RESUMEN
Cytotoxic CD8 T cells (CTLs) are classically described as the "serial killers" of the immune system, where they play a pivotal role in protective immunity against a wide spectrum of pathogens and tumors. Ironically, they are critical drivers of transplant rejection and autoimmune diseases, a scenario very similar to the famous novel "The strange case of Dr. Jekyll and Mr. Hyde". Until recently, it has not been well-appreciated whether CTLs can also acquire non-cytotoxic functions in health and disease. Several investigations into this question revealed their non-cytotoxic functions through interactions with various immune and non-immune cells. In this review, we will establish a new classification for CD8 T cell functions including cytotoxic and non-cytotoxic. Further, we will discuss this novel concept and speculate on how these functions could contribute to homeostasis of the immune system as well as immunological responses in transplantation, cancer, and autoimmune diseases.
Asunto(s)
Enfermedades Autoinmunes , Neoplasias , Linfocitos T CD8-positivos , Humanos , Linfocitos T CitotóxicosRESUMEN
T cells are endowed with the capacity to sense their environment including other T cells around them. They do so to set their numbers and activation thresholds. This form of regulation has been well-studied within a given T cell population - i.e., within the naïve or memory pool; however, less is known about the cross-talk between T cell subsets. Here, we tested whether memory T cells interact with and influence surrounding naïve T cells. We report that human naïve CD8 T cells (TN) undergo phenotypic and transcriptional changes in the presence of autologous activated-memory CD8 T cells (TMem). Following in vitro co-culture with activated central memory cells (TCM), ~3% of the TN acquired activation/memory canonical markers (CD45RO and CD95) in an MHC-I dependent-fashion. Using scRNA-seq, we also observed that ~3% of the TN acquired an activated/memory signature, while ~84% developed a unique activated transcriptional profile hybrid between naïve and activated memory. Pseudotime trajectory analysis provided further evidence that TN with an activated/memory or hybrid phenotype were derived from TN. Our data reveal a non-cytotoxic function of TMem with potential to activate autologous TN into the activated/memory pool. These findings may have implications for host-protection and autoimmunity that arises after vaccination, infection or transplantation.
Asunto(s)
Memoria Inmunológica , Células T de Memoria , Linfocitos T CD8-positivos , Humanos , Subgrupos de Linfocitos TRESUMEN
Host immunity is classically divided into "innate" and "adaptive." While the former has always been regarded as the first, rapid, and antigen-nonspecific reaction to invading pathogens, the latter represents the more sophisticated and antigen-specific response that has the potential to persist and generate memory. Recent work however has challenged this dogma, where murine studies have successfully demonstrated the ability of innate immune cells (monocytes and macrophages) to acquire antigen-specific memory to allogeneic major histocompatibility complex (MHC) molecules. The immunoreceptors so far identified that mediate innate immune memory are the paired immunoglobulin-like receptors (PIRs) in mice, which are orthologous to human leukocyte immunoglobulin-like receptors (LILRs). These receptor families are mainly expressed by the myelomonocytic cell lineage, suggesting an important role in the innate immune response. In this review, we will discuss the role of immunoglobulin-like receptors in the development of innate immune memory across species.
Asunto(s)
Inmunidad Innata , Memoria Inmunológica , Animales , Inmunoglobulinas , Macrófagos , Ratones , MonocitosRESUMEN
Direct allorecognition, the ability of host T cells to recognize intact allogeneic MHC molecules on transplanted tissues, is often assumed to be less dependent on the peptide bound to the MHC molecule than are other antigen recognition pathways. In this issue of the JCI, Son et al. provide unequivocal, in vivo evidence that direct allorecognition depends on the self-peptides bound to the non-self MHC molecule. The authors demonstrate that the induction of allospecific tolerance required the presentation of self-peptides by the non-self MHC molecule, and that only a handful of these peptides accounted for a sizeable proportion of the immunogenicity of the MHC antigen. These are important findings for transplant immunologists because they provide molecular insights into the biology of direct allorecognition, the prime driver of the alloimmune response to MHC-mismatched grafts, and much-needed tools, peptide-MHC multimers, to track and study polyclonal alloreactive T cells.
Asunto(s)
Isoantígenos , Linfocitos T , Tolerancia Inmunológica , Péptidos , Linfocitos T/inmunologíaRESUMEN
To gain insight into the signaling determinants of effector-associated DNA methylation programming among CD8 T cells, we explore the role of interleukin (IL)-12 in the imprinting of IFNg expression during CD8 T cell priming. We observe that anti-CD3/CD28-mediated stimulation of human naive CD8 T cells is not sufficient to induce substantial demethylation of the IFNg promoter. However, anti-CD3/CD28 stimulation in the presence of the inflammatory cytokine, IL-12, results in stable demethylation of the IFNg locus that is commensurate with IFNg expression. IL-12-associated demethylation of the IFNg locus is coupled to cell division through TET2-dependent demethylation in an ex vivo human chimeric antigen receptor T cell model system and an in vivo immunologically competent murine system. Collectively, these data illustrate that IL-12 signaling promotes TET2-mediated effector DNA demethylation programming in CD8 T cells and serve as proof of concept that cytokines can guide induction of epigenetically regulated traits for T cell-based immunotherapies.
Asunto(s)
Linfocitos T CD8-positivos/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Metilación de ADN/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Dioxigenasas/metabolismo , Interferón gamma/metabolismo , Interleucina-12/farmacología , Coriomeningitis Linfocítica/enzimología , Células T de Memoria/efectos de los fármacos , Animales , Linfocitos T CD8-positivos/enzimología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Proteínas de Unión al ADN/genética , Dioxigenasas/genética , Modelos Animales de Enfermedad , Humanos , Memoria Inmunológica/efectos de los fármacos , Interferón gamma/genética , Coriomeningitis Linfocítica/genética , Coriomeningitis Linfocítica/inmunología , Virus de la Coriomeningitis Linfocítica/inmunología , Virus de la Coriomeningitis Linfocítica/patogenicidad , Células T de Memoria/enzimología , Células T de Memoria/inmunología , Células T de Memoria/virología , Ratones Endogámicos C57BL , Ratones Noqueados , Prueba de Estudio Conceptual , Transducción de SeñalRESUMEN
The pool of beta cell-specific CD8+ T cells in type 1 diabetes (T1D) sustains an autoreactive potential despite having access to a constant source of antigen. To investigate the long-lived nature of these cells, we established a DNA methylation-based T cell 'multipotency index' and found that beta cell-specific CD8+ T cells retained a stem-like epigenetic multipotency score. Single-cell assay for transposase-accessible chromatin using sequencing confirmed the coexistence of naive and effector-associated epigenetic programs in individual beta cell-specific CD8+ T cells. Assessment of beta cell-specific CD8+ T cell anatomical distribution and the establishment of stem-associated epigenetic programs revealed that self-reactive CD8+ T cells isolated from murine lymphoid tissue retained developmentally plastic phenotypic and epigenetic profiles relative to the same cells isolated from the pancreas. Collectively, these data provide new insight into the longevity of beta cell-specific CD8+ T cell responses and document the use of this methylation-based multipotency index for investigating human and mouse CD8+ T cell differentiation.
Asunto(s)
Linfocitos T CD8-positivos/fisiología , Diabetes Mellitus Tipo 1/inmunología , Células Secretoras de Insulina/inmunología , Células Madre Pluripotentes/fisiología , Adolescente , Adulto , Animales , Autoantígenos/inmunología , Plasticidad de la Célula , Células Cultivadas , Metilación de ADN , Epigénesis Genética , Femenino , Citometría de Flujo , Humanos , Memoria Inmunológica , Masculino , Ratones , Análisis de la Célula Individual , Adulto JovenRESUMEN
Cancer arises from the accumulation of genetic alterations, which can lead to the production of mutant proteins not expressed by normal cells. These mutant proteins can be processed and presented on the cell surface by major histocompatibility complex molecules as neoepitopes, allowing CD8+ T cells to mount responses against them. For solid tumors, only an average 2% of neoepitopes predicted by algorithms have detectable endogenous antitumor T cell responses. This suggests that low mutation burden tumors, which include many pediatric tumors, are poorly immunogenic. Here, we report that pediatric patients with acute lymphoblastic leukemia (ALL) have tumor-associated neoepitope-specific CD8+ T cells, responding to 86% of tested neoantigens and recognizing 68% of the tested neoepitopes. These responses include a public neoantigen from the ETV6-RUNX1 fusion that is targeted in seven of nine tested patients. We characterized phenotypic and transcriptional profiles of CD8+ tumor-infiltrating lymphocytes (TILs) at the single-cell level and found a heterogeneous population that included highly functional effectors. Moreover, we observed immunodominance hierarchies among the CD8+ TILs restricted to one or two putative neoepitopes. Our results indicate that robust antitumor immune responses are induced in pediatric ALL despite their low mutation burdens and emphasize the importance of immunodominance in shaping cellular immune responses. Furthermore, these data suggest that pediatric cancers may be amenable to immunotherapies aimed at enhancing immune recognition of tumor-specific neoantigens.
Asunto(s)
Antígenos de Neoplasias/inmunología , Linfocitos T CD8-positivos/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Presentación de Antígeno/inmunología , Niño , Heterogeneidad Genética , Humanos , Epítopos Inmunodominantes/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Reproducibilidad de los Resultados , Transcripción GenéticaRESUMEN
BACKGROUND: Allogeneic hematopoietic stem-cell transplantation for X-linked severe combined immunodeficiency (SCID-X1) often fails to reconstitute immunity associated with T cells, B cells, and natural killer (NK) cells when matched sibling donors are unavailable unless high-dose chemotherapy is given. In previous studies, autologous gene therapy with γ-retroviral vectors failed to reconstitute B-cell and NK-cell immunity and was complicated by vector-related leukemia. METHODS: We performed a dual-center, phase 1-2 safety and efficacy study of a lentiviral vector to transfer IL2RG complementary DNA to bone marrow stem cells after low-exposure, targeted busulfan conditioning in eight infants with newly diagnosed SCID-X1. RESULTS: Eight infants with SCID-X1 were followed for a median of 16.4 months. Bone marrow harvest, busulfan conditioning, and cell infusion had no unexpected side effects. In seven infants, the numbers of CD3+, CD4+, and naive CD4+ T cells and NK cells normalized by 3 to 4 months after infusion and were accompanied by vector marking in T cells, B cells, NK cells, myeloid cells, and bone marrow progenitors. The eighth infant had an insufficient T-cell count initially, but T cells developed in this infant after a boost of gene-corrected cells without busulfan conditioning. Previous infections cleared in all infants, and all continued to grow normally. IgM levels normalized in seven of the eight infants, of whom four discontinued intravenous immune globulin supplementation; three of these four infants had a response to vaccines. Vector insertion-site analysis was performed in seven infants and showed polyclonal patterns without clonal dominance in all seven. CONCLUSIONS: Lentiviral vector gene therapy combined with low-exposure, targeted busulfan conditioning in infants with newly diagnosed SCID-X1 had low-grade acute toxic effects and resulted in multilineage engraftment of transduced cells, reconstitution of functional T cells and B cells, and normalization of NK-cell counts during a median follow-up of 16 months. (Funded by the American Lebanese Syrian Associated Charities and others; LVXSCID-ND ClinicalTrials.gov number, NCT01512888.).
Asunto(s)
Busulfano/administración & dosificación , Terapia Genética , Vectores Genéticos , Subunidad gamma Común de Receptores de Interleucina/genética , Lentivirus , Acondicionamiento Pretrasplante , Enfermedades por Inmunodeficiencia Combinada Ligada al Cromosoma X/terapia , Antígenos de Diferenciación de Linfocitos T/sangre , Linfocitos B/fisiología , Trasplante de Células Madre Hematopoyéticas , Humanos , Inmunoglobulina M/sangre , Lactante , Células Asesinas Naturales , Recuento de Linfocitos , Masculino , Linfocitos T , Enfermedades por Inmunodeficiencia Combinada Ligada al Cromosoma X/genética , Enfermedades por Inmunodeficiencia Combinada Ligada al Cromosoma X/inmunologíaRESUMEN
Memory CD8 T cells have a unique ability to provide lifelong immunity against pathogens containing their cognate epitope. Because of their ability to provide lifelong protection, the generation of memory T cells is now a major focus for current vaccination or adoptive cell therapy approaches to treat chronic viral infections and cancer. It is now clear that maintenance of memory CD8 T cells occurs through a process of antigen-independent homeostatic proliferation, which is regulated in part by the gamma chain cytokines IL-7 and IL-15. Here, we will describe the role of these cytokines in the survival and self-renewal of memory CD8 T cells. Further, we will describe the role of epigenetics in the maintenance of acquired functions among memory CD8 T cells during homeostatic proliferation.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epigénesis Genética/genética , Regulación de la Expresión Génica/genética , Expresión Génica/inmunología , Homeostasis/inmunología , Memoria Inmunológica/inmunología , Animales , Humanos , Interleucina-15/inmunología , Interleucina-7/inmunología , Activación de Linfocitos/inmunología , Ratones , Transducción de Señal/inmunologíaRESUMEN
In vivo persistence of chimeric antigen receptor (CAR)-modified T cells correlates with therapeutic efficacy, yet CAR-specific factors that support persistence are not well resolved. Using a CD33-specific CAR in an acute myeloid leukemia (AML) model, we show how CAR expression alters T cell differentiation in a ligand independent manner. Ex vivo expanded CAR-T cells demonstrated decreased naïve and stem memory populations and increased effector subsets relative to vector-transduced control cells. This was associated with reduced in vivo persistence. Decreased persistence was not due to specificity or tumor presence, but to pre-transfer tonic signaling through the CAR CD3ζ ITAMs. We identified activation of the PI3K pathway in CD33 CAR-T cells as responsible. Treatment with a PI3K inhibitor modulated the differentiation program of CAR-T cells, preserved a less differentiated state without affecting T cell expansion, and improved in vivo persistence and reduced tumor burden. These results resolve mechanisms by which tonic signaling of CAR-T cells modulates their fate, and identifies a novel pharmacologic approach to enhance the durability of CAR-T cells for immunotherapy.
Asunto(s)
Inmunoterapia Adoptiva/métodos , Leucemia Mieloide Aguda/terapia , Fosfatidilinositol 3-Quinasas/metabolismo , Receptores Quiméricos de Antígenos/uso terapéutico , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Humanos , Activación de Linfocitos/efectos de los fármacos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Lectina 3 Similar a Ig de Unión al Ácido Siálico/farmacología , Lectina 3 Similar a Ig de Unión al Ácido Siálico/uso terapéutico , Linfocitos T , Carga Tumoral/efectos de los fármacosRESUMEN
The differentiation of human memory CD8 T cells is not well understood. Here we address this issue using the live yellow fever virus (YFV) vaccine, which induces long-term immunity in humans. We used in vivo deuterium labelling to mark CD8 T cells that proliferated in response to the virus and then assessed cellular turnover and longevity by quantifying deuterium dilution kinetics in YFV-specific CD8 T cells using mass spectrometry. This longitudinal analysis showed that the memory pool originates from CD8 T cells that divided extensively during the first two weeks after infection and is maintained by quiescent cells that divide less than once every year (doubling time of over 450 days). Although these long-lived YFV-specific memory CD8 T cells did not express effector molecules, their epigenetic landscape resembled that of effector CD8 T cells. This open chromatin profile at effector genes was maintained in memory CD8 T cells isolated even a decade after vaccination, indicating that these cells retain an epigenetic fingerprint of their effector history and remain poised to respond rapidly upon re-exposure to the pathogen.
Asunto(s)
Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/inmunología , Epigénesis Genética , Memoria Inmunológica/inmunología , Vacuna contra la Fiebre Amarilla/inmunología , Animales , Linfocitos T CD8-positivos/metabolismo , Diferenciación Celular/genética , Proliferación Celular , Cromatina/genética , Cromatina/metabolismo , Metilación de ADN , Deuterio , Perfilación de la Expresión Génica , Semivida , Humanos , Memoria Inmunológica/genética , Recuento de Linfocitos , Ratones , Técnica de Dilución de Radioisótopos , Transcripción Genética , Fiebre Amarilla/inmunología , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/inmunologíaRESUMEN
Long-lived T-cell-mediated immunity requires persistence of memory T cells in an antigen-free environment while also maintaining a heightened capacity to recall effector functions. Such antigen-independent homeostatic proliferation is mediated in part by the common gamma-chain cytokines IL-7 and IL-15. To further explore the mechanisms governing maintenance of effector functions in long-lived memory T cells during antigen-independent proliferation, human naïve and memory CD8 T cells can be sorted from peripheral blood mononuclear cells (PBMCs), labeled with the proliferation-tracking dye carboxyfluorescein succinimidyl ester (CFSE), and then purified based on their levels of cell division. This allows investigators to assess differences in the desired molecular target in cells that have undergone cytokine-driven proliferation. We provide here a protocol for assessing epigenetic programs in divided and undivided human naïve and memory CD8 T cells following 7 days in culture with IL-7 and IL-15 to illustrate how this approach can shed light on the mechanism(s) that governs the preservation of effector functions during homeostasis of long-lived memory CD8 T cells.
RESUMEN
Infection of the central nervous system (CNS) by murine polyomavirus (MuPyV), a persistent natural mouse pathogen, establishes brain-resident memory CD8 T cells (bTRM) that uniformly and chronically express programmed cell death protein 1 (PD-1) irrespective of the expression of αE integrin CD103, a TRM cell marker. In contrast, memory antiviral CD8 T cells in the spleen are PD-1-, despite viral loads being similar in both the brain and spleen during persistent infection. Repetitive antigen engagement is central to sustained PD-1 expression by T cells in chronic viral infections; however, recent evidence indicates that expression of inhibitory receptors, including PD-1, is part of the TRM differentiation program. Here we asked whether PD-1 expression by CD8 bTRM cells during persistent MuPyV encephalitis is antigen dependent. By transferring MuPyV-specific CD8 bTRM cells into the brains of naive mice and mice infected with cognate epitope-sufficient and -deficient MuPyVs, we demonstrate that antigen and inflammation are dispensable for PD-1 maintenance. In vitro and direct ex vivo analyses indicate that CD103- MuPyV-specific CD8 bTRM retain functional competence. We further show that the Pdcd-1 promoter of anti-MuPyV bTRM cells is epigenetically fixed in a demethylated state in the brain. In contrast, the PD-1 promoter of splenic antiviral memory CD8 T cells undergoes remethylation after being demethylated during acute infection. These data show that PD-1 expression is an intrinsic property of brain TRM cells in a persistent CNS viral infection.
Asunto(s)
Encéfalo/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por Polyomavirus/inmunología , Poliomavirus/fisiología , Receptor de Muerte Celular Programada 1/metabolismo , Traslado Adoptivo , Animales , Encéfalo/virología , Linfocitos T CD8-positivos/virología , Diferenciación Celular , Células Cultivadas , Epigénesis Genética , Epítopos de Linfocito T/inmunología , Femenino , Regulación de la Expresión Génica , Memoria Inmunológica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor de Muerte Celular Programada 1/genética , Carga ViralRESUMEN
Immune-checkpoint-blockade (ICB)-mediated rejuvenation of exhausted T cells has emerged as a promising approach for treating various cancers and chronic infections. However, T cells that become fully exhausted during prolonged antigen exposure remain refractory to ICB-mediated rejuvenation. We report that blocking de novo DNA methylation in activated CD8 T cells allows them to retain their effector functions despite chronic stimulation during a persistent viral infection. Whole-genome bisulfite sequencing of antigen-specific murine CD8 T cells at the effector and exhaustion stages of an immune response identified progressively acquired heritable de novo methylation programs that restrict T cell expansion and clonal diversity during PD-1 blockade treatment. Moreover, these exhaustion-associated DNA-methylation programs were acquired in tumor-infiltrating PD-1hi CD8 T cells, and approaches to reverse these programs improved T cell responses and tumor control during ICB. These data establish de novo DNA-methylation programming as a regulator of T cell exhaustion and barrier of ICB-mediated T cell rejuvenation.
Asunto(s)
Linfocitos T CD8-positivos/citología , Epigénesis Genética , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Adenocarcinoma/tratamiento farmacológico , Animales , Linfocitos T CD8-positivos/inmunología , Metilación de ADN , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Neoplasias de la Próstata/tratamiento farmacológico , Virosis/tratamiento farmacológicoRESUMEN
Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell-mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (TEM), and longer-lived central memory (TCM) and stem cell memory (TSCM) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7- and IL-15-mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of TCM and TSCM memory cells resulted in phenotypic conversion into TEM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired TEM-associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epigénesis Genética , Homeostasis/genética , Homeostasis/inmunología , Memoria Inmunológica/genética , Traslado Adoptivo , Linfocitos T CD8-positivos/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Proliferación Celular/efectos de los fármacos , Reprogramación Celular/efectos de los fármacos , Reprogramación Celular/genética , Citocinas/farmacología , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Epigénesis Genética/efectos de los fármacos , Sitios Genéticos , Genoma Humano , Trasplante de Células Madre Hematopoyéticas , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Homeostasis/efectos de los fármacos , Humanos , Huésped Inmunocomprometido , Memoria Inmunológica/efectos de los fármacos , Subgrupos Linfocitarios/efectos de los fármacos , Subgrupos Linfocitarios/inmunología , Fenotipo , Receptores CCR7/metabolismo , Donantes de TejidosRESUMEN
T-cell-based immunological memory has the potential to provide the host with life-long protection against pathogen reexposure and thus offers tremendous promise for the design of vaccines targeting chronic infections or cancer. In order to exploit this potential in the design of new vaccines, it is necessary to understand how and when memory T cells acquire their poised effector potential, and moreover, how they maintain these properties during homeostatic proliferation. To gain insight into the persistent nature of memory T-cell functions, investigators have turned their attention to epigenetic mechanisms. Recent efforts have revealed that many of the properties acquired among memory T cells are coupled to stable changes in DNA methylation and histone modifications. Furthermore, it has recently been reported that the delineating features among memory T cells subsets are also linked to distinct epigenetic events, such as permissive and repressive histone modifications and DNA methylation programs, providing exciting new hypotheses regarding their cellular ancestry. Here, we review recent studies focused on epigenetic programs acquired during effector and memory T-cell differentiation and discuss how these data may shed new light on the developmental path for generating long-lived CD8(+) T-cell memory.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Epigénesis Genética , Regulación de la Expresión Génica , Memoria Inmunológica/genética , Animales , Linfocitos T CD8-positivos/citología , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Reprogramación Celular/genética , Reprogramación Celular/inmunología , Metilación de ADN , Histonas/metabolismo , Humanos , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Transcripción GenéticaRESUMEN
Glioma is a brain tumor that arises from glial cells or glial progenitor cells, and represents 80% of malignant brain tumor incidence in the United States. Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor malignancy with fewer than 8% of patients with GBM surviving for more than 3 years. Over the past 10 years, despite improvement in diagnosis and therapies for cancer, the survival rate for high-grade glioma patients remains dismal. The main focus of our research is to identify potent novel antiglioma small molecules. We previously showed that EDL-360, a tetrahydroisoquinoline (THIQ) analog, as being highly cytotoxic to human glioma cell cultures. Here we show that EDL-360 significantly induced apoptosis in human glioma cell lines (U87 and LN18). However, in normal astrocytic cells, EDL-360 induced a modest G0/G1 cell cycle arrest but did not induce apoptosis. In an attempt to enhance EDL-360 induced cell death, we tested simultaneous treatment with EDL-360 and embelin (an inhibitor of the anti-apoptotic protein, XIAP). We found that, glioma cells had significant lower viability when EDL-360 and embelin were used in combination when compared to EDL-360 alone. We also used combination treatment of EDL-360 with decylubiquinone (dUb), a caspase-9 inhibitor, and found that the combination treatment induced a significant cell death when compared to treatment with EDL-360 alone. This is the first report that suggests that dUb has anticancer activity, and perhaps acts as a XIAP inhibitor. Finally, our in vivo data showed that EDL-360 treatment induced a partial regression in glioma tumorigenesis and induced cell death in the treated tumors as shown by H&E staining. Taken together these data suggests that EDL-360 has a potential therapeutic application for treating glioma, especially when combined with XIAP inhibitors.
RESUMEN
We showed previously that nonmyeloablative total lymphoid irradiation/rabbit anti-thymocyte serum (TLI/ATS) conditioning facilitates potent donor-recipient immune tolerance following bone marrow transplantation (BMT) across MHC barriers via recipient invariant NKT (iNKT) cell-derived IL-4-dependent expansion of donor Foxp3(+) naturally occurring regulatory T cells (nTregs). In this study, we report a more specific mechanism. Wild-type (WT) BALB/c (H-2(d)) hosts were administered TLI/ATS and BMT from WT or STAT6(-/-) C57BL/6 (H-2(b)) donors. Following STAT6(-/-) BMT, donor nTregs demonstrated no loss of proliferation in vivo, indicating that an IL-4-responsive population in the recipient, rather than the donor, drives donor nTreg proliferation. In graft-versus-host disease (GVHD) target organs, three recipient CD11b(+) cell subsets (Gr-1(high)CD11c(-), Gr-1(int)CD11c(-), and Gr-1(low)CD11c(+)) were enriched early after TLI/ATS + BMT versus total body irradiation/ATS + BMT. Gr-1(low)CD11c(+) cells induced potent H-2K(b+)CD4(+)Foxp3(+) nTreg proliferation in vitro in 72-h MLRs. Gr-1(low)CD11c(+) cells were reduced significantly in STAT6(-/-) and iNKT cell-deficient Jα18(-/-) BALB/c recipients after TLI/ATS + BMT. Depletion of CD11b(+) cells resulted in severe acute GVHD, and adoptive transfer of WT Gr-1(low)CD11c(+) cells to Jα18(-/-) BALB/c recipients of TLI/ATS + BMT restored day-6 donor Foxp3(+) nTreg proliferation and protection from CD8 effector T cell-mediated GVHD. Blockade of programmed death ligand 1 and 2, but not CD40, TGF-ß signaling, arginase 1, or iNOS, inhibited nTreg proliferation in cocultures of recipient-derived Gr-1(low)CD11c(+) cells with donor nTregs. Through iNKT-dependent Th2 polarization, myeloid-derived immunomodulatory dendritic cells are expanded after nonmyeloablative TLI/ATS conditioning and allogeneic BMT, induce PD-1 ligand-dependent donor nTreg proliferation, and maintain potent graft-versus-host immune tolerance.
Asunto(s)
Trasplante de Médula Ósea , Células Dendríticas/inmunología , Factores de Transcripción Forkhead/metabolismo , Células Mieloides/inmunología , Linfocitos T Reguladores/inmunología , Tolerancia al Trasplante/inmunología , Animales , Antígeno CD11c , Antígenos CD4/metabolismo , Proliferación Celular , Factores de Transcripción Forkhead/genética , Inmunomodulación , Irradiación Linfática , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Receptor de Muerte Celular Programada 1/metabolismo , Factor de Transcripción STAT6/genética , Donantes de TejidosRESUMEN
Chlamydia trachomatis infections are a global health problem. This obligate intracellular bacterial pathogen comprises lymphogranuloma venereum (L1-L3), ocular (A-C) and genital (D-K) serovars. Although genetically similar, each serovar group differs in disease severity and tissue tropism through mechanisms that are not well understood. It is clear that host genetic differences also play a role in chlamydial disease outcome and key host polymorphisms are beginning to emerge from both human and experimental animal studies. In this review, we will highlight pathogen and host genes that link genetic diversity, disease severity and tissue tropism. We will also use this information to provide new insights that may be helpful in developing improved management strategies for these important pathogens.
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Infecciones por Chlamydia/microbiología , Infecciones por Chlamydia/patología , Chlamydia trachomatis/clasificación , Chlamydia trachomatis/genética , Variación Genética , Interacciones Huésped-Patógeno , Animales , Modelos Animales de Enfermedad , HumanosRESUMEN
Hypersensitivity pneumonitis (HP) is an interstitial lung disease that develops following repeated exposure to environmental antigens. The disease results in alveolitis, granuloma formation and may progress to a fibrotic chronic form, which is associated with significant morbidity and mortality. The severity of the disease correlates with a neutrophil rich influx and an IL-17 response. We used the Saccharopolysporarectivirgula (SR) model of HP to determine whether Toll-like receptors (TLR) 2 and 9 cooperate in neutrophil recruitment and IL-17-associated cytokine production during the development of HP. Stimulation of bone marrow derived macrophages (BMDMs) from C57BL/6, MyD88(-/-) and TLR2/9(-/-) mice with SR demonstrate that SR is a strong inducer of neutrophil chemokines and growth factors. The cytokines induced by SR were MyD88-dependent and, of those, most were partially or completely dependent on TLRs 2 and 9. Following in vivo exposure to SR, CXCL2 production and neutrophil recruitment were reduced in TLR2(-/-) and TLR2/9(-/-) mice suggesting that the response was largely dependent on TLR2; however the reduction was greatest in the TLR2/9(-/-) double knockout mice indicating TLR9 may also contribute to the response. There was a reduction in the levels of pro-inflammatory cytokines TNFα and IL-6 as well as CCL3 and CCL4 in the BALF from TLR2/9(-/-) mice compared to WT and single knockout (SKO) mice exposed one time to SR. The decrease in neutrophil recruitment and TNFα production in the TLR2/9(-/-) mice was maintained throughout 3 weeks of SR exposures in comparison to WT and SKO mice. Both TLRs 2 and 9 contributed to the Th17 response; there was a decrease in Th17 cells and IL-17 mRNA in the TLR2/9(-/-) mice in comparison to the WT and SKO mice. Despite the effects on neutrophil recruitment and the IL-17 response, TLR2/9(-/-) mice developed granuloma formation similarly to WT and SKO mice suggesting that there are additional mediators and pattern recognition receptors involved in the disease.