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1.
J Autoimmun ; 103: 102289, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31176558

RESUMO

Adoptive immunotherapy with ex vivo expanded, polyspecific regulatory T cells (Tregs) is a promising treatment for graft-versus-host disease. Animal transplantation models used by us and others have demonstrated that the adoptive transfer of allospecific Tregs offers greater protection from graft rejection than that of polyclonal Tregs. This finding is in contrast to those of autoimmune models, where adoptive transfer of polyspecific Tregs had very limited effects, while antigen-specific Tregs were promising. However, antigen-specific Tregs in autoimmunity cannot be isolated in sufficient numbers. Chimeric antigen receptors (CARs) can modify T cells and redirect their specificity toward needed antigens and are currently clinically used in leukemia patients. A major benefit of CAR technology is its "off-the-shelf" usability in a translational setting in contrast to major histocompatibility complex (MHC)-restricted T cell receptors. We used CAR technology to redirect T cell specificity toward insulin and redirect T effector cells (Teffs) to Tregs by Foxp3 transduction. Our data demonstrate that our converted, insulin-specific CAR Tregs (cTregs) were functional stable, suppressive and long-lived in vivo. This is a proof of concept for both redirection of T cell specificity and conversion of Teffs to cTregs.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Células Cultivadas , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Fatores de Transcrição Forkhead , Engenharia Genética , Humanos , Insulina/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Especificidade do Receptor de Antígeno de Linfócitos T , Linfócitos T Reguladores/transplante
2.
Dig Dis ; 36(2): 156-166, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29020680

RESUMO

For the development of autoimmune hepatitis (AIH), genetic predisposition and environmental triggers are of major importance. Although experimental AIH can be induced in genetically susceptible mice, the low precursor frequency of autoreactive T cells hampers a deeper analysis of liver-specific T cells. Here, we established a system where the model antigen hemagglutinin (HA) is expressed exclusively in hepatocytes of Rosa26-HA mice following administration of a replication deficient adenovirus expressing Cre recombinase (Ad-Cre). Under these conditions, hepatocytes mimic the generation of altered-self neoantigens. To follow autoreactive T cells during AIH, we adoptively transferred HA--specific Cl4-TCR and 6.5-TCR T cells into Ad-Cre infected -Rosa26-HA mice. Alternatively, Rosa26-HA mice have been crossed with TCR transgenic mice that were infected with Ad-Cre to break hepatic tolerance and induce the expression of the HA antigen as a hepatic self-antigen. Surprisingly, neither adoptive transfer nor a very high precursor frequency of autoreactive T cells was able to break tolerance in the context of adenoviral infection. The low proliferation of the antigen experienced autoreactive T cells despite the presence of the autoantigen and inflammation points to anergy as a potential tolerance mechanism. This model underscores the crucial importance of genetic susceptibility to break tolerance against hepatic autoantigens.


Assuntos
Tolerância Imunológica , Inflamação/imunologia , Inflamação/patologia , Fígado/imunologia , Fígado/patologia , Linfócitos T/imunologia , Adenoviridae/metabolismo , Transferência Adotiva , Animais , Autoantígenos/imunologia , Proliferação de Células , Anergia Clonal , Modelos Animais de Doenças , Hepatite Autoimune/imunologia , Ativação Linfocitária/imunologia , Camundongos Transgênicos , Especificidade de Órgãos , Reprodutibilidade dos Testes
3.
J Autoimmun ; 78: 39-45, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27974250

RESUMO

Autoimmune hepatitis (AIH) is defined as a chronic liver inflammation with loss of tolerance against hepatocytes. The etiology and pathophysiology of AIH are still poorly understood because reliable animal models are limited. Therefore, we recently introduced a model of experimental murine AIH by a self-limited adenoviral infection with the AIH type 2 antigen formiminotransferase cyclodeaminase (FTCD). We could demonstrate that break of humoral tolerance towards liver specific autoantigens like FTCD and cytochrome P450 2D6 (CYP2D6) is not dependent on the genetic background. However, the development of AIH in autoantibody positive animals is determined by genetic background genes. We could also show that the break of humoral tolerance is necessary but not sufficient for the development of AIH. In contrast the break of tolerance against the ubiquitously expressed nuclear antigens (ANAs) is strictly dependent on genetic predisposition. Priming with the UGA suppressor tRNA-associated protein (soluble liver antigen; SLA) is a strong inducer of ANA reactivity, but not sufficient to cause AIH development thereby questioning the importance of anti-SLA immune response as an important driver in AIH. Monogenetic mutations such as Aire-deficiency can cause AIH in otherwise genetically resistant strains. CONCLUSION: The results have important implications for our understanding of the pathophysiology of AIH development and for the interpretation of humoral antibody responses in AIH.


Assuntos
Autoantígenos/imunologia , Autoimunidade/genética , Predisposição Genética para Doença , Hepatite Autoimune/etiologia , Animais , Citocromo P-450 CYP2D6/genética , Modelos Animais de Doenças , Meio Ambiente , Hepatite Autoimune/metabolismo , Hepatite Autoimune/patologia , Humanos , Soros Imunes/imunologia , Tolerância Imunológica , Imunidade Humoral , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Transgênicos , Mutação
4.
Blood ; 117(3): 1030-41, 2011 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-21063028

RESUMO

Adoptive transfer (AT) of T cells forced to express tumor-reactive T-cell receptor (TCR) genes is an attractive strategy to direct autologous T-cell immunity against tumor-associated antigens. However, clinical effectiveness has been hampered by limited in vivo persistence. We investigated whether the use of major histocompatibility complex-mismatched T cells would prolong the in vivo persistence of tumor-reactive TCR gene expressing T cells by continuous antigen-driven proliferation via the endogenous potentially alloreactive receptor. Donor-derived CD8(+) T cells engineered to express a TCR against a leukemia-associated antigen mediated strong graft-versus-leukemia (GVL) effects with reduced graft-versus-host disease (GVHD) severity when given early after transplantation. AT later after transplantation resulted in a complete loss of GVL. Loss of function was associated with reduced expansion of TCR-transduced T cells as assessed by CDR3 spectratyping analysis and PD-1 up-regulation on T cells in leukemia-bearing recipients. PD-L1 blockade in allogeneic transplant recipients largely restored the GVL efficacy without triggering GVHD, whereas no significant antileukemia effects of PD-L1 blockade were observed in syngeneic controls. These data suggest a clinical approach in which the AT of gene-modified allogeneic T cells early after transplantation can provide a potent GVL effect without GVHD, whereas later AT is effective only with concurrent PD-L1 blockade.


Assuntos
Antígeno B7-1/imunologia , Linfócitos T CD8-Positivos/imunologia , Efeito Enxerto vs Leucemia/imunologia , Glicoproteínas de Membrana/imunologia , Peptídeos/imunologia , Transferência Adotiva/métodos , Sequência de Aminoácidos , Animais , Antígeno B7-1/metabolismo , Antígeno B7-H1 , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/transplante , Linhagem Celular Tumoral , Citometria de Fluxo , Sobrevivência de Enxerto/imunologia , Doença Enxerto-Hospedeiro/imunologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Leucemia Experimental/imunologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Peptídeos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Fatores de Tempo , Transfecção , Transplante Homólogo , Transplante Isogênico
5.
Hepatol Commun ; 6(2): 320-333, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34532981

RESUMO

Nonalcoholic steatohepatitis (NASH) is induced by steatosis and metabolic inflammation. While involvement of the innate immune response has been shown, the role of the adaptive immune response in NASH remains controversial. Likewise, the role of regulatory T cells (Treg) in NASH remains unclear although initial clinical trials aim to target these regulatory responses. High-fat high-carbohydrate (HF-HC) diet feeding of NASH-resistant BALB/c mice as well as the corresponding recombination activating 1 (Rag)-deficient strain was used to induce NASH and to study the role of the adaptive immune response. HF-HC diet feeding induced strong activation of intrahepatic T cells in BALB/c mice, suggesting an antigen-driven effect. In contrast, the effects of the absence of the adaptive immune response was notable. NASH in BALB/c Rag1-/- mice was substantially worsened and accompanied by a sharp increase of M1-like macrophage numbers. Furthermore, we found an increase in intrahepatic Treg numbers in NASH, but either adoptive Treg transfer or anti-cluster of differentiation (CD)3 therapy unexpectedly increased steatosis and the alanine aminotransferase level without otherwise affecting NASH. Conclusion: Although intrahepatic T cells were activated and marginally clonally expanded in NASH, these effects were counterbalanced by increased Treg numbers. The ablation of adaptive immunity in murine NASH led to marked aggravation of NASH, suggesting that Tregs are not regulators of metabolic inflammation but rather enhance it.


Assuntos
Hepatopatia Gordurosa não Alcoólica/imunologia , Linfócitos T Reguladores/fisiologia , Imunidade Adaptativa , Transferência Adotiva , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Complexo CD3/imunologia , Dieta da Carga de Carboidratos , Dieta Hiperlipídica , Modelos Animais de Doenças , Progressão da Doença , Fatores Imunológicos/uso terapêutico , Inflamação/fisiopatologia , Camundongos Endogâmicos BALB C , Hepatopatia Gordurosa não Alcoólica/enzimologia , Hepatopatia Gordurosa não Alcoólica/fisiopatologia
6.
Blood ; 113(18): 4440-8, 2009 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-19182207

RESUMO

Antigen-presenting cells (APCs) of host origin drive graft-versus-leukemia (GVL) effects but can also trigger life-threatening graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) across major histocompatibility complex (MHC) barriers. We show that in vitro priming of donor lymphocytes can circumvent the need of recipient-derived APCs in vivo for mediating robust GVL effects and significantly diminishes the risk of severe GVHD. In vitro, generated and expanded T cells (ETCs) mediate anti-leukemia effects only when primed on recipient-derived APCs. Loading of APCs in vitro with leukemia cell lysate, chimerism status of the recipient, and timing of adoptive transfer after HCT are important factors determining the outcome. Delayed transfer of ETCs resulted in strong GVL effects in leukemia-bearing full chimera (FC) and mixed chimera (MC) recipients, which were comparable with the GVL/GVHD rates observed after the transfer of naive donor lymphocyte infusion (DLI). Upon early transfer, GVL effects were more pronounced with ETCs but at the expense of significant GVHD. The degree of GVHD was most severe in MCs after transfer of ETCs that had been in vitro primed either on nonpulsed recipient-derived APCs or with donor-derived APCs.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Leucemia/imunologia , Leucemia/imunologia , Complexo Principal de Histocompatibilidade , Linfócitos T/imunologia , Quimeras de Transplante/imunologia , Animais , Feminino , Citometria de Fluxo , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/metabolismo , Taxa de Sobrevida , Doadores de Tecidos
7.
Front Immunol ; 8: 748, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28702031

RESUMO

Regulatory T cells (Tregs) are critical for the maintenance of immune homeostasis and self-tolerance and can be therapeutically used for prevention of unwanted immune responses such as allotransplant rejection. Tregs are characterized by expression of the transcription factor Foxp3, and recent work suggests that epigenetic imprinting of Foxp3 and other Treg-specific epigenetic signatures genes is crucial for the stabilization of both Foxp3 expression and immunosuppressive properties within Tregs. Lately, vitamin C was reported to enhance the activity of enzymes of the ten-eleven translocation family, thereby fostering the demethylation of Foxp3 and other Treg-specific epigenetic signatures genes in developing Tregs. Here, we in vitro generated alloantigen-induced Foxp3+ Tregs (allo-iTregs) in presence of vitamin C. Although vitamin C hardly influenced the transcriptome of allo-iTregs as revealed by RNA-seq, those vitamin C-treated allo-iTregs showed a more pronounced demethylation of Foxp3 and other Treg-specific epigenetic signatures genes accompanied with an enhanced stability of Foxp3 expression. Accordingly, when being tested in vivo in an allogeneic skin transplantation model, vitamin C-treated allo-iTregs showed a superior suppressive capacity. Together, our results pave the way for the establishment of novel protocols for the in vitro generation of alloantigen-induced Foxp3+ Tregs for therapeutic use in transplantation medicine.

8.
Nat Med ; 17(5): 581-8, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21516086

RESUMO

Inflammatory cell recruitment after myocardial infarction needs to be tightly controlled to permit infarct healing while avoiding fatal complications such as cardiac rupture. Growth differentiation factor-15 (GDF-15), a transforming growth factor-ß (TGF-ß)-related cytokine, is induced in the infarcted heart of mice and humans. We show that coronary artery ligation in Gdf15-deficient mice led to enhanced recruitment of polymorphonuclear leukocytes (PMNs) into the infarcted myocardium and an increased incidence of cardiac rupture. Conversely, infusion of recombinant GDF-15 repressed PMN recruitment after myocardial infarction. In vitro, GDF-15 inhibited PMN adhesion, arrest under flow and transendothelial migration. Mechanistically, GDF-15 counteracted chemokine-triggered conformational activation and clustering of ß(2) integrins on PMNs by activating the small GTPase Cdc42 and inhibiting activation of the small GTPase Rap1. Intravital microscopy in vivo in Gdf15-deficient mice showed that Gdf-15 is required to prevent excessive chemokine-activated leukocyte arrest on the endothelium. Genetic ablation of ß(2) integrins in myeloid cells rescued the mortality of Gdf15-deficient mice after myocardial infarction. To our knowledge, GDF-15 is the first cytokine identified as an inhibitor of PMN recruitment by direct interference with chemokine signaling and integrin activation. Loss of this anti-inflammatory mechanism leads to fatal cardiac rupture after myocardial infarction.


Assuntos
Fator 15 de Diferenciação de Crescimento/fisiologia , Integrinas/fisiologia , Infarto do Miocárdio/fisiopatologia , Neutrófilos/fisiologia , Animais , Antígenos CD18/genética , Antígenos CD18/fisiologia , Adesão Celular , Movimento Celular , Fator 15 de Diferenciação de Crescimento/deficiência , Fator 15 de Diferenciação de Crescimento/genética , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/patologia , Células Mieloides/fisiologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Neutrófilos/patologia , Transdução de Sinais , Proteína cdc42 de Ligação ao GTP/fisiologia , Proteínas rap1 de Ligação ao GTP/fisiologia
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