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1.
ESC Heart Fail ; 11(3): 1602-1611, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38378979

RESUMEN

AIMS: The aim of this study is to evaluate and compare the impact of the bicaval technique versus the biatrial technique (by Lower and Shumway) in paediatric heart transplant patients. Only a few studies investigate this matter regarding the long-term outcome after paediatric heart transplantation. We compared the two surgical methods regarding survival, the necessity of pacemaker implantation. METHODS AND RESULTS: All 134 patients (aged <18 years) - (group-1) biatrial (n = 84), versus (group-2) bicaval (n = 50), who underwent heart transplantation between October 1988 and December 2021, were analysed. Freedom from events were estimated using the Kaplan-Meier method. Potential differences were analysed using the log rank test and Cox proportional hazard models. Mean ± standard deviation: Bypass time (per minutes) was higher in the group 1 as compared with group 2 (P = 0.050). Survival was not significantly different (P = 0.604) in either groups. Eighteen patients required permanent pacemaker implantation in the group 1 and only one patient required it in the group 2 (P = 0.001). CONCLUSIONS: Paediatric heart transplantation using bicaval technique results similar long-term survival compared with the biatrial technique. The incidence of atrial rhythm disorders was significantly higher in the biatrial group, requiring a higher frequency of pacemaker implantation in this group. As a results, the bicaval technique has replaced the biatrial technique in our centre.


Asunto(s)
Trasplante de Corazón , Humanos , Trasplante de Corazón/métodos , Masculino , Femenino , Niño , Estudios Retrospectivos , Estudios de Seguimiento , Factores de Tiempo , Preescolar , Adolescente , Tasa de Supervivencia/tendencias , Resultado del Tratamiento , Lactante , Complicaciones Posoperatorias/epidemiología
2.
J Heart Lung Transplant ; 42(4): 512-521, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36333208

RESUMEN

BACKGROUND: Elevated pulmonary vascular resistance (PVR) is broadly accepted as an imminent risk factor for mortality after heart transplantation (HTx). However, no current HTx recipient risk score includes PVR or other hemodynamic parameters. This study examined the utility of various hemodynamic parameters for risk stratification in a contemporary HTx population. METHODS: Patients from seven German HTx centers undergoing HTx between 2011 and 2015 were included retrospectively. Established risk factors and complete hemodynamic datasets before HTx were analyzed. Outcome measures were overall all-cause mortality, 12-month mortality, and right heart failure (RHF) after HTx. RESULTS: The final analysis included 333 patients (28% female) with a median age of 54 (IQR 46-60) years. The median mean pulmonary artery pressure was 30 (IQR 23-38) mm Hg, transpulmonary gradient 8 (IQR 5-10) mm Hg, and PVR 2.1 (IQR 1.5-2.9) Wood units. Overall mortality was 35.7%, 12-month mortality was 23.7%, and the incidence of early RHF was 22.8%, which was significantly associated with overall mortality (log-rank HR 4.11, 95% CI 2.47-6.84; log-rank p < .0001). Pulmonary arterial elastance (Ea) was associated with overall mortality (HR 1.74, 95% CI 1.25-2.30; p < .001) independent of other non-hemodynamic risk factors. Ea values below a calculated cutoff represented a significantly reduced mortality risk (HR 0.38, 95% CI 0.19-0.76; p < .0001). PVR with the established cutoff of 3.0 WU was not significant. Ea was also significantly associated with 12-month mortality and RHF. CONCLUSIONS: Ea showed a strong impact on post-transplant mortality and RHF and should become part of the routine hemodynamic evaluation in HTx candidates.


Asunto(s)
Insuficiencia Cardíaca , Trasplante de Corazón , Enfermedades Vasculares , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón/mortalidad , Hemodinámica , Circulación Pulmonar/fisiología , Estudios Retrospectivos , Enfermedades Vasculares/complicaciones , Enfermedades Vasculares/mortalidad , Enfermedades Vasculares/fisiopatología , Resistencia Vascular/fisiología
3.
Int J Mol Sci ; 22(8)2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33923774

RESUMEN

Cardiac sarcoidosis (CS) is a poorly understood disease and is characterized by the focal accumulation of immune cells, thus leading to the formation of granulomata (GL). To identify the developmental principles of fatal GL, fluorescence microscopy and Western blot analysis of CS and control patients is presented here. CS is visualized macroscopically by positron emission tomography (PET)/ computed tomography (CT). A battery of antibodies is used to determine structural, cell cycle and inflammatory markers. GL consist of CD68+, CD163+ and CD206+ macrophages surrounded by T-cells within fibrotic areas. Cell cycle markers such as phospho-histone H3, phospho-Aurora and Ki67 were moderately present; however, the phosphorylated ERM (ezrin, radixin and moesin) and Erk1/2 proteins, strong expression of the myosin motor protein and the macrophage transcription factor PU.1 indicate highly active GL. Mild apoptosis is consistent with PI3 kinase and Akt activation. Massive amounts of the IL-1R antagonist reflect a mild activation of stress and inflammatory pathways in GL. High levels of oncostatin M and the Reg3A and Reg3γ chemokines are in accordance with macrophage accumulation in areas of remodeling cardiomyocytes. We conclude that the formation of GL occurs mainly through chemoattraction and less by proliferation of macrophages. Furthermore, activation of the oncostatin/Reg3 axis might help at first to wall-off substances but might initiate the chronic development of heart failure.


Asunto(s)
Cardiomiopatías/metabolismo , Granuloma/metabolismo , Miocardio/metabolismo , Oncostatina M/metabolismo , Proteínas Asociadas a Pancreatitis/metabolismo , Sarcoidosis/metabolismo , Adulto , Apoptosis , Aurora Quinasas/metabolismo , Cardiomiopatías/patología , Proliferación Celular , Proteínas del Citoesqueleto/metabolismo , Femenino , Granuloma/patología , Histonas/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Macrófagos/metabolismo , Macrófagos/fisiología , Masculino , Proteínas de la Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Persona de Mediana Edad , Sarcoidosis/patología
4.
Clin Res Cardiol ; 109(12): 1531-1539, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32783099

RESUMEN

AIMS: Heart transplantation may represent a particular risk factor for severe coronavirus infectious disease 2019 (COVID-19) due to chronic immunosuppression and frequent comorbidities. We conducted a nation-wide survey of all heart transplant centers in Germany presenting the clinical characteristics of heart transplant recipients with COVID-19 during the first months of the pandemic in Germany. METHODS AND RESULTS: A multicenter survey of all heart transplant centers in Germany evaluating the current status of COVID-19 among adult heart transplant recipients was performed. A total of 21 heart transplant patients with COVID-19 was reported to the transplant centers during the first months of the pandemic in Germany. Mean patient age was 58.6 ± 12.3 years and 81.0% were male. Comorbidities included arterial hypertension (71.4%), dyslipidemia (71.4%), diabetes mellitus (33.3%), chronic kidney failure requiring dialysis (28.6%) and chronic-obstructive lung disease/asthma (19.0%). Most patients received an immunosuppressive drug regimen consisting of a calcineurin inhibitor (71.4%), mycophenolate mofetil (85.7%) and steroids (71.4%). Eight of 21 patients (38.1%) displayed a severe course needing invasive mechanical ventilation. Those patients showed a high mortality (87.5%) which was associated with right ventricular dysfunction (62.5% vs. 7.7%; p = 0.014), arrhythmias (50.0% vs. none; p = 0.012), and thromboembolic events (50.0% vs. none; p = 0.012). Elevated high-sensitivity cardiac troponin T- and N-terminal prohormone of brain natriuretic peptide were significantly associated with the severe form of COVID-19 (p = 0.017 and p < 0.001, respectively). CONCLUSION: Severe course of COVID-19 was frequent in heart transplanted patients. High mortality was associated with right ventricular dysfunction, arrhythmias, thromboembolic events, and markedly elevated cardiac biomarkers.


Asunto(s)
COVID-19/epidemiología , Trasplante de Corazón/efectos adversos , Inmunosupresores/efectos adversos , Infecciones Oportunistas/epidemiología , Anciano , COVID-19/inmunología , COVID-19/mortalidad , COVID-19/terapia , Femenino , Alemania/epidemiología , Encuestas de Atención de la Salud , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Infecciones Oportunistas/inmunología , Infecciones Oportunistas/mortalidad , Infecciones Oportunistas/terapia , Factores de Riesgo , Factores de Tiempo , Receptores de Trasplantes , Resultado del Tratamiento
5.
Am J Transplant ; 2019 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-30884079

RESUMEN

In the 12-month, open-label MANDELA study, patients were randomized at month 6 after heart transplantation to (i) convert to calcineurin inhibitor (CNI)-free immunosuppression with everolimus (EVR), mycophenolic acid and steroids (CNI-free, n=71), or to (ii) continue reduced-exposure CNI, with EVR and steroids (EVR/redCNI, n=74). Tacrolimus was administered in 48.8% of EVR/redCNI patients and 52.6% of CNI-free patients at radomization. Both strategies improved and stabilized renal function based on the primary endpoint (estimated GFR at month 18 post-transplant post-randomization) with superiority of the CNI-free group versus EVR/redCNI : mean 64.1mL/min/1.73m2 versus 52.9mL/min/1.73m2 ; difference +11.3mL/min/1.73m2 (p<0.001). By month 18, estimated GFR had increased by ≥10mL/min/1.732 in 31.8% and 55.2% of EVR/redCNI and CNI-free patients, respectively, and by ≥25 mL/min/1.73m2 in 4.5% and 20.9%. Rates of biopsy-proven acute rejection (BPAR) were 6.8% and 21.1%; all cases were without hemodynamic compromise. BPAR was less frequent with EVR/redCNI versus the CNI-free regimen (p=0.015); 6/15 episodes in CNI-free patients occurred with EVR concentration <5ng/mL. Rates of adverse events and associated discontinuations were comparable EVR/redCNI from month 6 achieved stable renal function with infrequent BPAR. One-year renal function can be improved by early conversion to EVR-based CNI-free therapy but requires close EVR monitoring. This article is protected by copyright. All rights reserved.

6.
Contemp Clin Trials ; 45(Pt B): 356-363, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26363128

RESUMEN

In recent years a series of trials has sought to define the optimal protocol for everolimus-based immunosuppression in heart transplantation, with the goal of minimizing exposure to calcineurin inhibitors (CNIs) and harnessing the non-immunosuppressive benefits of everolimus. Randomized studies have demonstrated that immunosuppressive potency can be maintained in heart transplant patients receiving everolimus despite marked CNI reduction, although very early CNI withdrawal may be inadvisable. A potential renal advantage has been shown for everolimus, but the optimal time for conversion and the adequate reduction in CNI exposure remain to be defined. Other reasons for use of everolimus include a substantial reduction in the risk of cytomegalovirus infection, and evidence for inhibition of cardiac allograft vasculopathy, a major cause of graft loss. The ongoing MANDELA study is a 12-month multicenter, randomized, open-label, parallel-group study in which efficacy, renal function and safety are compared in approximately 200 heart transplant patients. Patients receive CNI therapy, steroids and everolimus or mycophenolic acid during months 3 to 6 post-transplant, and are then randomized at month 6 post-transplant (i) to convert to CNI-free immunosuppression with everolimus and mycophenolic acid or (ii) to continue reduced-exposure CNI, with concomitant everolimus. Patients are then followed to month 18 post-transplant The rationale and expectations for the trial and its methodology are described herein.


Asunto(s)
Everolimus/uso terapéutico , Trasplante de Corazón/métodos , Inmunosupresores/uso terapéutico , Ácido Micofenólico/uso terapéutico , Corticoesteroides/administración & dosificación , Inhibidores de la Calcineurina/administración & dosificación , Inhibidores de la Calcineurina/efectos adversos , Infecciones por Citomegalovirus/epidemiología , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Everolimus/administración & dosificación , Rechazo de Injerto/prevención & control , Humanos , Inmunosupresores/administración & dosificación , Enfermedades Renales/inducido químicamente , Ácido Micofenólico/administración & dosificación , Proyectos de Investigación
7.
J Heart Lung Transplant ; 34(5): 634-42, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25701373

RESUMEN

BACKGROUND: Although acute cellular rejection after heart transplantation (HTX) can be controlled by full-dose calcineurin inhibitor (CNI)-based immunosuppressive regimens, cardiac allograft vasculopathy (CAV), nephrotoxicity, and malignancy remain ongoing problems. To evaluate the potential beneficial effects of sirolimus and CNI reduction, we compared de novo low-dose tacrolimus and sirolimus with standard tacrolimus and mycophenolate mofetil (MMF)-based immunosuppression after HTX. METHODS: We analyzed a long-term follow-up cohort of 126 patients who underwent HTX during the period 1998-2005 and received either de novo low-dose tacrolimus/sirolimus (lowTAC/SIR; n = 61) or full-dose tacrolimus/MMF (TAC/MMF; n = 64). RESULTS: Freedom from treatment switch was less in the low TAC/SIR group than in the TAC/MMF group (51.7% vs 73.0%, p = 0.038) 8 years after HTX. Freedom from acute rejection was 90.6% in the low TAC/SIR group vs 80.3% in the TAC/MMF group (p = 0.100). There was no difference in freedom from International Society for Heart and Lung Transplantation CAV grade ≥ 1 (55.4% vs 60.0%, p = 0.922), time until CAV diagnosis (4.2 ± 2.0 years vs 3.2 ± 2.4 years, p = 0.087), and CAV severity (p = 0.618). The benefit of reduced early maximum creatinine for low TAC/SIR treatment (1.8 ± 0.9 mg/dl vs 2.4 ± 1.1 mg/dl in TAC/MMF group, p < 0.001) did not continue 5 years and 8 years after HTX (1.4 ± 0.4 mg/dl vs 1.7 ± 1.2 mg/dl, p = 0.333, and 1.6 ± 1.1 mg/dl vs 1.6 ± 0.8 mg/dl, p = 0.957). The trend for superior survival at 5 years with low TAC/SIR treatment (93.1% vs 81.3% in TAC/MMF group, p = 0.051) could not be confirmed after 8 years (84.7% vs 75.0%, p = 0.138). Multivariate analysis at 8 years did not reveal any benefit of low TAC/SIR treatment. CONCLUSIONS: Reduction of de novo CNI did not result in superior long-term renal function. Low-dose mechanistic target of rapamycin inhibition did not achieve any benefit in CAV prevention compared with full-dose TAC/MMF after HTX.


Asunto(s)
Rechazo de Injerto/prevención & control , Trasplante de Corazón , Terapia de Inmunosupresión/métodos , Ácido Micofenólico/análogos & derivados , Sirolimus/administración & dosificación , Tacrolimus/administración & dosificación , Enfermedad Aguda , Adulto , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Supervivencia de Injerto/efectos de los fármacos , Humanos , IMP Deshidrogenasa/antagonistas & inhibidores , Inmunosupresores/administración & dosificación , Masculino , Persona de Mediana Edad , Ácido Micofenólico/administración & dosificación , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
9.
Transplantation ; 95(4): 629-34, 2013 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-23423270

RESUMEN

BACKGROUND: Long-term results of prospective randomized trials comparing triple immunosuppressive strategies combining tacrolimus (TAC) or cyclosporine A (CsA) with mycophenolate mofetil (MMF) and steroids after heart transplantation (HTX) are rarely published. Therefore, we collected long-term follow-up data of an intervention cohort 10 years after randomization. METHODS: Ten-year follow-up data of 60 patients included in a prospective, randomized trial between 1998 and 2000 were analyzed as intention-to-treat (TAC-MMF n=30; CsA-MMF n=30). Baseline characteristics were well balanced. Cardiac allograft vasculopathy (CAV) was graduated in accordance with the new ISHLT classification. RESULTS: Survival at 1, 5, and 10 years was 96.7%, 80.0%, and 66.7% for TAC-MMF and 90.0%, 83.3%, and 80.0% for CsA-MMF (P=ns). Freedom from acute rejection (AR) was significantly higher in TAC-MMF versus CsA-MMF (65.5% vs. 21.7%, log-rank 8.3, P=0.004). Freedom from ISHLT≥CAV1 after 5 and 10 years was in TAC-MMF 64.0% and 45.8%, and in CsA-MMF 36.0% (log-rank 3.0, P=0.085) and 8.0% (log-rank 9.0, P=0.003). No difference in long-term results for freedom from coronary angioplasty or stenting, renal dysfunction, diabetes mellitus, CMV infection, or malignancy was detected. CONCLUSION: Cross-over effects because of treatment switch may result in impairment of significance between the groups. The long-term analysis resulted in a significant difference in manifestation of CAV between the groups after 10 years. Less rejection in the TAC-group might have contributed to the lower incidence of CAV. Superior freedom from AR and CAV in the TAC-MMF group did not result in better long-term survival.


Asunto(s)
Ciclosporina/uso terapéutico , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón/inmunología , Inmunosupresores/uso terapéutico , Ácido Micofenólico/análogos & derivados , Tacrolimus/uso terapéutico , Adulto , Distribución de Chi-Cuadrado , Enfermedad de la Arteria Coronaria/etiología , Enfermedad de la Arteria Coronaria/terapia , Ciclosporina/efectos adversos , Ciclosporina/sangre , Monitoreo de Drogas , Quimioterapia Combinada , Femenino , Alemania , Rechazo de Injerto/inmunología , Rechazo de Injerto/mortalidad , Trasplante de Corazón/efectos adversos , Trasplante de Corazón/mortalidad , Humanos , Inmunosupresores/efectos adversos , Inmunosupresores/sangre , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Persona de Mediana Edad , Ácido Micofenólico/efectos adversos , Ácido Micofenólico/sangre , Ácido Micofenólico/uso terapéutico , Estudios Prospectivos , Factores de Riesgo , Tacrolimus/efectos adversos , Tacrolimus/sangre , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
10.
J Heart Lung Transplant ; 32(3): 277-84, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23415313

RESUMEN

BACKGROUND: Despite improvements in immunosuppressive therapy, the most advantageous combination for cardiac transplant recipients has not been established. This randomized controlled trial was performed to evaluate the efficacy and safety of 3 immunosuppressive protocols. METHODS: Between 2003 and 2005, 78 de novo cardiac transplant recipients were randomized 2:2:1 to receive steroids and tacrolimus plus mycophenolate mofetil (TAC/MMF; n = 34), TAC and sirolimus (TAC/SRL; n = 29), or SRL and MMF (SRL/MMF) plus anti-thymocyte globulin (ATG; n = 15). Steroids were withdrawn after 6 months. RESULTS: The 5-year survival was 85.3% for TAC/MMF, 93.1% for TAC/SRL, and 86.7% for SRL/MMF (p = 0.31 for TAC/MMF vs TAC/SIR; p = 0.47 for TAC/MMF vs SIR/MMF and p = 0.86 for TAC/SIR vs SIR/MMF). Despite the use of ATG, patients in the SRL/MMF group revealed numerically fewer freedom from acute rejection episodes: TAC/MMF, 82.4%; TAC/SRL, 85.2%; SRL/MMF, 73.3% (p = 0.33). Mean creatinine at 5 years revealed preservation of renal function in the SRL/MMF vs the TAC/MMF group (p = 0.045): TAC/MMF, 1.70±0.91 mg/dl; TAC/SRL, 1.44±0.65 mg/dl; and SRL/MMF, 1.25±0.46 mg/dl. Freedom from cardiac allograft vasculopathy was improved in the SRL/MMF group (93.3%) compared with TAC/MMF (73.5%) and TAC/SRL (80.8%) groups, reaching no statistical significance. Freedom from cytomegalovirus infection was TAC/MMF, 72.2%; TAC/SRL, 89.7%; and SRL/MMF, 86.7%. There was a trend toward improved freedom from cytomegalovirus infection with TAC/SRL vs TAC/MMF (p = 0.076). More frequent discontinuations of study medication occurred in SRL-based immunosuppression protocols (TAC/SRL vs TAC/MMF, p = 0.034; SRL/MMF vs TAC/MMF, p = 0.003). CONCLUSIONS: The 3 strategies yield no survival advantage at 5 years, with higher numeric rates of rejection and adverse effects in the calcineurin inhibitor-free arm. A trend was observed in favor of freedom from cardiac allograft vasculopathy and preservation of renal function in the calcineurin inhibitor-free arm. However, the clinical relevance on outcomes is unclear because only few patients were receiving the assigned treatment protocols.


Asunto(s)
Trasplante de Corazón , Terapia de Inmunosupresión , Inmunosupresores/administración & dosificación , Ácido Micofenólico/análogos & derivados , Sirolimus/administración & dosificación , Tacrolimus/administración & dosificación , Quimioterapia Combinada , Femenino , Humanos , Inmunosupresores/efectos adversos , Masculino , Persona de Mediana Edad , Ácido Micofenólico/administración & dosificación , Ácido Micofenólico/efectos adversos , Sirolimus/efectos adversos , Tacrolimus/efectos adversos , Factores de Tiempo
11.
Ann Transplant ; 17(4): 149-51, 2012 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-23274337

RESUMEN

BACKGROUND: Lung transplantation for end-stage pulmonary disease is an established procedure and the number of transplantations is increasing worldwide even in developing countries. Usually donor lungs are transported in an inflated state and the bronchi are closed with a stapler device. CASE REPORT: We present a technique that avoids costly stapler devices and is even less time consuming than reloading the staplers. After both lungs are inflated the separation of the two main bronchi is facilitated by using sterile umbilical cord clamps for the bronchus closure. We did not experience any air leaks and since the bronchi are resected prior to implantation there is always enough space to place the clamps. CONCLUSIONS: The umbilical cord clamp technique reduces the explantation costs for lung retrievals significantly. The technique is less time consuming and offers equal safety compared to stapler devices.


Asunto(s)
Trasplante de Pulmón , Recolección de Tejidos y Órganos/instrumentación , Femenino , Humanos , Persona de Mediana Edad , Recolección de Tejidos y Órganos/métodos
12.
Ann N Y Acad Sci ; 1070: 422-6, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16888203

RESUMEN

A PCR-based search for splice variants of the VPAC2 G protein-coupled receptor for vasoactive intestinal peptide (VIP) revealed: (a) a short-deletion variant in mouse lymphocytes termed VPAC2de367-380, that lacks 14 amino acids in the seventh transmembrane domain, and (b) a long-deletion variant in human lymphocytes termed VPAC2de325-438(i325-334), that lacks 114 amino acids beginning with the carboxyl-terminal end of the third cytoplasmic loop and has 10 new carboxy-terminal amino acids. VPAC2de367-380 binds VIP normally, but shows reduced VIP-evoked signaling and effects on immune functions, whereas VPAC2de325-438(i325-334) shows reduced binding affinity for VIP and a complex pattern of functional differences. These splice variants may modify the immunoregulatory contributions of the VIP-VPAC2 axis.


Asunto(s)
Variación Genética/genética , Linfocitos/metabolismo , Empalme del ARN/genética , Receptores de Tipo II del Péptido Intestinal Vasoactivo/genética , Péptido Intestinal Vasoactivo/metabolismo , Secuencia de Aminoácidos , Animales , Humanos , Ratones , Datos de Secuencia Molecular , Receptores de Tipo II del Péptido Intestinal Vasoactivo/química
13.
J Biol Chem ; 279(39): 40259-62, 2004 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-15302876

RESUMEN

The vasoactive intestinal peptide (VIP) and its G protein-coupled receptors VPAC1 and VPAC2 prominently mediate diverse physiological functions in the neural, endocrine, and immune systems. A deletion variant of mouse VPAC2 has been identified in immune cells that lacks amino acids 367-380 at the carboxyl-terminal end of the seventh transmembrane domain. When expressed at equivalent levels in a human Jurkat T cell line, which has very low endogenous expression of human VPAC1 and VPAC2, wild-type and deletion-variant VPAC2 bound the same amount of 125I-VIP with similar affinity. Unlike wild-type VPAC2, however, deletion-variant VPAC2 did not transduce VIP-elicited increases in intracellular concentration of cyclic AMP, chemotaxis, or suppression of generation of interleukin-2. Natural deletion of part of the last transmembrane domain of VPAC2 thus abrogates signaling functions without apparent alterations of expression or ligand binding.


Asunto(s)
Receptores Acoplados a Proteínas G/química , Receptores de Péptido Intestinal Vasoactivo/química , Péptido Intestinal Vasoactivo/química , Animales , Quimiotaxis , AMP Cíclico/metabolismo , Femenino , Eliminación de Gen , Humanos , Interleucina-2/metabolismo , Células Jurkat , Ligandos , Ratones , Ratones Endogámicos C57BL , Mutación , Unión Proteica , Estructura Terciaria de Proteína , ARN Mensajero/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Péptido Intestinal Vasoactivo/metabolismo , Receptores de Tipo II del Péptido Intestinal Vasoactivo , Transducción de Señal , Transfección , Péptido Intestinal Vasoactivo/metabolismo
14.
J Immunol ; 170(1): 308-14, 2003 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-12496414

RESUMEN

Vasoactive intestinal peptide (VIP) and its two G protein-coupled receptors, VPAC1 and VPAC2, are quantitatively prominent and functionally critical in the immune system. Transgenic (T) mice constitutively expressing VPAC2 selectively in CD4 T cells, at levels higher than those found after maximal induction in CD4 T cells of wild-type (N) mice, have elevated blood concentrations of IgE, IgG1, and eosinophils; enhanced immediate-type hypersensitivity; and reduced delayed-type hypersensitivity. In contrast, VPAC2-null (K) mice manifest decreased immediate-type hypersensitivity and enhanced delayed-type hypersensitivity. The phenotypes are attributable to opposite skewing of the Th2/Th1 cytokine ratio, but no studies were conducted on the roles of T cell-derived VIP and altered expansion of the Th subsets. Dependence of the Th phenotype of T mice, but not of N or K mice, on T cell-derived VIP now is proven by showing that eliminating VIP from TCR-stimulated T cell cultures with VIPase IgG normalizes the elevated number of IL-4-secreting CD4 T cells, decreases the secretion of IL-4 and IL-10, and increases the secretion of IFN-gamma. Flexible responsiveness of CD4 T cells from N and K mice, but not T mice, to exogenous VIP in vitro and in vivo is shown by increased numbers of IL-4-secreting CD4 T cells, greater secretion of IL-4 and IL-10, and lesser secretion of IFN-gamma after TCR stimulation with VIP. The level of VIP recognized by CD4 T cells thus is a major determinant of the relative contributions of Th subsets to the immune effector phenotype.


Asunto(s)
Regulación de la Expresión Génica/inmunología , Inmunofenotipificación , Receptores de Péptido Intestinal Vasoactivo/biosíntesis , Receptores de Péptido Intestinal Vasoactivo/genética , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Péptido Intestinal Vasoactivo/farmacología , Animales , Anticuerpos Catalíticos/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Células Cultivadas , Citocinas/biosíntesis , Citocinas/metabolismo , Humanos , Hipersensibilidad Tardía/genética , Hipersensibilidad Inmediata/genética , Activación de Linfocitos/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Biosíntesis de Péptidos/genética , Biosíntesis de Péptidos/inmunología , Receptores de Antígenos de Linfocitos T/fisiología , Receptores de Péptido Intestinal Vasoactivo/deficiencia , Receptores de Tipo II del Péptido Intestinal Vasoactivo , Péptido Intestinal Vasoactivo/síntesis química , Péptido Intestinal Vasoactivo/inmunología , Péptido Intestinal Vasoactivo/metabolismo
15.
Regul Pept ; 109(1-3): 199-208, 2002 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-12409234

RESUMEN

Vasoactive intestinal peptide (VIP) and its two G protein-coupled receptors, VPAC1R and VPAC2R, are prominent in the immune system and potently affect T cells and macrophages. VPAC1Rs are expressed constitutively by blood and tissue T cells, with an order of prevalence of Th2>Th1>>Ts, and transmit signals suppressive for migration, proliferation and cytokine production. Immune activation of T cells downregulates VPAC1Rs and upregulates VPAC2Rs. VPAC2Rs mediate T cell chemotaxis, stimulation of some Th2-type cytokines, and inhibition of some Th1-type cytokines. A tentative hypothesis that the VIP-VPAC2R axis is the major neuroregulator of Th2/Th1 balance has been confirmed by finding an increased ratio in CD4 T cells of transgenic (TG) mice, expressing high levels of VPAC2Rs, and a decreased ratio in CD4 T cells of VPAC2R-null (K/O) mice. VPAC2R TG mice exhibit an allergic phenotype, whereas the K/O mice are hypoallergic and have heightened delayed-type hypersensitivity. The mechanisms of VIP-VPAC2R effects include decreased Th2 apoptosis, increased Th2-type cytokine production, and greater generation of Th2 memory cells. VPAC2R antagonists are being developed to alleviate allergic diseases and strengthen effector Th1 cell-mediated immunoprotection.


Asunto(s)
Péptido Intestinal Vasoactivo/inmunología , Animales , Diferenciación Celular , Humanos , Receptores de Péptido Intestinal Vasoactivo/genética , Receptores de Péptido Intestinal Vasoactivo/metabolismo , Receptores de Tipo II del Péptido Intestinal Vasoactivo , Receptores de Tipo I del Polipéptido Intestinal Vasoactivo , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Timo/citología , Timo/inmunología , Péptido Intestinal Vasoactivo/metabolismo , Péptido Intestinal Vasoactivo/farmacología
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