Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
PLoS Comput Biol ; 17(3): e1008688, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33690626

RESUMEN

Outbreaks of SARS-CoV-2 are threatening the health care systems of several countries around the world. The initial control of SARS-CoV-2 epidemics relied on non-pharmaceutical interventions, such as social distancing, teleworking, mouth masks and contact tracing. However, as pre-symptomatic transmission remains an important driver of the epidemic, contact tracing efforts struggle to fully control SARS-CoV-2 epidemics. Therefore, in this work, we investigate to what extent the use of universal testing, i.e., an approach in which we screen the entire population, can be utilized to mitigate this epidemic. To this end, we rely on PCR test pooling of individuals that belong to the same households, to allow for a universal testing procedure that is feasible with the limited testing capacity. We evaluate two isolation strategies: on the one hand pool isolation, where we isolate all individuals that belong to a positive PCR test pool, and on the other hand individual isolation, where we determine which of the individuals that belong to the positive PCR pool are positive, through an additional testing step. We evaluate this universal testing approach in the STRIDE individual-based epidemiological model in the context of the Belgian COVID-19 epidemic. As the organisation of universal testing will be challenging, we discuss the different aspects related to sample extraction and PCR testing, to demonstrate the feasibility of universal testing when a decentralized testing approach is used. We show through simulation, that weekly universal testing is able to control the epidemic, even when many of the contact reductions are relieved. Finally, our model shows that the use of universal testing in combination with stringent contact reductions could be considered as a strategy to eradicate the virus.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/epidemiología , COVID-19/prevención & control , Epidemias/prevención & control , SARS-CoV-2 , Bélgica/epidemiología , COVID-19/transmisión , Prueba de Ácido Nucleico para COVID-19/estadística & datos numéricos , Prueba de Ácido Nucleico para COVID-19/tendencias , Biología Computacional , Simulación por Computador , Trazado de Contacto/métodos , Trazado de Contacto/estadística & datos numéricos , Trazado de Contacto/tendencias , Reacciones Falso Negativas , Composición Familiar , Estudios de Factibilidad , Humanos , Tamizaje Masivo/métodos , Tamizaje Masivo/estadística & datos numéricos , Tamizaje Masivo/tendencias , Modelos Estadísticos , Cuarentena/métodos , Cuarentena/estadística & datos numéricos , Cuarentena/tendencias , Viaje
2.
BMC Med ; 18(1): 191, 2020 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-32586336

RESUMEN

BACKGROUND: Current outbreaks of COVID-19 are threatening the health care systems of several countries around the world. Control measures, based on isolation, contact tracing, and quarantine, can decrease and delay the burden of the ongoing epidemic. With respect to the ongoing COVID-19 epidemic, recent modeling work shows that these interventions may be inadequate to control local outbreaks, even when perfect isolation is assumed. The effect of infectiousness prior to symptom onset combined with asymptomatic infectees further complicates the use of contact tracing. We aim to study whether antivirals, which decrease the viral load and reduce infectiousness, could be integrated into control measures in order to augment the feasibility of controlling the epidemic. METHODS: Using a simulation-based model of viral transmission, we tested the efficacy of different intervention measures to control local COVID-19 outbreaks. For individuals that were identified through contact tracing, we evaluate two procedures: monitoring individuals for symptoms onset and testing of individuals. Additionally, we investigate the implementation of an antiviral compound combined with the contact tracing process. RESULTS: For an infectious disease in which asymptomatic and presymptomatic infections are plausible, an intervention measure based on contact tracing performs better when combined with testing instead of monitoring, provided that the test is able to detect infections during the incubation period. Antiviral drugs, in combination with contact tracing, quarantine, and isolation, result in a significant decrease of the final size and the peak incidence, and increase the probability that the outbreak will fade out. CONCLUSION: In all tested scenarios, the model highlights the benefits of control measures based on the testing of traced individuals. In addition, the administration of an antiviral drug, together with quarantine, isolation, and contact tracing, is shown to decrease the spread of the epidemic. This control measure could be an effective strategy to control local and re-emerging outbreaks of COVID-19.


Asunto(s)
Antivirales/uso terapéutico , Infecciones por Coronavirus/tratamiento farmacológico , Brotes de Enfermedades/prevención & control , Neumonía Viral/tratamiento farmacológico , Betacoronavirus , COVID-19 , Simulación por Computador , Trazado de Contacto , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Humanos , Incidencia , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Cuarentena , SARS-CoV-2
3.
BMC Immunol ; 19(1): 8, 2018 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-29433450

RESUMEN

BACKGROUND: Besides their prominent role in the elimination of infected or malignantly transformed cells, natural killer (NK) cells serve as modulators of adaptive immune responses. Enhancing bidirectional crosstalk between NK cells and dendritic cells (DC) is considered a promising tool to potentiate cancer vaccines. We investigated to what extent direct sensing of viral and bacterial motifs by NK cells contributes to the response of inflammatory DC against the same pathogenic stimulus. RESULTS: We demonstrated that sensing of bacterial and viral PAMPs by NK cells contributes to DC cytokine production via NK cell-derived soluble factors. This enhancement of DC cytokine production was dependent on the pattern recognition receptor (PRR) agonist but also on the cytokine environment in which NK cells recognized the pathogen, indicating the importance of accessory cell activation for this mechanism. We showed in blocking experiments that NK cell-mediated amplification of DC cytokine secretion is dependent on NK cell-derived IFN-γ irrespective of the PRR that is sensed by the NK cell. CONCLUSIONS: These findings illustrate the importance of bidirectional interaction between different PRR-expressing immune cells, which can have implications on the selection of adjuvants for vaccination strategies.


Asunto(s)
Citocinas/inmunología , Células Dendríticas/inmunología , Mediadores de Inflamación/inmunología , Interferón gamma/inmunología , Células Asesinas Naturales/inmunología , Monocitos/inmunología , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Interferón gamma/metabolismo , Células Asesinas Naturales/microbiología , Células Asesinas Naturales/virología , Activación de Linfocitos/inmunología , Monocitos/metabolismo , Moléculas de Patrón Molecular Asociado a Patógenos/inmunología , Moléculas de Patrón Molecular Asociado a Patógenos/metabolismo , Receptores de Reconocimiento de Patrones/inmunología , Receptores de Reconocimiento de Patrones/metabolismo
4.
Transfusion ; 58(1): 100-104, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29193117

RESUMEN

BACKGROUND: D antigens are not taken into account in the allocation of solid organs. Female transplant recipients with D antibodies as a consequence of D-mismatched kidney transplantation may develop hemolytic disease of the fetus and newborn in future pregnancies. We examined D antibody development in transplant recipients who received D-mismatched kidney transplantation in absence of D prophylaxis and in a setting of reduced immunosuppression. STUDY DESIGN AND METHODS: From 1993 until 2015, a total of 1355 kidney patients received transplantations in our center of whom 156 received a D-mismatched graft. A retrospective analysis was conducted; frozen stored sera obtained from transplant recipients 3 months after transplantation were tested for irregular red blood cell (RBC) antibodies using a three-cell screening and an identification panel. In the case of D antibody positivity, additional testing was performed 1 month before transplantation. RESULTS: In seven of 156 (4.5%) transplant recipients we found irregular RBC antibodies after transplantation, of which five (3.2%) were determined to be D antibodies. We observed only one (0.6%) recipient without D antibodies before transplantation. CONCLUSION: Although the risk of D antibody development is considerably lower after D-mismatched kidney transplantation than D-mismatched pregnancy, anti-D prophylaxis may still be advisable for female transplant recipients of childbearing age.


Asunto(s)
Terapia de Inmunosupresión/métodos , Trasplante de Riñón , Sistema del Grupo Sanguíneo Rh-Hr/inmunología , Globulina Inmune rho(D)/biosíntesis , Eritroblastosis Fetal/prevención & control , Femenino , Histocompatibilidad , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Masculino , Periodo Posoperatorio , Embarazo , Estudios Retrospectivos , Globulina Inmune rho(D)/sangre
5.
Kidney Int ; 91(6): 1420-1425, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28187980

RESUMEN

Thrombotic microangiopathy (TMA) is a pattern of endothelial damage that can be found in association with diverse clinical conditions such as malignant hypertension. Although the pathophysiological mechanisms differ, accumulating evidence links complement dysregulation to various TMA syndromes and in particular the atypical hemolytic uremic syndrome. Here, we evaluated the role of complement in nine consecutive patients with biopsy-proven renal TMA attributed to severe hypertension. Profound hematologic symptoms of TMA were uncommon. In six out of nine patients, we found mutations C3 in three, CFI in one, CD46 in one, and/or CFH in two patients either with or without the risk CFH-H3 haplotype in four patients. Elevated levels of the soluble C5b-9 and renal deposits of C3c and C5b-9 along the vasculature and/or glomerular capillary wall, confirmed complement activation in vivo. In contrast to patients without genetic defects, patients with complement defects invariably progressed to end-stage renal disease, and disease recurrence after kidney transplantation seems common. Thus, a subset of patients with hypertension-associated TMA falls within the spectrum of complement-mediated TMA, the prognosis of which is poor. Hence, testing for genetic complement abnormalities is warranted in patients with severe hypertension and TMA on renal biopsy to adopt suitable treatment options and prophylactic measures.


Asunto(s)
Presión Sanguínea , Activación de Complemento , Proteínas del Sistema Complemento/inmunología , Hipertensión/complicaciones , Riñón/inmunología , Microangiopatías Trombóticas/etiología , Adulto , Anciano , Biopsia , Complemento C3/genética , Complemento C3/inmunología , Factor H de Complemento/genética , Factor H de Complemento/inmunología , Factor I de Complemento/genética , Factor I de Complemento/inmunología , Proteínas del Sistema Complemento/genética , Análisis Mutacional de ADN , Progresión de la Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Predisposición Genética a la Enfermedad , Humanos , Hipertensión/fisiopatología , Hipertensión/terapia , Riñón/patología , Fallo Renal Crónico/etiología , Fallo Renal Crónico/inmunología , Masculino , Proteína Cofactora de Membrana/genética , Proteína Cofactora de Membrana/inmunología , Mutación , Fenotipo , Pronóstico , Índice de Severidad de la Enfermedad , Microangiopatías Trombóticas/sangre , Microangiopatías Trombóticas/inmunología , Microangiopatías Trombóticas/terapia
6.
Mediators Inflamm ; 2016: 5740373, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26980946

RESUMEN

A coordinated cellular interplay is of crucial importance in both host defense against pathogens and malignantly transformed cells. The various interactions of Dendritic Cells (DC), Natural Killer (NK) cells, and T helper (Th) cells can be influenced by a variety of pathogen-associated molecular patterns (PAMPs) and will lead to enhanced CD8(+) effector T cell responses. Specific Pattern Recognition Receptor (PRR) triggering during maturation enables DC to enhance Th1 as well as NK helper cell responses. This effect is correlated with the amount of IL-12p70 released by DC. Activated NK cells are able to amplify the proinflammatory cytokine profile of DC via the release of IFN-γ. The knowledge on how PAMP recognition can modulate the DC is of importance for the design and definition of appropriate therapeutic cancer vaccines. In this review we will discuss the potential role of specific PAMP-matured DC in optimizing therapeutic DC-based vaccines, as some of these DC are efficiently activating Th1, NK cells, and cytotoxic T cells. Moreover, to optimize these vaccines, also the inhibitory effects of tumor-derived suppressive factors, for example, on the NK-DC crosstalk, should be taken into account. Finally, the suppressive role of the tumor microenvironment in vaccination efficacy and some proposals to overcome this by using combination therapies will be described.


Asunto(s)
Células Dendríticas/metabolismo , Células Asesinas Naturales/metabolismo , Moléculas de Patrón Molecular Asociado a Patógenos/metabolismo , Linfocitos T Colaboradores-Inductores/metabolismo , Animales , Células Dendríticas/inmunología , Humanos , Células Asesinas Naturales/inmunología , Modelos Biológicos , Linfocitos T Colaboradores-Inductores/inmunología
7.
J Neuroinflammation ; 10: 13, 2013 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-23347579

RESUMEN

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is one of the most important causes of brain injury in preterm infants. Preterm HIE is predominantly caused by global hypoxia-ischemia (HI). In contrast, focal ischemia is most common in the adult brain and known to result in cerebral inflammation and activation of the peripheral immune system. These inflammatory responses are considered to play an important role in the adverse outcomes following brain ischemia. In this study, we hypothesize that cerebral and peripheral immune activation is also involved in preterm brain injury after global HI. METHODS: Preterm instrumented fetal sheep were exposed to 25 minutes of umbilical cord occlusion (UCO) (n = 8) at 0.7 gestation. Sham-treated animals (n = 8) were used as a control group. Brain sections were stained for ionized calcium binding adaptor molecule 1 (IBA-1) to investigate microglial proliferation and activation. The peripheral immune system was studied by assessment of circulating white blood cell counts, cellular changes of the spleen and influx of peripheral immune cells (MPO-positive neutrophils) into the brain. Pre-oligodendrocytes (preOLs) and myelin basic protein (MBP) were detected to determine white matter injury. Electro-encephalography (EEG) was recorded to assess functional impairment by interburst interval (IBI) length analysis. RESULTS: Global HI resulted in profound activation and proliferation of microglia in the hippocampus, periventricular and subcortical white matter. In addition, non-preferential mobilization of white blood cells into the circulation was observed within 1 day after global HI and a significant influx of neutrophils into the brain was detected 7 days after the global HI insult. Furthermore, global HI resulted in marked involution of the spleen, which could not be explained by increased splenic apoptosis. In concordance with cerebral inflammation, global HI induced severe brain atrophy, region-specific preOL vulnerability, hypomyelination and persistent suppressed brain function. CONCLUSIONS: Our data provided evidence that global HI in preterm ovine fetuses resulted in profound cerebral inflammation and mobilization of the peripheral innate immune system. These inflammatory responses were paralleled by marked injury and functional loss of the preterm brain. Further understanding of the interplay between preterm brain inflammation and activation of the peripheral immune system following global HI will contribute to the development of future therapeutic interventions in preterm HIE.


Asunto(s)
Encéfalo/inmunología , Encéfalo/patología , Movimiento Celular/inmunología , Hipoxia-Isquemia Encefálica/inmunología , Hipoxia-Isquemia Encefálica/patología , Animales , Animales Recién Nacidos , Femenino , Feto/inmunología , Feto/patología , Inmunidad Innata , Microglía/inmunología , Microglía/patología , Embarazo , Ovinos
8.
Blood ; 118(9): 2473-82, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21715307

RESUMEN

Among prostaglandins (PGs), PGE2 is abundantly expressed in various malignancies and is probably one of many factors promoting tumor growth by inhibiting tumor immune surveillance. In the current study, we report on a novel mechanism by which PGE2 inhibits in vitro natural killer-dendritic cell (NK-DC) crosstalk and thereby innate and adaptive immune responses via its effect on NK-DC crosstalk. The presence of PGE2 during IFN-γ/membrane fraction of Klebsiella pneumoniae DC maturation inhibits the production of chemokines (CCL5, CCL19, and CXCL10) and cytokines (IL-12 and IL-18), which is cAMP-dependent and imprinted during DC maturation. As a consequence, these DCs fail to attract NK cells and show a decreased capacity to trigger NK cell IFN-γ production, which in turn leads to reduced T-helper 1 polarization. In addition, the presence of PGE2 during DC maturation impairs DC-mediated augmentation of NK-cell cytotoxicity. Opposed to their inhibitory effects on peripheral blood-derived NK cells, PGE2 matured DCs induce IL-22 secretion of inflammation constraining NKp44(+) NK cells present in mucosa-associated lymphoid tissue. The inhibition of NK-DC interaction is a novel regulatory property of PGE2 that is of possible relevance in dampening immune responses in vivo.


Asunto(s)
Células Dendríticas/efectos de los fármacos , Dinoprostona/farmacología , Inflamación/inmunología , Células Asesinas Naturales/efectos de los fármacos , Alprostadil/análogos & derivados , Alprostadil/farmacología , Bucladesina/farmacología , Diferenciación Celular , Movimiento Celular/efectos de los fármacos , Células Cultivadas/efectos de los fármacos , Células Cultivadas/inmunología , Quimiocinas/biosíntesis , Quimiocinas/genética , Técnicas de Cocultivo , Citocinas/biosíntesis , Citocinas/genética , Citotoxicidad Inmunológica/efectos de los fármacos , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Terapia de Inmunosupresión , Interferón gamma/biosíntesis , Interferón gamma/genética , Células Asesinas Naturales/inmunología , Klebsiella pneumoniae/inmunología , Misoprostol/farmacología , Tonsila Palatina/citología , Linfocitos T Colaboradores-Inductores/inmunología
9.
Blood ; 115(2): 261-4, 2010 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-19828700

RESUMEN

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is a treatment option for patients with hematopoietic malignancies that is hampered by treatment-related morbidity and mortality, in part the result of opportunistic infections, a direct consequence of delayed T-cell recovery. Thymic output can be improved by facilitation of thymic immigration, known to require precommitment of CD34(+) cells. We demonstrate that Delta-like ligand-mediated predifferentiation of mobilized CD34(+) cells in vitro results in a population of thymocyte-like cells arrested at a T/natural killer (NK)-cell progenitor stage. On intrahepatic transfer to Rag2(-/-)gamma(c)(-/-) mice, these cells selectively home to the thymus and differentiate toward surface T-cell receptor-alphabeta(+) mature T cells considerably faster than animals transplanted with noncultured CD34(+) cells. This finding creates the opportunity to develop an early T-cell reconstitution therapy to combine with HSCT.


Asunto(s)
Antígenos CD34 , Células Asesinas Naturales/metabolismo , Células Progenitoras Linfoides/metabolismo , Linfocitos T/metabolismo , Timo/metabolismo , Animales , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Proteínas de Unión al ADN/metabolismo , Trasplante de Células Madre Hematopoyéticas , Humanos , Células Asesinas Naturales/citología , Células Asesinas Naturales/inmunología , Células Progenitoras Linfoides/citología , Células Progenitoras Linfoides/inmunología , Ratones , Ratones Noqueados , Linfocitos T/citología , Linfocitos T/inmunología , Timo/citología , Timo/inmunología , Trasplante Heterólogo , Trasplante Homólogo
10.
Biomedicines ; 10(5)2022 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-35625889

RESUMEN

BACKGROUND: Pathogens or trauma-derived danger signals induced maturation and activation of plasmacytoid dendritic cells (pDCs) is a pivotal step in pDC-dependent host defense. Exposure of pDC to cardiometabolic disease-associated lipids and proteins may well influence critical signaling pathways, thereby compromising immune responses against endogenous, bacterial and viral pathogens. In this study, we have addressed if hyperlipidemia impacts human pDC activation, cytokine response and capacity to prime CD4+ T cells. METHODS AND RESULTS: We show that exposure to pro-atherogenic oxidized low-density lipoproteins (oxLDL) led to pDC lipid accumulation, which in turn ablated a Toll-like receptor (TLR) 7 and 9 dependent up-regulation of pDC maturation markers CD40, CD83, CD86 and HLA-DR. Moreover, oxLDL dampened TLR9 activation induced the production of pro-inflammatory cytokines in a NUR77/IRF7 dependent manner and impaired the capacity of pDCs to prime and polarize CD4+ T helper (Th) cells. CONCLUSION: Our findings reveal profound effects of dyslipidemia on pDC responses to pathogen-derived signals.

11.
BMC Immunol ; 12: 17, 2011 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-21332988

RESUMEN

BACKGROUND: Haplo-identical hematopoietic stem cell (HSC) transplantation is very successful in eradicating haematological tumours, but the long post-transplant T-lymphopenic phase is responsible for high morbidity and mortality rates. Clark et al. have described a skin-explant system capable of producing host-tolerant donor-HSC derived T-cells. Because this T-cell production platform has the potential to replenish the T-cell levels following transplantation, we set out to validate the skin-explant system. RESULTS: Following the published procedures, while using the same commercial components, it was impossible to reproduce the skin-explant conditions required for HSC differentiation towards mature T-cells. The keratinocyte maturation procedure resulted in fragile cells with minimum expression of delta-like ligand (DLL). In most experiments the generated cells failed to adhere to carriers or were quickly outcompeted by fibroblasts. Consequently it was not possible to reproduce cell-culture conditions required for HSC differentiation into functional T-cells. Using cell-lines over-expressing DLL, we showed that the antibodies used by Clark et al. were unable to detect native DLL, but instead stained 7AAD+ cells. Therefore, it is unlikely that the observed T-lineage commitment from HSC is mediated by DLL expressed on keratinocytes. In addition, we did confirm expression of the Notch-ligand Jagged-1 by keratinocytes. CONCLUSIONS: Currently, and unfortunately, it remains difficult to explain the development or growth of T-cells described by Clark et al., but for the fate of patients suffering from lymphopenia it is essential to both reproduce and understand how these co-cultures really "work". Fortunately, alternative procedures to speed-up T-cell reconstitution are being established and validated and may become available for patients in the near future.


Asunto(s)
Diferenciación Celular , Células Madre Hematopoyéticas/citología , Piel/citología , Linfocitos T/citología , Animales , Técnicas de Cultivo de Célula , Línea Celular , Células Cultivadas , Técnicas de Cocultivo , Fibroblastos/citología , Fibroblastos/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Células Madre Hematopoyéticas/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Queratinocitos/citología , Queratinocitos/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/metabolismo
12.
Eur J Immunol ; 40(11): 3138-49, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20865789

RESUMEN

Besides their role in destruction of altered self-cells, NK cells have been shown to potentiate T-cell responses by interacting with DC. To take advantage of NK-DC crosstalk in therapeutic DC-based vaccination for infectious diseases and cancer, it is essential to understand the biology of this crosstalk. We aimed to elucidate the in vitro mechanisms responsible for NK-cell recruitment and activation by DC during infection. To mimic bacterial infection, DC were exposed to a membrane fraction of Klebsiella pneumoniae, which triggers TLR2/4. DC matured with these bacterial fragments can actively recruit NK cells in a CCR5-dependent manner. An additional mechanism of DC-induced NK-cell recruitment is characterized by the induction of CCR7 expression on CD56(dim) CD16(+) NK cells after physical contact with membrane fraction of K. pneumoniae-matured DC, resulting in an enhanced migratory responsiveness to the lymph node-associated chemokine CCL19. Bacterial fragment-matured DC do not only mediate NK-cell migration but also meet the prerequisites needed for augmentation of NK-cell cytotoxicity and IFN-γ production, the latter of which contributes to Th1 polarization.


Asunto(s)
Movimiento Celular/inmunología , Quimiocina CCL19/inmunología , Células Dendríticas/inmunología , Células Asesinas Naturales/inmunología , Infecciones por Klebsiella/inmunología , Klebsiella pneumoniae/inmunología , Activación de Linfocitos/inmunología , Receptores CCR5/inmunología , Células Cultivadas , Regulación de la Expresión Génica/inmunología , Humanos , Interferón gamma/inmunología , Receptores CCR7/inmunología , Células TH1/inmunología , Receptor Toll-Like 2/inmunología , Receptor Toll-Like 4/inmunología
13.
Mol Immunol ; 46(4): 738-42, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18952292

RESUMEN

Mucin-1 (MUC1) is a transmembrane glycoprotein that is upregulated upon maturation of dendritic cells (DC) in vitro or in vivo. One of the proposed functions of surface expressed MUC1 is its involvement in migration of cells. We hypothesized that MUC1 is involved in DC migration since mature DC (mDC) are highly migratory cells and MUC1 is upregulated on the surface of DC upon maturation. In this study we cultured DC using two maturation cocktails, one cocktail containing IL-4, GM-CSF, TNFalpha, PGE2, IL-1 beta and IL-6 (TP1,6-DC) and the other IL-13, GM-CSF, Ribomunyl and IFN-gamma (RI-DC). Both maturation cocktails render DC with a similar surface phenotype including CCR7 expression, but only the former induces a migratory capacity of DC to a CCL19 gradient. To analyze the role of surface-expression of MUC1 on TP1,6-DC, that are capable of migration, expression of MUC1 was prevented by adding an anti-MUC1 antibody (Ab) during the maturation process. Compared with matured DC in the absence of the Ab, no difference was observed in chemokine-induced migratory behaviour between the MUC1+ and MUC1- DC populations in a standard Transwell chemotaxis assay, nor in organotypic cultures. Our data clearly demonstrate that surface MUC1 on DC does not influence intrinsic cell-motility, nor is it involved in cell-cell and cell-matrix dependent migration.


Asunto(s)
Movimiento Celular/inmunología , Células Dendríticas/inmunología , Mucina-1/inmunología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Citocinas/farmacología , Células Dendríticas/efectos de los fármacos , Humanos , Molécula 1 de Adhesión Intercelular/inmunología , Molécula 1 de Adhesión Intercelular/metabolismo , Mucina-1/efectos de los fármacos
14.
PLoS One ; 14(5): e0215852, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31091250

RESUMEN

INTRODUCTION: Brown adipose tissue (BAT) is considered as a potential target for combating obesity in humans where active BAT metabolizes glucose and fatty acids as fuel resulting in heat production. Prospective studies in humans have been set up to further study the presence and metabolic activity of BAT mostly using Positron Emission Tomography (PET) imaging in cold-stimulated conditions with the radiolabeled glucose derivative [18F]FDG. However, radiotracers beyond [18F]FDG have been proposed to investigate BAT activity, targeting various aspects of BAT metabolism. It remains questionable which tracer is best suited to detect metabolic BAT activity and to what extent those results correlate with ex vivo metabolic BAT activity. METHODS: PET and Single Photon Emission Computed Tomography (SPECT) imaging, targeting different aspects of BAT activation such as glucose metabolism, fatty acid metabolism, noradrenergic stimulation, blood perfusion and amino acid transport system, was performed immediately after injection of the tracer in rats under different temperatures: room temperature, acute cold (4 °C for 4 h) or acclimated to cold (4 °C for 6 h per day during 28 days). Furthermore, Magnetic Resonance Spectroscopy (MRS)-derived BAT temperature was measured in control and cold-acclimated rats. RESULTS: At room temperature, only [18F]FDG visualized BAT. Glucose metabolism, fatty acid metabolism, noradrenergic stimulation and blood perfusion showed a clear tracer-dependent twofold increase in BAT uptake upon cold exposure. Only the tracer for the amino acid transport system did not show BAT specific uptake under any of the experimental conditions. MRS demonstrated that cold-acclimated animals had BAT with a stronger heat-production compared to control animals. CONCLUSION: BAT activity following cold exposure in rats was visualized by several tracers, while only [18F]FDG was also able to show BAT activity under non-stimulated conditions (room temperature). The variances in uptake of the different tracers should be taken into account when developing future clinical applications in humans.


Asunto(s)
Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/metabolismo , Tomografía de Emisión de Positrones , Tomografía Computarizada de Emisión de Fotón Único , Aclimatación , Animales , Frío , Masculino , ARN Mensajero/genética , Radiofármacos/farmacocinética , Ratas , Ratas Wistar , Distribución Tisular
15.
Proteomics ; 8(6): 1237-47, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18338825

RESUMEN

Leukemia inhibitory factor (LIF) promotes the survival of oligodendrocytes (OLG) both in vitro and in an animal model of multiple sclerosis. Here, we show that LIF protects mature rat OLG cultures selectively against the combined insult of the proinflammatory cytokines interferon-gamma and tumor necrosis factor-alpha, but it does not protect against oxidative stress nor against staurosporine induced apoptosis. We further demonstrate that LIF activates the janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) and the phosphatidylinositol 3 kinase/Akt pathway in mature OLG. We show that LIF protection is independent of suppressors of cytokine signaling and Bcl-2 mRNA expression levels. To gain further insight into the protective mechanism, a quantitative proteomic approach (DIGE) was applied to identify differentially expressed proteins in LIF-treated OLG. Our results indicate that LIF induces a shift in the cellular machinery toward a prosurvival execution program, illustrated by an enhanced expression of isoforms of the antiapoptotic molecule 14-3-3. These data provide further insight into the mechanisms of LIF-mediated protection of mature OLGs.


Asunto(s)
Proteínas 14-3-3/metabolismo , Apoptosis/efectos de los fármacos , Factor Inhibidor de Leucemia/farmacología , Oligodendroglía/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Western Blotting , Línea Celular , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Humanos , Oligodendroglía/citología , Oligodendroglía/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Espectrometría de Masa por Ionización de Electrospray , Proteínas Supresoras de la Señalización de Citocinas/genética , Espectrometría de Masas en Tándem , Transcripción Genética/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos
16.
J Neuroimmunol ; 195(1-2): 1-6, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18177950

RESUMEN

Macrophages are considered to be the predominant effector cells in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Ultra small particles of iron oxide (USPIO) can be used to detect macrophage infiltrates in the CNS with magnetic resonance imaging (MRI). Here, we investigated whether the kinetics of lesion formation in EAE can be visualised by altering the time point of USPIO injection and the time interval between particle injection and MRI. When USPIO are systemically injected 24 h before MRI, hypo intense regions are detected in different brain regions depending on the disease stage. These regions correspond to sites of macrophage infiltration. A more complete visualisation of sites of inflammation is accomplished by USPIO injection at disease onset and postponing MRI to top of disease. This study demonstrates that the distribution pattern and amount of inflammatory lesions detected with USPIO, depends on timing of USPIO administration and subsequent MRI. These findings are important for a correct application and interpretation of USPIO dependent contrast imaging of CNS inflammation.


Asunto(s)
Encefalomielitis Autoinmune Experimental/patología , Macrófagos/fisiología , Imagen por Resonancia Magnética , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Ensayos de Migración de Macrófagos , Encefalomielitis Autoinmune Experimental/fisiopatología , Femenino , Compuestos Férricos/farmacocinética , Macrófagos/efectos de los fármacos , Proteína Básica de Mielina/efectos adversos , Ratas , Ratas Endogámicas Lew , Factores de Tiempo
17.
Crit Rev Immunol ; 27(1): 1-13, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17430093

RESUMEN

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) of presumed autoimmune origin. On the basis of the pathophysiology of MS, inflammatory reactions in the CNS are considered detrimental. Recent evidence suggests that the injured CNS can also benefit from immune activity. In this review, we will first provide an overview of the mechanisms by which immune cells contribute to CNS injury in MS. We will further review evidence supporting a neuroprotective role of CNS inflammation with special focus on the protective properties of autoimmune reactions. Finally, we discuss the proposed mechanisms by which autoreactive T cells exert protection in the CNS and how this protection is regulated.


Asunto(s)
Encéfalo/inmunología , Esclerosis Múltiple/inmunología , Linfocitos T/fisiología , Presentación de Antígeno , Autoinmunidad , Movimiento Celular , Humanos , Factor Inhibidor de Leucemia/fisiología , Factores de Crecimiento Nervioso/fisiología
18.
PLoS One ; 13(9): e0203381, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30192820

RESUMEN

Human leukocyte antigen (HLA)-DRB3 is a functional HLA class II gene, which has a limited allele diversity in the human population. Furthermore, the HLA-DRB3 gene is only present in a subset of individuals. Therefore, in organ transplantation, this HLA molecule is frequently mismatched between patient and graft donor and thus antibodies against this mismatched HLA molecule can develop. In this study, we aimed to evaluate the prevalence and reactivity of these antibodies and aimed to identify factors that underlie antibody formation against HLA-DRB3. We showed in our patient cohort that HLA-DRB3 antibodies are identified in about 7% of all patients that were screened with solid phase assays. In these assays, we observed multiple antibody reactivity patterns indicating that HLA-DRB3 harbours multiple epitopes. In those cases, where we succeeded at tracing back the induction of these antibodies to the molecular HLA typing of the immunogenic event, we noticed a different frequency of HLA-DRB1 allele groups in the donors as compared to a control group. To a certain extent this distribution (e.g. HLA-DRB1*11 individuals) could be linked to an altered expression level. However, it also appears that different HLA-DRB3 alleles (e.g. HLA-DRB3*01 group) vary in their immunogenicity without having an expression difference. In conclusion, our study provides information on the immunogenicity and reactivity patterns of antibodies against HLA-DRB3 in kidney transplantation, and it points towards the possibility of HLA expression as a factor underlying antibody formation.


Asunto(s)
Anticuerpos/sangre , Antígenos HLA/genética , Cadenas HLA-DRB3/genética , Trasplante de Riñón , Alelos , Anticuerpos/inmunología , Epítopos/genética , Epítopos/metabolismo , Frecuencia de los Genes , Supervivencia de Injerto , Antígenos HLA/metabolismo , Cadenas HLA-DRB1/genética , Cadenas HLA-DRB1/metabolismo , Cadenas HLA-DRB3/inmunología , Cadenas HLA-DRB3/metabolismo , Prueba de Histocompatibilidad/métodos , Humanos , Donantes de Tejidos
19.
Front Immunol ; 9: 321, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29556227

RESUMEN

Individual HLA mismatches may differentially impact graft survival after kidney transplantation. Therefore, there is a need for a reliable tool to define permissible HLA mismatches in kidney transplantation. We previously demonstrated that donor-derived Predicted Indirectly ReCognizable HLA Epitopes presented by recipient HLA class II (PIRCHE-II) play a role in de novo donor-specific HLA antibodies formation after kidney transplantation. In the present Dutch multi-center study, we evaluated the possible association between PIRCHE-II and kidney graft failure in 2,918 donor-recipient couples that were transplanted between 1995 and 2005. For these donors-recipients couples, PIRCHE-II numbers were related to graft survival in univariate and multivariable analyses. Adjusted for confounders, the natural logarithm of PIRCHE-II was associated with a higher risk for graft failure [hazard ratio (HR): 1.13, 95% CI: 1.04-1.23, p = 0.003]. When analyzing a subgroup of patients who had their first transplantation, the HR of graft failure for ln(PIRCHE-II) was higher compared with the overall cohort (HR: 1.22, 95% CI: 1.10-1.34, p < 0.001). PIRCHE-II demonstrated both early and late effects on graft failure in this subgroup. These data suggest that the PIRCHE-II may impact graft survival after kidney transplantation. Inclusion of PIRCHE-II in donor-selection criteria may eventually lead to an improved kidney graft survival.


Asunto(s)
Rechazo de Injerto/epidemiología , Supervivencia de Injerto/inmunología , Antígenos HLA/inmunología , Prueba de Histocompatibilidad , Trasplante de Riñón , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Selección de Donante , Femenino , Rechazo de Injerto/inmunología , Rechazo de Injerto/patología , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Donantes de Tejidos
20.
J Immunol Methods ; 448: 21-25, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28522403

RESUMEN

Autoantibody detection for autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and autoimmune gastritis (AIG) is traditionally performed by IIF on a combination of tissues. Multiplex line/dot blots (LIA/DIA) offer multiple advantages, i.e. automation, objective reading, no interfering reactivities, no coincidental findings. In the current study we evaluated automated DIA (D-Tek) for detecting autoantibodies related to autoimmune diseases of the gastrointestinal tract. We tested samples of the Dutch EQC program and compared the results with the consensus of the participating labs. For the autoimmune liver diseases and AIG, respectively, 64 and 36 samples were tested. For anti-mitochondrial and anti-smooth muscle antibodies a concordance rate of 97% and 88% was observed, respectively. The concordance rate for anti-parietal cell antibodies was 92% when samples without EQC consensus (n=15) were excluded. For antibodies against intrinsic factor a concordance of 96% was observed. For all these antibodies discrepancies were identified that relate to the different test characteristics and the preponderance of IIF utilizing labs in the EQC program. In conclusion, we observed good agreement of the tested DIA blots with the consensus results of the Dutch EQC program. Taken together with the logistic advantages these blots are a good alternative for autoantibody detection in the respective diseases. A large prospective multicenter study is warranted to position these novel tests further in the whole spectrum of assays for the detection of these antibodies in a routine autoimmune laboratory.


Asunto(s)
Autoanticuerpos/sangre , Enfermedades Autoinmunes/diagnóstico , Autoinmunidad , Gastritis/diagnóstico , Inmunoensayo , Hepatopatías/diagnóstico , Mitocondrias/inmunología , Miocitos del Músculo Liso/inmunología , Células Parietales Gástricas/inmunología , Pruebas Serológicas , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/inmunología , Automatización de Laboratorios , Biomarcadores/sangre , Gastritis/sangre , Gastritis/inmunología , Humanos , Inmunoensayo/instrumentación , Inmunoensayo/normas , Hepatopatías/sangre , Hepatopatías/inmunología , Países Bajos , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Control de Calidad , Tiras Reactivas , Estándares de Referencia , Reproducibilidad de los Resultados , Pruebas Serológicas/instrumentación , Pruebas Serológicas/normas
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda