RESUMO
CD4+ T cells are central to various immune responses, but the molecular programs that drive and maintain CD4+ T cell immunity are not entirely clear. Here we identify a stem-like program that governs the CD4+ T cell response in transplantation models. Single-cell-transcriptomic analysis revealed that naive alloantigen-specific CD4+ T cells develop into TCF1hi effector precursor (TEP) cells and TCF1-CXCR6+ effectors in transplant recipients. The TCF1-CXCR6+CD4+ effectors lose proliferation capacity and do not reject allografts upon adoptive transfer into secondary hosts. By contrast, the TCF1hiCD4+ TEP cells have dual features of self-renewal and effector differentiation potential, and allograft rejection depends on continuous replenishment of TCF1-CXCR6+ effectors from TCF1hiCD4+ TEP cells. Mechanistically, TCF1 sustains the CD4+ TEP cell population, whereas the transcription factor IRF4 and the glycolytic enzyme LDHA govern the effector differentiation potential of CD4+ TEP cells. Deletion of IRF4 or LDHA in T cells induces transplant acceptance. These findings unravel a stem-like program that controls the self-renewal capacity and effector differentiation potential of CD4+ TEP cells and have implications for T cell-related immunotherapies.
Assuntos
Regulação da Expressão Gênica , Linfócitos T Reguladores , Diferenciação CelularAssuntos
Citocinas , Macrófagos , Humanos , Isquemia/etiologia , Isquemia/prevenção & controle , Organoides , Ativação de MacrófagosRESUMO
Understanding the factors that regulate T cell infiltration and functional states in solid tumors is crucial for advancing cancer immunotherapies. Here, we discovered that the expression of interferon regulatory factor 4 (IRF4) was a critical T cell intrinsic requirement for effective anti-tumor immunity. Mice with T-cell-specific ablation of IRF4 showed significantly reduced T cell tumor infiltration and function, resulting in accelerated growth of subcutaneous syngeneic tumors and allowing the growth of allogeneic tumors. Additionally, engineered overexpression of IRF4 in anti-tumor CD8+ T cells that were adoptively transferred significantly promoted their tumor infiltration and transition from a naive/memory-like cell state into effector T cell states. As a result, IRF4-engineered anti-tumor T cells exhibited significantly improved anti-tumor efficacy, and inhibited tumor growth either alone or in combination with PD-L1 blockade. These findings identify IRF4 as a crucial cell-intrinsic driver of T cell infiltration and function in tumors, emphasizing the potential of IRF4-engineering as an immunotherapeutic approach.
Assuntos
Transplante de Rim , Aloenxertos , Automação , Rejeição de Enxerto/diagnóstico , Biópsia , RimRESUMO
Gasdermin D (GSDMD) is a critical mediator of pyroptosis, which consists of a N-terminal pore-forming domain and a C-terminal autoinhibitory domain. Its cytolytic activity is sequestered by the intramolecular autoinhibitory mechanism. Upon caspase-1/11 mediated cleavage of GSDMD, the N-terminal pore-forming domain (GD-NT) is released to mediate pyroptosis. However, it remains unclear how GD-NT is regulated once it is generated. In the current study, we developed a TetOn system in which GD-NT was selectively induced in tumor cells to explore how the cytolytic activity of GD-NT is regulated. We found that the cytolytic activity of GD-NT was negatively regulated by the AMP-activated protein kinase (AMPK) and AMPK activation rendered tumor cells resistant to GD-NT-mediated pyroptosis. Mechanistically, AMPK phosphorylated GD-NT at the serine 46 (pS46-GD), which altered GD-NT oligomerization and subsequently eliminated its pore-forming ability. In our in vivo tumor model, AMPK-mediated phosphorylation abolished GD-NT-induced anti-tumor activity and resulted in an aggressive tumor growth. Thus, our data demonstrate the critical role of AMPK in negatively regulating the cytolytic activity of GD-NT. Our data also highlight an unexpected link between GSDMD-mediated pyroptosis and the AMPK signaling pathway in certain tumor cells.
Assuntos
Proteínas Quinases Ativadas por AMP , Piroptose , Proteínas Quinases Ativadas por AMP/metabolismo , Gasderminas , Fosforilação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Neoplasias/metabolismo , Inflamassomos/metabolismoRESUMO
T-cell-based immunotherapy is gaining momentum in cancer treatment; however, our comprehension of the transcriptional regulation governing T cell antitumor activity remains constrained. The objective of this study was to explore the function of interferon regulatory factor 4 (IRF4) in antitumor CD8+ T cells using the TRAMP-C1 prostate cancer and B16F10 melanoma model. To achieve this, we generated an Irf4GFP-DTR mouse strain and discovered that CD8+ tumor-infiltrating lymphocytes (TILs) expressing high levels of IRF4.GFP exhibited a more differentiated PD-1high cell phenotype. By administering diphtheria toxin to tumor-bearing Irf4GFP-DTR mice, we partially depleted IRF4.GFP+ TILs and observed an accelerated tumor growth. To specifically explore the function of IRF4 in antitumor CD8+ T cells, we conducted 3 adoptive cell therapy (ACT) models. Firstly, depleting IRF4.GFP+ CD8+ TILs derived from ACT significantly accelerated tumor growth, emphasizing their crucial role in controlling tumor progression. Secondly, deleting the Irf4 gene in antitumor CD8+ T cells used for ACT led to a reduction in the frequency and effector differentiation of CD8+ TILs, completely abolishing the antitumor effects of ACT. Lastly, we performed a temporal deletion of the Irf4 gene in antitumor CD8+ T cells during ACT, starting from 20 days after tumor implantation, which significantly compromised tumor control. Therefore, sustained expression of IRF4 is essential for maintaining CD8+ T cell immunity in the melanoma model, and these findings carry noteworthy implications for the advancement of more potent immunotherapies for solid tumors.
RESUMO
OBJECTIVE: This study investigated the ability of pre-transplant T-cell clonality to predict sepsis after liver transplant (LT). SUMMARY BACKGROUND DATA: Sepsis is a leading cause of death in LT recipients. Currently, no biomarkers predict sepsis before clinical symptom manifestation. METHODS: Between December 2013 and March 2018, our institution performed 478 LTs. After exclusions (eg, patients with marginal donor livers, autoimmune disorders, nonabdominal multi-organ, and liver retransplantations), 180 consecutive LT were enrolled. T-cell characterization was assessed within 48âhours before LT (immunoSEQ Assay, Adaptive Biotechnologies, Seattle, WA). Sepsis-2 and Sepsis-3 cases, defined by presence of acute infection plus ≥2 SIRS criteria, or clinical documentation of sepsis, were identified by chart review. Receiver-operating characteristic analyses determined optimal T-cell repertoire clonality for predicting post-LT sepsis. Kaplan-Meier and Cox proportional hazard modeling assessed outcome-associated prognostic variables. RESULTS: Patients with baseline T-cell repertoire clonality ≥0.072 were 3.82 (1.25, 11.40; P = 0.02), and 2.40 (1.00, 5.75; P = 0.049) times more likely to develop sepsis 3 and 12âmonths post-LT, respectively, when compared to recipients with lower (<0.072) clonality. T-cell repertoire clonality was the only predictor of sepsis 3 months post-LT in multivariate analysis (C-Statistic, 0.75). Adequate treatment resulted in equivalent survival rates between both groups: (93.4% vs 96.2%, respectively, P = 0.41) at 12âmonths post-LT. CONCLUSIONS: T-cell repertoire clonality is a novel biomarker predictor of sepsis before development of clinical symptoms. Early sepsis monitoring and management may reduce post-LT mortality. These findings have implications for developing sepsis-prevention protocols in transplantation and potentially other populations.
Assuntos
Hematopoiese Clonal/imunologia , Transplante de Fígado , Receptores de Antígenos de Linfócitos T/imunologia , Sepse/diagnóstico , Idoso , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Período Pré-Operatório , Sepse/imunologiaRESUMO
The exact relationships between group 2 innate lymphoid cells (ILC2s) and Th2 cells in type 2 pathology, as well as the mechanisms that restrain the responses of these cells, remain poorly defined. Here we examined the roles of ILC2s and Th2 cells in type 2 lung pathology in vivo using germline and conditional Relb-deficient mice. We found that mice with germline deletion of Relb (Relb-/-) spontaneously developed prominent type 2 pathology in the lung, which contrasted sharply with mice with T-cell-specific Relb deletion (Relbf/fCd4-Cre), which were healthy with no observed autoimmune pathology. We also found that in contrast to wild-type B6 mice, Relb-deficient mice showed markedly expanded ILC2s but not ILC1s or ILC3s. Moreover, adoptive transfer of naive CD4+ T cells into Rag1-/-Relb-/- hosts induced prominent type 2 lung pathology, which was inhibited by depletion of ILC2s. Mechanistically, we showed that Relb deletion led to enhanced expression of Bcl11b, a key transcription factor for ILC2s. We concluded that RelB plays a critical role in restraining ILC2s, primarily by suppressing Bcl11b activity, and consequently inhibits type 2 lung pathology in vivo.
Assuntos
Proteínas de Homeodomínio/fisiologia , Imunidade Inata , Pulmão/patologia , Linfócitos/patologia , Proteínas Repressoras/metabolismo , Células Th2/imunologia , Fator de Transcrição RelB/fisiologia , Proteínas Supressoras de Tumor/metabolismo , Transferência Adotiva , Animais , Citocinas/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Repressoras/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
Cell encapsulation is an attractive transplantation strategy to treat endocrine disorders. Transplanted cells offer a dynamic and stimulus-responsive system that secretes therapeutics based on patient need. Despite significant advancements, a challenge in allogeneic cell encapsulation is maintaining sufficient oxygen and nutrient exchange, while providing protection from the host immune system. To this end, we developed a subcutaneously implantable dual-reservoir encapsulation system integrating in situ prevascularization and local immunosuppressant delivery, termed NICHE. NICHE structure is 3D-printed in biocompatible polyamide 2200 and comprises of independent cell and drug reservoirs separated by a nanoporous membrane for sustained local release of immunosuppressant. Here we present the development and characterization of NICHE, as well as efficacy validation for allogeneic cell transplantation in an immunocompetent rat model. We established biocompatibility and mechanical stability of NICHE. Further, NICHE vascularization was achieved with the aid of mesenchymal stem cells. Our study demonstrated sustained local elution of immunosuppressant (CTLA4Ig) into the cell reservoir protected transcutaneously-transplanted allogeneic Leydig cells from host immune destruction during a 31-day study, and reduced systemic drug exposure by 12-fold. In summary, NICHE is the first encapsulation platform achieving both in situ vascularization and immunosuppressant delivery, presenting a viable strategy for allogeneic cell transplantation.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Preparações Farmacêuticas , Animais , Encapsulamento de Células , Imunossupressores , Masculino , Ratos , Transplante HomólogoRESUMO
Immunological memory specific to previously encountered antigens is a cardinal feature of adaptive lymphoid cells. However, it is unknown whether innate myeloid cells retain memory of prior antigenic stimulation and respond to it more vigorously on subsequent encounters. In this work, we show that murine monocytes and macrophages acquire memory specific to major histocompatibility complex I (MHC-I) antigens, and we identify A-type paired immunoglobulin-like receptors (PIR-As) as the MHC-I receptors necessary for the memory response. We demonstrate that deleting PIR-A in the recipient or blocking PIR-A binding to donor MHC-I molecules blocks memory and attenuates kidney and heart allograft rejection. Thus, innate myeloid cells acquire alloantigen-specific memory that can be targeted to improve transplant outcomes.
Assuntos
Rejeição de Enxerto/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunidade Inata , Memória Imunológica , Macrófagos/imunologia , Monócitos/imunologia , Receptores Imunológicos/fisiologia , Animais , Deleção de Genes , Rejeição de Enxerto/genética , Transplante de Coração , Transplante de Rim , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Receptores Imunológicos/genéticaRESUMO
Inflammasomes are intracellular complexes that form in the cytosol of inflammatory cells. NLRP3 is one of the sensor proteins in the complex that can recognize a wide variety of stimuli ranging from microbial components to environmental particulates. Here, we report that in mouse airway epithelial cells (AECs), inflammasome activation is inhibited by EphA2, a member of the transmembrane tyrosine kinase receptor family, via tyrosine phosphorylation of NLRP3 in a model of reovirus infection. We find that EphA2 depletion markedly enhances interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) production in response to the virus. EphA2-/- mice show stronger inflammatory infiltration and enhanced inflammasome activation upon viral infection, and aggravated asthma symptoms upon ovalbumin (ova) induction. Mechanistically, EphA2 binds to NLRP3 and induces its phosphorylation at Tyr132, thereby interfering with ASC speck formation and blocking the activation of the NLRP3-inflammasome. These data demonstrate that reovirus employs EphA2 to suppress inflammasome activation in AECs and that EphA2 deficiency causes a pathological exacerbation of asthma in an ova-induced asthma model.
Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Proteínas de Transporte , Células Epiteliais/metabolismo , Inflamassomos/genética , Inflamassomos/metabolismo , Interleucina-18 , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genéticaRESUMO
Exhaustion of T cells limits their ability to clear chronic infections or eradicate tumors. Here, in the context of transplant, we investigated whether T cell exhaustion occurs and has a role in determining transplant outcome. A peptide/MHC tetramer-based approach was used to track exhausted CD8+ T cells in a male-to-female skin transplant model. Transplant of large whole-tail skins, but not small tail skins (0.8 cm × 0.8 cm), led to exhaustion of anti-male tetramer+ CD8+ T cells and subsequently the acceptance of skin grafts. To study CD4+ T cell exhaustion, we used the TCR-transgenic B6 TEa cells that recognize a major transplant antigen I-Eα from Balb/c mice. TEa cells were adoptively transferred either into B6 recipients that received Balb/c donor skins or into CB6F1 mice that contained an excessive amount of I-Eα antigen. Adoptively transferred TEa cells in skin-graft recipients were not exhausted. By contrast, virtually all adoptively transferred TEa cells were exhausted in CB6F1 mice. Those exhausted TEa cells lost ability to reject Balb/c skins upon further transfer into lymphopenic B6.Rag1-/- mice. Hence, T cell exhaustion develops in the presence of abundant antigen and promotes transplant acceptance. These findings are essential for better understanding the nature of transplant tolerance.
Assuntos
Linfócitos T CD8-Positivos , Transplante de Pele , Animais , Linfócitos T CD4-Positivos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
The shift of emphasis from short-term to long-term graft outcomes has led to renewed interests in how the innate immune cells regulate transplant survival, an area that is traditionally dominated by T cells in the adaptive system. This shift is driven largely by the limited efficacy of current immunosuppression protocols which primarily target T cells in preventing chronic graft loss, as well as by the rapid advance of basic sciences in the realm of innate immunity. In fact, the innate immune cells have emerged as key players in the allograft response in various models, contributing to both graft rejection and graft acceptance. Here, we focus on the macrophages, highlighting their diversity, plasticity and emerging features in transplant models, as well as recent developments in our studies of diverse subsets of macrophages. We also discuss challenges, unsolved questions, and emerging approaches in therapeutically modulating macrophages in further improvement of transplant outcomes.
Assuntos
Aloenxertos/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Macrófagos/imunologia , Animais , Antígenos CD/análise , Carragenina/farmacologia , Diferenciação Celular , Linhagem da Célula , Citocinas/imunologia , Humanos , Imunidade Inata , Memória Imunológica , Macrófagos/classificação , Macrófagos/efeitos dos fármacos , Camundongos , Modelos Imunológicos , Células Supressoras Mieloides/imunologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidoresRESUMO
PURPOSE OF REVIEW: Allograft rejection involves both innate and adaptive immune cells, and the adaptive immune cells have dominated transplant studies for decades. Recent studies have identified surprising new features for the innate immune cells, including memory recall responses, which may have significant implications in further improvement of transplant outcomes. RECENT FINDINGS: Transplant survival is excellent in the short-term, but the long-term graft outcomes are not so, and most grafts are continuously lost to chronic rejection in the clinic. In both animal models and clinical settings, graft loss to chronic rejection is often dominated by innate immune cells, especially macrophages and natural killer (NK) cells in the grafts. Recent studies suggest that innate immune cells can acquire features of adaptive cells in that they either directly sense allogeneic nonself or become 'trained' in the allogeneic milieu, where they show features of memory recall responses. In certain models, targeting the adaptive features of such innate immune cells can promote long-term allograft survival. These findings may open new therapeutic opportunities in promoting transplant survival in the clinic. SUMMARY: The discovery of donor specificity and memory recall responses of certain innate immune cells, which are prominently featured in chronic allograft rejection, may open novel therapeutic opportunities in transplantation, as well as in treatment of cancers and autoimmune diseases.
Assuntos
Rejeição de Enxerto/imunologia , Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , HumanosRESUMO
Naive CD4+ T cells can be converted to Foxp3+ T regulatory cells (Tregs) in the periphery (iTregs), where induction of Foxp3 gene expression is central to Treg differentiation. OX40 signaling is known to inhibit Foxp3 expression and Treg induction, but the underlying mechanisms remain poorly defined. Here, we found that OX40 costimulation activates two distinct molecular pathways to suppress Foxp3 expression in freshly activated naive CD4+ T cells. Specifically, OX40 upregulates BATF3 and BATF, which produce a closed chromatin configuration to repress Foxp3 expression in a Sirt1/7-dependent manner. Moreover, OX40 can also activate the AKT-mTOR pathway, especially in the absence of BATF3 and BATF, to inhibit Foxp3 induction, and this is mediated by phosphorylation and nuclear exclusion of the transcription factor Foxo1. Taken together, our results provide key mechanistic insights into how OX40 inhibits Foxp3 expression and Treg induction in the periphery.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Receptores OX40/metabolismo , Proteínas Repressoras/metabolismo , Linfócitos T Reguladores/imunologia , Acetilação , Animais , Sequência de Bases , Montagem e Desmontagem da Cromatina , Loci Gênicos , Histonas/metabolismo , Camundongos Transgênicos , Sirtuínas/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
BACKGROUND: Chronic rejection of transplanted organs is a major obstacle in organ transplantation. The main symptoms of chronic rejection are vessel occlusion and tissue fibrosis. Macrophages play a crucial role in chronic rejection. We showed previously that RhoA deletion or RhoA/Rock inhibition using Y27632 inhibitor reorganizes macrophage actin cytoskeleton, prevents macrophage movement to the cardiac allografts, and abrogates chronic rejection in rodent models. Although besides Y27632 there are other RhoA/ROCK inhibitors available commercially, their efficacy in inhibition of chronic rejection remains unknown. METHODS: We screened four RhoA/Rock inhibitors for their ability to inhibit chronic rejection of BALB/c [H-2d] mouse cardiac allografts heterotopically transplanted into C57BL/6 [H-2b] recipients. We also tested the effect of inhibitors on macrophages in vitro. RESULTS: We found that out of four tested compounds, the Fasudil and Azaindole, inhibited vessel occlusion, tissue fibrosis, decreased M2 macrophage infiltration and abrogated chronic rejection of mouse cardiac allografts. The remaining inhibitors, SAR-407899 and SLX-2119, decreased only tissue fibrosis, and were ineffective or only slightly effective in inhibiting vessel occlusion. We also found that Azaindole and Fasudil affected actin cytoskeleton and protein expression in mouse peritoneal macrophages CONCLUSION: Results of these studies might help in development of anti-chronic rejection therapy for clinical use.