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Inhibition of antigen-specific immune responses by co-application of an indoleamine 2,3-dioxygenase (IDO)-encoding vector requires antigen transgene expression focused on dendritic cells. Amino Acids 2020; 52:411-424. [PMID: 32008091 DOI: 10.1007/s00726-020-02817-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 01/10/2020] [Indexed: 12/17/2022]
Abstract
We have previously shown that particle-mediated epidermal delivery (PMED) of plasmids encoding β-galactosidase (βGal) under control of the fascin-1 promoter (pFascin-βGal) yielded selective production of the protein in skin dendritic cells (DCs), and suppressed Th2 responses in a mouse model of type I allergy by inducing Th1/Tc1 cells. However, intranasal challenge of mice immunized with pFascin-βGal induced airway hyperreactivity (AHR) and neutrophilic inflammation in the lung. The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) has been implicated in immune suppression and tolerance induction. Here we investigated the consequences of co-application of an IDO-encoding vector on the modulatory effect of DNA vaccination by PMED using pFascin-βGal in models of eosinophilic allergic and non-eosinophilic intrinsic airway inflammation. IDO-encoding plasmids and pFascin-βGal or pCMV-βGal were co-applied to abdominal skin of BALB/c mice without, before or after sensitization with βGal protein. Immune responses in the lung were analysed after intranasal provocation and airway reactivity was determined by whole body plethysmography. Co-application of pCMV-IDO with pFascin-βGal, but not pCMV-βGal inhibited the Th1/Tc1 immune response after PMED. Moreover, AHR in those mice was attenuated following intranasal challenge. Therapeutic vaccination of βGal-sensitized mice with pFascin-βGal plus pCMV-IDO slightly suppressed airway inflammation and AHR after provocation with βGal protein, while prophylactic vaccination was not effective. Altogether, our data suggest that only the combination of DC-restricted antigen and ubiquitous IDO expression attenuated asthma responses in mice, most probably by forming a tryptophan-depleted and kynurenine-enriched micromilieu known to affect neutrophils and T cells.
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Hunter MC, Teijeira A, Montecchi R, Russo E, Runge P, Kiefer F, Halin C. Dendritic Cells and T Cells Interact Within Murine Afferent Lymphatic Capillaries. Front Immunol 2019; 10:520. [PMID: 30967863 PMCID: PMC6440485 DOI: 10.3389/fimmu.2019.00520] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/26/2019] [Indexed: 11/13/2022] Open
Abstract
Afferent lymphatic vessels contribute to immunity by transporting antigen and leukocytes to draining lymph nodes (LNs) and are emerging as new players in the regulation of peripheral tolerance. Performing intravital microscopy in inflamed murine ear skin we found that migrating dendritic cells (DCs) and antigen-experienced effector T cells spend considerable time arresting or clustering within afferent lymphatic capillaries. We also observed that intralymphatic T cells frequently interacted with DCs. When imaging polyclonal T cells during an ongoing contact-hypersensitivity response, most intralymphatic DC-T cell interactions were short-lived. Conversely, during a delayed-type-hypersensitivity response, cognate antigen-bearing DCs engaged in long-lived MHCII-(I-A/I-E)-dependent interactions with antigen-specific T cells. Long-lived intralymphatic DC-T cell interactions reduced the speed of DC crawling but did not delay overall DC migration to draining LNs. While further consequences of these intralymphatic interactions still need to be explored, our findings suggest that lymphatic capillaries represent a unique compartment in which adaptive immune interaction and modulation occur.
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Affiliation(s)
| | - Alvaro Teijeira
- Institute of Pharmaceutical Sciences, ETH Zürich, Zurich, Switzerland
| | | | - Erica Russo
- Institute of Pharmaceutical Sciences, ETH Zürich, Zurich, Switzerland
| | - Peter Runge
- Institute of Pharmaceutical Sciences, ETH Zürich, Zurich, Switzerland
| | - Friedemann Kiefer
- Max Planck Institute for Molecular Biomedicine, Münster, Germany.,European Institute for Molecular Imaging - EIMI, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Cornelia Halin
- Institute of Pharmaceutical Sciences, ETH Zürich, Zurich, Switzerland
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Fontaine M, Vogel I, Van Eycke YR, Galuppo A, Ajouaou Y, Decaestecker C, Kassiotis G, Moser M, Leo O. Regulatory T cells constrain the TCR repertoire of antigen-stimulated conventional CD4 T cells. EMBO J 2018; 37:398-412. [PMID: 29263148 PMCID: PMC5793804 DOI: 10.15252/embj.201796881] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 11/17/2017] [Accepted: 11/27/2017] [Indexed: 01/22/2023] Open
Abstract
To analyze the potential role of Tregs in controlling the TCR repertoire breadth to a non-self-antigen, a TCRβ transgenic mouse model (EF4.1) expressing a limited, yet polyclonal naïve T-cell repertoire was used. The response of EF4.1 mice to an I-Ab-associated epitope of the F-MuLV envelope protein is dominated by clones expressing a Vα2 gene segment, thus allowing a comprehensive analysis of the TCRα repertoire in a relatively large cohort of mice. Control and Treg-depleted EF4.1 mice were immunized, and the extent of the Vα2-bearing, antigen-specific TCR repertoire was characterized by high-throughput sequencing and spectratyping analysis. In addition to increased clonal expansion and acquisition of effector functions, Treg depletion led to the expression of a more diverse TCR repertoire comprising several private clonotypes rarely observed in control mice or in the pre-immune repertoire. Injection of anti-CD86 antibodies in vivo led to a strong reduction in TCR diversity, suggesting that Tregs may influence TCR repertoire diversity by modulating costimulatory molecule availability. Collectively, these studies illustrate an additional mechanism whereby Tregs control the immune response to non-self-antigens.
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MESH Headings
- Animals
- Antibodies, Viral/immunology
- B7-2 Antigen/immunology
- Cells, Cultured
- Friend murine leukemia virus/immunology
- Lymphocyte Depletion
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocytes, Regulatory/immunology
- Viral Envelope Proteins/immunology
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Affiliation(s)
- Martina Fontaine
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Isabel Vogel
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Yves-Rémi Van Eycke
- DIAPath, Center for Microscopy and Molecular Imaging, Université Libre de Bruxelles (ULB), Gosselies, Belgium
- Laboratories of Image, Signal processing & Acoustics Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Adrien Galuppo
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Yousra Ajouaou
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Christine Decaestecker
- DIAPath, Center for Microscopy and Molecular Imaging, Université Libre de Bruxelles (ULB), Gosselies, Belgium
- Laboratories of Image, Signal processing & Acoustics Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, London, UK
- Department of Medicine Faculty of Medicine, Imperial College London London, UK
| | - Muriel Moser
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Oberdan Leo
- Laboratoire d'Immunobiologie, Université Libre de Bruxelles (ULB), Gosselies, Belgium
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Riccomi A, Gesa V, Sacchi A, De Magistris MT, Vendetti S. Modulation of Phenotype and Function of Human CD4 +CD25 + T Regulatory Lymphocytes Mediated by cAMP-Elevating Agents. Front Immunol 2016; 7:358. [PMID: 27703455 PMCID: PMC5028705 DOI: 10.3389/fimmu.2016.00358] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/01/2016] [Indexed: 01/21/2023] Open
Abstract
We have shown that cholera toxin (CT) and other cyclic AMP (cAMP)-elevating agents induce upregulation of the inhibitory molecule CTLA-4 in human resting CD4+ T lymphocytes, which following the treatment acquired suppressive functions. In this study, we evaluated the effect of cAMP-elevating agents on human CD4+CD25+ T cells, which include the T regulatory cells (Tregs) that play a pivotal role in the maintenance of immunological tolerance. We found that cAMP-elevating agents induce upregulation of CTLA-4 in CD4+CD25− and further enhance its expression in CD4+CD25+ T cells. We observed an increase of two isoforms of mRNA coding for the membrane and the soluble CTLA-4 molecules, suggesting that the regulation of CTLA-4 expression by cAMP is at the transcriptional level. In addition, we found that the increase of cAMP in CD4+CD25+ T cells converts the CD4+CD25+Foxp3− T cells in CD4+CD25+Foxp3+ T cells, whereas the increase of cAMP in CD4+CD25− T cells did not upregulate Foxp3 in the absence of activation stimuli. To investigate the function of these cells, we performed an in vitro suppression assay by culturing CD4+CD25+ T cells untreated or pre-treated with CT with anti-CD3 mAbs-stimulated autologous peripheral blood mononuclear cell. We found that CT enhances the inhibitory function of CD4+CD25+ T cells, CD4+, and CD8+ T cell proliferation and IFNγ production are strongly inhibited by CD4+CD25+ T cells pre-treated with cAMP-elevating agents. Furthermore, we found that CD4+CD25+ T lymphocytes pre-treated with cAMP-elevating agents induce the upregulation of CD80 and CD86 co-stimulatory molecules on immature dendritic cells (DCs) in the absence of antigenic stimulation, however without leading to full DC maturation. These data show that the increase of intracellular cAMP modulates the phenotype and function of human CD4+CD25+ T cells.
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Affiliation(s)
- Antonella Riccomi
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità , Rome , Italy
| | - Valentina Gesa
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità , Rome , Italy
| | - Alessandra Sacchi
- Department of Epidemiology, Preclinical Research, and Advanced Diagnostics, National Institute for Infectious Diseases IRCCS "Lazzaro Spallanzani" , Rome , Italy
| | - Maria Teresa De Magistris
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità , Rome , Italy
| | - Silvia Vendetti
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità , Rome , Italy
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Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation. J Immunol Res 2016; 2016:1720827. [PMID: 27298831 PMCID: PMC4889823 DOI: 10.1155/2016/1720827] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/27/2016] [Indexed: 01/11/2023] Open
Abstract
T regulatory cells play a key role in the control of the immune response, both in health and during illness. While the mechanisms through which T regulatory cells exert their function have been extensively described, their molecular effects on effector cells have received little attention. Thus, this revision is aimed at summarizing our current knowledge on those regulation mechanisms on the target cells from a molecular perspective.
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