RESUMEN
Most aspects of physiology, including immunity, present 24-h variations called circadian rhythms. In this review, we examine the literature on the circadian regulation of CD8+ T cells, which are important to fight intracellular infections and tumors. CD8+ T cells express circadian clock genes, and â¼6% of their transcriptome presents circadian oscillations. CD8+ T cell counts present 24-h rhythms in the blood and in secondary lymphoid organs, which depend on the clock in these cells as well as on hormonal rhythms. Moreover, the strength of the response of these cells to Ag presentation varies according to time of day, a rhythm dependent on the CD8+ T cell clock. The relevance of CD8+ T cell circadian rhythms is shown by the daily variations in the fight of intracellular infections. Such a circadian regulation also has implications for cancer, as well as the optimization of vaccination and immunotherapy.
Asunto(s)
Relojes Circadianos , Relojes Circadianos/genética , Ritmo Circadiano/fisiología , Linfocitos T Citotóxicos , Linfocitos T CD8-positivosRESUMEN
Type 1 diabetes is an autoimmune disease characterized by pancreatic ß cell destruction. It is a complex genetic trait driven by >30 genetic loci with parallels between humans and mice. The NOD mouse spontaneously develops autoimmune diabetes and is widely used to identify insulin-dependent diabetes (Idd) genetic loci linked to diabetes susceptibility. Although many Idd loci have been extensively studied, the impact of the Idd2 locus on autoimmune diabetes susceptibility remains to be defined. To address this, we generated a NOD congenic mouse bearing B10 resistance alleles on chromosome 9 in a locus coinciding with part of the Idd2 locus and found that NOD.B10-Idd2 congenic mice are highly resistant to diabetes. Bone marrow chimera and adoptive transfer experiments showed that the B10 protective alleles provide resistance in an immune cell-intrinsic manner. Although no T cell-intrinsic differences between NOD and NOD.B10-Idd2 mice were observed, we found that the Idd2 resistance alleles limit the formation of spontaneous and induced germinal centers. Comparison of B cell and dendritic cell transcriptome profiles from NOD and NOD.B10-Idd2 mice reveal that resistance alleles at the Idd2 locus affect the expression of specific MHC molecules, a result confirmed by flow cytometry. Altogether, these data demonstrate that resistance alleles at the Idd2 locus impair germinal center formation and influence MHC expression, both of which likely contribute to reduced diabetes incidence.
Asunto(s)
Autoinmunidad , Diabetes Mellitus Tipo 1/etiología , Diabetes Mellitus Tipo 1/metabolismo , Sitios Genéticos , Predisposición Genética a la Enfermedad , Complejo Mayor de Histocompatibilidad/genética , Alelos , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Diabetes Mellitus Tipo 1/diagnóstico , Modelos Animales de Enfermedad , Resistencia a la Enfermedad/genética , Variación Genética , Prueba de Tolerancia a la Glucosa , Cambio de Clase de Inmunoglobulina/genética , Cambio de Clase de Inmunoglobulina/inmunología , Ratones , Ratones Congénicos , Ratones Endogámicos NOD , Ratones Noqueados , Fenotipo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
Central tolerance aims to limit the production of T lymphocytes bearing TCR with high affinity for self-peptide presented by MHC molecules. The accumulation of thymocytes with such receptors is limited by negative selection or by diversion into alternative differentiation, including T regulatory cell commitment. A role for the orphan nuclear receptor NR4A3 in negative selection has been suggested, but its function in this process has never been investigated. We find that Nr4a3 transcription is upregulated in postselection double-positive thymocytes, particularly those that have received a strong selecting signal and are destined for negative selection. Indeed, we found an accumulation of cells bearing a negative selection phenotype in NR4A3-deficient mice as compared with wild-type controls, suggesting that Nr4a3 transcriptional induction is necessary to limit accumulation of self-reactive thymocytes. This is consistent with a decrease of cleaved caspase-3+-signaled thymocytes and more T regulatory and CD4+Foxp3-HELIOS+ cells in the NR4A3-deficient thymus. We further tested the role for NR4A3 in negative selection by reconstituting transgenic mice expressing the OVA Ag under the control of the insulin promoter with bone marrow cells from OT-I Nr4a3 +/+ or OT-I Nr4a3 -/- mice. Accumulation of autoreactive CD8 thymocytes and autoimmune diabetes developed only in the absence of NR4A3. Overall, our results demonstrate an important role for NR4A3 in T cell development.
Asunto(s)
Diabetes Mellitus Tipo 1 , Receptores de Esteroides , Animales , Proteínas de Unión al ADN , Ratones , Ratones Transgénicos , Proteínas del Tejido Nervioso , Receptores de Hormona Tiroidea , Timocitos , Factores de TranscripciónRESUMEN
Enhancing long-term persistence while simultaneously potentiating the effector response of CD8+ T cells has been a long-standing goal in immunology to produce better vaccines and adoptive cell therapy products. NR4A3 is a transcription factor of the orphan nuclear receptor family. While it is rapidly and transiently expressed following T cell activation, its role in the early stages of T cell response is unknown. We show that NR4A3-deficient murine CD8+ T cells differentiate preferentially into memory precursor and central memory cells, but also produce more cytokines. This is explained by an early influence of NR4A3 deficiency on the memory transcriptional program and on accessibility of chromatin regions with motifs for bZIP transcription factors, which impacts the transcription of Fos/Jun target genes. Our results reveal a unique and early role for NR4A3 in programming CD8+ T cell differentiation and function. Manipulating NR4A3 activity may represent a promising strategy to improve vaccination and T cell therapy.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Proteínas de Unión al ADN/inmunología , Proteínas del Tejido Nervioso/inmunología , Receptores de Esteroides/inmunología , Receptores de Hormona Tiroidea/inmunología , Animales , Linfocitos T CD8-positivos/citología , Diferenciación Celular , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica , Memoria Inmunológica , Ratones , Proteínas del Tejido Nervioso/genética , Receptores de Esteroides/genética , Receptores de Hormona Tiroidea/genética , Factores de Transcripción/genética , Factores de Transcripción/inmunologíaRESUMEN
Notch signaling is emerging as a critical regulator of T cell activation and function. However, there is no reliable cell surface indicator of Notch signaling across activated T cell subsets. In this study, we show that Notch signals induce upregulated expression of the Gcnt1 glycosyltransferase gene in T cells mediating graft-versus-host disease after allogeneic bone marrow transplantation in mice. To determine if Gcnt1-mediated O-glycosylation could be used as a Notch signaling reporter, we quantified the core-2 O-glycoform of CD43 in multiple T cell subsets during graft-versus-host disease. Pharmacological blockade of Delta-like Notch ligands abrogated core-2 O-glycosylation in a dose-dependent manner after allogeneic bone marrow transplantation, both in donor-derived CD4+ and CD8+ effector T cells and in Foxp3+ regulatory T cells. CD43 core-2 O-glycosylation depended on cell-intrinsic canonical Notch signals and identified CD4+ and CD8+ T cells with high cytokine-producing ability. Gcnt1-deficient T cells still drove lethal alloreactivity, showing that core-2 O-glycosylation predicted, but did not cause, Notch-dependent T cell pathogenicity. Using core-2 O-glycosylation as a marker of Notch signaling, we identified Ccl19-Cre+ fibroblastic stromal cells as critical sources of Delta-like ligands in graft-versus-host responses irrespective of conditioning intensity. Core-2 O-glycosylation also reported Notch signaling in CD8+ T cell responses to dendritic cell immunization, Listeria infection, and viral infection. Thus, we uncovered a role for Notch in controlling core-2 O-glycosylation and identified a cell surface marker to quantify Notch signals in multiple immunological contexts. Our findings will help refine our understanding of the regulation, cellular source, and timing of Notch signals in T cell immunity.
Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Linfocitos T CD8-positivos/metabolismo , Enfermedad Injerto contra Huésped/inmunología , N-Acetilglucosaminiltransferasas/metabolismo , Receptores Notch/metabolismo , Animales , Biomarcadores/metabolismo , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Estudios de Factibilidad , Femenino , Citometría de Flujo/métodos , Glicosilación/efectos de los fármacos , Humanos , Leucosialina/metabolismo , Ligandos , Activación de Linfocitos/efectos de los fármacos , Masculino , Ratones , Sensibilidad y Especificidad , Sialomucinas/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Células del Estroma/inmunología , Células del Estroma/metabolismo , Trasplante Homólogo/efectos adversos , Regulación hacia ArribaRESUMEN
Circadian variations of various aspects of the immune system have been described. However, the circadian control of T cells has been relatively unexplored. Here, we investigated the role of circadian clocks in regulating CD8 T cell response to antigen presentation by dendritic cells (DCs). The in vivo CD8 T cell response following vaccination with DCs loaded with the OVA257-264 peptide antigen (DC-OVA) leads to a higher expansion of OVA-specific T cells in response to vaccination done in the middle of the day, compared to other time points. This rhythm was dampened when DCs deficient for the essential clock gene Bmal1 were used and abolished in mice with a CD8 T cell-specific Bmal1 deletion. Thus, we assessed the circadian transcriptome of CD8 T cells and found an enrichment in the daytime of genes and pathways involved in T cell activation. Based on this, we investigated early T cell activation events. Three days postvaccination, we found higher T cell activation markers and related signaling pathways (including IRF4, mTOR, and AKT) after a vaccination done during the middle of the day compared to the middle of the night. Finally, the functional impact of the stronger daytime response was shown by a more efficient response to a bacterial challenge at this time of day. Altogether, these results suggest that the clock of CD8 T cells modulates the response to vaccination by shaping the transcriptional program of these cells and making them more prone to strong and efficient activation and proliferation according to the time of day.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Relojes Circadianos/inmunología , Ritmo Circadiano/inmunología , Transducción de Señal , Presentación de Antígeno/inmunología , Antígenos/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Activación de Linfocitos/inmunología , Modelos Biológicos , VacunaciónRESUMEN
In response to microbial stimulation, monocytes can differentiate into macrophages or monocyte-derived dendritic cells (MoDCs) but the molecular requirements guiding these possible fates are poorly understood. In addition, the physiological importance of MoDCs in the host cellular and immune responses to microbes remains elusive. Here, we demonstrate that the nuclear orphan receptor NR4A3 is required for the proper differentiation of MoDCs but not for other types of DCs. Indeed, the generation of DC-SIGN+ MoDCs in response to LPS was severely impaired in Nr4a3-/- mice, which resulted in the inability to mount optimal CD8+ T cell responses to gram-negative bacteria. Transcriptomic analyses revealed that NR4A3 is required to skew monocyte differentiation toward MoDCs, at the expense of macrophages, and allows the acquisition of migratory characteristics required for MoDC function. Altogether, our data identify that the NR4A3 transcription factor is required to guide the fate of monocytes toward MoDCs.
Asunto(s)
Linaje de la Célula/inmunología , Proteínas de Unión al ADN/genética , Células Dendríticas/inmunología , Lipopolisacáridos/farmacología , Monocitos/inmunología , Proteínas del Tejido Nervioso/genética , Receptores de Esteroides/genética , Receptores de Hormona Tiroidea/genética , Animales , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/inmunología , Diferenciación Celular , Linaje de la Célula/genética , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/inmunología , Células Dendríticas/citología , Células Dendríticas/efectos de los fármacos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Interleucina-4/farmacología , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Activación de Linfocitos , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Ratones Noqueados , Monocitos/citología , Monocitos/efectos de los fármacos , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/inmunología , Cultivo Primario de Células , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Receptores de Esteroides/deficiencia , Receptores de Esteroides/inmunología , Receptores de Hormona Tiroidea/deficiencia , Receptores de Hormona Tiroidea/inmunología , Transducción de Señal , Linfocitos T/citología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunologíaRESUMEN
Graft-versus-host disease (GVHD) is the most serious complication of allogeneic hematopoietic cell transplantation. Notch signals delivered during the first 48 h after transplantation drive proinflammatory cytokine production in conventional T cells (Tconv) and inhibit the expansion of regulatory T cells (Tregs). Short-term Notch inhibition induces long-term GVHD protection. However, it remains unknown whether Notch blockade blunts GVHD through its effects on Tconv, Tregs, or both and what early Notch-regulated molecular events occur in alloantigen-specific T cells. To address these questions, we engineered T cell grafts to achieve selective Notch blockade in Tconv versus Tregs and evaluated their capacity to trigger GVHD in mice. Notch blockade in Tconv was essential for GVHD protection as GVHD severity was similar in the recipients of wild-type Tconv combined with Notch-deprived versus wild-type Tregs. To identify the impact of Notch signaling on the earliest steps of T cell activation in vivo, we established a new acute GVHD model mediated by clonal alloantigen-specific 4C CD4+ Tconv. Notch-deprived 4C T cells had preserved early steps of activation, IL-2 production, proliferation, and Th cell polarization. In contrast, Notch inhibition dampened IFN-γ and IL-17 production, diminished mTORC1 and ERK1/2 activation, and impaired transcription of a subset of Myc-regulated genes. The distinct Notch-regulated signature had minimal overlap with known Notch targets in T cell leukemia and developing T cells, highlighting the specific impact of Notch signaling in mature T cells. Our findings uncover a unique molecular program associated with the pathogenic effects of Notch in T cells at the earliest stages of GVHD.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Enfermedad Injerto contra Huésped/inmunología , Isoantígenos/inmunología , Receptores Notch/inmunología , Animales , Trasplante de Médula Ósea/efectos adversos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Transducción de Señal/inmunología , Linfocitos T Reguladores/inmunología , Trasplante Homólogo/efectos adversosRESUMEN
Vaccination with antigen-pulsed CD40-activated B (CD40-B) cells can efficiently lead to the in vivo differentiation of naive CD8+ T cells into fully functional effectors. In contrast to bone marrow-derived dendritic cell (BMDC) vaccination, CD40-B cell priming does not allow for memory CD8+ T-cell generation but the reason for this deficiency is unknown. Here, we show that compared to BMDCs, murine CD40-B cells induce lower expression of several genes regulated by T-cell receptor signaling, costimulation, and inflammation (signals 1-3) in mouse T cells. The reduced provision of signals 1 and 2 by CD40-B cells can be explained by a reduction in the quality and duration of the interactions with naive CD8+ T cells as compared to BMDCs. Furthermore, CD40-B cells produce less inflammatory mediators, such as IL-12 and type I interferon, and increasing inflammation by coadministration of polyriboinosinic-polyribocytidylic acid with CD40-B-cell immunization allowed for the generation of long-lived and functional CD8+ memory T cells. In conclusion, it is possible to manipulate CD40-B-cell vaccination to promote the formation of long-lived functional CD8+ memory T cells, a key step before translating the use of CD40-B cells for therapeutic vaccination.
Asunto(s)
Linfocitos B/inmunología , Células de la Médula Ósea/inmunología , Linfocitos T CD8-positivos/inmunología , Inflamación/inmunología , Polinucleótidos/administración & dosificación , Animales , Linfocitos B/trasplante , Antígenos CD40/metabolismo , Ligando de CD40/genética , Ligando de CD40/metabolismo , Diferenciación Celular , Células Cultivadas , Técnicas de Cocultivo , Fibroblastos/inmunología , Fibroblastos/metabolismo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Humanos , Memoria Inmunológica , Interleucina-4/inmunología , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Poli I-C , VacunaciónRESUMEN
Diverse signals received by CD8+ T cells are integrated to achieve the required magnitude of cell expansion and the appropriate balance of effector/memory CD8+ T cell generation. Notably, the strength and nature of TCR signaling influence the differentiation and functional capacity of effector and memory CD8+ T cells. Dok-1 and Dok-2, the two members of the Dok family expressed in T cells, negatively regulate TCR signaling in vitro. However, the role of Dok proteins in modulating T cell function in vivo has not yet studied. We studied the function of Dok-1 and Dok-2 proteins in the regulation of the CD8+ T cell response to vaccinia virus infection. Comparison of responses to vaccinia virus expressing OVA peptide SIINFEKL by wild-type and Dok-1/2-/- CD8+ OT-I cells showed that the absence of Dok-1 and Dok-2 slightly reduced the magnitude of virus-specific effector CD8+ T cell expansion. This was not due to reduced proliferation or enhanced apoptosis of effector CD8+ T cells. Dok-1/2-deficient effector CD8+ T cells showed increased cell surface TCR expression following virus infection in vivo and increased expression of granzyme B and TNF upon stimulation with peptide Ag ex vivo. Finally, Dok-1/2-deficient effector CD8+ T had a severe defect in survival that resulted in impaired generation of memory CD8+ T cells. These results reveal the critical involvement of Dok-1 and Dok-2 in a negative-feedback loop that prevents overactivation of CD8+ T cells and promotes memory formation.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Linfocitos T CD8-positivos/inmunología , Proteínas de Unión al ADN/metabolismo , Memoria Inmunológica , Fosfoproteínas/metabolismo , Proteínas de Unión al ARN/metabolismo , Vaccinia/inmunología , Virosis/inmunología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Linfocitos T CD8-positivos/virología , Diferenciación Celular , Supervivencia Celular , Células Cultivadas , Proteínas de Unión al ADN/genética , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosfoproteínas/genética , Proteínas de Unión al ARN/genética , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Transducción de SeñalRESUMEN
To stimulate a productive T cell response, dendritic cells (DC) must undergo maturation characterized by heightened cell surface expression of MHC and costimulatory molecules as well as cytokine production. Conversely, the inhibition of DC maturation is a central mechanism of immune tolerance. The control of the DC maturation process relies on the integration of several cellular stimulatory or inhibitory signals. The soluble factors and their receptors controlling this central aspect of DC biology are incompletely characterized. We show that murine bone marrow-derived DC (BMDC) maturation induced by LPS, as opposed to polyinosinic:polycytidylic acid or cytosine-phosphate-guanine, is robustly inhibited by vascular endothelial growth factor (VEGF), a previously identified immunosuppressive cytokine. Using BMDC from wild type and conditional knockout mice, we show that neuropilin-1 (NRP-1), a known receptor of VEGF, is necessary to suppress LPS-dependent BMDC maturation. The absence of NRP-1 had no ostensible effects on the biology of BMDC in the absence of VEGF. However, NRP-1-deficient BMDC remained completely insensitive to the VEGF-dependent inhibition of BMDC maturation in culture. In the presence of VEGF, NRP-1 directly interacted with the LPS receptor TLR4 and suppressed downstream signaling through ERK and NF-κß, resulting in a sharp inhibition of MHC class II and costimulatory molecules (CD40, CD86) expression as well as proinflammatory cytokine production. Consequently, we identify NRP-1 as a target to optimize DC maturation within environments that are rich in VEGF, such as tumors.
Asunto(s)
Células Dendríticas/efectos de los fármacos , Células Dendríticas/fisiología , Neuropilina-1/inmunología , Neuropilina-1/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Antígeno B7-2/efectos de los fármacos , Antígeno B7-2/genética , Células de la Médula Ósea/inmunología , Células de la Médula Ósea/fisiología , Antígenos CD40/efectos de los fármacos , Antígenos CD40/genética , Diferenciación Celular , Células Cultivadas , Citocinas/biosíntesis , Citocinas/efectos de los fármacos , Citocinas/genética , Células Dendríticas/inmunología , Genes MHC Clase II/efectos de los fármacos , Genes MHC Clase II/genética , Tolerancia Inmunológica/efectos de los fármacos , Lipopolisacáridos/inmunología , Sistema de Señalización de MAP Quinasas/fisiología , Ratones , Subunidad p50 de NF-kappa B/fisiología , Neuropilina-1/deficiencia , Poli I-C/farmacología , Transducción de Señal/inmunología , Transducción de Señal/fisiología , Receptor Toll-Like 4/metabolismo , Factor A de Crecimiento Endotelial Vascular/farmacologíaRESUMEN
BACKGROUND: Circadian clocks control cell cycle factors, and circadian disruption promotes cancer. To address whether enhancing circadian rhythmicity in tumor cells affects cell cycle progression and reduces proliferation, we compared growth and cell cycle events of B16 melanoma cells and tumors with either a functional or dysfunctional clock. RESULTS: We found that clock genes were suppressed in B16 cells and tumors, but treatments inducing circadian rhythmicity, such as dexamethasone, forskolin and heat shock, triggered rhythmic clock and cell cycle gene expression, which resulted in fewer cells in S phase and more in G1 phase. Accordingly, B16 proliferation in vitro and tumor growth in vivo was slowed down. Similar effects were observed in human colon carcinoma HCT-116 cells. Notably, the effects of dexamethasone were not due to an increase in apoptosis nor to an enhancement of immune cell recruitment to the tumor. Knocking down the essential clock gene Bmal1 in B16 tumors prevented the effects of dexamethasone on tumor growth and cell cycle events. CONCLUSIONS: Here we demonstrated that the effects of dexamethasone on cell cycle and tumor growth are mediated by the tumor-intrinsic circadian clock. Thus, our work reveals that enhancing circadian clock function might represent a novel strategy to control cancer progression.
Asunto(s)
Relojes Circadianos , Melanoma Experimental/genética , Melanoma Experimental/patología , Factores de Transcripción ARNTL/metabolismo , Animales , Ciclo Celular/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relojes Circadianos/efectos de los fármacos , Relojes Circadianos/genética , Ritmo Circadiano/efectos de los fármacos , Colforsina/farmacología , Dexametasona/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Células HCT116 , Respuesta al Choque Térmico/efectos de los fármacos , Humanos , Ratones Endogámicos C57BL , Modelos BiológicosRESUMEN
Following an infection, naive CD8(+) T cells expand and differentiate into two main populations of effectors: short-lived effector cells (SLECs) and memory precursor effector cells (MPECs). There is limited understanding of the molecular mechanism and cellular processes governing this cell fate. Notch is a key regulator of cell fate decision relevant in many immunological pathways. In this study, we add to the role of Notch in cell fate decision and demonstrate that the Notch signaling pathway controls the MPEC/SLEC differentiation choice following both Listeria infection and dendritic cell immunization of mice. Although fewer SLECs were generated, Notch deficiency did not alter the rate of memory CD8(+) T cell generation. Moreover, we reveal that the Notch signaling pathway plays a context-dependent role for optimal cytokine production by effector CD8(+) T cells. Together, our results unravel critical functions for the Notch signaling pathway during effector CD8(+) T cell differentiation.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Memoria Inmunológica , Receptores Notch/metabolismo , Transducción de Señal , Animales , Linfocitos T CD8-positivos/citología , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Citocinas/biosíntesis , Expresión Génica , Listeria/inmunología , Listeriosis/inmunología , Listeriosis/metabolismo , Activación de Linfocitos/inmunología , Ratones , Ratones Noqueados , Receptores Notch/genética , Proteínas de Dominio T Box/genética , Proteínas de Dominio T Box/metabolismoRESUMEN
During infection or vaccination, only a small proportion of CD8(+) T cells differentiate into memory cells. The mechanisms underlying the differentiation of CD8(+) T cells into short-lived effector cells (SLECs) or memory precursor effector cells are poorly defined. It was recently shown in infectious models that the transcriptional repressor B lymphocyte-induced maturation protein 1 (Blimp-1) enhances the formation of SLECs. The factors controlling Blimp-1 expression leading to the in vivo formation of SLECs are still not known. However, it has been shown that cytokines such as IL-2 induce Blimp-1 expression in vitro. In this study, we took advantage of the low-inflammation model of dendritic cell immunization to study the role of the IL-2/Blimp-1 axis in SLEC differentiation as well as the importance of Blimp-1 expression in memory precursor effector cells for proper CD8(+) memory generation. Our results show that Blimp-1 deficiency affects effector differentiation and function in the absence of inflammation. Unexpectedly, memory generation was not affected in Blimp-1-deficient OT-I cells responding to vaccination. In addition, modulation of the bioavailability of IL-2 by injection either of a blocking Ab or of the cytokine, demonstrates a link between IL-2, Blimp-1 induction, and SLEC formation in wild-type cells. Conversely, injection of IL-2 had less effect on Blimp-1-deficient CD8(+) T cells, indicating that the effect of IL-2 on in vivo SLEC differentiation is mediated by Blimp-1. In conclusion, IL-2 induction of Blimp-1 expression is a key regulator of SLEC differentiation in vivo.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Vacunas contra el Cáncer/inmunología , Memoria Inmunológica , Interleucina-2/inmunología , Factores de Transcripción/biosíntesis , Animales , Anticuerpos Bloqueadores/inmunología , Apoptosis/inmunología , Diferenciación Celular/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Femenino , Granzimas/biosíntesis , Inflamación/inmunología , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Subunidad alfa del Receptor de Interleucina-7/biosíntesis , Subunidad alfa del Receptor de Interleucina-7/genética , Lectinas Tipo C , Listeria monocytogenes/genética , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ovalbúmina/inmunología , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Receptores Inmunológicos/biosíntesis , Receptores Inmunológicos/genética , Factores de Transcripción/genéticaRESUMEN
Developing new adjuvants and vaccination strategies is of paramount importance to successfully fight against many life-threatening infectious diseases and cancer. Very few adjuvants are currently authorized for human use, and these mainly stimulate a humoral response. However, specific Abs are not sufficient to confer protection against persisting infections or cancer. Therefore, development of adjuvants and immunomodulators able to enhance cell-mediated immune responses represents a major medical need. We recently showed that papaya mosaic virus nanoparticles (PapMV), self-assembled from the coat protein of a plant virus and a noncoding ssRNA molecule, are highly immunogenic in mice. PapMV can be used either as a vaccine delivery platform, through fusion of various epitopes to the coat protein or as adjuvant to enhance humoral immune responses against coadministered Ags or vaccines. However, the mechanisms that confer these immunomodulatory properties to PapMV and its ability to enhance T cell vaccines remain unknown. Using immunization studies in mice, we demonstrate in this paper that PapMV represents a novel TLR7 agonist with strong immunostimulatory properties. More importantly, pretreatment with PapMV significantly improves effector and memory CD8(+) T cell responses generated through dendritic cell vaccination increasing protection against a Listeria monocytogenes challenge.
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Adyuvantes Inmunológicos , Linfocitos T CD8-positivos/inmunología , Listeria monocytogenes/inmunología , Listeriosis/prevención & control , Glicoproteínas de Membrana/agonistas , Subgrupos de Linfocitos T/inmunología , Receptor Toll-Like 7/agonistas , Tymovirus/inmunología , Vacunación , Inmunidad Adaptativa , Animales , Células Dendríticas/inmunología , Evaluación Preclínica de Medicamentos , Femenino , Inmunoglobulina G/biosíntesis , Memoria Inmunológica , Interferón Tipo I/inmunología , Listeriosis/inmunología , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/inmunología , Ratones , Ratones Endogámicos C57BL , Factor 88 de Diferenciación Mieloide/deficiencia , Factor 88 de Diferenciación Mieloide/inmunología , Nanopartículas , Ovalbúmina/inmunología , ARN Viral/inmunología , Receptor de Interferón alfa y beta/deficiencia , Receptor Toll-Like 7/deficiencia , Receptor Toll-Like 7/inmunología , Tymovirus/genéticaRESUMEN
Extracellular signal-regulated kinase 3 (ERK3 )is an atypical member of the mitogen-activated protein kinase (MAPK) family. We have previously shown that ERK3 is expressed during thymocyte differentiation and that its expression is induced in mature peripheral T cells following activation of ERK1/2 by T-cell receptor (TCR) signalling. Herein, we have investigated whether ERK3 expression is required for proper T-cell selection. Using a knock-in mouse model in which the coding sequence of ERK3 is replaced by the gene encoding for the ß-galactosidase reporter, we show that ERK3 is expressed by double-positive (DP) thymocytes undergoing positive selection. In ERK3-deficient mice with a polyclonal TCR repertoire, we observe a decrease in positive selection. This reduction in positive selection was also observed when ERK3-deficient mice were backcrossed to class I- and class II-restricted TCR transgenic mice. Furthermore, the response of DP thymocytes to in vitro TCR stimulation was strongly reduced in ERK3-deficient mice. Together, these results show that ERK3 expression following TCR signalling is critical for proper thymic positive selection.
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Selección Clonal Mediada por Antígenos , Sistema de Señalización de MAP Quinasas/inmunología , Proteína Quinasa 6 Activada por Mitógenos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T/inmunología , Timocitos/inmunología , Timo/inmunología , Animales , Regulación Enzimológica de la Expresión Génica/genética , Regulación Enzimológica de la Expresión Génica/inmunología , Sistema de Señalización de MAP Quinasas/genética , Ratones , Ratones Noqueados , Proteína Quinasa 3 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/inmunología , Proteína Quinasa 6 Activada por Mitógenos/genética , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/citología , Timocitos/citología , Timo/citologíaRESUMEN
Does time of day matter for cancer immunotherapy? Whereas the concept of optimizing the time of treatment is well documented for chemotherapy, whether it applies to immunotherapy, a revolutionizing treatment exploiting the power of immune cells to control tumors, has recently been addressed in a study published in Cell.
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Inmunoterapia , Neoplasias , Humanos , Inmunoterapia/métodos , Neoplasias/inmunología , Neoplasias/terapia , AnimalesRESUMEN
Programmed cell death 1 (PD-1) is an inhibitory receptor involved in T-cell activation, tolerance and exhaustion. Little is known on how the expression of PD-1 is controlled during T-cell activation. Recent studies demonstrated that NFATc1 and IRF9 regulate Pdcd1 (PD-1) transcription and that T-bet acts as a transcriptional repressor. In this study, we have investigated the role of the Notch signaling pathway in PD-1 regulation. Using specific inhibitors of the Notch signaling pathway, we showed decreased PD-1 expression and inhibition of Pdcd1 transcription by activated CD8(+) T cells. Chromatin immunoprecipitation further showed occupancy of the Pdcd1 promoter with RBPJk and Notch1 intracellular domain at RBPJk-binding sites. Our results identify the Notch signaling pathway as an important regulator of PD-1 expression by activated CD8(+) T cells.
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Linfocitos T CD8-positivos/inmunología , Regulación de la Expresión Génica/inmunología , Activación de Linfocitos/fisiología , Receptor de Muerte Celular Programada 1/inmunología , Receptor Notch1/inmunología , Transducción de Señal/fisiología , Animales , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/metabolismo , Línea Celular , Regulación de la Expresión Génica/genética , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón/genética , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón/inmunología , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón/metabolismo , Ratones , Factores de Transcripción NFATC/genética , Factores de Transcripción NFATC/inmunología , Factores de Transcripción NFATC/metabolismo , Receptor de Muerte Celular Programada 1/biosíntesis , Receptor de Muerte Celular Programada 1/genética , Receptor Notch1/genética , Receptor Notch1/metabolismo , Elementos de Respuesta/genética , Elementos de Respuesta/inmunología , Transcripción Genética/genética , Transcripción Genética/inmunologíaRESUMEN
The invariant chain (Ii; CD74) has pleiotropic functions and Ii-deficient mice show defects in MHC class II (MHC II) transport and B cell maturation. In humans, but not in mice, a minor Iip35 isoform of unknown function includes an endoplasmic reticulum-retention motif that is masked upon binding of MHC II molecules. To gain further insight into the roles of Ii in B cell homeostasis, we generated Iip35 transgenic mice (Tgp35) and bred these with mice deficient for Ii (Tgp35/mIiKO). Iip35 was shown to compete with mIi for the binding to I-A(b) . In addition, classical endosomal degradation products (p20/p10) and the class II-associated invariant chain peptide (CLIP) fragment were detected. Moreover, Iip35 favored the formation of compact peptide-MHC II complexes in the Tgp35/mIiKO mice. I-A(b) levels were restored at the plasma membrane of mature B cells but Iip35 affected the fine conformation of MHC II molecules as judged by the increased reactivity of the AF6-120.1 antibody in permeabilized cells. However, the human Iip35 cannot fully replace the endogenous Ii. Indeed, most immature B cells in the bone marrow and spleen of transgenic mice had reduced surface expression of MHC II molecules, demonstrating a dominant-negative effect of Iip35 in Tgp35 mice. Interestingly, while maturation to follicular B cells was normal, Iip35 expression appeared to reduce the proportions of marginal zone B cells. These results emphasize the importance of Ii in B cell homeostasis and suggest that Iip35 could have regulatory functions.
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Antígenos de Diferenciación de Linfocitos B/genética , Linfocitos B/inmunología , Diferenciación Celular , Antígenos de Histocompatibilidad Clase II/genética , Animales , Presentación de Antígeno , Antígenos de Diferenciación de Linfocitos B/metabolismo , Linfocitos B/citología , Antígenos de Histocompatibilidad Clase II/química , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Ratones , Ratones Noqueados , Ratones TransgénicosRESUMEN
Circadian clocks regulate many important aspects of physiology, and their disturbance leads to various medical conditions. Circadian variations have been found in immune system variables, including daily rhythms in circulating WBC numbers and serum concentration of cytokines. However, control of immune functional responses by the circadian clock has remained relatively unexplored. In this study, we show that mouse lymph nodes exhibit rhythmic clock gene expression. T cells from lymph nodes collected over 24 h show a circadian variation in proliferation after stimulation via the TCR, which is blunted in Clock gene mutant mice. The tyrosine kinase ZAP70, which is just downstream of the TCR in the T cell activation pathway and crucial for T cell function, exhibits rhythmic protein expression. Lastly, mice immunized with OVA peptide-loaded dendritic cells in the day show a stronger specific T cell response than mice immunized at night. These data reveal circadian control of the Ag-specific immune response and a novel regulatory mode of T cell proliferation, and may provide clues for more efficient vaccination strategies.