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| 2. |
- Vornhagen, J., et al.
(författare)
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Group B streptococcus exploits vaginal epithelial exfoliation for ascending infection
- 2018
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Ingår i: Journal of Clinical Investigation. - : American Society for Clinical Investigation. - 0021-9738 .- 1558-8238. ; 128:5, s. 1985-1999
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Tidskriftsartikel (refereegranskat)abstract
- Thirteen percent of pregnancies result in preterm birth or stillbirth, accounting for fifteen million preterm births and three and a half million deaths annually. A significant cause of these adverse pregnancy outcomes is in utero infection by vaginal microorganisms. To establish an in utero infection, vaginal microbes enter the uterus by ascending infection; however, the mechanisms by which this occurs are unknown. Using both in vitro and murine models of vaginal colonization and ascending infection, we demonstrate how a vaginal microbe, group B streptococcus (GBS), which is frequently associated with adverse pregnancy outcomes, uses vaginal exfoliation for ascending infection. GBS induces vaginal epithelial exfoliation by activation of integrin and beta-catenin signaling. However, exfoliation did not diminish GBS vaginal colonization as reported for other vaginal microbes. Rather, vaginal exfoliation increased bacterial dissemination and ascending GBS infection, and abrogation of exfoliation reduced ascending infection and improved pregnancy outcomes. Thus, for some vaginal bacteria, exfoliation promotes ascending infection rather than preventing colonization. Our study provides insight into mechanisms of ascending infection by vaginal microbes.
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| 3. |
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| 4. |
- van Montfoort, Nadine, et al.
(författare)
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Circulating specific antibodies enhance systemic cross-priming by delivery of complexed antigen to dendritic cells in vivo
- 2012
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 42:3, s. 598-606
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Tidskriftsartikel (refereegranskat)abstract
- Increasing evidence suggests that antibodies can have stimulatory effects on T-cell immunity. However, the contribution of circulating antigen-specific antibodies on MHC class I cross-priming in vivo has not been conclusively established. Here, we defined the role of circulating antibodies in cross-presentation of antigen to CD8+ T cells. Mice with hapten-specific circulating antibodies, but naϊve for the T-cell antigen, were infused with haptenated antigen and CD8+ T-cell induction was measured. Mice with circulating hapten-specific antibodies showed significantly enhanced cross-presentation of the injected antigen compared with mice that lacked these antibodies. The enhanced cross-presentation in mice with circulating antigen-specific antibodies was associated with improved antigen capture by APCs. Importantly, CD11c+ APCs were responsible for the enhanced and sustained cross-presentation, although CD11c− APCs had initially captured a significant amount of the injected antigen. Thus, in vivo formation of antigen-antibody immune complexes improves MHC class I cross-presentation, and CD8+ T-cell activation, demonstrating that humoral immunity can aid the initiation of systemic cellular immunity. These findings have important implications for the understanding of the action of therapeutic antibodies against tumor-associated antigens intensively used in the clinic nowadays.
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| 5. |
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| 6. |
- Fletcher, Erika, et al.
(författare)
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Formation of Immune Complexes with a Tetanus-Derived B Cell Epitope Boosts Human T Cell Responses to Covalently Linked Peptides in an Ex Vivo Blood Loop System
- 2018
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 201:1, s. 87-97
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Tidskriftsartikel (refereegranskat)abstract
- Enhancing T cell responses against both viral and tumor Ags requires efficient costimulation and directed delivery of peptide Ags into APCs. Long peptide vaccines are considered favorable vaccine moieties from a clinical perspective, as they can harbor more than one immunogenic epitope enabling treatment of a broader target population. In addition, longer peptides are not extracellularly loaded on MHC class I; rather, they require intracellular processing and will thereby be presented to T cells mainly by professional APCs, thereby avoiding the risk of tolerance induction. The drawback of peptide vaccines regardless of peptide length is that naked peptides are not actively targeted to and taken up by APCs, and the standard nonconjugated adjuvant-peptide mixtures do not ensure cotargeting of the two to the same APC. We have identified a tetanus toxin-derived B cell epitope that can mediate the formation of immune complexes in the presence of circulating Abs. In this study, we show that these immune complexes improve both Ag uptake by APCs (blood monocytes and CD1c(+) dendritic cells) and consequently improve CD8(+) T cell recall responses in a human ex vivo blood loop system. The uptake of the peptide conjugate by blood monocytes is dependent on Abs and the complement component C1q. We envision that this strategy can be used to facilitate active uptake of Ags into APCs to improve T cell responses against pathogens or cancer.
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| 7. |
- Kessler, Jan H., et al.
(författare)
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Antigen processing by nardilysin and thimet oligopeptidase generates cytotoxic T cell epitopes
- 2010
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Ingår i: Nature Immunology. - : Springer Science and Business Media LLC. - 1529-2908 .- 1529-2916. ; 12:1, s. 45-53
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Tidskriftsartikel (refereegranskat)abstract
- Cytotoxic T lymphocytes (CTLs) recognize peptides presented by HLA class I molecules on the cell surface. The C terminus of these CTL epitopes is considered to be produced by the proteasome. Here we demonstrate that the cytosolic endopeptidases nardilysin and thimet oligopeptidase (TOP) complemented proteasome activity. Nardilysin and TOP were required, either together or alone, for the generation of a tumor-specific CTL epitope from PRAME, an immunodominant CTL epitope from Epstein-Barr virus protein EBNA3C, and a clinically important epitope from the melanoma protein MART-1. TOP functioned as C-terminal trimming peptidase in antigen processing, and nardilysin contributed to both the C-terminal and N-terminal generation of CTL epitopes. By broadening the antigenic peptide repertoire, nardilysin and TOP strengthen the immune defense against intracellular pathogens and cancer.
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| 8. |
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| 9. |
- Melief, C, et al.
(författare)
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Protective T-cell responses against tumours
- 1998
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Ingår i: Research in immunology. - : Elsevier BV. - 0923-2494. ; 149:9, s. 877-879
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Nasi, A, et al.
(författare)
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Reactive oxygen species as an initiator of toxic innate immune responses in retort to SARS-CoV-2 in an ageing population, consider N-acetylcysteine as early therapeutic intervention
- 2020
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Ingår i: Toxicology reports. - : Elsevier Inc.. - 2214-7500. ; 7, s. 768-771
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Tidskriftsartikel (refereegranskat)abstract
- During the current COVID-19 pandemic, a need for evaluation of already available drugs for treatment of the disease is crucial. Hereby, based on literature review from the current pandemic and previous outbreaks with corona viruses we analyze the impact of the virus infection on cell stress responses and redox balance. High levels of mortality are noticed in elderly individuals infected with SARS-CoV2 and during the previous SARS-CoV1 outbreak. Elderly individuals maintain a chronic low level of inflammation which is associated with oxidative stress and inflammatory cytokine production, a condition that increases the severity of viral infections in this population. Coronavirus infections can lead to alterations of redox balance in infected cells through modulation of NAD + biosynthesis, PARP function along with altering proteasome and mitochondrial function in the cell thereby leading to enhanced cell stress responses which further exacerbate inflammation. ROS production can increase IL-6 production and lipid peroxidation resulting in cell damage. Therefore, early treatment with anti-oxidants such as NAC during COVID-19 can be a way to bypass the excessive inflammation and cell damage that lead to severe infection, thus early NAC as intervention should be evaluated in a clinical trial setting.
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