| 1. |
- Adam, Lucille, et al.
(författare)
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Innate Molecular and Cellular Signature in the Skin Preceding Long-Lasting T Cell Responses after Electroporated DNA Vaccination
- 2020
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 204:12, s. 3375-3388
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Tidskriftsartikel (refereegranskat)abstract
- DNA vaccines delivered with electroporation (EP) have shown promising results in preclinical models and are evaluated in clinical trials. In this study, we aim to characterize early mechanisms occurring in the skin after intradermal injection and EP of the auxoGTUmultiSIV DNA vaccine in nonhuman primates. First, we show that EP acts as an adjuvant by enhancing local inflammation, notably via granulocytes, monocytes/macrophages, and CD1a(int)-expressing cell recruitment. EP also induced Langerhans cell maturation, illustrated by CD86, CD83, and HLA-DR upregulation and their migration out of the epidermis. Second, we demonstrate the crucial role of the DNA vaccine in soluble factors release, such as MCP-1 or IL-15. Transcriptomic analysis showed that EP played a major role in gene expression changes postvaccination. However, the DNA vaccine is required to strongly upregulate several genes involved in inflammatory responses (e.g., Saa4), cell migration (e.g., Ccl3, Ccl5, or Cxcl10), APC activation (e.g., Cd86), and IFN-inducible genes (e.g., Ifit3, Ifit5, Irf7, Isg15, orMx1), illustrating an antiviral response signature. Also, AIM-2, a cytosolic DNA sensor, appeared to be strongly upregulated only in the presence of the DNA vaccine and trends to positively correlate with several IFN-inducible genes, suggesting the potential role of AIM-2 in vaccine sensing and the subsequent innate response activation leading to strong adaptive T cell responses. Overall, these results demonstrate that a combined stimulation of the immune response, in which EP and the auxoGTUmultiSIV vaccine triggered different components of the innate immunity, led to strong and persistent cellular recall responses.
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| 2. |
- Aggio, JB, et al.
(författare)
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Vaccinia Virus Infection Inhibits Skin Dendritic Cell Migration to the Draining Lymph Node
- 2021
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 206:4, s. 776-784
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Tidskriftsartikel (refereegranskat)abstract
- There is a paucity of information on dendritic cell (DC) responses to vaccinia virus (VACV), including the traffic of DCs to the draining lymph node (dLN). In this study, using a mouse model of infection, we studied skin DC migration in response to VACV and compared it with the tuberculosis vaccine Mycobacterium bovis bacille Calmette–Guérin (BCG), another live attenuated vaccine administered via the skin. In stark contrast to BCG, skin DCs did not relocate to the dLN in response to VACV. Infection with UV-inactivated VACV or modified VACV Ankara promoted DC movement to the dLN, indicating that interference with skin DC migration requires replication-competent VACV. This suppressive effect of VACV was capable of mitigating responses to a secondary challenge with BCG in the skin, ablating DC migration, reducing BCG transport, and delaying CD4+ T cell priming in the dLN. Expression of inflammatory mediators associated with BCG-triggered DC migration were absent from virus-injected skin, suggesting that other pathways invoke DC movement in response to replication-deficient VACV. Despite adamant suppression of DC migration, VACV was still detected early in the dLN and primed Ag-specific CD4+ T cells. In summary, VACV blocks skin DC mobilization from the site of infection while retaining the ability to access the dLN to prime CD4+ T cells.
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| 3. |
- Al Adwani, Salma, et al.
(författare)
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Citrullination Alters the Antibacterial and Anti-Inflammatory Functions of the Host Defense Peptide Canine Cathelicidin K9CATH In Vitro
- 2021
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 207:3, s. 974-984
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Tidskriftsartikel (refereegranskat)abstract
- K9CATH is the sole cathelicidin in canines (dogs) and exhibits broad antimicrobial activity against both Gram-positive and Gram-negative bacteria. K9CATH also modulates inflammatory responses and binds to LPS. These activities depend on the secondary structure and a net-positive charge of the peptide. Peptidylarginine deiminases (PAD) convert cationic peptidyl arginine to neutral citrulline. Thus, we hypothesized that citrullination is a biologically relevant modification of the peptide that would reduce the antibacterial and LPS-binding activities of K9CATH. Recombinant PAD2 and PAD4 citrullinated K9CATH to various extents and circular dichroism spectroscopy revealed that both native and citrullinated K9CATH exhibited similar α-helical secondary structures. Notably, citrullination of K9CATH reduced its bactericidal activity, abolished its ability to permeabilize the membrane of Gram-negative bacteria and reduced the hemolytic capacity. Electron microscopy showed that citrullinated K9CATH did not cause any morphological changes of Gram-negative bacteria, whereas the native peptide caused clear alterations of membrane integrity, concordant with a rapid bactericidal effect. Finally, citrullination of K9CATH impaired its capacity to inhibit LPS-mediated release of proinflammatory molecules from mouse and canine macrophages. In conclusion, citrullination attenuates the antibacterial and the LPS-binding properties of K9CATH, demonstrating the importance of a net positive charge for antibacterial lysis of bacteria and LPS-binding effects and suggests that citrullination is a means to regulate cathelicidin activities.
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| 4. |
- Astori, Audrey, et al.
(författare)
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ARID1a Associates with Lymphoid-Restricted Transcription Factors and Has an Essential Role in T Cell Development
- 2020
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 205:5, s. 1419-1432
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Tidskriftsartikel (refereegranskat)abstract
- Maturation of lymphoid cells is controlled by the action of stage and lineage-restricted transcription factors working in concert with the general transcription and chromatin remodeling machinery to regulate gene expression. To better understand this functional interplay, we used Biotin Identification in human embryonic kidney cells to identify proximity interaction partners for GATA3, TCF7 (TCF1), SPI1, HLF, IKZF1, PAX5, ID1, and ID2. The proximity interaction partners shared among the lineagerestricted transcription factors included ARID1a, a BRG1-associated factor complex component. CUT&RUN analysis revealed that ARID1a shared binding with TCF7 and GATA3 at a substantial number of putative regulatory elements in mouse T cell progenitors. In support of an important function for ARID1a in lymphocyte development, deletion of Aridla in early lymphoid progenitors in mice resulted in a pronounced developmental arrest in early T cell development with a reduction of CD4(+)CD8(+) cells and a 20-fold reduction in thymic cellularity. Exploring gene expression patterns in DN3 cells from Wt and Aridla-deficient mice suggested that the developmental block resided in the DN3a to DN3b transition, indicating a deficiency in beta-selection. Our work highlights the critical importance of functional interactions between stage and lineage-restricted factors and the basic transcription machinery during lymphocyte differentiation.
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| 5. |
- Bonner, Michael Y., et al.
(författare)
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Formyl peptide receptor (FPR) agonists promote immune evasion independent of functional Ncf1 derived ROS
- 2020
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 204:1_Supplement, s. 242.46-242.46
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have shown that in both the absence of the Ncf1 gene or in the presence of a loss-of-function SNP, mice have a lower tumor burden when compared to wildtype animals. Here, we investigate a formyl peptide receptor (FPR) agonist in this setting and demonstrate that it promotes tumor immune evasion through an immune-Ncf1/ROS-dependent mechanism. We observed an increased colonization of B16F10 tumor cells in the lungs of FPR-agonist-treated wildtype C57BL6N mice compared to vehicle-control-treated mice. A significant reduction in tumor burden was expectedly seen in the Ncf1*/* mutant strain compared to the wildtype. However, FPR-agonist treatment did not promote tumor growth in Ncf1*/* treated mice when compared to vehicle-control-treated Ncf1*/* mice. These results suggest that FPR agonists can promote tumor evasion by acting through FPRs on immune cells in a NOX2/ROS-independent fashion and in a fashion independent of FPRs on the tumor.
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| 6. |
- Boulouis, C, et al.
(författare)
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Mucosa-Associated Invariant T Cell Hypersensitivity to Staphylococcus aureus Leukocidin ED and Its Modulation by Activation
- 2022
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 208:5, s. 1170-1179
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Tidskriftsartikel (refereegranskat)abstract
- Mucosa-associated invariant T (MAIT) cells recognize bacterial riboflavin metabolite Ags presented by MHC class Ib–related protein (MR1) and play important roles in immune control of microbes that synthesize riboflavin. This includes the pathobiont Staphylococcus aureus, which can also express a range of virulence factors, including the secreted toxin leukocidin ED (LukED). In this study, we found that human MAIT cells are hypersensitive to LukED-mediated lysis and lost on exposure to the toxin, leaving a T cell population devoid of MAIT cells. The cytolytic effect of LukED on MAIT cells was rapid and occurred at toxin concentrations lower than those required for toxicity against conventional T cells. Furthermore, this coincided with high MAIT cell expression of CCR5, and loss of these cells was efficiently inhibited by the CCR5 inhibitor maraviroc. Interestingly, exposure and preactivation of MAIT cells with IL-12 and IL-18, or activation via TCR triggering, partially protected from LukED toxicity. Furthermore, analysis of NK cells indicated that LukED targeted the mature cytotoxic CD57+ NK cell subset in a CCR5-independent manner. Overall, these results indicate that LukED efficiently eliminates immune cells that can respond rapidly to S. aureus in an innate fashion without the need for clonal expansion, and that MAIT cells are exceptionally vulnerable to this toxin. Thus, the findings support a model where LukED secretion may allow S. aureus to avoid recognition by the rapid cell-mediated responses mediated by MAIT cells and NK cells.
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| 7. |
- Boulouis, C, et al.
(författare)
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Opsonization-Enhanced Antigen Presentation by MR1 Activates Rapid Polyfunctional MAIT Cell Responses Acting as an Effector Arm of Humoral Antibacterial Immunity
- 2020
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 205:1, s. 67-77
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Tidskriftsartikel (refereegranskat)abstract
- Mucosa-associated invariant T (MAIT) cells are innate-like antimicrobial T cells recognizing a breadth of important pathogens via presentation of microbial riboflavin metabolite Ags by MHC class Ib–related (MR1) molecules. However, the interaction of human MAIT cells with adaptive immune responses and the role they may play in settings of vaccinology remain relatively little explored. In this study we investigated the interplay between MAIT cell–mediated antibacterial effector functions and the humoral immune response. IgG opsonization of the model microbe Escherichia coli with pooled human sera markedly enhanced the capacity of monocytic APC to stimulate MAIT cells. This effect included greater sensitivity of recognition and faster response kinetics, as well as a markedly higher polyfunctionality and magnitude of MAIT cell responses involving a range of effector functions. The boost of MAIT cell responses was dependent on strongly enhanced MR1-mediated Ag presentation via increased FcγR-mediated uptake and signaling primarily mediated by FcγRI. To investigate possible translation of this effect to a vaccine setting, sera from human subjects before and after vaccination with the 13-valent–conjugated Streptococcus pneumoniae vaccine were assessed in a MAIT cell activation assay. Interestingly, vaccine-induced Abs enhanced Ag presentation to MAIT cells, resulting in more potent effector responses. These findings indicate that enhancement of Ag presentation by IgG opsonization allows innate-like MAIT cells to mount a faster, stronger, and qualitatively more complex response and to function as an effector arm of vaccine-induced humoral adaptive antibacterial immunity.
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| 8. |
- Budeus, B., et al.
(författare)
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Human cord blood b cells differ from the adult counterpart by conserved ig repertoires and accelerated response dynamics
- 2021
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 206:12, s. 2839-2851
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Tidskriftsartikel (refereegranskat)abstract
- Neonatal and infant immune responses are characterized by a limited capability to generate protective Ab titers and memory B cells as seen in adults. Multiple studies support an immature or even impaired character of umbilical cord blood (UCB) B cells themselves. In this study, we provide a comprehensive molecular and functional comparison of B cell subsets from UCB and adult peripheral blood. Most UCB B cells have a mature, naive B cell phenotype as seen in adults. The UCB Ig repertoire is highly variable but interindividually conserved, as BCR clonotypes are frequently shared between neonates. Furthermore, UCB B cells show a distinct transcriptional program that confers accelerated responsiveness to stimulation and facilitated IgA class switching. Stimulation drives extensive differentiation into Ab-secreting cells, presumably limiting memory B cell formation. Humanized mice suggest that the distinctness of UCB versus adult B cells is already reflected by the developmental program of hematopoietic precursors, arguing for a layered B-1/B-2 lineage system as in mice, albeit our findings suggest only partial comparability to murine B-1 cells. Our study shows that UCB B cells are not immature or impaired but differ from their adult mature counterpart in a conserved BCR repertoire, efficient IgA class switching, and accelerated, likely transient response dynamics. © 2021 by TheAmericanAssociation of Immunologists, Inc.
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| 9. |
- Czeh, M, et al.
(författare)
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DNMT1 Deficiency Impacts on Plasmacytoid Dendritic Cells in Homeostasis and Autoimmune Disease
- 2022
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 208:2, s. 358-370
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCs) are heterogeneous immune regulators involved in autoimmune diseases. Epigenomic mechanisms orchestrating DC development and DC subset diversification remain insufficiently understood but could be important to modulate DC fate for clinical purposes. By combining whole-genome methylation assessment with the analysis of mice expressing reduced DNA methyltransferase 1 levels, we show that distinct DNA methylation levels and patterns are required for the development of plasmacytoid DC and conventional DC subsets. We provide clonal in vivo evidence for DC lineage establishment at the stem cell level, and we show that a high DNA methylation threshold level is essential for Flt3-dependent survival of DC precursors. Importantly, reducing methylation predominantly depletes plasmacytoid DC and alleviates systemic lupus erythematosus in an autoimmunity mouse model. This study shows how DNA methylation regulates the production of DC subsets and provides a potential rationale for targeting autoimmune disease using hypomethylating agents.
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| 10. |
- Daams, Renée, et al.
(författare)
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Deletion of nemo-like kinase in T cells reduces single-positive CD8+thymocyte population
- 2020
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 205:7, s. 1830-1841
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Tidskriftsartikel (refereegranskat)abstract
- The β-catenin/Wnt signaling pathway plays an important role in all stages of T cell development. Nemo-like kinase (NLK) is an evolutionary conserved serine/threonine kinase and a negative regulator of the Wnt signaling pathway. NLK can directly phosphorylate histone deacetylase 1 (HDAC1), as well as T cell factor/lymphoid enhancer-binding factor (TCF/LEF), causing subsequent repression of target gene transcription. By engineering mice lacking NLK in early stages of T cell development, we set out to characterize the role NLK plays in T cell development and found that deletion of NLK does not affect mouse health or lymphoid tissue development. Instead, these mice harbored a reduced number of single-positive (SP) CD8+ thymocytes without any defects in the SP CD4+ thymocyte population. The decrease in SP CD8+ thymocytes was not caused by a block in differentiation from double-positive CD4+CD8+ cells. Neither TCR signaling nor activation was altered in the absence of NLK. Instead, we observed a significant increase in cell death and reduced phosphorylation of LEF1 as well as HDAC1 among NLK-deleted SP CD8+ cells. Thus, NLK seems to play an important role in the survival of CD8+ thymocytes. Our data provide evidence for a new function for NLK with regard to its involvement in T cell development and supporting survival of SP CD8+ thymocytes.
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