TY - JOUR A1 - Riquelme, Paloma A1 - Haarer, Jan A1 - Kammler, Anja A1 - Walter, Lisa A1 - Tomiuk, Stefan A1 - Ahrens, Norbert A1 - Wege, Anja K. A1 - Goecze, Ivan A1 - Zecher, Daniel A1 - Banas, Bernhard A1 - Spang, Rainer A1 - Fändrich, Fred A1 - Lutz, Manfred B. A1 - Sawitzki, Birgit A1 - Schlitt, Hans J. A1 - Ochando, Jordi A1 - Geissler, Edward K. A1 - Hutchinson, James A. T1 - TIGIT\(^+\) iTregs elicited by human regulatory macrophages control T cell immunity JF - Nature Communications N2 - Human regulatory macrophages (Mreg) have shown early clinical promise as a cell-based adjunct immunosuppressive therapy in solid organ transplantation. It is hypothesised that recipient CD4(+) T cell responses are actively regulated through direct allorecognition of donor-derived Mregs. Here we show that human Mregs convert allogeneic CD4(+) T cells to IL-10-producing, TIGIT(+) FoxP3(+)-induced regulatory T cells that non-specifically suppress bystander T cells and inhibit dendritic cell maturation. Differentiation of Mreg-induced Tregs relies on multiple non-redundant mechanisms that are not exclusive to interaction of Mregs and T cells, including signals mediated by indoleamine 2,3-dioxygenase, TGF-beta, retinoic acid, Notch and progestagen-associated endometrial protein. Preoperative administration of donor-derived Mregs to living-donor kidney transplant recipients results in an acute increase in circulating TIGIT(+) Tregs. These results suggest a feed-forward mechanism by which Mreg treatment promotes allograft acceptance through rapid induction of direct-pathway Tregs. KW - Allotransplantation KW - Immunosuppression KW - Monocytes and macrophages KW - Regulatory T cells Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226321 VL - 9 IS - 9 ER - TY - JOUR A1 - Kleist, Christian A1 - Mohr, Elisabeth A1 - Gaikwad, Sadanand A1 - Dittmar, Laura A1 - Kuerten, Stefanie A1 - Platten, Michael A1 - Mier, Walter A1 - Schmitt, Michael A1 - Opelz, Gerhard A1 - Terness, Peter T1 - Autoantigen-specific immunosuppression with tolerogenic peripheral blood cells prevents relapses in a mouse model of relapsing-remitting multiple sclerosis JF - Journal of Translational Medicine N2 - Background: Dendritic cells (DCs) rendered suppressive by treatment with mitomycin C and loaded with the autoantigen myelin basic protein demonstrated earlier their ability to prevent experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis (MS). This provides an approach for prophylactic vaccination against autoimmune diseases. For clinical application such DCs are difficult to generate and autoantigens hold the risk of exacerbating the disease. Methods: We replaced DCs by peripheral mononuclear cells and myelin autoantigens by glatiramer acetate (Copaxone ®), a drug approved for the treatment of MS. Spleen cells were loaded with Copaxone®, incubated with mitomycin C (MICCop) and injected into mice after the first bout of relapsing-remitting EAE. Immunosuppression mediated by MICCop was investigated in vivo by daily assessment of clinical signs of paralysis and in in vitro restimulation assays of peripheral immune cells. Cytokine profiling was performed by enzyme-linked immunosorbent assay (ELISA). Migration of MICCop cells after injection was examined by biodistribution analysis of 111Indium-labelled MICCop. The number and inhibitory activity of CD4+CD25+FoxP3+ regulatory T cells were analysed by histology, flow cytometry and in vitro mixed lymphocyte cultures. In order to assess the specificity of MICCop-induced suppression, treated EAE mice were challenged with the control protein ovalbumin. Humoral and cellular immune responses were then determined by ELISA and in vitro antigen restimulation assay. Results: MICCop cells were able to inhibit the harmful autoreactive T-cell response and prevented mice from further relapses without affecting general immune responses. Administered MICCop migrated to various organs leading to an increased infiltration of the spleen and the central nervous system with CD4+CD25+FoxP3+ cells displaying a suppressive cytokine profile and inhibiting T-cell responses. Conclusion: We describe a clinically applicable cell therapeutic approach for controlling relapses in autoimmune encephalomyelitis by specifically silencing the deleterious autoimmune response. KW - Autoimmunity KW - Cell therapy KW - Copaxone® KW - Immune tolerance KW - Mitomycin C KW - Relapsing-remitting MS KW - Regulatory T cells Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165787 VL - 14 IS - 99 ER - TY - JOUR A1 - Prelog, Martina A1 - Schönlaub, Jörn A1 - Würzner, Reinhard A1 - Koppelstaetter, Christian A1 - Almanzar, Giovanni A1 - Brunner, Andrea A1 - Gasser, Martin A1 - Prommegger, Rupert A1 - Häusler, Gabriele A1 - Kapelari, Klaus A1 - Högler, Wolfgang T1 - Lower CD28+ T cell proportions were associated with CMV-seropositivity in patients with Hashimoto’s thyroiditis JF - BMC Endocrine Disorders N2 - Background Alterations in the naive T cell subpopulations have been demonstrated in patients with T cell mediated autoimmune disorders, reminiscent of immunological changes found in the elderly during immunosenescence, including the switch from CD45RA + to CD45RO + T cells and decreased thymic function with increased compensatory proliferative mechanisms, partly associated with latent Cytomegalovirus (CMV) infection. The present study was aimed to investigate proportions of lymphocytes, their relation to CMV-seropositivity and the replicative history of CD45RA + expressing T cells in Hashimoto’s thyroiditis (HT, n = 18) and healthy controls (HC, n = 70). Methods Proportions of peripheral T cells were investigated by flow cytometry. The replicative history was assessed by T cell receptor excision circles (TRECs) and relative telomere length (RTL). Expression of CD62L was analyzed by immunohistochemistry in thyroid sections. The role of CMV was assessed by serology, ELISPOT assay and in situ hybridization. Results Our results demonstrated a significant increase of CD28-negative T cells, associated with CMV-seropositivity in HT patients. HT showed abundant CD45RO + T cells with peripheral loss of CD62L-expressing CD8 + CD45RA + T cells, the latter mainly depending on disease duration. CD62L was expressed in thyroid lymphocyte infiltrations. The diagnosis of HT and within the HT group CMV-seropositivity were the main determinants for the loss of CD28 expression. RTL was not different between HC and HT. HT showed significantly lower TRECs in CD4 + CD45RA + T cells compared to HC. Conclusions Patients with HT display a peripheral T cell phenotype reminiscent of findings in elderly persons or other autoimmune disorders. Whether these mechanisms are primary or secondary to the immunological alterations of autoimmune conditions should be investigated in longitudinal studies which may open research on new therapeutic regimes for treatment of HT and associated autoimmune diseases. KW - Immunosenescence KW - CD62L KW - Regulatory T cells KW - TREC KW - Telomere Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96352 UR - http://www.biomedcentral.com/1472-6823/13/34 ER - TY - THES A1 - Yu-Hwa, Huang T1 - The Role of HLA-G-expressing Regulatory T cells in Multiple Sclerosis: A Perspective of Beneficial Inflammation in the Central Nervous System Inflammation T1 - Die Rolle HLA-G-exprimierender regulatorischer T-Zellen in multipler Sklerose: Möglichkeit einer hilfreichen Entzündung bei Entzündungserkrankung des zentralen Nervensystems N2 - Die Regulation von Effektor-T-Zellen ist ein wichtiger Mechanismus zur Kontrolle organspezifischer Entzündungen. Dabei sind regulatorische T-Zellen (Treg) maßgeblich an der Aufrechterhaltung peripherer Immuntoleranz und parenchymaler Immunhomöostase beteiligt. Eine neue Population von humanen, natürlich vorkommenden Treg Zellen wurde durch ihre konstitutive Expression des immuntolerogenen Moleküls HLA-G identifiziert. Im ersten Teil dieser Arbeit wurden die Mechanismen, durch die CD4+ HLA-Gpos Treg Zellen ihre Zielzellen (autologe HLA-Gneg T-Zellen) modulieren, aufgeklärt. Unter Verwendung eines Suppressionsansatzes in Abwesenheit von antigenpräsentierenden Zellen (APC) wurden T-T-Zell-Interaktionen, die die Proliferation von HLA-Gneg T-Zellen hemmen, demonstriert. Diese Suppression, die durch die Stimulierung des T-Zell-Rezeptors auf HLA-Gpos Treg Zellen verstärkt wurde, war unabhängig vom Zell-Zell-Kontakt. Die HLA-Gneg T-Zellen erlangten nach Entfernung der HLA-Gpos Treg Zellen und einer erneuten Stimulierung ihrer T-Zell- Rezeptoren ihre Fähigkeit zur Proliferation wieder. Dies wies auf die Umkehrbarkeit dieser Suppression hin. Darüber hinaus war die HLA-Gpos Treg-vermittelte Suppression entscheidend von der IL-10- Sekretion, nicht jedoch von TGF-β abhängig. Zusammengefasst beschreibt dieser Teil der Arbeit eine detaillierte Charakterisierung der Mechanismen, wie HLA-Gpos Treg HLA-Gneg TZellen supprimieren. Das tiefere Verständnis der Wirkmechanismen von HLA-Gpos Treg könnte in therapeutischen Strategien verwendet werden, in denen die regulatorische Funktion der T-Zell-Suppression verstärkt oder moduliert werden soll. Im zweiten Teil dieser Arbeit wurde die potenzielle Rolle von HLA-Gpos Treg bei der Multiplen Sklerose (MS) untersucht, einer klassischen Autoimmunerkrankung des Zentralnervensystems (ZNS). Im Gegensatz zu Vergleichspatienten mit nicht-entzündlichen Erkrankungen konnte im Liquor von MS Patienten eine erhöhte Anzahl von HLA-Gpos Treg gefunden werden. Diese aus dem Liquor isolierten HLA-Gpos Treg wiesen phänotypische Merkmale von zentralen Gedächtnis-T-Zellen (CD45RA- CD27+) auf, exprimierten den Aktivierungsmarker ICOS sowie deutlich höhere Level des Chemokinrezeptors (CCR) CCR5 und agierten als starke Suppressoren der autologen CD4+ T-Zellproliferation. Durch Verwendung eines in vitro Modells der humanen Bluthirnschranke konnte demonstriert werden, dass HLA-Gpos Treg eine starke Neigung zur Migration haben, die durch die CCR5- Liganden MIP1α und RANTES, nicht jedoch durch MIP3β (Ligand von CCR7) unterstützt wird. Diese Chemokin-induzierte Migration von HLA-Gpos Treg war auch mit einer Steigerung der suppressiven Kapazität nach Zelltransmigration assoziiert. Im Gegensatz zu CD4+CD25+, FoxP3-exprimierenden Treg zeigten HLA-Gpos Treg von MS-Patienten keine beeinträchtigte Funktionalität. Dies deutet auf eine selektive Rekrutierung von HLA-Gpos Treg zu Entzündungsherden im ZNS und ihre Beteiligung an der Bekämpfung der destruktiven Entzündung hin. Die Ergebnisse dieser Studien tragen zum weitergehenden Verständnis der Rolle und Funktion HLA-Gpos Treg Zellen bei und stellen somit ein wichtiges pathophysiologisches Beispiel „gutartiger“ T-Zell-Entzündung während der ZNS Autoimmunität dar, das sowohl aus pathophysiologischer als auch therapeutischer Sicht interessant ist. N2 - Regulation of effector T cells is an important mechanism to control organ-specific inflammation. Thereby regulatory T cells (Treg cells) are essential for maintaining peripheral immune tolerance and for establishing parenchyma immune homeostasis. A novel population of natural human Treg characterized by the constitutive expression of the immune-tolerogenic human HLA-G molecule has been identified. In the first part of the study, we elucidated the mechanism(s) by which CD4+ HLA-Gpos Treg modulates their cellular targets namely autologous HLA-G negative responder T cells (HLAGneg Tresp). Using a suppression system free of antigen-presenting cells (APC), we demonstrate a T-T cell interaction resulting in suppression of HLA-Gneg Tresp. We could also show that this suppression was independent of cell-cell contact. Importantly, stimulus of T cell receptor (TCR) on HLA-Gpos Treg facilitated their suppressive capacity. We also observed that removal of HLA-Gpos Treg from the established co-cultures could restore the ability of HLA-Gneg Tresp to proliferate upon TCR re-stimulation, indicating that the suppression was reversible. Further, HLA-Gpos Treg–mediated suppression was critically depending on the secretion of IL-10 but not TGF-β. Taken together, this part of the work provides an in-depth characterization of the mechanisms of how HLA-Gpos Treg suppresses T responder cells in direct T-T interactions. Understanding the suppressive mechanism used by HLA-Gpos Treg may help to develop therapeutic strategies to modulate regulatory arms of T-cell suppression. In the second part of this study, the potential role of HLA-Gpos Treg in the pathophysiological process of Multiple Sclerosis (MS), a prototypic autoimmune inflammatory central nervous system (CNS), has been investigated. We found that HLA-Gpos Treg are enriched in the cerebrospinal fluid (CSF) from MS patients, but not in non-inflammatory controls. CSFderived HLA-Gpos Treg showed predominance of central memory (CD45RA-CD27+) phenotype, exhibited markers of activation (ICOS), and had significantly higher expression of the inflammatory chemokine receptor CCR5. Importantly, these cells demonstrated as potent suppressors to autologous CD4+ T-cell proliferation. Using an in vitro model of human blood brain barrier, we showed that HLA-Gpos Treg have a strong propensity to migrate, which could be facilitated by MIP1α and RANTES (ligands of CCR5) but not MIP3β (a ligand of CCR7). The HLA-Gpos Treg migration triggered by chemokines was also associated with a gain of suppressive capacity upon cellular transmigration. In contrast to CD4+CD25+ naturally occurring FoxP3-expressing Treg, HLA-Gpos Treg from patients with MS did not exhibit impaired function, suggesting that HLA-Gpos Treg are selectively recruited to the sites of CNS inflammation in an effort to combat destructive inflammation during MS. Our results contribute to the understanding of the role and function of HLA-Gpos Treg and provide an important example of “beneficial” T-cell inflammation in CNS autoimmunity- interesting both from a patho/-physiological and a therapeutically point of view. KW - Regulatorische T-Zellen KW - Multiplen Sklerose KW - HLA-G KW - Zentralnervensystems KW - Chemokinrezeptors KW - Regulatory T cells KW - Multiple Sclerosis KW - HLA-G KW - Central Nervous System KW - Chemokine Receptor Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39957 ER -