrate the IgA induction. Effective B cell help in the germinal center (GC) is maintained by antigen-specific TFH cells, while IgA class-switch recombination (CSR) is promoted by tTregs independently of the immunizing antigen. It should be emphasized that the default response pathway activated by oral antigen administration is oral tolerance. In this doctoral thesis, I demonstrate that the suppressive pathway is regulated by IL-10. Thus, CD4 T cells upon exposer to cognate antigen in the presence of IL-10 differentiate into peripherally induced Tregs (pTreg). In the absence of IL-10 or after addition of CT adjuvant TFH differentiation is enhanced, resulting in a strong gut IgA response. CT has been reported to be the most potent oral adjuvant. Some reports suggest that CT preferentially exerts the adjuvant function via Th17 cells. The immuno-dominant part of CT is its B subunit, therefore, I used CTB-specific tetramer to monitor if CT induced T cell response is dominated by Th17 cells. Surprisingly, the CTB-specific T cell repertoire was nearly absent of Th17 lineage, however that did not prevent adjuvant’s ability to induce a strong gut IgA response. Instead, CT induced CD4 T cells were overrepresented by TFH lineage that did not derive from Th17 cells as shown by using IL-17 fate reporter mice. These observations were confirmed using single-cell RNAseq technology. Gene signature of sorted CTB-specific CD4 T cells showed an almost complete dominance of the TFH phenotype with virtually no Th17 signature. Besides, the adoptive transfer of Th17 deficient CD4 T cells (Rorc-/-) into nude host allowed for a robust gut IgA induction after oral immunization with CT. These findings argue strongly against the observations that upon CT immunization gut IgA B cell responses are driven by Th17 cells that exhibit great plasticity towards the TFH lineage. Interestingly, obtained data suggest that TFH cells in the PP do not share clonal relatedness with Th17, Th1 or Treg cells which have been a long-standing controversy in this field. Together, these findings provide a new paradigm for how gut IgA responses are regulated and which two types of CD4 T cell subsets are needed; tTregs for IgA CSR and TFH for GC formation and B cell maturation.
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| 7. |
- Park, Kyong-Su, et al.
(författare)
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Detoxified synthetic bacterial membrane vesicles as a vaccine platform against bacteria and SARS-CoV-2
- 2023
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Ingår i: Journal of Nanobiotechnology. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- The development of vaccines based on outer membrane vesicles (OMV) that naturally bud off from bacteria is an evolving field in infectious diseases. However, the inherent inflammatory nature of OMV limits their use as human vaccines. This study employed an engineered vesicle technology to develop synthetic bacterial vesicles (SyBV) that activate the immune system without the severe immunotoxicity of OMV. SyBV were generated from bacterial membranes through treatment with detergent and ionic stress. SyBV induced less inflammatory responses in macrophages and in mice compared to natural OMV. Immunization with SyBV or OMV induced comparable antigen-specific adaptive immunity. Specifically, immunization with Pseudomonas aeruginosa-derived SyBV protected mice against bacterial challenge, and this was accompanied by significant reduction in lung cell infiltration and inflammatory cytokines. Further, immunization with Escherichia coli-derived SyBV protected mice against E. coli sepsis, comparable to OMV-immunized group. The protective activity of SyBV was driven by the stimulation of B-cell and T-cell immunity. Also, SyBV were engineered to display the SARS-CoV-2 S1 protein on their surface, and these vesicles induced specific S1 protein antibody and T-cell responses. Collectively, these results demonstrate that SyBV may be a safe and efficient vaccine platform for the prevention of bacterial and viral infections
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| 8. |
- Park, Kyong-Su, et al.
(författare)
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Mesenchymal stromal cell-derived nanovesicles ameliorate bacterial outer membrane vesicle-induced sepsis via IL-10.
- 2019
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Ingår i: Stem cell research & therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis remains a source of high mortality in hospitalized patients despite proper antibiotic approaches. Encouragingly, mesenchymal stromal cells (MSCs) and their produced extracellular vesicles (EVs) have been shown to elicit anti-inflammatory effects in multiple inflammatory conditions including sepsis. However, EVs are generally released from mammalian cells in relatively low amounts, and high-yield isolation of EVs is still challenging due to a complicated procedure. To get over these limitations, vesicles very similar to EVs can be produced by serial extrusions of cells, after which they are called nanovesicles (NVs). We hypothesized that MSC-derived NVs can attenuate the cytokine storm induced by bacterial outer membrane vesicles (OMVs) in mice, and we aimed to elucidate the mechanism involved.NVs were produced from MSCs by the breakdown of cells through serial extrusions and were subsequently floated in a density gradient. Morphology and the number of NVs were analyzed by transmission electron microscopy and nanoparticle tracking analysis. Mice were intraperitoneally injected with Escherichia coli-derived OMVs to establish sepsis, and then injected with 2×109 NVs. Innate inflammation was assessed in peritoneal fluid and blood through investigation of infiltration of cells and cytokine production. The biodistribution of NVs labeled with Cy7 dye was analyzed using near-infrared imaging.Electron microscopy showed that NVs have a nanometer-size spherical shape and harbor classical EV marker proteins. In mice, NVs inhibited eye exudates and hypothermia, signs of a systemic cytokine storm, induced by intraperitoneal injection of OMVs. Moreover, NVs significantly suppressed cytokine release into the systemic circulation, as well as neutrophil and monocyte infiltration in the peritoneum. The protective effect of NVs was significantly reduced by prior treatment with anti-interleukin (IL)-10 monoclonal antibody. In biodistribution study, NVs spread to the whole mouse body and localized in the lung, liver, and kidney at 6h.Taken together, these data indicate that MSC-derived NVs have beneficial effects in a mouse model of sepsis by upregulating the IL-10 production, suggesting that artificial NVs may be novel EV-mimetics clinically applicable to septic patients.
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| 9. |
- Park, Kyong-Su, et al.
(författare)
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Synthetic bacterial vesicles combined with tumour extracellular vesicles as cancer immunotherapy
- 2021
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial outer membrane vesicles (OMV) have gained attention as a promising new cancer vaccine platform for efficiently provoking immune responses. However, OMV induce severe toxicity by activating the innate immune system. In this study, we applied a simple isolation approach to produce artificial OMV that we have named Synthetic Bacterial Vesicles (SyBV) that do not induce a severe toxic response. We also explored the potential of SyBV as an immunotherapy combined with tumour extracellular vesicles to induce anti-tumour immunity. Bacterial SyBV were produced with high yield by a protocol including lysozyme and high pH treatment, resulting in pure vesicles with very few cytosolic components and no RNA or DNA. These SyBV did not cause systemic pro-inflammatory cytokine responses in mice compared to naturally released OMV. However, SyBV and OMV were similarly effective in activation of mouse bone marrow-derived dendritic cells. Co-immunization with SyBV and melanoma extracellular vesicles elicited tumour regression in melanoma-bearing mice through Th-1 type T cell immunity and balanced antibody production. Also, the immunotherapeutic effect of SyBV was synergistically enhanced by anti-PD-1 inhibitor. Moreover, SyBV displayed significantly greater adjuvant activity than other classical adjuvants. Taken together, these results demonstrate a safe and efficient strategy for eliciting specific anti-tumour responses using immunotherapeutic bacterial SyBV.
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| 10. |
- Schussek, Sophie, et al.
(författare)
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The CTA1-DD adjuvant strongly potentiates follicular dendritic cell function and germinal center formation, which results in improved neonatal immunization
- 2020
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Ingår i: Mucosal Immunology. - : Elsevier BV. - 1933-0219. ; 13, s. 545-557
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Tidskriftsartikel (refereegranskat)abstract
- Vaccination of neonates and young infants is hampered by the relative immaturity of their immune systems and the lack of safe and efficacious vaccine adjuvants. Immaturity of the follicular dendritic cells (FDCs), in particular, appears to play a critical role for the inability to stimulate immune responses. Using the CD21mT/mG mouse model we found that at 7 days of life, FDCs exhibited a mature phenotype only in the Peyer ' s patches (PP), but our unique adjuvant, CTA1-DD, effectively matured FDCs also in peripheral lymph nodes following systemic, as well as mucosal immunizations. This was a direct effect of complement receptor 2-binding to the FDC and a CTA1-enzyme-dependent enhancing effect on gene transcription, among which CR2, IL-6, ICAM-1, IL-1 beta, and CXCL13 encoding genes were upregulated. This way we achieved FDC maturation, increased germinal center B-cell- and Tfh responses, and enhanced specific antibody levels close to adult magnitudes. Oral priming immunization of neonates against influenza infection with CTA1-3M2e-DD effectively promoted anti-M2e-immunity and significantly reduced morbidity against a live virus challenge infection. To the best of our knowledge, this is the first study to demonstrate direct effects of an adjuvant on FDC gene transcriptional functions and the subsequent enhancement of neonatal immune responses.
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