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1.
Nat Commun ; 12(1): 5074, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417463

RESUMO

ß cells may participate and contribute to their own demise during Type 1 diabetes (T1D). Here we report a role of their expression of Tet2 in regulating immune killing. Tet2 is induced in murine and human ß cells with inflammation but its expression is reduced in surviving ß cells. Tet2-KO mice that receive WT bone marrow transplants develop insulitis but not diabetes and islet infiltrates do not eliminate ß cells even though immune cells from the mice can transfer diabetes to NOD/scid recipients. Tet2-KO recipients are protected from transfer of disease by diabetogenic immune cells.Tet2-KO ß cells show reduced expression of IFNγ-induced inflammatory genes that are needed to activate diabetogenic T cells. Here we show that Tet2 regulates pathologic interactions between ß cells and immune cells and controls damaging inflammatory pathways. Our data suggests that eliminating TET2 in ß cells may reduce activating pathologic immune cells and killing of ß cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 1/patologia , Inflamação/patologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Proteínas Proto-Oncogênicas/metabolismo , Animais , Sequência de Bases , Citotoxicidade Imunológica , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Progressão da Doença , Feminino , Humanos , Imunidade , Inflamação/genética , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Linfócitos T/imunologia , Transcrição Genética
2.
JCI Insight ; 2(21)2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-29093268

RESUMO

The microbiome affects development and activity of the immune system, and may modulate immune therapies, but there is little direct information about this control in vivo. We studied how the microbiome affects regulation of human immune cells in humanized mice. When humanized mice were treated with a cocktail of 4 antibiotics, there was an increase in the frequency of effector T cells in the gut wall, circulating levels of IFN-γ, and appearance of anti-nuclear antibodies. Teplizumab, a non-FcR-binding anti-CD3ε antibody, no longer delayed xenograft rejection. An increase in CD8+ central memory cells and IL-10, markers of efficacy of teplizumab, were not induced. IL-10 levels were only decreased when the mice were treated with all 4 but not individual antibiotics. Antibiotic treatment affected CD11b+CD11c+ cells, which produced less IL-10 and IL-27, and showed increased expression of CD86 and activation of T cells when cocultured with T cells and teplizumab. Soluble products in the pellets appeared to be responsible for the reduced IL-27 expression in DCs. Similar changes in IL-10 induction were seen when human peripheral blood mononuclear cells were cultured with human stool samples. We conclude that changes in the microbiome may impact the efficacy of immunosuppressive medications by altering immune regulatory pathways.


Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Microbioma Gastrointestinal/imunologia , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Imunidade Adaptativa/imunologia , Animais , Anticorpos Antinucleares , Anticorpos Monoclonais Humanizados/farmacologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/microbiologia , Antígeno B7-2/metabolismo , Antígeno CD11b , Antígeno CD11c , Complexo CD3 , Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Trato Gastrointestinal/microbiologia , Rejeição de Enxerto/imunologia , Humanos , Imunossupressores/farmacologia , Imunoterapia , Interferon gama , Interleucina-10/metabolismo , Interleucina-27/metabolismo , Camundongos , Camundongos Knockout , Membrana Mucosa/imunologia , Fator de Transcrição STAT5/metabolismo , Transplante de Pele , Linfócitos T/imunologia , Transplante Heterólogo
3.
Clin Immunol ; 183: 240-246, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28739191

RESUMO

Oral administration of biologics may be a feasible approach for immune therapy that improves drug safety and potentiates mechanisms of tolerance at mucosal barriers. We tested the ability of a fully human non-FcR binding anti-CD3 mAb, foralumab, to prevent skin xenograft rejection in mice with human immune systems. At an intragastric dose of 15µg, the drug could transit through the small bowel. Serum absorption and binding of lymphoid cells was seen and proliferative responses of splenic CD8+ T cells to mitogen were reduced. Five consecutive daily doses, then weekly dosing led to indefinite graft acceptance without depletion of peripheral T cells. Proliferative and cytokine responses to activation of splenocytes with PHA were reduced. The serum levels of IL-10 but not TNF were increased 6days after application of the skin graft. Oral treatment with anti-CD3 mAb may represent a feasible approach for immune modulation.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Complexo CD3/imunologia , Complexo CD3/metabolismo , Rejeição de Enxerto/prevenção & controle , Transplante de Pele , Administração Oral , Animais , Proliferação de Células , Humanos , Camundongos , Linfócitos T
4.
Cell Metab ; 25(3): 727-738, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28190773

RESUMO

Type 1 diabetes (T1D) is a chronic autoimmune disease that involves immune-mediated destruction of ß cells. How ß cells respond to immune attack is unknown. We identified a population of ß cells during the progression of T1D in non-obese diabetic (NOD) mice that survives immune attack. This population develops from normal ß cells confronted with islet infiltrates. Pathways involving cell movement, growth and proliferation, immune responses, and cell death and survival are activated in these cells. There is reduced expression of ß cell identity genes and diabetes antigens and increased immune inhibitory markers and stemness genes. This new subpopulation is resistant to killing when diabetes is precipitated with cyclophosphamide. Human ß cells show similar changes when cultured with immune cells. These changes may account for the chronicity of the disease and the long-term survival of ß cells in some patients.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/patologia , Animais , Anticorpos Monoclonais/farmacologia , Complexo CD3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Células Cultivadas , Feminino , Humanos , Imunoterapia , Células Secretoras de Insulina/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Camundongos Endogâmicos NOD , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Transcrição Genética/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
5.
J Biol Chem ; 291(21): 11230-40, 2016 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-26994137

RESUMO

Type 1 diabetes mellitus is caused by the killing of insulin-producing ß cells by CD8+T cells. The disease progression, which is chronic, does not follow a course like responses to conventional antigens such as viruses, but accelerates as glucose tolerance deteriorates. To identify the unique features of the autoimmune effectors that may explain this behavior, we analyzed diabetogenic CD8+ T cells that recognize a peptide from the diabetes antigen IGRP (NRP-V7-reactive) in prediabetic NOD mice and compared them to others that shared their phenotype (CD44(+)CD62L(lo)PD-1(+)CXCR3(+)) but negative for diabetes antigen tetramers and to LCMV (lymphocytic choriomeningitis)-reactive CD8+ T cells. There was an increase in the frequency of the NRP-V7-reactive cells coinciding with the time of glucose intolerance. The T cells persisted in hyperglycemic NOD mice maintained with an insulin pellet despite destruction of ß cells. We compared gene expression in the three groups of cells compared with the other two subsets of cells, and the NRP-V7-reactive cells exhibited gene expression of memory precursor effector cells. They had reduced cellular proliferation and were less dependent on oxidative phosphorylation. When prediabetic NOD mice were treated with 2-deoxyglucose to block aerobic glycolysis, there was a reduction in the diabetes antigen versus other cells of similar phenotype and loss of lymphoid cells infiltrating the islets. In addition, treatment of NOD mice with 2-deoxyglucose resulted in improved ß cell granularity. These findings identify a link between metabolic disturbances and autoreactive T cells that promotes development of autoimmune diabetes.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diabetes Mellitus Tipo 1/genética , Animais , Insulina , Ilhotas Pancreáticas/imunologia , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Estado Pré-Diabético/imunologia
6.
Diabetologia ; 59(5): 1021-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26910463

RESUMO

AIMS/HYPOTHESIS: Type 1 diabetes is caused by the immunological destruction of pancreatic beta cells. Preclinical and clinical data indicate that there are changes in beta cell function at different stages of the disease, but the fate of beta cells has not been closely studied. We studied how immune factors affect the function and epigenetics of beta cells during disease progression and identified possible triggers of these changes. METHODS: We studied FACS sorted beta cells and infiltrating lymphocytes from NOD mouse and human islets. Gene expression was measured by quantitative real-time RT-PCR (qRT-PCR) and methylation of the insulin genes was investigated by high-throughput and Sanger sequencing. To understand the role of DNA methyltransferases, Dnmt3a was knocked down with small interfering RNA (siRNA). The effects of cytokines on methylation and expression of the insulin gene were studied in humans and mice. RESULTS: During disease progression in NOD mice, there was an inverse relationship between the proportion of infiltrating lymphocytes and the beta cell mass. In beta cells, methylation marks in the Ins1 and Ins2 genes changed over time. Insulin gene expression appears to be most closely regulated by the methylation of Ins1 exon 2 and Ins2 exon 1. Cytokine transcription increased with age in NOD mice, and these cytokines could induce methylation marks in the insulin DNA by inducing methyltransferases. Similar changes were induced by cytokines in human beta cells in vitro. CONCLUSIONS/INTERPRETATION: Epigenetic modification of DNA by methylation in response to immunological stressors may be a mechanism that affects insulin gene expression during the progression of type 1 diabetes.


Assuntos
Metilação de DNA/genética , DNA/genética , Células Secretoras de Insulina/metabolismo , Insulina/genética , Adulto , Animais , Citocinas , Diabetes Mellitus Tipo 1 , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD
7.
Diabetes ; 65(5): 1310-6, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26718498

RESUMO

There is an ongoing need to develop strategic combinations of therapeutic agents to prevent type 1 diabetes (T1D) or to preserve islet ß-cell mass in new-onset disease. Although clinical trials using candidate therapeutics are commonly based on preclinical studies, concern is growing regarding the reproducibility as well as the potential clinical translation of reported results using animal models of human disorders. In response, the National Institutes of Health Immune Tolerance Network and JDRF established a multicenter consortium of academic institutions designed to assess the efficacy and intergroup reproducibility of clinically applicable immunotherapies for reversing new-onset disease in the NOD mouse model of T1D. Predicated on prior studies, this consortium conducted coordinated, prospective studies, using joint standard operating procedures, fixed criteria for study entry, and common reagents, to optimize combined anti-CD3 treatment plus interleukin-1 (IL-1) blockade to reverse new-onset disease in NOD mice. We did not find that IL-1 blockade with anti-IL-1ß monoclonal antibody or IL-1trap provided additional benefit for reversing new-onset disease compared with anti-CD3 treatment alone. These results demonstrate the value of larger, multicenter preclinical studies for vetting and prioritizing therapeutics for future clinical use.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Doenças Autoimunes/tratamento farmacológico , Complexo CD3/química , Diabetes Mellitus Tipo 1/tratamento farmacológico , Células Secretoras de Insulina/efeitos dos fármacos , Insulina/metabolismo , Interleucina-1beta/antagonistas & inibidores , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/uso terapêutico , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Pesquisa Biomédica/métodos , Complexo CD3/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Esquema de Medicação , Quimioterapia Combinada , Feminino , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Imunoterapia/métodos , Secreção de Insulina , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Proteína Acessória do Receptor de Interleucina-1/antagonistas & inibidores , Proteína Acessória do Receptor de Interleucina-1/metabolismo , Interleucina-1beta/metabolismo , Camundongos Endogâmicos NOD , Estudos Multicêntricos como Assunto , Projetos Piloto , Receptores Tipo I de Interleucina-1/antagonistas & inibidores , Receptores Tipo I de Interleucina-1/metabolismo , Proteínas Recombinantes de Fusão/uso terapêutico , Reprodutibilidade dos Testes , Projetos de Pesquisa , Organismos Livres de Patógenos Específicos , Estados Unidos
8.
J Clin Invest ; 125(11): 4212-22, 2015 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-26524592

RESUMO

FOXP3+ Tregs are central for the maintenance of self-tolerance and can be defective in autoimmunity. In multiple sclerosis and type-1 diabetes, dysfunctional self-tolerance is partially mediated by a population of IFNγ-secreting Tregs. It was previously reported that increased NaCl concentrations promote the induction of proinflammatory Th17 cells and that high-salt diets exacerbate experimental models of autoimmunity. Here, we have shown that increasing NaCl, either in vitro or in murine models via diet, markedly impairs Treg function. NaCl increased IFNγ secretion in Tregs, and reducing IFNγ - either by neutralization with anti-IFNγ antibodies or shRNA-mediated knockdown - restored suppressive activity in Tregs. The heightened IFNγ secretion and loss of Treg function were mediated by the serum/glucocorticoid-regulated kinase (SGK1). A high-salt diet also impaired human Treg function and was associated with the induction of IFNγ-secreting Tregs in a xenogeneic graft-versus-host disease model and in adoptive transfer models of experimental colitis. Our results demonstrate a putative role for an environmental factor that promotes autoimmunity by inducing proinflammatory responses in CD4 effector cells and Treg pathways.


Assuntos
Autoimunidade/efeitos dos fármacos , Cloreto de Sódio na Dieta/efeitos adversos , Cloreto de Sódio/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Transferência Adotiva , Animais , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Células Cultivadas , Técnicas de Cocultura , Colite/imunologia , Citocinas/biossíntese , Citocinas/genética , Fatores de Transcrição Forkhead/análise , Fatores de Transcrição Forkhead/genética , Perfilação da Expressão Gênica , Genes Reporter , Doença Enxerto-Hospedeiro/imunologia , Xenoenxertos , Humanos , Proteínas Imediatamente Precoces/fisiologia , Inflamação , Interferon gama/genética , Interferon gama/metabolismo , Interferon gama/farmacologia , Leucócitos Mononucleares/transplante , Masculino , Camundongos , Proteínas Serina-Treonina Quinases/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética , Cloreto de Sódio na Dieta/farmacologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
9.
J Clin Invest ; 124(10): 4603-13, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25202978

RESUMO

Regulatory T cells (Tregs), which express CD4 and FOXP3, are critical for modulating the immune response and promoting immune tolerance. Consequently, methods to expand Tregs for therapeutic use are of great interest. While transfer of Tregs after massive ex vivo expansion can be achieved, in vivo expansion of Tregs would be more practical. Here, we demonstrate that targeting the CD45 tyrosine phosphatase with a tolerogenic anti-CD45RB mAb acutely increases Treg numbers in WT mice, even in absence of exogenous antigen. Treg expansion occurred through substantial augmentation of homeostatic proliferation in the preexisting Treg population. Moreover, anti-CD45RB specifically increased Treg proliferation in response to cognate antigen. Compared with conventional T cells, Tregs differentially regulate their conjugation with DCs. Therefore, we determined whether CD45 ligation could alter interactions between Tregs and DCs. Live imaging showed that CD45 ligation specifically reduced Treg motility in an integrin-dependent manner, resulting in enhanced interactions between Tregs and DCs in vivo. Increased conjugate formation, in turn, augmented nuclear translocation of nuclear factor of activated T cells (NFAT) and Treg proliferation. Together, these results demonstrate that Treg peripheral homeostasis can be specifically modulated in vivo to promote Treg expansion and tolerance by increasing conjugation between Tregs and DCs.


Assuntos
Células Dendríticas/citologia , Antígenos Comuns de Leucócito/metabolismo , Linfócitos T Reguladores/citologia , Animais , Proliferação de Células , Feminino , Fatores de Transcrição Forkhead/metabolismo , Homeostase , Tolerância Imunológica , Interleucina-2/metabolismo , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fatores de Transcrição NFATC/metabolismo
10.
J Immunol ; 193(2): 587-96, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24943216

RESUMO

Immune-deficient mice, reconstituted with human stem cells, have been used to analyze human immune responses in vivo. Although they have been used to study immune responses to xenografts, allografts, and pathogens, there have not been models of autoimmune disease in which the mechanisms of the pathologic process can be analyzed. We have found that reconstituted "humanized" mice treated with anti-CTLA-4 Ab (ipilimumab) develop autoimmune disease characterized by hepatitis, adrenalitis, sialitis, anti-nuclear Abs, and weight loss. Induction of autoimmunity involved activation of T cells and cytokine production, and increased infiltration of APCs. When anti-CTLA-4 mAb-treated mice were cotreated with anti-CD3 mAb (teplizumab), hepatitis and anti-nuclear Abs were no longer seen and weight loss did not occur. The anti-CD3 blocked proliferation and activation of T cells, release of IFN-γ and TNF, macrophage infiltration, and release of IP-10 that was induced with anti-CTLA-4 mAb. We also found increased levels of T regulatory cells (CD25(+)CD127(-)) in the spleen and mesenteric lymph nodes in the mice treated with both Abs and greater constitutive phosphorylation of STAT5 in T regulatory cells in spleen cells compared with mice treated with anti-CTLA-4 mAb alone. We describe a model of human autoimmune disease in vivo. Humanized mice may be useful for understanding the mechanisms of biologics that are used in patients. Hepatitis, lymphadenopathy, and other inflammatory sequelae are adverse effects of ipilimumab treatment in humans, and this study may provide insights into this pathogenesis and the effects of immunologics on autoimmunity.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Doenças Autoimunes/terapia , Modelos Animais de Doenças , Transplante de Células-Tronco/métodos , Linfócitos T/imunologia , Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/imunologia , Glândulas Suprarrenais/metabolismo , Animais , Anticorpos Monoclonais/toxicidade , Doenças Autoimunes/induzido quimicamente , Doenças Autoimunes/imunologia , Citocinas/sangue , Citocinas/imunologia , Citocinas/metabolismo , Citometria de Fluxo , Humanos , Subunidade gama Comum de Receptores de Interleucina/deficiência , Subunidade gama Comum de Receptores de Interleucina/genética , Ipilimumab , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Fosforilação/efeitos dos fármacos , Fosforilação/imunologia , Fator de Transcrição STAT5/imunologia , Fator de Transcrição STAT5/metabolismo , Análise de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Transplante Heterólogo , Perda de Peso/efeitos dos fármacos , Perda de Peso/imunologia
11.
Diabetes ; 62(5): 1676-80, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23423576

RESUMO

Type 1 diabetes (T1D) results from immune-mediated destruction of insulin-producing ß-cells. The killing of ß-cells is not currently measurable; ß-cell functional studies routinely used are affected by environmental factors such as glucose and cannot distinguish death from dysfunction. Moreover, it is not known whether immune therapies affect killing. We developed an assay to identify ß-cell death by measuring relative levels of unmethylated INS DNA in serum and used it to measure ß-cell death in a clinical trial of teplizumab. We studied 43 patients with recent-onset T1D, 13 nondiabetic subjects, and 37 patients with T1D treated with FcR nonbinding anti-CD3 monoclonal antibody (teplizumab) or placebo. Patients with recent-onset T1D had higher rates of ß-cell death versus nondiabetic control subjects, but patients with long-standing T1D had lower levels. When patients with recent-onset T1D were treated with teplizumab, ß-cell function was preserved (P < 0.05) and the rates of ß-cell were reduced significantly (P < 0.05). We conclude that there are higher rates of ß-cell death in patients with recent-onset T1D compared with nondiabetic subjects. Improvement in C-peptide responses with immune intervention is associated with decreased ß-cell death.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Citotoxicidade Imunológica/efeitos dos fármacos , Diabetes Mellitus Tipo 1/terapia , Fatores Imunológicos/uso terapêutico , Imunoterapia , Células Secretoras de Insulina/efeitos dos fármacos , Adulto , Peptídeo C/sangue , Complexo CD3/química , Testes Imunológicos de Citotoxicidade , Metilação de DNA , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/genética , Insulina/metabolismo , Insulina/uso terapêutico , Secreção de Insulina , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Masculino , Período Pós-Prandial , Adulto Jovem
12.
Sci Transl Med ; 4(118): 118ra12, 2012 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-22277969

RESUMO

The development and optimization of immune therapies in patients has been hampered by the lack of preclinical models in which their effects on human immune cells can be studied. As a result, observations that have been made in preclinical studies have suggested mechanisms of drug action in murine models that have not been confirmed in clinical studies. Here, we used a humanized mouse reconstituted with human hematopoietic stem cells to study the mechanism of action of teplizumab, an Fc receptor nonbinding humanized monoclonal antibody to CD3 being tested in clinical trials for the treatment of patients with type 1 diabetes mellitus. In this model, human gut-tropic CCR6(+) T cells exited the circulation and secondary lymph organs and migrated to the small intestine. These cells then produced interleukin-10 (IL-10), a regulatory cytokine, in quantities that could be detected in the peripheral circulation. Blocking T cell migration to the small intestine with natalizumab, which prevents cellular adhesion by inhibiting α(4) integrin binding, abolished the treatment effects of teplizumab. Moreover, IL-10 expression by CD4(+)CD25(high)CCR6(+)FoxP3 cells returning to the peripheral circulation was increased in patients with type 1 diabetes treated with teplizumab. These findings demonstrate that humanized mice may be used to identify novel immunologic mechanisms that occur in patients treated with immunomodulators.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Trato Gastrointestinal/citologia , Trato Gastrointestinal/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Animais , Anticorpos Monoclonais Humanizados/uso terapêutico , Complexo CD3/imunologia , Movimento Celular/efeitos dos fármacos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/imunologia , Fatores de Transcrição Forkhead/metabolismo , Trato Gastrointestinal/efeitos dos fármacos , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Interleucina-10/metabolismo , Intestino Delgado/citologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/imunologia , Selectina L/metabolismo , Camundongos , Membrana Mucosa/citologia , Membrana Mucosa/efeitos dos fármacos , Membrana Mucosa/imunologia , Natalizumab , Análise de Sequência com Séries de Oligonucleotídeos , Receptores CCR6/metabolismo
13.
J Immunol ; 186(5): 2809-18, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21270412

RESUMO

Rapamycin (Rapa), an immunosuppressive drug that acts through mammalian target of Rapa inhibition, broadly synergizes with tolerogenic agents in animal models of transplantation and autoimmunity. Rapa preferentially inhibits conventional CD4(+) Foxp3(-) T cells (Tconv) and promotes outgrowth of CD4(+)Foxp3(+) regulatory T cells (Treg) during in vitro expansion. Moreover, Rapa is widely perceived as augmenting both expansion and conversion of Treg in vivo. However, most quantitative studies were performed in lymphopenic hosts or in graft-versus-host disease models. We show in this study that in replete wild-type mice, Rapa significantly inhibits both homeostatic and alloantigen-induced proliferation of Treg, and promotes their apoptosis. Together, these lead to significant Treg depletion. Tconv undergo depletion to a similar degree, resulting in no change in the percent of Treg among CD4 cells. Moreover, in this setting, there was no evidence of conversion of Tconv into Treg. However, after withdrawal of Rapa, Treg recover Ag-induced proliferation more quickly than Tconv, leading to recovery to baseline numbers and an increase in the percent of Treg compared with Tconv. These findings suggest that the effects of Rapa on Treg survival, homeostasis, and induction, depend heavily on the cellular milieu and degree of activation. In vivo, the resistance of Treg to mammalian target of Rapa inhibition is relative and results from lymphopenic and graft-versus-host disease models cannot be directly extrapolated to settings more typical of solid organ transplantation or autoimmunity. Moreover, these results have important implications for the timing of Rapa therapy with tolerogenic agents designed to increase the number of Treg in vivo.


Assuntos
Proliferação de Células , Homeostase/imunologia , Isoantígenos/fisiologia , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Técnicas de Introdução de Genes , Homeostase/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Depleção Linfocítica , Tecido Linfoide/citologia , Tecido Linfoide/efeitos dos fármacos , Tecido Linfoide/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Sirolimo/administração & dosagem , Transplante de Pele/imunologia , Transplante de Pele/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/transplante
14.
Ann N Y Acad Sci ; 1150: 217-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19120299

RESUMO

Type 1 diabetes is an autoimmune disease characterized by T cell-mediated destruction of pancreatic islet beta cells. Pancreatic islet transplantation with long-term immunosuppressive drug treatment is an accepted therapeutic option for patients with type 1 diabetes suffering from disabling hypoglycemia on insulin treatment. Here we investigated the replacement of immunosuppressive drug treatment with immune tolerance establishment induced by temporary B cell-depletion therapy for islet transplantation. The result suggested that the combined therapy of B cell depletion and syngeneic islet transplantation may reverse the disease in hCD20/NOD mice.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígenos CD20/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante das Ilhotas Pancreáticas/métodos , Animais , Anticorpos Monoclonais/farmacologia , Linfócitos B/imunologia , Linfócitos B/fisiologia , Separação Celular , Diabetes Mellitus Tipo 1/imunologia , Sobrevivência de Enxerto/imunologia , Transplante das Ilhotas Pancreáticas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Prevenção Secundária , Transplante Isogênico
15.
J Immunol ; 176(4): 2292-8, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16455985

RESUMO

The role of CTLA-4 in tolerance is primarily inferred from knockout and blocking studies. Anti-CD45RB mediates allograft tolerance in mice by inducing CTLA-4 expression on CD4 cells, providing a novel opportunity to determine how therapeutic enhancement of CTLA-4 promotes tolerance. We now show that induced CTLA-4 expression normally resolves by day 17. Although thymectomy prolongs enhanced CTLA-4 expression, long-term engraftment is unaffected. To address the temporal relationship between increased CTLA-4 expression and engraftment, transplantation was delayed for various times after anti-CD45RB treatment. Delaying transplantation for 7 days (when CTLA-4 expression had peaked but treatment mAb was no longer detectable), resulted in long-term engraftment comparable to transplantation with no delay (day 0). Delaying transplantation from 10 to 18 days led to a progressively poorer outcome as CTLA-4 expression returned to baseline. This suggested that Ag exposure while CTLA-4 expression is enhanced is sufficient to induce long-term engraftment. To substantiate this, on day 0, anti-CD45RB-treated mice received BALB/c vs unrelated alloantigen, followed by transplantation of BALB/c islets 10 days later. Whereas recipients exposed to unrelated Ag experienced acute rejection, recipients exposed to donor Ag achieved long-term engraftment. Anti-CD45RB-treated mice exposed to alloantigen exhibited anergic CD4(+)CD25(-) effector cells and regulatory CD4(+)CD25(+) cells. Moreover, CD25 depletion in the peritransplant period prevented anti-CD45RB-mediated engraftment. Thus, exposure of CD4 cells expressing CTLA-4 to donor Ag is necessary and sufficient to induce long-term engraftment which appears to be mediated by both regulation and anergy.


Assuntos
Antígenos de Diferenciação/metabolismo , Antígenos/imunologia , Transplante das Ilhotas Pancreáticas/imunologia , Tolerância ao Transplante/imunologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos CD , Antígeno CTLA-4 , Antígenos Comuns de Leucócito/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Timectomia , Fatores de Tempo , Transplante Homólogo
16.
J Immunol ; 174(10): 6161-8, 2005 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15879112

RESUMO

Immune responses are suppressed in immunologically privileged sites, which may provide a unique opportunity to prolong allograft survival. However, it is unknown whether testicular immune privilege promotes transplantation tolerance. Mechanisms underlying immune privilege are also not well understood. Here we found that islet transplantation in the testis, an immunologically privileged site, generates much less memory CD8(+) T cells but induces more Ag-specific CD4(+)CD25(+) regulatory T cells than in a conventional site. These CD4(+)CD25(+) cells exhibited the suppression of alloimmune responses in vivo and in vitro. Despite the immune regulation, intratesticular islet allografts all were rejected within 42 days after transplantation although they survived longer than renal subcapsular islet allografts. However, blocking CD40/CD40L costimulation induced the tolerance of intratesticular, but not renal subcapsular, islet allografts. Tolerance to intratesticular islet allografts spread to skin allografts in the non-privileged sites. Either transfer of memory CD8(+) T cells or deletion of CD25(+) T cells in vivo broke islet allograft tolerance. Thus, transplantation tolerance requires both costimulatory blockade, which suppresses acute allograft rejection, and a favorable balance between memory and regulatory T cells that could favorably prevent late allograft failure. These findings reveal novel mechanisms of immune privilege and provide direct evidence that testicular immune privilege fosters the induction of transplantation tolerance to allografts in both immunologically privileged and non-privileged sites.


Assuntos
Memória Imunológica , Transplante das Ilhotas Pancreáticas/imunologia , Linfócitos T Reguladores/imunologia , Testículo/imunologia , Tolerância ao Transplante/imunologia , Animais , Anticorpos Bloqueadores/farmacologia , Apoptose/imunologia , Antígenos CD40/imunologia , Ligante de CD40/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Inibidores do Crescimento/farmacologia , Transplante das Ilhotas Pancreáticas/patologia , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores de Interleucina-2/biossíntese , Linfócitos T Reguladores/metabolismo , Transplante Heterotópico/imunologia , Transplante Heterotópico/patologia
17.
J Immunol ; 174(3): 1165-70, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15661869

RESUMO

Foreign Ags that enter immunologically privileged sites such as the eye, brain, and testis persist for an extended period of time, whereas the same Ags are rapidly eliminated at conventional sites. Immune privilege, therefore, provides unwanted refuge for pathogens and tumor cells but is beneficial for the survival of allogeneic grafts. In this study, we asked whether memory T cells can eliminate foreign Ags deposited at an immunologically privileged site by studying CD8 memory T cell-mediated rejection of pancreatic islet allografts placed either in the testis (a privileged organ) or under the kidney capsule (a nonprivileged site) of diabetic mice. We found that CD8 memory T cells reject intratesticular grafts at a significantly slower rate than the rejection of intrarenal grafts. Delayed graft rejection in the testis was not due to reduced homing or proliferation of memory T cells but due to their increased apoptosis at that site. Apoptosis was mediated by the combined actions of two TNFR family members that are up-regulated on activated memory T cells, Fas, and CD30. Therefore, memory T cells survey immunologically privileged tissues but are subject to the immunosuppressive mechanisms present at these sites.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica , Testículo/citologia , Testículo/imunologia , Animais , Apoptose/genética , Apoptose/imunologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/transplante , Movimento Celular/genética , Movimento Celular/imunologia , Epitopos de Linfócito T/imunologia , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Transplante das Ilhotas Pancreáticas/imunologia , Transplante das Ilhotas Pancreáticas/métodos , Transplante das Ilhotas Pancreáticas/patologia , Antígeno Ki-1/fisiologia , Rim/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Camundongos Knockout , Camundongos Mutantes , Camundongos Transgênicos , Testículo/patologia , Transplante Heterotópico/imunologia , Transplante Heterotópico/métodos , Transplante Heterotópico/patologia , Receptor fas/fisiologia
18.
J Immunol ; 171(11): 5673-7, 2003 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-14634073

RESUMO

Knockout and blocking studies have shown a critical role for CTLA-4 in peripheral tolerance, however, it is unknown whether augmenting CTLA-4 expression actually promotes tolerance. Here we demonstrate a specific and requisite role for CTLA-4 and its up-regulation in tolerance through anti-CD45RB. First, long-term murine islet allograft survival induced by anti-CD45RB is prevented by CTLA4-Ig, which interferes with B7:CTLA-4 interactions. Second, anti-CD45RB is ineffective in recipients lacking CTLA-4, B7-1, and B7-2. In contrast, CTLA4-Ig, which targets B7 on allogeneic cells, promotes long-term engraftment in these mice. Moreover, anti-CD45RB was effective in B7-deficient controls expressing CTLA-4. Finally, in wild-type mice, CTLA-4 expression returned to baseline 17 days after receiving anti-CD45RB, and was refractory to further increase. Transplantation and anti-CD45RB therapy at this time could neither augment CTLA-4 nor prolong engraftment. These data demonstrate a specific role for CTLA-4 in anti-CD45RB-mediated tolerance and indicate that CTLA-4 up-regulation can directly promote allograft survival.


Assuntos
Adjuvantes Imunológicos/biossíntese , Antígenos de Diferenciação/biossíntese , Facilitação Imunológica de Enxerto , Tolerância ao Transplante/imunologia , Abatacepte , Adjuvantes Imunológicos/deficiência , Adjuvantes Imunológicos/genética , Adjuvantes Imunológicos/fisiologia , Animais , Anticorpos Monoclonais/administração & dosagem , Antígenos CD , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/fisiologia , Antígeno CTLA-4 , Facilitação Imunológica de Enxerto/métodos , Sobrevivência de Enxerto/genética , Sobrevivência de Enxerto/imunologia , Imunoconjugados/administração & dosagem , Injeções Intraperitoneais , Injeções Intravenosas , Transplante das Ilhotas Pancreáticas/imunologia , Antígenos Comuns de Leucócito/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Tolerância ao Transplante/genética , Regulação para Cima/genética , Regulação para Cima/imunologia
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