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1.
JAMA Cardiol ; 9(5): 475-479, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38506880

RESUMEN

Importance: Previous studies of professional basketball athletes have characterized manifestations of athletic remodeling by echocardiography and electrocardiography (ECG) in males and echocardiography in females. There is a paucity of female, basketball-specific ECG data. Objective: To generate reference range ECG data for female professional basketball athletes. Design, Setting, and Participants: This is a cross-sectional study of ECGs performed on female professional basketball athletes. The Women's National Basketball Association mandates annual preseason ECGs and echocardiograms for each athlete and has partnered with Columbia University Irving Medical Center to annually review these studies. Data for this study were collected during preseason ECG and echocardiography cardiac screening between April and May 2022. Data analysis was performed between February and July 2023. Exposure: Athlete ECGs and echocardiograms were sent to Columbia University Irving Medical Center for core lab analysis. Main Outcomes and Measures: Quantitative ECG variables were measured. ECG data were qualitatively analyzed for training-related and abnormal findings using the International Recommendations for Electrocardiographic Interpretation in Athletes. Findings from ECGs were compared with corresponding echocardiographic data. Results: There were a total of 173 athletes (mean [SD] age 26.5 [4.1] years; mean [SD] height, 183.4 [9.1] cm; mean [SD] body surface area, 2.0 [0.2] m2), including 129 Black athletes (74.5%) and 40 White athletes (23.1%). By international criteria, 136 athletes (78.6%) had training-related ECG changes and 8 athletes (4.6%) had abnormal ECG findings. Among athletes with at least 1 training-related ECG finding, left ventricular structural adaptations associated with athletic remodeling were present in 64 athletes (47.1%). Increased relative wall thickness, reflecting concentric left ventricular geometry, was more prevalent in athletes with the repolarization variant demonstrating convex ST elevation combined with T-wave inversions in leads V1 to V4 (6 of 12 athletes [50.0%]) than in athletes with early repolarization (5 of 42 athletes [11.9%]) (odds ratio, 7.40; 95% CI, 1.71-32.09; P = .01). Abnormal ECG findings included T-wave inversions (3 athletes [1.7%]), Q waves (2 athletes [1.2%]), prolonged QTc interval (2 athletes [1.2%]), and frequent premature ventricular contractions (1 athlete [0.6%]). Conclusions and Relevance: This cross-sectional study provides reference ECG data for elite female basketball athletes. International criteria-defined training-related findings were common, whereas abnormal ECG findings were rare in this athlete group. These reference data may assist basketball programs and health care professionals using ECGs in screening for female athletes and may be used as a stimulus for future female-specific ECG inquiries.


Asunto(s)
Atletas , Baloncesto , Ecocardiografía , Electrocardiografía , Humanos , Baloncesto/fisiología , Femenino , Estudios Transversales , Adulto , Adulto Joven , Valores de Referencia
2.
JACC Case Rep ; 4(17): 1070-1073, 2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36124146

RESUMEN

Commotio cordis is a rare cause of sudden cardiac arrest from blunt chest trauma; however, it is a diagnosis of exclusion. We present a case of sudden cardiac arrest in a collegiate athlete initially attributed to commotio cordis but in whom further history and workup revealed another rare condition. (Level of Difficulty: Advanced.).

4.
Arterioscler Thromb Vasc Biol ; 35(7): 1663-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26109739

RESUMEN

OBJECTIVE: We previously demonstrated that subjects with functional ATP-binding cassette (ABC) A1 mutations have increased atherosclerosis, which has been attributed to the role of ABCA1 in reverse cholesterol transport. More recently, a proinflammatory effect of Abca1 deficiency was shown in mice, potentially contributing to atherogenesis. In this study, we investigated whether ABCA1 deficiency was associated with proinflammatory changes in humans. APPROACH AND RESULTS: Thirty-one heterozygous, 5 homozygous ABCA1 mutation carriers, and 21 matched controls were studied. (18)Fluorodeoxyglucose positron emission tomography with computed tomographic scanning was performed in a subset of carriers and controls to assess arterial wall inflammation (target:background ratio). Heterozygous ABCA1 mutation carriers had a 20% higher target:background ratio than in controls (target:background ratio; P=0.008). In carriers using statins (n=7), target:background ratio was 21% reduced than in nonstatin users (n=7; P=0.03). We then measured plasma cytokine levels. Tumor necrosis factor α, monocyte chemoattractant protein-1, and interleukin-6 levels were increased in heterozygous and homozygous ABCA1 mutation carriers. We isolated monocytes from carriers and controls and measured inflammatory gene expression. Only TNFα mRNA was increased in monocytes from heterozygous ABCA1 mutation carriers. Additional studies in THP-1 macrophages showed that both ABCA1 deficiency and lipoprotein-deficient plasma from ABCA1 mutation carriers increased inflammatory gene expression. CONCLUSIONS: Our data suggest a proinflammatory state in ABCA1 mutation carriers as reflected by an increased positron emission tomography-MRI signal in nonstatin using subjects, and increased circulating cytokines. The increased inflammation in ABCA1 mutation carriers seems to be attenuated by statins.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Inflamación/genética , Mutación , Placa Aterosclerótica/genética , Apolipoproteínas B/sangre , Transporte Biológico , Colesterol/sangre , Citocinas/sangre , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Inflamación/metabolismo , Inflamación/prevención & control , Lipoproteínas/sangre , Macrófagos/metabolismo , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/prevención & control
5.
Atherosclerosis ; 229(1): 79-85, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23684512

RESUMEN

Previous studies have shown that mice with defects in cellular cholesterol efflux show hematopoietic stem cell (HSPC) and myeloid proliferation, contributing to atherogenesis. We hypothesized that the combination of hypercholesterolemia and defective cholesterol efflux would promote HSPC expansion and leukocytosis more prominently than either alone. We crossed Ldlr(-/-) with Apoa1(-/-) mice and found that compared to Ldlr(-/-) mice, Ldlr(-/-)/Apoa1(+/-) mice, with similar LDL-cholesterol levels but reduced HDL-cholesterol (HDL-C) levels, had expansion of HSPCs, monocytosis and neutrophilia. Ex vivo studies showed that HSPCs expressed high levels of Ldlr, Scarb1 (Srb1), and Lrp1 and were able to take up both native and oxidized LDL. Native LDL directly stimulated HSPC proliferation, while co-incubation with reconstituted HDL attenuated this effect. We also assessed the impact of HDL-C levels on monocytes in children with familial hypercholesterolemia (FH) (n = 49) and found that subjects with the lowest level of HDL-C, had increased monocyte counts compared to the mid and higher HDL-C levels. Overall, HDL-C was inversely correlated with the monocyte count. These data suggest that in mice, a balance of cholesterol uptake and efflux mechanisms may be one factor in driving HSPC proliferation and monocytosis. Higher monocyte counts in children with FH and low HDL-cholesterol suggest a similar pattern in humans.


Asunto(s)
Aterosclerosis/metabolismo , HDL-Colesterol/metabolismo , Células Madre Hematopoyéticas/citología , Hiperlipoproteinemia Tipo II/metabolismo , Monocitos/citología , Adolescente , Animales , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Aterosclerosis/inmunología , Aterosclerosis/patología , Proliferación Celular , Niño , LDL-Colesterol/metabolismo , Femenino , Células Madre Hematopoyéticas/metabolismo , Humanos , Hiperlipoproteinemia Tipo II/inmunología , Hiperlipoproteinemia Tipo II/patología , Lipoproteínas LDL/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/metabolismo , Neutrófilos/citología , Neutrófilos/metabolismo
6.
J Clin Invest ; 121(10): 4138-49, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21968112

RESUMEN

Leukocytosis is associated with increased cardiovascular disease risk in humans and develops in hypercholesterolemic atherosclerotic animal models. Leukocytosis is associated with the proliferation of hematopoietic stem and multipotential progenitor cells (HSPCs) in mice with deficiencies of the cholesterol efflux-promoting ABC transporters ABCA1 and ABCG1 in BM cells. Here, we have determined the role of endogenous apolipoprotein-mediated cholesterol efflux pathways in these processes. In Apoe⁻/⁻ mice fed a chow or Western- type diet, monocytosis and neutrophilia developed in association with the proliferation and expansion of HSPCs in the BM. In contrast, Apoa1⁻/⁻ mice showed no monocytosis compared with controls. ApoE was found on the surface of HSPCs, in a proteoglycan-bound pool, where it acted in an ABCA1- and ABCG1-dependent fashion to decrease cell proliferation. Accordingly, competitive BM transplantation experiments showed that ApoE acted cell autonomously to control HSPC proliferation, monocytosis, neutrophilia, and monocyte accumulation in atherosclerotic lesions. Infusion of reconstituted HDL and LXR activator treatment each reduced HSPC proliferation and monocytosis in Apoe⁻/⁻ mice. These studies suggest a specific role for proteoglycanbound ApoE at the surface of HSPCs to promote cholesterol efflux via ABCA1/ABCG1 and decrease cell proliferation, monocytosis, and atherosclerosis. Although endogenous apoA-I was ineffective, pharmacologic approaches to increasing cholesterol efflux suppressed stem cell proliferative responses.


Asunto(s)
Apolipoproteínas E/fisiología , Aterosclerosis/patología , Aterosclerosis/fisiopatología , Células Madre Hematopoyéticas/patología , Células Madre Hematopoyéticas/fisiología , Monocitos/patología , Transportador 1 de Casete de Unión a ATP , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1 , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Apolipoproteína A-I/deficiencia , Apolipoproteína A-I/genética , Apolipoproteína A-I/fisiología , Apolipoproteínas E/deficiencia , Apolipoproteínas E/genética , Proliferación Celular , Colesterol/metabolismo , Modelos Animales de Enfermedad , Humanos , Leucocitosis/patología , Leucocitosis/fisiopatología , Lipoproteínas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Cardiovasculares , Proteoglicanos/metabolismo , Receptores de LDL/deficiencia , Receptores de LDL/genética , Receptores de LDL/fisiología
7.
J Biol Chem ; 282(26): 18722-31, 2007 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-17475625

RESUMEN

Because the mechanisms of Helicobacter pylori-induced gastric injury are incompletely understood, we examined the hypothesis that H. pylori induces matrix metalloproteinase-1 (MMP-1) secretion, with potential to disrupt gastric stroma. We further tested the role of CagA, an H. pylori virulence factor, in MMP-1 secretion. Co-incubation of AGS cells with Tx30a, an H. pylori strain lacking the cagA virulence gene, stimulated MMP-1 secretion, confirming cagA-independent secretion. Co-incubation with strain 147C (cagA(+)) resulted in CagA translocation into AGS cells and increased MMP-1 secretion relative to Tx30a. Transfection of cells with the recombinant 147C cagA gene also induced MMP-1 secretion, indicating that CagA can independently stimulate MMP-1 secretion. Co-incubation with strain 147A, containing a cagA gene that lacks an EPIYA tyrosine phosphorylation motif, as well as transfection with 147A cagA, yielded an MMP-1 secretion intermediate between no treatment and 147C, indicating that CagA tyrosine phosphorylation regulates cellular signaling in this model system. H. pylori induced activation of the MAP kinase ERK, with CagA-independent (early) and dependent (later) components. MEK inhibitors UO126 and PD98059 inhibited both CagA-independent and -dependent MMP-1 secretion, whereas p38 inhibition enhanced MMP-1 secretion and ERK activation, suggesting p38 negative regulation of MMP-1 and ERK. These data indicate H. pylori effects on host epithelial MMP-1 expression via ERK, with p38 playing a potential regulatory role.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Infecciones por Helicobacter/microbiología , Helicobacter pylori/metabolismo , Metaloproteinasa 1 de la Matriz/metabolismo , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Línea Celular Tumoral , Células Epiteliales/enzimología , Células Epiteliales/microbiología , Genotipo , Infecciones por Helicobacter/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Sistema de Señalización de MAP Quinasas/fisiología , Neoplasias Glandulares y Epiteliales , Neoplasias Gástricas , Transfección , Virulencia
8.
J Biol Chem ; 280(11): 9973-9, 2005 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-15640153

RESUMEN

Because matrix metalloproteinases (MMPs) play roles in inflammatory tissue injury, we asked whether MMP secretion by gastric epithelial cells may contribute to gastric injury in response to signals involved in Helicobacter pylori-induced inflammation and/or cyclooxygenase inhibition. Tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and epidermal growth factor (EGF) stimulated gastric cell MMP-1 secretion, indicating that MMP-1 secretion occurs in inflammatory as well as non-inflammatory situations. MMP-1 secretion required activation of the MAPK Erk and subsequent protein synthesis but was down-regulated by the alternate MAPK, p38. In contrast, secretion of MMP-13 was stimulated by TNF-alpha/IL-1beta but not EGF and was Erk-independent and mediated by p38. MMP-13 secretion was more rapid (peak, 6 h) than MMP-1 (peak > or =30 h) and only partly depended on protein synthesis, suggesting initial release of a pre-existing MMP-13 pool. Therefore, MMP-1 and MMP-13 secretion are differentially regulated by MAPKs. MMP-1 secretion was regulated by E prostaglandins (PGEs) in an Erk-dependent manner. PGEs enhanced Erk activation and MMP-1 secretion in response to EGF but inhibited Erk and MMP-1 when TNF-alpha and IL-1beta were the stimuli, indicating that the effects of PGEs on gastric cell responses are context-dependent. These data show that secretion of MMPs is differentially regulated by MAPKs and suggest mechanisms through which H. pylori infection and/or cyclooxygenase inhibition may induce epithelial cell signaling to contribute to gastric ulcerogenesis.


Asunto(s)
Células Epiteliales/metabolismo , Mucosa Gástrica/metabolismo , Sistema de Señalización de MAP Quinasas , Metaloproteinasas de la Matriz/metabolismo , Prostaglandinas E/metabolismo , Línea Celular Tumoral , Colagenasas/metabolismo , Cicloheximida/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Regulación hacia Abajo , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Factor de Crecimiento Epidérmico/metabolismo , Células Epiteliales/microbiología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación Enzimológica de la Expresión Génica , Helicobacter pylori/metabolismo , Humanos , Inflamación , Interleucina-1/metabolismo , Cinética , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 13 de la Matriz , Modelos Biológicos , Inhibidores de la Síntesis de la Proteína/farmacología , Transducción de Señal , Estómago/microbiología , Factores de Tiempo , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Br J Pharmacol ; 142(6): 973-82, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15210577

RESUMEN

1 Nabumetone is a prodrug that is converted in vivo into 6-methoxy-2-naphthylacetic acid (6MNA), a cyclooxygenase inhibitor with anti-inflammatory properties. We tested the effects of nabumetone and 6MNA on the inflammatory responses of synovial fibroblasts (SFs). 2 Brief exposures to 6MNA (50-150 microm) had no effect on IL-1beta/TNF-alpha (each 20 ng ml(-1))-stimulated Erk activation. Longer exposures depleted prostaglandin E1 (PGE1) as much as 70%, and stimulated Erk as much as 300%. Nabumetone (150 microm) inhibited Erk activation by 60-80%. 6MNA (50-150 microm) stimulated (approximately 200%) and nabumetone (150 microm) inhibited (approximately 50%) matrix metalloproteinase (MMP)-1, but not MMP-13 secretion from SFs. 3 6MNA stimulation of MMP-1 secretion was inhibited approximately 30% by PGE1 (1 microm) and approximately 80% by the Erk pathway inhibitor UO126 (10 microm), confirming that PGE depletion and Erk activation mediate MMP-1 secretion by 6MNA. 4 Consistent with its role as an Erk inhibitor, nabumetone (150 microm) abrogated 6MNA enhancement of MMP-1 secretion. 5 UO126 (10 microm) and nabumetone (150 microm) inhibited (approximately 70 and 40%, respectively), but 6MNA (150 microm) enhanced (approximately 40%), NF-kappaB activation. 6 Our data indicate that 6MNA shares with other COX inhibitors several proinflammatory effects on synovial fibroblasts. In contrast, nabumetone demonstrates anti-inflammatory and potentially arthroprotective effects that have not been previously appreciated.


Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fibroblastos/metabolismo , Metaloendopeptidasas/metabolismo , FN-kappa B/metabolismo , Prostaglandinas E/metabolismo , Alprostadil/metabolismo , Análisis de Varianza , Animales , Butadienos/farmacología , Butanonas/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprost/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Imidazoles/farmacología , Interleucina-1/farmacología , Metaloproteinasa 1 de la Matriz/metabolismo , Nabumetona , Ácidos Naftalenoacéticos/farmacología , Óxido Nítrico/biosíntesis , Nitrilos/farmacología , Fosforilación/efectos de los fármacos , Piridinas/farmacología , Conejos , Membrana Sinovial/citología , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/metabolismo , Factor de Necrosis Tumoral alfa/farmacología
10.
J Immunol ; 171(11): 6080-9, 2003 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-14634122

RESUMEN

We examined the regulation of matrix metalloproteinase (MMP) production by mitogen-activated protein kinases and cyclooxygenases (COXs) in fibroblast-like synoviocytes (FLSCs). IL-1beta and TNF-alpha stimulated FLSC extracellular signal-regulated kinase (ERK) activation as well as MMP-1 and -13 release. Pharmacologic inhibitors of ERK inhibited MMP-1, but not MMP-13 expression. Whereas millimolar salicylates inhibited both ERK and MMP-1, nonsalicylate COX and selective COX-2 inhibitors enhanced stimulated MMP-1 release. Addition of exogenous PGE(1) or PGE(2) inhibited MMP-1, reversed the effects of COX inhibitors, and inhibited ERK activation, suggesting that COX-2 activity tonically inhibits MMP-1 production via ERK inhibition by E PGs. Exposure of FLSCs to nonselective COX and selective COX-2 inhibitors in the absence of stimulation resulted in up-regulation of MMP-1 expression in an ERK-dependent manner. Moreover, COX inhibition sufficient to reduce PGE levels increased ERK activity. Our data indicate that: 1) ERK activation mediates MMP-1 but not MMP-13 release from FLSCs, 2) COX-2-derived E PGs inhibit MMP-1 release from FLSCs via inhibition of ERK, and 3) COX inhibitors, by attenuating PGE inhibition of ERK, enhance the release of MMP-1 by FLSC.


Asunto(s)
Regulación hacia Abajo/fisiología , Fibroblastos/enzimología , Isoenzimas/fisiología , Metaloproteinasa 1 de la Matriz/biosíntesis , Inhibidores de la Metaloproteinasa de la Matriz , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Prostaglandina-Endoperóxido Sintasas/fisiología , Prostaglandinas E/fisiología , Membrana Sinovial/enzimología , Animales , Antiinflamatorios no Esteroideos , Aspirina/farmacología , Células Cultivadas , Ciclooxigenasa 2 , Activación Enzimática/efectos de los fármacos , Activación Enzimática/inmunología , Inhibidores Enzimáticos/farmacología , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/enzimología , Fibroblastos/efectos de los fármacos , Fibroblastos/inmunología , Fibroblastos/metabolismo , Humanos , Interleucina-1/farmacología , Isoenzimas/antagonistas & inhibidores , Metaloproteinasa 1 de la Matriz/metabolismo , Proteínas de la Membrana , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/fisiología , Conejos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/inmunología , Membrana Sinovial/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Regulación hacia Arriba/efectos de los fármacos
11.
J Immunol ; 171(10): 5244-54, 2003 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-14607925

RESUMEN

Defective expression of Fas leads to B cell autoimmunity, indicating the importance of this apoptotic pathway in eliminating autoreactive B cells. However, B cells with anti-self specificities occasionally escape such regulation in individuals with intact Fas, suggesting ways of precluding this apoptosis. Here, we examine whether coligation of the B cell Ag receptor (BCR) with the complement (C3)-binding CD21/CD19/CD81 costimulatory complex can enhance the escape of human B cells from Fas-induced death. This was warranted given that BCR-initiated signals induce resistance to Fas apoptosis, some (albeit not all) BCR-triggered events are amplified by coligation of BCR and the co-stimulatory complex, and several self Ags targeted in autoimmune diseases effectively activate complement. Using a set of affinity-diverse surrogate Ags (receptor-specific mAb:dextran conjugates) with varying capacity to engage CD21, it was established that BCR:CD21 coligation lowers the BCR engagement necessary for inducing protection from Fas apoptosis. Enhanced protection was associated with altered expression of several molecules known to regulate Fas apoptosis, suggesting a unique molecular model for how BCR:CD21 coligation augments protection. BCR:CD21 coligation impairs the generation of active fragments of caspase-8 via dampened expression of membrane Fas and augmented expression of FLIP(L). This, in turn, diminishes the generation of cells that would be directly triggered to apoptosis via caspase-8 cleavage of caspase 3 (type I cells). Any attempt to use the mitochondrial apoptotic protease-activating factor 1 (Apaf-1)-dependent pathway for apoptosis (as type II cells) is further blocked because BCR:CD21 coligation promotes up-regulation of the mitochondrial antiapoptotic molecule, Bcl-2.


Asunto(s)
Adyuvantes Inmunológicos/fisiología , Antígenos CD19/fisiología , Antígenos CD/fisiología , Apoptosis/inmunología , Linfocitos B/inmunología , Complemento C3/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Proteínas de la Membrana/fisiología , Receptores de Complemento 3d/fisiología , Receptor fas/fisiología , Proteínas Adaptadoras Transductoras de Señales , Adyuvantes Inmunológicos/metabolismo , Adolescente , Anticuerpos Monoclonales/farmacología , Antígenos CD/metabolismo , Antígenos CD19/metabolismo , Proteínas Reguladoras de la Apoptosis , Linfocitos B/citología , Linfocitos B/metabolismo , Sitios de Unión/inmunología , Antígenos CD40/farmacología , Ligando de CD40/farmacología , Proteínas Portadoras/biosíntesis , Caspasa 8 , Caspasas/biosíntesis , Caspasas/metabolismo , Supervivencia Celular/inmunología , Células Cultivadas , Niño , Preescolar , Proteínas Co-Represoras , Fragmentación del ADN/inmunología , Proteína Ligando Fas , Humanos , Ligandos , Sustancias Macromoleculares , Glicoproteínas de Membrana/biosíntesis , Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana/metabolismo , Chaperonas Moleculares , Proteínas Nucleares/biosíntesis , Unión Proteica/inmunología , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de Complemento 3d/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF , Tetraspanina 28 , Factor de Necrosis Tumoral alfa/biosíntesis , Proteína bcl-X , Receptor fas/biosíntesis , Receptor fas/inmunología , Receptor fas/metabolismo
12.
Cell Immunol ; 216(1-2): 50-64, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12381350

RESUMEN

The impact of BCR:CD21 co-engagement on B cell expression of molecules critical for T cell activation was investigated with receptor-specific mAbs conjugated to high MW dextran as stimulatory ligands. In the absence of IL-4, BCR:CD21 co-ligation augmented BCR-triggered CD86 only under conditions of very low BCR ligand dose or affinity, and CD80 was minimally induced by BCR and/or CD21 crosslinking. In the presence of IL-4, BCR:CD21 co-ligation augmented CD86 and CD80 expression under conditions of greater BCR engagement. However, with very high level BCR engagement, no bonus effect of BCR:CD21 crosslinking was observed. Co-ligation-promoted CD86 and CD80 expression was associated with heightened B cell activation of resting allogeneic T cells. The data suggest that co-clustering of BCR and the CD21/CD19 co-stimulatory complex following B cell engagement with C3d-bound microbial or self-antigens will enhance B cell recruitment of T cell help only when IL-4 is present and/or BCR engagement is very limiting.


Asunto(s)
Antígenos CD19/fisiología , Antígenos CD/fisiología , Linfocitos B/inmunología , Antígeno B7-1/fisiología , Interleucina-4/fisiología , Glicoproteínas de Membrana/fisiología , Receptores de Antígenos de Linfocitos B/fisiología , Receptores de Complemento 3d/fisiología , Regulación hacia Arriba , Adolescente , Antígeno B7-2 , Niño , Preescolar , Relación Dosis-Respuesta Inmunológica , Humanos , Interleucina-4/análisis , Interleucina-4/biosíntesis , Activación de Linfocitos , Receptores de Interleucina-4 , Linfocitos T/inmunología
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