RESUMO
Clinical studies suggested that endothelial dysfunction and damage could be involved in the development and severity of acute graft-versus-host disease (aGVHD). Accordingly, we found increased percentage of apoptotic Casp3+ blood vessels in duodenal and colonic mucosa biopsies of patients with severe aGVHD. In murine experimental aGVHD, we detected severe microstructural endothelial damage and reduced endothelial pericyte coverage accompanied by reduced expression of endothelial tight junction proteins leading to increased endothelial leakage in aGVHD target organs. During intestinal aGVHD, colonic vasculature structurally changed, reflected by increased vessel branching and vessel diameter. Because recent data demonstrated an association of endothelium-related factors and steroid refractory aGVHD (SR-aGVHD), we analyzed human biopsies and murine tissues from SR-aGVHD. We found extensive tissue damage but low levels of alloreactive T cell infiltration in target organs, providing the rationale for T-cell independent SR-aGVHD treatment strategies. Consequently, we tested the endothelium-protective PDE5 inhibitor sildenafil, which reduced apoptosis and improved metabolic activity of endothelial cells in vitro. Accordingly, sildenafil treatment improved survival and reduced target organ damage during experimental SR-aGVHD. Our results demonstrate extensive damage, structural changes, and dysfunction of the vasculature during aGVHD. Therapeutic intervention by endothelium-protecting agents is an attractive approach for SR-aGVHD complementing current anti-inflammatory treatment options.
Assuntos
Doença Enxerto-Hospedeiro , Animais , Células Endoteliais , Endotélio , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Humanos , Camundongos , Esteroides , Linfócitos TRESUMO
Lymph vessels play a crucial role in immune reactions in health and disease. In oncology the inhibition of lymphangiogenesis is an established therapeutic concept for reducing metastatic spreading of tumor cells. During allogeneic tissue transplantation, the inhibition of lymphangiogenesis has been successfully used to attenuate graft rejection. Despite its critical importance for tumor growth, alloimmune responses, and inflammation, the role of lymphangiogenesis has not been investigated during allogeneic hematopoietic stem cell transplantation (allo-HSCT). We found that acute graft-versus-host disease (aGVHD) is associated with lymphangiogenesis in murine allo-HSCT models as well as in patient intestinal biopsies. Inhibition of aGVHD-associated lymphangiogenesis by monoclonal antibodies against vascular endothelial growth factor receptor 3 (VEGFR-3) ameliorated aGVHD and improved survival in murine models. The administration of anti-VEGFR-3 antibodies did not interfere with hematopoietic engraftment and improved immune reconstitution in allo-HSCT recipients with aGVHD. Anti-VEGFR-3 therapy had no significant impact on growth of malignant lymphoma after allo-HSCT. We conclude that aGVHD is associated with lymphangiogenesis in intestinal lesions and in lymph nodes. Our data show that anti-VEGFR-3 treatment ameliorates lethal aGVHD and identifies the lymphatic vasculature as a novel therapeutic target in the setting of allo-HSCT.
Assuntos
Doença Enxerto-Hospedeiro/prevenção & controle , Linfangiogênese , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Anticorpos Monoclonais/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Enteropatias , Linfonodos/patologia , Camundongos , Transplante Homólogo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/imunologiaRESUMO
The inhibition of inflammation-associated angiogenesis ameliorates inflammatory diseases by reducing the recruitment of tissue-infiltrating leukocytes. However, it is not known if angiogenesis has an active role during the initiation of inflammation or if it is merely a secondary effect occurring in response to stimuli by tissue-infiltrating leukocytes. Here, we show that angiogenesis precedes leukocyte infiltration in experimental models of inflammatory bowel disease and acute graft-versus-host disease (GVHD). We found that angiogenesis occurred as early as day+2 after allogeneic transplantation mainly in GVHD typical target organs skin, liver, and intestines, whereas no angiogenic changes appeared due to conditioning or syngeneic transplantation. The initiation phase of angiogenesis was not associated with classical endothelial cell (EC) activation signs, such as Vegfa/VEGFR1+2 upregulation or increased adhesion molecule expression. During early GVHD at day+2, we found significant metabolic and cytoskeleton changes in target organ ECs in gene array and proteomic analyses. These modifications have significant functional consequences as indicated by profoundly higher deformation in real-time deformability cytometry. Our results demonstrate that metabolic changes trigger alterations in cell mechanics, leading to enhanced migratory and proliferative potential of ECs during the initiation of inflammation. Our study adds evidence to the hypothesis that angiogenesis is involved in the initiation of tissue inflammation during GVHD.
Assuntos
Doença Enxerto-Hospedeiro/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Neovascularização Patológica/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Doença Aguda , Aloenxertos , Animais , Modelos Animais de Doenças , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Camundongos , Camundongos Transgênicos , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
The NOD mouse strain spontaneously develops autoimmune diabetes. A deficiency in costimulatory molecules, such as B7-2, on the NOD genetic background prevents diabetes but instead triggers an inflammatory peripheral neuropathy. This constitutes a shift in the target of autoimmunity, but the underlying mechanism remains unknown. In this study, we demonstrate that NOD mice deficient for isoforms of ICAM-1, which comediate costimulatory functions, spontaneously develop a chronic autoimmune peripheral neuritis instead of diabetes. The disease is transferred by CD4(+) T cells, which infiltrate peripheral nerves together with macrophages and B cells and are autoreactive against peripheral myelin protein zero. These Icam1(tm1Jcgr)NOD mice exhibit unaltered numbers of regulatory T cells, but increased IL-17-producing T cells, which determine the severity, but not the target specificity, of autoimmunity. Ab-mediated ICAM-1 blockade triggers neuritis only in young NOD mice. Thymic epithelium from Icam1(tm1Jcgr)NOD mice features an altered expression of costimulatory molecules and induces neuritis and myelin autoreactivity after transplantation into nude mice in vivo. Icam1(tm1Jcgr)NOD mice exhibit a specifically altered TCR repertoire. Our findings introduce a novel animal model of chronic inflammatory neuropathies and indicate that altered expression of ICAM-1 on thymic epithelium shifts autoimmunity specifically toward peripheral nerves. This improves our understanding of autoimmunity in the peripheral nervous system with potential relevance for human diseases.
Assuntos
Diabetes Mellitus Tipo 1/imunologia , Molécula 1 de Adesão Intercelular/genética , Neurite Autoimune Experimental/genética , Neurite Autoimune Experimental/imunologia , Transferência Adotiva , Animais , Autoimunidade/imunologia , Linfócitos B/imunologia , Epitélio , Interleucina-17 , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína P0 da Mielina/imunologia , Bainha de Mielina/imunologia , Nervos Periféricos/imunologia , Nervos Periféricos/patologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Timo/citologiaRESUMO
The German Centre for Cardiovascular Research (DZHK) is one of the German Centres for Health Research and aims to conduct early and guideline-relevant studies to develop new therapies and diagnostics that impact the lives of people with cardiovascular disease. Therefore, DZHK members designed a collaboratively organised and integrated research platform connecting all sites and partners. The overarching objectives of the research platform are the standardisation of prospective data and biological sample collections among all studies and the development of a sustainable centrally standardised storage in compliance with general legal regulations and the FAIR principles. The main elements of the DZHK infrastructure are web-based and central units for data management, LIMS, IDMS, and transfer office, embedded in a framework consisting of the DZHK Use and Access Policy, and the Ethics and Data Protection Concept. This framework is characterised by a modular design allowing a high standardisation across all studies. For studies that require even tighter criteria additional quality levels are defined. In addition, the Public Open Data strategy is an important focus of DZHK. The DZHK operates as one legal entity holding all rights of data and biological sample usage, according to the DZHK Use and Access Policy. All DZHK studies collect a basic set of data and biosamples, accompanied by specific clinical and imaging data and biobanking. The DZHK infrastructure was constructed by scientists with the focus on the needs of scientists conducting clinical studies. Through this, the DZHK enables the interdisciplinary and multiple use of data and biological samples by scientists inside and outside the DZHK. So far, 27 DZHK studies recruited well over 11,200 participants suffering from major cardiovascular disorders such as myocardial infarction or heart failure. Currently, data and samples of five DZHK studies of the DZHK Heart Bank can be applied for.
Assuntos
Bancos de Espécimes Biológicos , Humanos , Estudos ProspectivosAssuntos
Citofagocitose , Doença Enxerto-Hospedeiro/patologia , Hemossiderose/etiologia , Doença Aguda , Animais , Ferritinas/sangue , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/mortalidade , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Ativação de Macrófagos , Camundongos , Estudos Retrospectivos , Análise de Sobrevida , Transplante HomólogoRESUMO
OBJECTIVE: To assess whether IV immunoglobulins (IVIgs) as a first-line treatment for chronic inflammatory demyelinating polyneuropathy (CIDP) have a regulative effect on natural killer (NK) cells that is related to clinical responsiveness to IVIg. METHODS: In a prospective longitudinal study, we collected blood samples of 29 patients with CIDP before and after initiation of IVIg treatment for up to 6 months. We used semiquantitative PCR and flow cytometry in the peripheral blood to analyze the effects of IVIg on the NK cells. The results were correlated with clinical aspects encompassing responsiveness. RESULTS: We found a reduction in the expression of several typical NK cell genes 1 day after IVIg administration. Flow cytometry furthermore revealed a reduced cytotoxic CD56dim NK cell population, whereas regulatory CD56bright NK cells remained mostly unaffected or were even increased after IVIg treatment. Surprisingly, the observed effects on NK cells almost exclusively occurred in IVIg-responsive patients with CIDP. CONCLUSIONS: The correlation between the altered NK cell population and treatment efficiency suggests a crucial role for NK cells in the still speculative mode of action of IVIg treatment. Analyzing NK cell subsets after 24 hours of treatment initiation appeared as a predictive marker for IVIg responsiveness. Further studies are warranted investigating the potential of NK cell status as a routine parameter in patients with CIDP before IVIg therapy. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that NK cell markers predict clinical response to IVIg in patients with CIDP.
Assuntos
Imunoglobulinas Intravenosas/farmacologia , Fatores Imunológicos/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Avaliação de Resultados em Cuidados de Saúde , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/sangue , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/tratamento farmacológico , Adulto , Idoso , Biomarcadores , Antígeno CD56 , Feminino , Humanos , Células Matadoras Naturais/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-IdadeRESUMO
Despite its involvement in various immune functions, including the allogeneic activation of T-lymphocytes, the relevance of calcium (Ca2+) for GVHD pathobiology is largely unknown. To elucidate a potential association between Ca2+and GVHD, we analyzed Ca2+-sensing G-protein coupled receptor 6a (GPRC6a) signaling in preclinical GVHD models and conducted a prospective EBMT study on Ca2+ serum levels prior alloSCT including 363 matched sibling allogeneic peripheral blood stem cell transplantations (alloSCTs). In experimental models, we found decreased Gprc6a expression during intestinal GVHD. GPRC6a deficient alloSCT recipients had higher clinical and histopathological GVHD scores leading to increased mortality. As possible underlying mechanism, we found increased antigen presentation potential in GPRC6a-/- alloSCT recipients demonstrated by higher proliferation rates of T-lymphocytes. In patients with low Ca2+ serum levels (≤median 2.2 mmol/l) before alloSCT, we found a higher incidence of acute GVHD grades II-IV (HR = 2.3 Cl = 1.45-3.85 p = 0.0006), severe acute GVHD grades III-IV (HR = 3.3 CI = 1.59-7.14, p = 0.002) and extensive chronic GVHD (HR = 2.0 Cl = 1.04-3.85 p = 0.04). In conclusion, experimental and clinical data suggest an association of reduced Ca2+ signaling with increased severity of GVHD. Future areas of interest include the in depth analysis of involved molecular pathways and the investigation of Ca2+ signaling as a therapeutic target during GVHD.
Assuntos
Sinalização do Cálcio , Suscetibilidade a Doenças , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/metabolismo , Animais , Biomarcadores , Cálcio/sangue , Modelos Animais de Doenças , Feminino , Doença Enxerto-Hospedeiro/diagnóstico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Imunofenotipagem , Incidência , Leucócitos/imunologia , Leucócitos/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Prognóstico , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Recidiva , Transplante HomólogoRESUMO
Angiogenesis and endothelial activation and dysfunction have been associated with acute graft-vs.-host disease (aGVHD), pointing to the endothelium as a potential target for pharmacological intervention. Defibrotide (DF) is a drug with an endothelium-protective effect that has been approved for the treatment of veno-occlusive disease/sinusoidal obstruction syndrome after allogeneic hematopoietic cell transplantation. Clinical data suggest that DF also reduces the incidence of aGVHD; however, the mechanisms of DF-mediated aGVHD regulation have not been examined. To investigate possible DF-mediated prophylactic and therapeutic mechanisms in aGVHD, we performed in vitro studies using endothelial cell (EC) lines. We found that DF significantly and dose-dependently suppressed EC proliferation and notably reduced their ability to form vascular tubes in Matrigel. To explore whether DF administered prophylactically or therapeutically has a significant effect on aGVHD endothelial dysfunction, ECs were exposed to media containing sera from patients with aGVHD (n = 22) in the absence or presence of DF and from patients that did not develop aGVHD (n = 13). ECs upregulated adhesion molecules (vascular cell adhesion molecule 1, intercellular adhesion molecule 1), the adherence junction protein VE-cadherin, von Willebrand factor (VWF), and Akt phosphorylation in response to aGVHD sera. These responses were suppressed upon treatment with DF. In summary, DF inhibits vascular angiogenesis and endothelial activation induced by sera from aGVHD patients. Our results support the view that DF has notable positive effects on endothelial biology during aGVHD.
Assuntos
Endotélio/metabolismo , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas , Células Endoteliais da Veia Umbilical Humana/metabolismo , Polidesoxirribonucleotídeos/administração & dosagem , Doença Aguda , Endotélio/patologia , Feminino , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/patologia , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , MasculinoRESUMO
Microbial products influence immunity after allogeneic hematopoietic stem cell transplantation (allo-SCT). In this context, the role of cathepsin E (Ctse), an aspartate protease known to cleave bacterial peptides for antigen presentation in dendritic cells (DCs), has not been studied. During experimental acute graft-versus-host disease (GVHD), we found infiltration by Ctse-positive immune cells leading to higher Ctse RNA- and protein levels in target organs. In Ctse-deficient allo-SCT recipients, we found ameliorated GVHD, improved survival, and lower numbers of tissue-infiltrating DCs. Donor T cell proliferation was not different in Ctse-deficient vs. wild-type allo-SCT recipients in MHC-matched and MHC-mismatched models. Furthermore, Ctse-deficient DCs had an intact ability to induce allogeneic T cell proliferation, suggesting that its role in antigen presentation may not be the main mechanism how Ctse impacts GVHD. We found that Ctse deficiency significantly decreases DC motility in vivo, reduces adhesion to extracellular matrix (ECM), and diminishes invasion through ECM. We conclude that Ctse has a previously unrecognized role in regulating DC motility that possibly contributes to reduced DC counts and ameliorated inflammation in GVHD target organs of Ctse-deficient allo-SCT recipients. However, our data do not provide definite proof that the observed effect of Ctse-/- deficiency is exclusively mediated by DCs. A contribution of Ctse-/--mediated functions in other recipient cell types, e.g., macrophages, cannot be excluded.
RESUMO
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disabling autoimmune disorder of the peripheral nervous system (PNS). Intravenous immunoglobulins (IVIg) are effective in CIDP, but the treatment response varies greatly between individual patients. Understanding this interindividual variability and predicting the response to IVIg constitute major clinical challenges in CIDP. We previously established intercellular adhesion molecule (ICAM)-1 deficient non-obese diabetic (NOD) mice as a novel animal model of CIDP. Here, we demonstrate that similar to human CIDP patients, ICAM-1 deficient NOD mice respond to IVIg treatment by clinical and histological measures. Nerve magnetic resonance imaging and histology demonstrated that IVIg ameliorates abnormalities preferentially in distal parts of the sciatic nerve branches. The IVIg treatment response also featured great heterogeneity allowing us to identify IVIg responders and non-responders. An increased production of interleukin (IL)-17 positively predicted IVIg treatment responses. In human sural nerve biopsy sections, high numbers of IL-17 producing cells were associated with younger age and shorter disease duration. Thus, our novel animal model can be utilized to identify prognostic markers of treatment responses in chronic inflammatory neuropathies and we identify IL-17 production as one potential such prognostic marker.
Assuntos
Imunoglobulinas Intravenosas/farmacologia , Neurite (Inflamação)/tratamento farmacológico , Animais , Doença Crônica , Modelos Animais de Doenças , Feminino , Imunoglobulinas Intravenosas/uso terapêutico , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-17/biossíntese , Interleucina-17/sangue , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos NOD , Neurite (Inflamação)/diagnóstico por imagem , Neurite (Inflamação)/metabolismo , Neurite (Inflamação)/patologia , Nervo Sural/diagnóstico por imagem , Nervo Sural/efeitos dos fármacos , Nervo Sural/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Resultado do TratamentoRESUMO
Inflammatory neuropathies represent disabling human autoimmune disorders with considerable disease variability. Animal models provide insights into defined aspects of their disease pathogenesis. Forkhead box P3 (FoxP3)+ regulatory T lymphocytes (Treg) are anti-inflammatory cells that maintain immune tolerance and counteract tissue damage in a variety of immune-mediated disorders. Dysfunction or a reduced frequency of Tregs have been associated with different human autoimmune disorders. We here analyzed the functional relevance of Tregs in determining disease manifestation and severity in murine models of autoimmune neuropathies. We took advantage of the DEREG mouse system allowing depletion of Treg with high specificity as well as anti-CD25 directed antibodies to deplete Tregs in mice in actively induced experimental autoimmune neuritis (EAN). Furthermore antibody-depletion was performed in an adoptive transfer model of chronic neuritis. Early Treg depletion increased clinical EAN severity both in active and adoptive transfer chronic neuritis. This was accompanied by increased proliferation of myelin specific T cells and histological signs of peripheral nerve inflammation. Late stage Treg depletion after initial disease manifestation however did not exacerbate inflammatory neuropathy symptoms further. We conclude that Tregs determine disease severity in experimental autoimmune neuropathies during the initial priming phase, but have no major disease modifying function after disease manifestation. Potential future therapeutic approaches targeting Tregs should thus be performed early in inflammatory neuropathies.