RESUMO
Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic cell transplantation (HCT). DCs play critical roles in GVHD induction. Modulating autophagy represents a promising therapeutic strategy for the treatment of immunological diseases. Complement receptors C3aR/C5aR expressed on DCs regulate immune responses by translating extracellular signals into intracellular activity. In the current study, we found that C3aR/C5aR deficiency enhanced ceramide-dependent lethal mitophagy (CDLM) in DCs. Cotransfer of host-type C3aR-/-/C5aR-/- DCs in the recipients significantly improved GVHD outcome after allogeneic HCT, primarily through enhancing CDLM in DCs. C3aR/C5aR deficiency in the host hematopoietic compartment significantly reduced GVHD severity via impairing Th1 differentiation and donor T cell glycolytic activity while enhancing Treg generation. Prophylactic treatment with C3aR/C5aR antagonists effectively alleviated GVHD while maintaining the graft-versus-leukemia (GVL) effect. Altogether, we demonstrate that inhibiting C3aR/C5aR induces lethal mitophagy in DCs, which represents a potential therapeutic approach to control GVHD while preserving the GVL effect.
Assuntos
Células Dendríticas/imunologia , Doença Enxerto-Hospedeiro/imunologia , Mitofagia , Receptor da Anafilatoxina C5a/imunologia , Animais , Apoptose , Autofagia , Diferenciação Celular , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor da Anafilatoxina C5a/genética , Receptor da Anafilatoxina C5a/metabolismo , Linfócitos T , Linfócitos T Reguladores/imunologia , Células Th1RESUMO
Janus kinase 2 (JAK2) signal transduction is a critical mediator of the immune response. JAK2 is implicated in the onset of graft-versus-host disease (GVHD), which is a significant cause of transplant-related mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Transfer of JAK2-/- donor T cells to allogeneic recipients leads to attenuated GVHD yet maintains graft-versus-leukemia. Th1 differentiation among JAK2-/- T cells is significantly decreased compared with wild-type controls. Conversely, iTreg and Th2 polarization is significantly increased among JAK2-/- T cells. Pacritinib is a multikinase inhibitor with potent activity against JAK2. Pacritinib significantly reduces GVHD and xenogeneic skin graft rejection in distinct rodent models and maintains donor antitumor immunity. Moreover, pacritinib spares iTregs and polarizes Th2 responses as observed among JAK2-/- T cells. Collectively, these data clearly identify JAK2 as a therapeutic target to control donor alloreactivity and promote iTreg responses after allo-HCT or solid organ transplantation. As such, a phase I/II acute GVHD prevention trial combining pacritinib with standard immune suppression after allo-HCT is actively being investigated (https://clinicaltrials.gov/ct2/show/NCT02891603).
Assuntos
Diferenciação Celular , Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Leucemia/imunologia , Janus Quinase 2/fisiologia , Mielofibrose Primária/imunologia , Linfócitos T/imunologia , Células Th2/imunologia , Animais , Feminino , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/prevenção & controle , Efeito Enxerto vs Leucemia/genética , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Mielofibrose Primária/genética , Mielofibrose Primária/prevenção & controle , Transplante de Pele , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Allogeneic hematopoietic cell transplantation (allo-HCT) is an effective immunotherapy for a variety of hematologic malignances, yet its efficacy is impeded by the development of graft-versus-host disease (GVHD). GVHD is characterized by activation, expansion, cytokine production, and migration of alloreactive donor T cells. Hence, strategies to limit GVHD are highly desirable. Ceramides are known to contribute to inflammation and autoimmunity. However, their involvement in T-cell responses to alloantigens is undefined. In the current study, we specifically characterized the role of ceramide synthase 6 (CerS6) after allo-HCT using genetic and pharmacologic approaches. We found that CerS6 was required for optimal T cell activation, proliferation, and cytokine production in response to alloantigen and for subsequent induction of GVHD. However, CerS6 was partially dispensable for the T cell-mediated antileukemia effect. At the molecular level, CerS6 was required for efficient TCR signal transduction, including tyrosine phosphorylation, ZAP-70 activation, and PKCθ/TCR colocalization. Impaired generation of C16-ceramide was responsible for diminished allogeneic T cell responses. Furthermore, targeting CerS6 using a specific inhibitor significantly reduced T cell activation in mouse and human T cells in vitro. Our study provides a rationale for targeting CerS6 to control GVHD, which would enhance the efficacy of allo-HCT as an immunotherapy for hematologic malignancies in the clinic.
RESUMO
Graft-versus-host disease (GVHD) is a significant cause of non-relapse mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Existing strategies to prevent and treat GVHD are incomplete, where a significant portion of allo-HCT recipients developed this complication. Despite this, one such therapy has emerged involving the use of regulatory T cells (Tregs) to control GVHD. The use of natural Tregs (nTregs) yielded positive pre-clinical results and are actively under investigation to reduce GVHD. However, broad application of this approach may require standardization of Treg expansion methods and dosing. Inducible Tregs (iTregs) can be seamlessly generated, but controversial pre-clinical findings and phenotype instability have hampered their translation into the clinic. Here, we review the current biological differences between nTregs and iTregs, as well as their effects on GVHD and graft-versus-leukemia (GVL) responses. We conclude by exploring the idea of combinational cellular therapies for the prevention of GVHD and preservation of GVL.
RESUMO
Adoptive natural regulatory T cell (nTreg) therapy has improved the outcome for patients suffering from graft-versus-host disease (GVHD) following allogeneic hematopoietic cell transplantation (Allo-HCT). However, fear of broad immune suppression and subsequent dampening of beneficial graft-versus-leukemia (GVL) responses remains a challenge. To address this concern, we generated alloreactive induced Tregs (iTregs) from resting CD4(+) or CD8(+) T cells and tested their ability to suppress GVH and maintain GVL responses. We utilized major mismatched and haploidentical murine models of HCT with host-derived lymphoma or leukemia cell lines to evaluate GVH and GVL responses simultaneously. Alloreactive CD4(+) iTregs were effective in preventing GVHD, but abrogated the GVL effect against aggressive leukemia. Alloreactive CD8(+) iTregs moderately attenuated GVHD while sparing the GVL effect. Hence, we reasoned that using a combination of CD4(+) and CD8(+) iTregs could achieve the optimal goal of Allo-HCT. Indeed, the combinational therapy was superior to CD4(+) or CD8(+) iTreg singular therapy in GVHD control; importantly, the combinational therapy maintained GVL responses. Cellular analysis uncovered potent suppression of both CD4(+) and CD8(+) effector T cells by the combinational therapy that resulted in effective prevention of GVHD, which could not be achieved by either singular therapy. Gene expression profiles revealed alloreactive CD8(+) iTregs possess elevated expression of multiple cytolytic molecules compared to CD4(+) iTregs, which likely contributes to GVL preservation. Our study uncovers unique differences between alloreactive CD4(+) and CD8(+) iTregs that can be harnessed to create an optimal iTreg therapy for GVHD prevention with maintained GVL responses.
RESUMO
Alloreactive donor T cells are the driving force in the induction of graft-versus-host disease (GVHD), yet little is known about T cell metabolism in response to alloantigens after hematopoietic cell transplantation (HCT). Here, we have demonstrated that donor T cells undergo metabolic reprograming after allogeneic HCT. Specifically, we employed a murine allogeneic BM transplant model and determined that T cells switch from fatty acid ß-oxidation (FAO) and pyruvate oxidation via the tricarboxylic (TCA) cycle to aerobic glycolysis, thereby increasing dependence upon glutaminolysis and the pentose phosphate pathway. Glycolysis was required for optimal function of alloantigen-activated T cells and induction of GVHD, as inhibition of glycolysis by targeting mTORC1 or 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) ameliorated GVHD mortality and morbidity. Together, our results indicate that donor T cells use glycolysis as the predominant metabolic process after allogeneic HCT and suggest that glycolysis has potential as a therapeutic target for the control of GVHD.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Isoantígenos/imunologia , Ativação Linfocitária , Aloenxertos , Animais , Ciclo do Ácido Cítrico/genética , Ciclo do Ácido Cítrico/imunologia , Glicólise/genética , Glicólise/imunologia , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/patologia , Isoantígenos/genética , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Complexos Multiproteicos/genética , Complexos Multiproteicos/imunologia , Fosfofrutoquinase-2/genética , Fosfofrutoquinase-2/imunologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/imunologiaRESUMO
Beyond its critical role in T cells, T-bet regulates the functions of APCs including dendritic cells and B cells, as well as NK cells. Given that recipient APCs are essential for priming allogeneic T cells and recipient NK or T cells are able to reject allogeneic donor cells, we evaluated the role of T-bet on the host in acute graft-versus-host disease (GVHD) using murine models of allogeneic bone marrow transplantation. T-bet(-/-) recipients developed significantly milder GVHD than their wild type counterparts in MHC-mismatched or CD4-dependent minor histocompatibility Ag-mismatched models. Allogeneic donor T cells, in particular, CD4 subset, significantly reduced IFN-γ production, proliferation and migration, and caused less injury in liver and gut of T-bet(-/-) recipients. We further observed that T-bet on recipient hematopoietic cells was primarily responsible for the donor T cell response and pathogenicity in GVHD. T-bet(-/-) dendritic cells expressed higher levels of Trail, whereas they produced lower levels of IFN-γ and IL-12/23 p40, as well as chemokine CXCL9, resulting in significantly higher levels of apoptosis, less priming, and infiltration of donor T cells. Meanwhile, NK cells in T-bet(-/-) hosts partially contribute to the decreased donor T cell proliferation. Furthermore, although T-bet on hematopoietic cells was required for GVHD development, it was largely dispensable for the graft-versus-leukemia effect. Taken together with our previous findings, we propose that T-bet is a potential therapeutic target for the control of GVHD through regulating donor T cells and recipient hematopoietic cells.
Assuntos
Células da Medula Óssea/metabolismo , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Doença Aguda , Animais , Transplante de Medula Óssea , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Efeito Enxerto vs Leucemia/genética , Efeito Enxerto vs Leucemia/imunologia , Interferon gama/biossíntese , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Baço/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Doadores de Tecidos , Transplante HomólogoRESUMO
Bruton's Tyrosine Kinase (BTK) and IL-2 Inducible T-cell Kinase (ITK) are enzymes responsible for the phosphorylation and activation of downstream effectors in the B-cell receptor (BCR) signaling and T cell receptor (TCR) signaling pathways, respectively. Ibrutinib is an FDA-approved potent inhibitor of both BTK and ITK that impairs B-cell and T-cell function. CD4 T cells and B cells are essential for the induction of chronic graft-versus-host disease (cGVHD). We evaluated these targets by testing the ability of Ibrutinib to prevent or ameliorate cGVHD, which is one of the major complications for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We found that Ibrutinib significantly alleviated cGVHD across four different mouse models, accompanied by increased long-term survival and reduced clinical score. The clinical improvements in Ibrutinib-treated recipients were associated with decreased serum-autoantibodies, costimulatory molecule activation, B-cell proliferation, and glomerulonephritis compared to vehicle controls. Ibrutinib was also able to alleviate the clinical manifestations in acute GVHD (aGVHD), where the recipients were given grafts with or without B cells, suggesting that an inhibitory effect of Ibrutinib on T cells contributes to a reduction in both aGVHD and cGVHD pathogenesis. An effective prophylactic regimen is still lacking to both reduce the incidence and severity of human cGVHD following allo-HSCT. Our study shows that Ibrutinib is an effective prophylaxis against several mouse models of cGVHD with minimal toxicity and could be a promising strategy to combat human cGVHD clinically.
Assuntos
Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Adenina/análogos & derivados , Tirosina Quinase da Agamaglobulinemia , Animais , Linfócitos B/efeitos dos fármacos , Doença Enxerto-Hospedeiro/enzimologia , Doença Enxerto-Hospedeiro/patologia , Humanos , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Piperidinas , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/biossíntese , Pirazóis/efeitos adversos , Pirimidinas/efeitos adversos , Transdução de Sinais/efeitos dos fármacosRESUMO
MicroRNAs (miRs) play important roles in orchestrating many aspects of the immune response. The miR-17-92 cluster, which encodes 6 miRs including 17, 18a, 19a, 20a, 19b-1, and 92-1, is among the best characterized of these miRs. The miR-17-92 cluster has been shown to regulate a variety of immune responses including infection, tumor, and autoimmunity, but the role of this cluster in T-cell response to alloantigens has not been previously explored. By using major histocompatibility complex (MHC)-matched, -mismatched, and haploidentical murine models of allogeneic bone marrow transplantation (allo-BMT), we demonstrate that the expression of miR-17-92 on donor T cells is essential for the induction of graft-versus-host disease (GVHD), but dispensable for the graft-versus-leukemia (GVL) effect. The miR-17-92 plays a major role in promoting CD4 T-cell activation, proliferation, survival, and Th1 differentiation, while inhibiting Th2 and iTreg differentiation. Alternatively, miR-17-92 may promote migration of CD8 T cells to GVHD target organs, but has minimal impact on CD8 T-cell proliferation, survival, or cytolytic function, which could contribute to the preserved GVL effect mediated by T cells deficient for miR-17-92. Furthermore, we evaluated a translational approach and found that systemic administration of antagomir to block miR-17 or miR-19b in this cluster significantly inhibited alloreactive T-cell expansion and interferon-γ (IFNγ) production, and prolonged the survival in recipients afflicted with GVHD while preserving the GVL effect. Taken together, the current work provides a strong rationale and demonstrates the feasibility to target miR-17-92 for the control of GVHD while preserving GVL activity after allo-BMT.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Leucemia Experimental/imunologia , MicroRNAs/genética , MicroRNAs/imunologia , Linfócitos T/imunologia , Aloenxertos , Animais , Transplante de Medula Óssea , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Doença Enxerto-Hospedeiro/genética , Efeito Enxerto vs Leucemia/genética , Efeito Enxerto vs Leucemia/imunologia , Interferon gama/biossíntese , Leucemia Experimental/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , MicroRNAs/antagonistas & inibidores , Oligonucleotídeos/farmacologiaRESUMO
Naturally derived regulatory T cells (Tregs) may prevent graft-versus-host disease (GVHD) while preserving graft-versus-leukemia (GVL) activity. However, clinical application of naturally derived regulatory T cells has been severely hampered by their scarce availability and nonselectivity. To overcome these limitations, we took alternative approaches to generate Ag-specific induced Tregs (iTregs) and tested their efficacy and selectivity in the prevention of GVHD in preclinical models of bone marrow transplantation. We selected HY as a target Ag because it is a naturally processed, ubiquitously expressed minor histocompatibility Ag (miHAg) with a proven role in GVHD and GVL effect. We generated HY-specific iTregs (HY-iTregs) from resting CD4 T cells derived from TCR transgenic mice, in which CD4 cells specifically recognize HY peptide. We found that HY-iTregs were highly effective in preventing GVHD in male (HY(+)) but not female (HY(-)) recipients using MHC II-mismatched, parentâF1, and miHAg-mismatched murine bone marrow transplantation models. Interestingly, the expression of target Ag (HY) on the hematopoietic or nonhematopoietic compartment alone was sufficient for iTregs to prevent GVHD. Furthermore, treatment with HY-iTregs still preserved the GVL effect even against pre-established leukemia. We found that HY-iTregs were more stable in male than in female recipients. Furthermore, HY-iTregs expanded extensively in male but not female recipients, which in turn significantly reduced donor effector T cell expansion, activation, and migration into GVHD target organs, resulting in effective prevention of GVHD. This study demonstrates that iTregs specific for HY miHAgs are highly effective in controlling GVHD in an Ag-dependent manner while sparing the GVL effect.
Assuntos
Transplante de Medula Óssea , Doença Enxerto-Hospedeiro/prevenção & controle , Antígeno H-Y/imunologia , Leucemia/terapia , Linfócitos T Reguladores/imunologia , Animais , Proliferação de Células , Feminino , Expressão Gênica , Efeito Enxerto vs Leucemia , Antígeno H-Y/genética , Teste de Histocompatibilidade , Leucemia/genética , Leucemia/imunologia , Leucemia/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fatores Sexuais , Análise de Sobrevida , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/transplante , Transplante Homólogo , Irradiação Corporal TotalRESUMO
Graft-versus-host disease (GVHD), in both its acute (aGVHD) and chronic (cGVHD) forms, remains a major obstacle impeding successful allogeneic hematopoietic stem cell transplantation (allo-HSCT). T cells, in particular pathogenic T helper (Th) 1 and Th17 subsets, are a driving force for the induction of GVHD. IL-12 and IL-23 cytokines share a common p40 subunit and play a critical role in driving Th1 differentiation and in stabilizing the Th17 phenotype, respectively. In our current study, we hypothesized that p40 is an essential cytokine in the development of GVHD. By using p40-deficient mice, we found that both donor- and host-derived p40 contribute to the development of aGVHD. Neutralization of p40 with an anti-p40 mAb inhibited Th1- and Th17-polarization in vitro. Furthermore, anti-p40 treatment reduced aGVHD severity while preserving the graft-versus-leukemia (GVL) activity. Alleviation of aGVHD was associated with an increase of Th2 differentiation and a decrease of Th1 and Th17 effector T cells in the GVHD target organs. In addition, anti-p40 treatment attenuated the severity of sclerodermatous cGVHD. These results provide a strong rationale that blockade of p40 may represent a promising therapeutic strategy in preventing and treating aGVHD and cGVHD while sparing the GVL effect after allo-HSCT.
Assuntos
Anticorpos Neutralizantes/farmacologia , Transplante de Medula Óssea/efeitos adversos , Doença Enxerto-Hospedeiro/terapia , Subunidade p40 da Interleucina-12/imunologia , Leucemia Mieloide Aguda/terapia , Linfoma de Células B/terapia , Animais , Diferenciação Celular , Modelos Animais de Doenças , Expressão Gênica , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Leucemia , Teste de Histocompatibilidade , Humanos , Subunidade p40 da Interleucina-12/deficiência , Subunidade p40 da Interleucina-12/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Depleção Linfocítica , Linfoma de Células B/genética , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Cultura Primária de Células , Células Th1/imunologia , Células Th1/patologia , Células Th17/imunologia , Células Th17/patologia , Células Th2/imunologia , Células Th2/patologia , Transplante HomólogoRESUMO
T-bet is a master regulator for IFN-γ production and Th1 differentiation. We evaluated the roles of T-bet and IFN-γ in T cell responses in acute graft-versus-host disease (GVHD) and found that T-bet(-/-) T cells induced significantly less GVHD compared with wild-type or IFN-γ(-/-) counterparts in both MHC-mismatched and MHC-matched but minor histocompatibility Ag-mismatched models driven by CD4 T cells. T-bet(-/-), but not IFN-γ(-/-), CD4 T cells had a markedly reduced ability to cause tissue damage in liver and gut. This distinct outcome is reflected by the differential gene expression on donor CD4 T cells deficient for T-bet or IFN-γ. At mRNA and protein levels, we defined several T-bet-dependent molecules that may account for the impaired ability of T-bet(-/-) T cells to migrate into target organs and to produce Th1-related cytokines. Moreover, these molecules were independent of either endogenous IFN-γ, such as CXCR3 and programmed death-1, or systematic IFN-γ, such as NKG2D, I-A(b), and granzyme B. Although both T-bet(-/-) and IFN-γ(-/-) CD4 T cells are prone to differentiate into Th17 cells, polarized Th17 cells deficient for T-bet but not for IFN-γ had a significantly reduced ability to cause GVHD. Finally, T-bet(-/-) T cells had a compromised graft-versus-leukemia effect, which could be essentially reversed by neutralization of IL-17 in the recipients. We conclude that T-bet is required for Th1 differentiation and migration, as well as for optimal function of Th17 cells. Thus, targeting T-bet or regulating its downstream effectors independent of IFN-γ may be a promising strategy to control GVHD in the clinic.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Interferon gama/genética , Proteínas com Domínio T/genética , Células Th1/imunologia , Células Th17/imunologia , Animais , Diferenciação Celular/imunologia , Movimento Celular/genética , Movimento Celular/imunologia , Regulação da Expressão Gênica/imunologia , Granzimas/biossíntese , Antígenos de Histocompatibilidade Classe II/biossíntese , Interleucina-17/antagonistas & inibidores , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Subfamília K de Receptores Semelhantes a Lectina de Células NK/biossíntese , Receptor de Morte Celular Programada 1/biossíntese , RNA Mensageiro/genética , Receptores CXCR3/biossíntese , Receptores de Interferon/biossíntese , Receptores de Interferon/genética , Células Th1/citologia , Células Th17/citologia , Receptor de Interferon gamaRESUMO
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapeutic option for many malignant diseases. However, the efficacy of allo-HSCT is limited by the occurrence of destructive graft-versus-host disease (GVHD). Since allogeneic T cells are the driving force in the development of GVHD, their activation, proliferation, and differentiation are key factors to understanding GVHD pathogenesis. This review focuses on one critical aspect: the differentiation and function of helper T (Th) cells in acute GVHD. We first summarize well-established subsets including Th1, Th2, Th17, and T-regulatory cells; their flexibility, plasticity, and epigenetic modification; and newly identified subsets including Th9, Th22, and T follicular helper cells. Next, we extensively discuss preclinical findings of Th-cell lineages in GVHD: the networks of transcription factors involved in differentiation, the cytokine and signaling requirements for development, the reciprocal differentiation features, and the regulation of microRNAs on T-cell differentiation. Finally, we briefly summarize the recent findings on the roles of T-cell subsets in clinical GVHD and ongoing strategies to modify T-cell differentiation for controlling GVHD in patients. We believe further exploration and understanding of the immunobiology of T-cell differentiation in GVHD will expand therapeutic options for the continuing success of allo-HSCT.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Complicações Pós-Operatórias/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Diferenciação Celular , Doença Enxerto-Hospedeiro/etiologia , Hematopoese , Humanos , Transplante HomólogoRESUMO
Allogeneic hematopoietic cell transplantation (HCT) is the most effective therapy for hematopoietic malignancies through T-cell-mediated graft-vs-leukemia (GVL) effects but often leads to severe graft-vs-host disease (GVHD). Given that protein kinase Cθ (PKCθ), in cooperation with PKCα, is essential for T-cell signaling and function, we have evaluated PKCθ and PKCα as potential therapeutic targets in allogeneic HCT using genetic and pharmacologic approaches. We found that the ability of PKCα(-/-)/θ(-/-) donor T cells to induce GVHD was further reduced compared with PKCθ(-/-) T cells in relation with the relevance of both isoforms to allogeneic donor T-cell proliferation, cytokine production, and migration to GVHD target organs. Treatment with a specific inhibitor for both PKCθ and PKCα impaired donor T-cell proliferation, migration, and chemokine/cytokine production and significantly decreased GVHD in myeloablative preclinical murine models of allogeneic HCT. Moreover, pharmacologic inhibition of PKCθ and PKCα spared T-cell cytotoxic function and GVL effects. Our findings indicate that PKCα and θ contribute to T-cell activation with overlapping functions essential for GVHD induction while less critical to the GVL effect. Thus, targeting PKCα and PKCθ signaling with pharmacologic inhibitors presents a therapeutic option for GVHD prevention while largely preserving the GVL activity in patients receiving HCT.
Assuntos
Doença Enxerto-Hospedeiro/prevenção & controle , Efeito Enxerto vs Leucemia/efeitos dos fármacos , Isoenzimas/antagonistas & inibidores , Proteína Quinase C-alfa/antagonistas & inibidores , Proteína Quinase C/antagonistas & inibidores , Animais , Separação Celular , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Doença Enxerto-Hospedeiro/enzimologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia/terapia , Ativação Linfocitária/efeitos dos fármacos , Linfoma/terapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase C-theta , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
We and others have previously shown that ICOS plays an important role in inducing acute graft-versus-host disease (GVHD) in murine models of allogeneic bone marrow transplantation. ICOS potentiates TCR-mediated PI3K activation and intracellular calcium mobilization. However, ICOS signal transduction pathways involved in GVHD remain unknown. In this study, we examined the contribution of ICOS-PI3K signaling in the pathogenic potential of T cells using a knock-in mouse strain, ICOS-YF, which selectively lost the ability to activate PI3K. We found that when total T cells were used as alloreactive T cells, ICOS-YF T cells caused less severe GVHD compared with ICOS wild-type T cells, but they induced much more aggressive disease than ICOS knockout T cells. This intermediate level of pathogenic capacity of ICOS-YF T cells was correlated with similar levels of IFN-γ-producing CD8 T cells that developed in the recipients of ICOS-WT or ICOS-YF T cells. We further evaluated the role of ICOS-PI3K signaling in CD4 versus CD8 T cell compartment using GVHD models that are exclusively driven by CD4 or CD8 T cells. Remarkably, ICOS-YF CD8 T cells caused disease similar to ICOS wild-type CD8 T cells, whereas ICOS-YF CD4 T cells behaved very similarly to their ICOS knockout counterparts. Consistent with their in vivo pathogenic potential, CD8 T cells responded to ICOS ligation in vitro by PI3K-independent calcium flux, T cell activation, and proliferation. Thus, in acute GVHD in mice, CD4 T cells heavily rely on ICOS-PI3K signaling pathways; in contrast, CD8 T cells can use PI3K-independent ICOS signaling pathways, possibly through calcium.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/fisiologia , Ativação Linfocitária/imunologia , Fosfatidilinositol 3-Quinase/fisiologia , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/imunologia , Doença Aguda , Animais , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Doença Enxerto-Hospedeiro/enzimologia , Proteína Coestimuladora de Linfócitos T Induzíveis/deficiência , Ativação Linfocitária/genética , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Transdução de Sinais/genética , Subpopulações de Linfócitos T/enzimologia , Subpopulações de Linfócitos T/metabolismoRESUMO
BACKGROUND: Secreted factors from epicardial adipose tissue (EAT) have been implicated in the development of cardiomyocyte dysfunction. This study aimed to assess whether alterations in the secretory profile of EAT in patients with type 2 diabetes mellitus (DM2) affect contractile function and insulin action in cardiomyocytes. METHODS AND RESULTS: Contractile function and insulin action were analyzed in primary adult rat cardiomyocytes incubated with conditioned media (CM) generated from explants of EAT biopsies obtained from patients without and with DM2. CM from subcutaneous and pericardial adipose tissue biopsies from the same patients served as the control. Cardiomyocytes treated with CM (EAT) from DM2 patients showed reductions in sarcomere shortening, cytosolic Ca(2+) fluxes, expression of sarcoplasmic endoplasmic reticulum ATPase 2a, and decreased insulin-mediated Akt-Ser473-phosphorylation as compared with CM from the other groups. Profiling of the CM showed that activin A, angiopoietin-2, and CD14 selectively accumulated in CM-EAT-DM2 versus CM-EAT in patients without DM2 and CM from the other fat depots. Accordingly, EAT biopsies from DM2 patients were characterized by clusters of CD14-positive monocytes. Furthermore, SMAD2-phosphorylation, a downstream target of activin A signaling, was elevated in cardiomyocytes treated with CM (EAT) from DM2 patients, and the detrimental effects of CM (EAT) from DM2 patients were partially abolished in cardiomyocytes pretreated with a neutralizing antibody against activin A. Finally, both recombinant activin A and angiopoietin-2 reduced cardiomyocyte contractile function, but only activin A reduced the expression of sarcoplasmic endoplasmic reticulum ATPase 2a. CONCLUSIONS: Collectively, our data implicate DM2-related alterations in the secretory profile of EAT in the pathogenesis of diabetes mellitus-related heart disease.
Assuntos
Ativinas/farmacologia , Tecido Adiposo/metabolismo , Angiopoietina-2/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Pericárdio/metabolismo , Ativinas/metabolismo , Tecido Adiposo/patologia , Idoso , Angiopoietina-2/metabolismo , Animais , Biópsia , Cálcio/metabolismo , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Humanos , Insulina/metabolismo , Masculino , Modelos Animais , Miócitos Cardíacos/patologia , Pericárdio/patologia , Ratos , Ratos Endogâmicos Lew , Sarcômeros/efeitos dos fármacos , Sarcômeros/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Polyphenism is the expression of multiple, discrete phenotypes from one genotype, and understanding the environmental factors that trigger development of alternative phenotypes is a critical step toward understanding the evolution of polyphenism and its developmental control. While much is known about the ecology of the well-known carnivore/omnivore polyphenism in spadefoot toad tadpoles, the environmental cues for the development of the specialized carnivore phenotype are not completely clear. We examined 27 different experimental treatments in two spadefoot toad species and used over 1,000 tadpoles in an attempt to elucidate those cues. While only 44 carnivores developed in these treatments, they were concentrated at cooler water temperatures and a diet that included fairy shrimp. However, while a diet of fairy shrimp promoted carnivore development, it was not necessary for inducing carnivore development at lower and intermediate water temperatures. Evidence also suggested a role for social inhibition that limited the proportion of interacting tadpoles that become carnivores. Tadpoles of Spea multiplicata grew larger at cooler temperatures and larger when their diets included fairy shrimp, whereas tadpoles of S. bombifrons grew larger at warmer temperatures and when their diets did not include fairy shrimp. These results indicate that carnivore induction can occur through different cues and that our current model for carnivore development is too limited. Finally, we argue that the carnivore/omnivore spadefoot system is neither a polyphenism nor a polymorphism but is a continuously distributed plasticity.