Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Cell ; 184(12): 3143-3162.e32, 2021 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-34004147

RESUMEN

Gene expression by RNA polymerase II (RNAPII) is tightly controlled by cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The pausing checkpoint following transcription initiation is primarily controlled by CDK9. We discovered that CDK9-mediated, RNAPII-driven transcription is functionally opposed by a protein phosphatase 2A (PP2A) complex that is recruited to transcription sites by the Integrator complex subunit INTS6. PP2A dynamically antagonizes phosphorylation of key CDK9 substrates including DSIF and RNAPII-CTD. Loss of INTS6 results in resistance to tumor cell death mediated by CDK9 inhibition, decreased turnover of CDK9 phospho-substrates, and amplification of acute oncogenic transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill both leukemic and solid tumor cells, providing therapeutic benefit in vivo. These data demonstrate that fine control of gene expression relies on the balance between kinase and phosphatase activity throughout the transcription cycle, a process dysregulated in cancer that can be exploited therapeutically.


Asunto(s)
Quinasa 9 Dependiente de la Ciclina/metabolismo , Terapia Molecular Dirigida , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Proteína Fosfatasa 2/metabolismo , Proteínas de Unión al ARN/metabolismo , Transcripción Genética , Proteínas Supresoras de Tumor/metabolismo , Animales , Línea Celular Tumoral , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones Endogámicos NOD , Fosforilación , Unión Proteica , ARN Polimerasa II/química , ARN Polimerasa II/metabolismo , Especificidad por Sustrato
2.
Immunity ; 55(3): 423-441.e9, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35139355

RESUMEN

Cell death plays an important role during pathogen infections. Here, we report that interferon-γ (IFNγ) sensitizes macrophages to Toll-like receptor (TLR)-induced death that requires macrophage-intrinsic death ligands and caspase-8 enzymatic activity, which trigger the mitochondrial apoptotic effectors, BAX and BAK. The pro-apoptotic caspase-8 substrate BID was dispensable for BAX and BAK activation. Instead, caspase-8 reduced pro-survival BCL-2 transcription and increased inducible nitric oxide synthase (iNOS), thus facilitating BAX and BAK signaling. IFNγ-primed, TLR-induced macrophage killing required iNOS, which licensed apoptotic caspase-8 activity and reduced the BAX and BAK inhibitors, A1 and MCL-1. The deletion of iNOS or caspase-8 limited SARS-CoV-2-induced disease in mice, while caspase-8 caused lethality independent of iNOS in a model of hemophagocytic lymphohistiocytosis. These findings reveal that iNOS selectively licenses programmed cell death, which may explain how nitric oxide impacts disease severity in SARS-CoV-2 infection and other iNOS-associated inflammatory conditions.


Asunto(s)
COVID-19/inmunología , Caspasa 8/metabolismo , Interferón gamma/metabolismo , Linfohistiocitosis Hemofagocítica/inmunología , Macrófagos/inmunología , Mitocondrias/metabolismo , SARS-CoV-2/fisiología , Animales , Caspasa 8/genética , Células Cultivadas , Citotoxicidad Inmunológica , Humanos , Interferón gamma/genética , Activación de Macrófagos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico Sintasa de Tipo II/metabolismo , Moléculas de Patrón Molecular Asociado a Patógenos/inmunología , Transducción de Señal , Proteína Destructora del Antagonista Homólogo bcl-2/genética , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo
3.
Nature ; 577(7788): 103-108, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31827281

RESUMEN

RIPK1 is a key regulator of innate immune signalling pathways. To ensure an optimal inflammatory response, RIPK1 is regulated post-translationally by well-characterized ubiquitylation and phosphorylation events, as well as by caspase-8-mediated cleavage1-7. The physiological relevance of this cleavage event remains unclear, although it is thought to inhibit activation of RIPK3 and necroptosis8. Here we show that the heterozygous missense mutations D324N, D324H and D324Y prevent caspase cleavage of RIPK1 in humans and result in an early-onset periodic fever syndrome and severe intermittent lymphadenopathy-a condition we term 'cleavage-resistant RIPK1-induced autoinflammatory syndrome'. To define the mechanism for this disease, we generated a cleavage-resistant Ripk1D325A mutant mouse strain. Whereas Ripk1-/- mice died postnatally from systemic inflammation, Ripk1D325A/D325A mice died during embryogenesis. Embryonic lethality was completely prevented by the combined loss of Casp8 and Ripk3, but not by loss of Ripk3 or Mlkl alone. Loss of RIPK1 kinase activity also prevented Ripk1D325A/D325A embryonic lethality, although the mice died before weaning from multi-organ inflammation in a RIPK3-dependent manner. Consistently, Ripk1D325A/D325A and Ripk1D325A/+ cells were hypersensitive to RIPK3-dependent TNF-induced apoptosis and necroptosis. Heterozygous Ripk1D325A/+ mice were viable and grossly normal, but were hyper-responsive to inflammatory stimuli in vivo. Our results demonstrate the importance of caspase-mediated RIPK1 cleavage during embryonic development and show that caspase cleavage of RIPK1 not only inhibits necroptosis but also maintains inflammatory homeostasis throughout life.


Asunto(s)
Caspasa 8/metabolismo , Enfermedades Autoinflamatorias Hereditarias/metabolismo , Mutación , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Animales , Caspasa 3/metabolismo , Femenino , Enfermedades Autoinflamatorias Hereditarias/genética , Enfermedades Autoinflamatorias Hereditarias/patología , Humanos , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Linaje , Proteína Serina-Treonina Quinasas de Interacción con Receptores/deficiencia , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética
4.
EMBO Rep ; 24(11): e56865, 2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37846472

RESUMEN

Programmed cell death pathways play an important role in innate immune responses to infection. Activation of intrinsic apoptosis promotes infected cell clearance; however, comparatively little is known about how this mode of cell death is regulated during infections and whether it can induce inflammation. Here, we identify that the pro-survival BCL-2 family member, A1, controls activation of the essential intrinsic apoptotic effectors BAX/BAK in macrophages and monocytes following bacterial lipopolysaccharide (LPS) sensing. We show that, due to its tight transcriptional and post-translational regulation, A1 acts as a molecular rheostat to regulate BAX/BAK-dependent apoptosis and the subsequent NLRP3 inflammasome-dependent and inflammasome-independent maturation of the inflammatory cytokine IL-1ß. Furthermore, induction of A1 expression in inflammatory monocytes limits cell death modalities and IL-1ß activation triggered by Neisseria gonorrhoeae-derived outer membrane vesicles (NOMVs). Consequently, A1-deficient mice exhibit heightened IL-1ß production in response to NOMV injection. These findings reveal that bacteria can induce A1 expression to delay myeloid cell death and inflammatory responses, which has implications for the development of host-directed antimicrobial therapeutics.


Asunto(s)
Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Animales , Ratones , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Células Mieloides/metabolismo , Muerte Celular , Interleucina-1beta/metabolismo
5.
Nature ; 560(7717): 253-257, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30069049

RESUMEN

Acetylation of histones by lysine acetyltransferases (KATs) is essential for chromatin organization and function1. Among the genes coding for the MYST family of KATs (KAT5-KAT8) are the oncogenes KAT6A (also known as MOZ) and KAT6B (also known as MORF and QKF)2,3. KAT6A has essential roles in normal haematopoietic stem cells4-6 and is the target of recurrent chromosomal translocations, causing acute myeloid leukaemia7,8. Similarly, chromosomal translocations in KAT6B have been identified in diverse cancers8. KAT6A suppresses cellular senescence through the regulation of suppressors of the CDKN2A locus9,10, a function that requires its KAT activity10. Loss of one allele of KAT6A extends the median survival of mice with MYC-induced lymphoma from 105 to 413 days11. These findings suggest that inhibition of KAT6A and KAT6B may provide a therapeutic benefit in cancer. Here we present highly potent, selective inhibitors of KAT6A and KAT6B, denoted WM-8014 and WM-1119. Biochemical and structural studies demonstrate that these compounds are reversible competitors of acetyl coenzyme A and inhibit MYST-catalysed histone acetylation. WM-8014 and WM-1119 induce cell cycle exit and cellular senescence without causing DNA damage. Senescence is INK4A/ARF-dependent and is accompanied by changes in gene expression that are typical of loss of KAT6A function. WM-8014 potentiates oncogene-induced senescence in vitro and in a zebrafish model of hepatocellular carcinoma. WM-1119, which has increased bioavailability, arrests the progression of lymphoma in mice. We anticipate that this class of inhibitors will help to accelerate the development of therapeutics that target gene transcription regulated by histone acetylation.


Asunto(s)
Bencenosulfonatos/farmacología , Senescencia Celular/efectos de los fármacos , Histona Acetiltransferasas/antagonistas & inhibidores , Hidrazinas/farmacología , Linfoma/tratamiento farmacológico , Linfoma/patología , Sulfonamidas/farmacología , Acetilación/efectos de los fármacos , Animales , Bencenosulfonatos/uso terapéutico , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Desarrollo de Medicamentos , Fibroblastos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Histona Acetiltransferasas/deficiencia , Histona Acetiltransferasas/genética , Histonas/química , Histonas/metabolismo , Hidrazinas/uso terapéutico , Linfoma/enzimología , Linfoma/genética , Lisina/química , Lisina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Sulfonamidas/uso terapéutico
6.
Blood ; 135(13): 1019-1031, 2020 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-31978211

RESUMEN

Deregulated overexpression of MYC is implicated in the development and malignant progression of most (∼70%) human tumors. MYC drives cell growth and proliferation, but also, at high levels, promotes apoptosis. Here, we report that the proliferative capacity of MYC-driven normal and neoplastic B lymphoid cells depends on MNT, a MYC-related transcriptional repressor. Our genetic data establish that MNT synergizes with MYC by suppressing MYC-driven apoptosis, and that it does so primarily by reducing the level of pro-apoptotic BIM. In Eµ-Myc mice, which model the MYC/IGH chromosome translocation in Burkitt's lymphoma, homozygous Mnt deletion greatly reduced lymphoma incidence by enhancing apoptosis and markedly decreasing premalignant B lymphoid cell populations. Strikingly, by inducing Mnt deletion within transplanted fully malignant Eµ-Myc lymphoma cells, we significantly extended transplant recipient survival. The dependency of lymphomas on MNT for survival suggests that drugs inhibiting MNT could significantly boost therapy of MYC-driven tumors by enhancing intrinsic MYC-driven apoptosis.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Transformación Celular Neoplásica/genética , Linfoma/genética , Linfoma/mortalidad , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-myc/genética , Animales , Antineoplásicos/uso terapéutico , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Médula Ósea/metabolismo , Médula Ósea/patología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Eliminación de Gen , Regulación Neoplásica de la Expresión Génica , Humanos , Estimación de Kaplan-Meier , Linfoma/tratamiento farmacológico , Linfoma/patología , Linfoma de Células B/genética , Ratones , Ratones Transgénicos , Proteínas Represoras/genética , Ensayos Antitumor por Modelo de Xenoinjerto
7.
Nature ; 538(7626): 518-522, 2016 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-27750279

RESUMEN

It is widely accepted that complex interactions between cancer cells and their surrounding microenvironment contribute to disease development, chemo-resistance and disease relapse. In light of this observed interdependency, novel therapeutic interventions that target specific cancer stroma cell lineages and their interactions are being sought. Here we studied a mouse model of human T-cell acute lymphoblastic leukaemia (T-ALL) and used intravital microscopy to monitor the progression of disease within the bone marrow at both the tissue-wide and single-cell level over time, from bone marrow seeding to development/selection of chemo-resistance. We observed highly dynamic cellular interactions and promiscuous distribution of leukaemia cells that migrated across the bone marrow, without showing any preferential association with bone marrow sub-compartments. Unexpectedly, this behaviour was maintained throughout disease development, from the earliest bone marrow seeding to response and resistance to chemotherapy. Our results reveal that T-ALL cells do not depend on specific bone marrow microenvironments for propagation of disease, nor for the selection of chemo-resistant clones, suggesting that a stochastic mechanism underlies these processes. Yet, although T-ALL infiltration and progression are independent of the stroma, accumulated disease burden leads to rapid, selective remodelling of the endosteal space, resulting in a complete loss of mature osteoblastic cells while perivascular cells are maintained. This outcome leads to a shift in the balance of endogenous bone marrow stroma, towards a composition associated with less efficient haematopoietic stem cell function. This novel, dynamic analysis of T-ALL interactions with the bone marrow microenvironment in vivo, supported by evidence from human T-ALL samples, highlights that future therapeutic interventions should target the migration and promiscuous interactions of cancer cells with the surrounding microenvironment, rather than specific bone marrow stroma, to combat the invasion by and survival of chemo-resistant T-ALL cells.


Asunto(s)
Células de la Médula Ósea/citología , Leucemia-Linfoma de Células T del Adulto/patología , Trasplante de Neoplasias , Microambiente Tumoral , Animales , Movimiento Celular , Progresión de la Enfermedad , Femenino , Células Madre Hematopoyéticas/citología , Humanos , Microscopía Intravital , Masculino , Ratones , Osteoblastos/citología , Análisis de la Célula Individual
8.
Blood ; 133(16): 1729-1741, 2019 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-30755422

RESUMEN

Somatically acquired mutations in PHF6 (plant homeodomain finger 6) frequently occur in hematopoietic malignancies and often coincide with ectopic expression of TLX3. However, there is no functional evidence to demonstrate whether these mutations contribute to tumorigenesis. Similarly, the role of PHF6 in hematopoiesis is unknown. We report here that Phf6 deletion in mice resulted in a reduced number of hematopoietic stem cells (HSCs), an increased number of hematopoietic progenitor cells, and an increased proportion of cycling stem and progenitor cells. Loss of PHF6 caused increased and sustained hematopoietic reconstitution in serial transplantation experiments. Interferon-stimulated gene expression was upregulated in the absence of PHF6 in hematopoietic stem and progenitor cells. The numbers of hematopoietic progenitor cells and cycling hematopoietic stem and progenitor cells were restored to normal by combined loss of PHF6 and the interferon α and ß receptor subunit 1. Ectopic expression of TLX3 alone caused partially penetrant leukemia. TLX3 expression and loss of PHF6 combined caused fully penetrant early-onset leukemia. Our data suggest that PHF6 is a hematopoietic tumor suppressor and is important for fine-tuning hematopoietic stem and progenitor cell homeostasis.


Asunto(s)
Células Madre Hematopoyéticas/citología , Proteínas de Homeodominio/metabolismo , Leucemia/etiología , Proteínas Represoras/fisiología , Animales , Carcinogénesis , Regulación de la Expresión Génica , Humanos , Ratones , Ratones Noqueados , Receptores de Interferón , Proteínas Represoras/genética , Proteínas Supresoras de Tumor
9.
Immunol Cell Biol ; 98(6): 439-448, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32133683

RESUMEN

The protection of a multicellular organism from infection, at both cell and humoral levels, has been a tremendous driver of gene selection and cellular response strategies. Here we focus on a critical event in the development of humoral immunity: The transition from principally innate responses to a system of adaptive cell selection, with all the attendant mechanical problems that must be solved in order for it to work effectively. Here we review recent advances, but our major goal is to highlight that the development of adaptive immunity resulted from the adoption, reuse and repurposing of an ancient, autonomous cellular program that combines and exploits three titratable cellular fate timers. We illustrate how this common cell machinery recurs and appears throughout biology, and has been essential for the evolution of complex organisms, at many levels of scale.


Asunto(s)
Inmunidad Adaptativa , Evolución Biológica , Inmunidad Humoral , Diferenciación Celular , Humanos
10.
Immunol Cell Biol ; 98(3): 203-214, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31916630

RESUMEN

The NZB/W F1 (F1) mice develop severe disease that is similar to human systemic lupus erythematosus. By contrast, each parent strain, NZB or NZW, has limited autoimmunity, suggesting traits of both strains contribute to pathogenesis. Although many of the contributing genes have been identified, the contributing cellular abnormality associated with each parent strain remains unresolved. Given that plasmacytoid dendritic cells (pDCs) are key to the pathogenesis of lupus, we investigated the properties of pDCs from NZB and NZW mice. We found that NZB mouse had higher numbers of pDCs, with much of the increase being contributed by a more abundant CD8+ pDC subset. This was associated with prolonged survival and stronger proliferation of CD4+ T cells. By contrast, NZW pDCs had heightened capacity to produce interferon-α (IFNα) and IFNλ, and promoted stronger B-cell proliferation upon CpG stimulation. Thus, our data reveal the different functional and numerical characteristics of pDCs from NZW and NZB mouse.


Asunto(s)
Autoinmunidad , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Lupus Eritematoso Sistémico/inmunología , Activación de Linfocitos/inmunología , Animales , Linfocitos B/inmunología , Antígenos CD8/inmunología , Antígenos CD8/metabolismo , Supervivencia Celular/inmunología , Células Dendríticas/citología , Células Dendríticas/metabolismo , Células Dendríticas/patología , Factores de Transcripción Forkhead/metabolismo , Interferón-alfa/metabolismo , Interferones/metabolismo , Lupus Eritematoso Sistémico/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos NZB , Ratones Noqueados , Ratones Transgénicos , Oligodesoxirribonucleótidos/farmacología
11.
Blood ; 131(14): 1507-1511, 2018 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-29487069

RESUMEN

The interplay of cancer cells and surrounding stroma is critical in disease progression. This is particularly evident in hematological malignancies that infiltrate the bone marrow and peripheral lymphoid organs. Despite clear evidence for the existence of these interactions, the precise repercussions on the growth of leukemic cells are poorly understood. Recent development of novel imaging technology and preclinical disease models has advanced our comprehension of leukemia-microenvironment crosstalk and has potential implications for development of novel treatment options.


Asunto(s)
Médula Ósea/metabolismo , Neoplasias Hematológicas/metabolismo , Leucemia/metabolismo , Neoplasias Experimentales/metabolismo , Microambiente Tumoral , Animales , Médula Ósea/patología , Neoplasias Hematológicas/patología , Neoplasias Hematológicas/terapia , Humanos , Leucemia/patología , Leucemia/terapia , Neoplasias Experimentales/patología , Neoplasias Experimentales/terapia
12.
Immunol Cell Biol ; 97(2): 229-235, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30422351

RESUMEN

The majority of acute myeloid leukemia (AML) patients have a poor response to conventional chemotherapy. The survival of chemoresistant cells is thought to depend on leukemia-bone marrow (BM) microenvironment interactions, which are not well understood. The CXCL12/CXCR4 axis has been proposed to support AML growth but was not studied at the single AML cell level. We recently showed that T-cell acute lymphoblastic leukemia (T-ALL) cells are highly motile in the BM; however, the characteristics of AML cell migration within the BM remain undefined. Here, we characterize the in vivo migratory behavior of AML cells and their response to chemotherapy and CXCR4 antagonism, using high-resolution 2-photon and confocal intravital microscopy of mouse calvarium BM and the well-established MLL-AF9-driven AML mouse model. We used the Notch1-driven T-ALL model as a benchmark comparison and AMD3100 for CXCR4 antagonism experiments. We show that AML cells are migratory, and in contrast with T-ALL, chemoresistant AML cells become less motile. Moreover, and in contrast with T-ALL, the in vivo exploratory behavior of expanding and chemoresistant AML cells is unaffected by AMD3100. These results expand our understanding of AML cells-BM microenvironment interactions, highlighting unique traits of leukemia of different lineages.


Asunto(s)
Movimiento Celular , Quimiocina CXCL12/metabolismo , Compuestos Heterocíclicos/antagonistas & inhibidores , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Receptores CXCR4/metabolismo , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Bencilaminas , Médula Ósea/metabolismo , Médula Ósea/patología , Línea Celular Tumoral , Ciclamas , Resistencia a Antineoplásicos/efectos de los fármacos , Compuestos Heterocíclicos/metabolismo , Microscopía Intravital , Leucemia Mieloide Aguda/metabolismo , Ratones , Microscopía Confocal , Microscopía de Fluorescencia por Excitación Multifotónica , Microambiente Tumoral
13.
Immunol Cell Biol ; 97(1): 29-38, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30107066

RESUMEN

BPSM1 (Bone phenotype spontaneous mutant 1) mice develop severe polyarthritis and heart valve disease as a result of a spontaneous mutation in the Tnf gene. In these mice, the insertion of a retrotransposon in the 3' untranslated region of Tnf causes a large increase in the expression of the cytokine. We have found that these mice also develop inducible bronchus-associated lymphoid tissue (iBALT), as well as nodular lymphoid hyperplasia (NLH) in the bone marrow. Loss of TNFR1 prevents the development of both types of follicles, but deficiency of TNFR1 in the hematopoietic compartment only prevents the iBALT and not the NLH phenotype. We show that the development of arthritis and heart valve disease does not depend on the presence of the tertiary lymphoid tissues. Interestingly, while loss of IL-17 or IL-23 limits iBALT and NLH development to some extent, it has no effect on polyarthritis or heart valve disease in BPSM1 mice.


Asunto(s)
Tejido Linfoide/patología , Receptores del Factor de Necrosis Tumoral/genética , Receptores del Factor de Necrosis Tumoral/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Médula Ósea/patología , Hiperplasia , Interleucina-17/genética , Interleucina-17/metabolismo , Interleucina-23/genética , Interleucina-23/metabolismo , Tejido Linfoide/metabolismo , Ratones , Factor de Necrosis Tumoral alfa/genética
14.
Immunol Cell Biol ; 97(1): 39-53, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30152893

RESUMEN

Antibody-mediated immunity is highly protective against disease. The majority of current vaccines confer protection through humoral immunity, but there is high variability in responsiveness across populations. Identifying immune mechanisms that mediate low antibody responsiveness may provide potential strategies to boost vaccine efficacy. Here, we report diverse antibody responsiveness to unadjuvanted as well as adjuvanted immunization in substrains of BALB/c mice, resulting in high and low antibody response phenotypes. Furthermore, these antibody phenotypes were not affected by changes in environmental factors such as the gut microbiota composition. Antigen-specific B cells following immunization had a marked difference in capability to class switch, resulting in perturbed IgG isotype antibody production. In vitro, a B-cell intrinsic defect in the regulation of class-switch recombination was identified in mice with low IgG antibody production. Whole genome sequencing identified polymorphisms associated with the magnitude of antibody produced, and we propose candidate genes that may regulate isotype class-switching capability. This study highlights that mice sourced from different vendors can have significantly altered humoral immune response profiles, and provides a resource to interrogate genetic regulators of antibody responsiveness. Together these results further our understanding of immune heterogeneity and suggest additional research on the genetic influences of adjuvanted vaccine strategies is warranted for enhancing vaccine efficacy.


Asunto(s)
Formación de Anticuerpos/genética , Ratones Endogámicos BALB C , Animales , Linfocitos B/inmunología , Cambio de Clase de Inmunoglobulina , Ratones , Ratones Endogámicos BALB C/genética , Ratones Endogámicos BALB C/inmunología , Polimorfismo Genético/genética , Vacunas/inmunología , Secuenciación Completa del Genoma
15.
Immunol Cell Biol ; 94(3): 306-11, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26391810

RESUMEN

Lethal giant larvae-1 (Lgl-1) is an evolutionary conserved protein that regulates cell polarity in diverse lineages; however, the role of Lgl-1 in the polarity and function of immune cells remains to be elucidated. To assess the role of Lgl-1 in T cells, we generated chimeric mice with a hematopoietic system deficient for Lgl-1. Lgl-1 deficiency did not impair the activation or function of peripheral CD8(+) T cells in response to antigen presentation in vitro, but did skew effector and memory T-cell differentiation. When challenged with antigen-expressing virus or tumor, Lgl-1-deficient mice displayed altered T-cell responses. This manifested in a stronger antiviral and antitumor effector CD8(+) T-cell response, the latter resulting in enhanced control of MC38-OVA tumors. These results reveal a novel role for Lgl-1 in the regulation of virus-specific T-cell responses and antitumor immunity.


Asunto(s)
Antígenos/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Glicoproteínas/deficiencia , Animales , Presentación de Antígeno/inmunología , Inmunofenotipificación , Virus de la Influenza A/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Noqueados , Neoplasias/genética , Neoplasias/inmunología , Neoplasias/metabolismo , Neoplasias/patología , Fenotipo
16.
J Immunol ; 192(2): 553-7, 2014 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-24337740

RESUMEN

DNAX accessory molecule 1 (DNAM-1) is expressed on all CD8(+) T cells and promotes their activation and effector function. DNAM-1 interacts with LFA-1, a critical molecule for immunological synapse formation between T cells and APCs, and for cytotoxic killing of target cells. Mice that lack DNAM-1 display abnormal T cell responses and antitumor activity; however, the mechanism involved is unclear. In this article, we show that DNAM-1 deficiency results in reduced proliferation of CD8(+) T cells after Ag presentation and impaired cytotoxic activity. We also demonstrate that DNAM-1-deficient T cells show reduced conjugations with tumor cells and decreased recruitment of both LFA-1 and lipid rafts to the immunological synapse, which correlates with reduced tumor cell killing in vitro. This synapse defect may explain why DNAM-1-deficient mice cannot clear tumors in vivo, and highlights the importance of DNAM-1 and the immunological synapse in T cell-mediated antitumor immunity.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/metabolismo , Linfocitos T CD8-positivos/inmunología , Sinapsis Inmunológicas/inmunología , Animales , Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Antígenos de Diferenciación de Linfocitos T/inmunología , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral , Proliferación Celular , Sinapsis Inmunológicas/genética , Sinapsis Inmunológicas/metabolismo , Lípidos/genética , Lípidos/inmunología , Antígeno-1 Asociado a Función de Linfocito/genética , Antígeno-1 Asociado a Función de Linfocito/inmunología , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Ratones , Ratones Endogámicos C57BL
17.
Blood ; 119(11): 2510-22, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-22174158

RESUMEN

The stem cell-intrinsic model of self-renewal via asymmetric cell division (ACD) posits that fate determinants be partitioned unequally between daughter cells to either activate or suppress the stemness state. ACD is a purported mechanism by which hematopoietic stem cells (HSCs) self-renew, but definitive evidence for this cellular process remains open to conjecture. To address this issue, we chose 73 candidate genes that function within the cell polarity network to identify potential determinants that may concomitantly alter HSC fate while also exhibiting asymmetric segregation at cell division. Initial gene-expression profiles of polarity candidates showed high and differential expression in both HSCs and leukemia stem cells. Altered HSC fate was assessed by our established in vitro to in vivo screen on a subcohort of candidate polarity genes, which revealed 6 novel positive regulators of HSC function: Ap2a2, Gpsm2, Tmod1, Kif3a, Racgap1, and Ccnb1. Interestingly, live-cell videomicroscopy of the endocytic protein AP2A2 shows instances of asymmetric segregation during HSC/progenitor cell cytokinesis. These results contribute further evidence that ACD is functional in HSC self-renewal, suggest a role for Ap2a2 in HSC activity, and provide a unique opportunity to prospectively analyze progeny from HSC asymmetric divisions.


Asunto(s)
Complejo 2 de Proteína Adaptadora/metabolismo , Subunidades alfa de Complejo de Proteína Adaptadora/metabolismo , División Celular Asimétrica/fisiología , Polaridad Celular/genética , Endocitosis/genética , Células Madre Hematopoyéticas/citología , Células Madre Neoplásicas/patología , Células Madre/citología , Complejo 2 de Proteína Adaptadora/antagonistas & inhibidores , Complejo 2 de Proteína Adaptadora/genética , Subunidades alfa de Complejo de Proteína Adaptadora/antagonistas & inhibidores , Subunidades alfa de Complejo de Proteína Adaptadora/genética , Animales , Biomarcadores/metabolismo , Western Blotting , Diferenciación Celular , Linaje de la Célula , Proliferación Celular , Citometría de Flujo , Perfilación de la Expresión Génica , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/fisiología , Leucemia/metabolismo , Leucemia/patología , Ratones , Células Madre Neoplásicas/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/fisiología
18.
J Immunol ; 188(8): 3886-92, 2012 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-22427643

RESUMEN

Recently, it has been reported that human B cells express and secrete the cytotoxic protease granzyme B (GrB) after stimulation with IL-21 and BCR cross-linking. To date, there are few clues on the function of GrB in B cell biology. As experimental transgenic murine systems should provide insights into these issues, we assayed for GrB in C57BL/6 B cells using an extensive array of physiologically relevant stimuli but were unable to detect either GrB expression or its proteolytic activity, even when Ag-specific transgenic BCRs were engaged. Similar results were also obtained with B cells from DBA/2, CBA, or BALB/c mice. In vivo, infection with either influenza virus or murine γ-herpesvirus induced the expected expression of GrB in CTLs, but not in B cell populations. We also investigated a possible role of GrB on the humoral immune response to the model Ag 4-hydroxy-3-nitrophenylacetyl-keyhole limpet hemocyanin, but GrB-deficient mice produced normal amounts of Ab with typical affinity maturation and a heightened secondary response, demonstrating conclusively the redundancy of GrB for Ab responses. Our results highlight the complex evolutionary differences that have shaped the immune systems of mice and humans. The physiological consequences of GrB expression in human B cells remain unclear, and the current study suggests that experimental mouse models will not be helpful in addressing this issue.


Asunto(s)
Linfocitos B/inmunología , Granzimas/metabolismo , Infecciones por Herpesviridae/inmunología , Infecciones por Orthomyxoviridae/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Anticuerpos Antivirales/biosíntesis , Anticuerpos Antivirales/inmunología , Linfocitos B/metabolismo , Linfocitos B/virología , Células Cultivadas , Gammaherpesvirinae , Granzimas/inmunología , Haptenos , Hemocianinas/farmacología , Infecciones por Herpesviridae/enzimología , Humanos , Inmunidad Humoral , Interleucinas/farmacología , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Ratones Transgénicos , Orthomyxoviridae , Infecciones por Orthomyxoviridae/enzimología , Receptores de Antígenos de Linfocitos B/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Especificidad de la Especie , Linfocitos T Citotóxicos/metabolismo , Linfocitos T Citotóxicos/virología
19.
EMBO Mol Med ; 16(7): 1717-1749, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38750308

RESUMEN

Necroptosis is a lytic form of regulated cell death reported to contribute to inflammatory diseases of the gut, skin and lung, as well as ischemic-reperfusion injuries of the kidney, heart and brain. However, precise identification of the cells and tissues that undergo necroptotic cell death in vivo has proven challenging in the absence of robust protocols for immunohistochemical detection. Here, we provide automated immunohistochemistry protocols to detect core necroptosis regulators - Caspase-8, RIPK1, RIPK3 and MLKL - in formalin-fixed mouse and human tissues. We observed surprising heterogeneity in protein expression within tissues, whereby short-lived immune barrier cells were replete with necroptotic effectors, whereas long-lived cells lacked RIPK3 or MLKL expression. Local changes in the expression of necroptotic effectors occurred in response to insults such as inflammation, dysbiosis or immune challenge, consistent with necroptosis being dysregulated in disease contexts. These methods will facilitate the precise localisation and evaluation of necroptotic signaling in vivo.


Asunto(s)
Inmunohistoquímica , Necroptosis , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Animales , Humanos , Ratones , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Inmunohistoquímica/métodos , Proteínas Quinasas/metabolismo , Proteínas Quinasas/genética , Caspasa 8/metabolismo , Transducción de Señal , Ratones Endogámicos C57BL
20.
J Immunol ; 187(3): 1166-75, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21709155

RESUMEN

Granzymes A and B (GrAB) are known principally for their role in mediating perforin-dependent death of virus-infected or malignant cells targeted by CTL. In this study, we show that granzymes also play a critical role as inducers of Ag cross-presentation by dendritic cells (DC). This was demonstrated by the markedly reduced priming of naive CD8(+) T cells specific for the model Ag OVA both in vitro and in vivo in response to tumor cells killed in the absence of granzymes. Reduced cross-priming was due to impairment of phagocytosis of tumor cell corpses by CD8α(+) DC but not CD8α(-) DC, demonstrating the importance of granzymes in inducing the exposure of prophagocytic "eat-me" signals on the dying target cell. Our data reveal a critical and previously unsuspected role for granzymes A and B in dictating immunogenicity by influencing the mode of tumor cell death and indicate that granzymes contribute to the efficient generation of immune effector pathways in addition to their well-known role in apoptosis induction.


Asunto(s)
Antígenos de Neoplasias/metabolismo , Reactividad Cruzada/inmunología , Granzimas/fisiología , Fagocitosis/inmunología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/patología , Animales , Antígenos de Neoplasias/inmunología , Muerte Celular/inmunología , Línea Celular Tumoral , Pollos , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Granzimas/deficiencia , Granzimas/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Ovalbúmina/toxicidad , Fragmentos de Péptidos/toxicidad , Linfocitos T Citotóxicos/enzimología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA