RESUMEN
A caesium lutetium(III) silicate, Cs3LuSi3O9, was synthesized by heating a pelletized mixture of Cs2CO3, Lu2O3 and SiO2 at 1273â K. Single crystals of the title compound were grown in a melted area of the pellet. Cs3LuSi3O9 is a single-chain silicate (ortho-rhom-bic space group Pna21) with a chain periodicity of six and is isostructural with Cs3 RE IIIGe3O9 (RE = Pr, Nd and Sm-Yb). The two symmetry-dependent [Si6O18]12- chains in the unit cell lie parallel to the [011] direction. The Lu3+ ions are octa-hedrally coordinated by O atoms of the silicate chains, generating a three-dimensional framework. Cs+ ions are located in the voids in the framework.
RESUMEN
This paper describes an electrocardiograph (ECG) monitoring SoC using a non-volatile MCU (NVMCU) and a noise-tolerant instantaneous heartbeat detector. The novelty of this work is the combination of the non-volatile MCU for normally off computing and a noise-tolerant-QRS (heartbeat) detector to achieve both low-power and noise tolerance. To minimize the stand-by current of MCU, a non-volatile flip-flop and a 6T-4C NVRAM are used. Proposed plate-line charge-share and bit-line non-precharge techniques also contribute to mitigate the active power overhead of 6T-4C NVRAM. The proposed accurate heartbeat detector uses coarse-fine autocorrelation and a template matching technique. Accurate heartbeat detection also contributes system-level power reduction because the active ratio of ADC and digital block can be reduced using heartbeat prediction. Measurement results show that the fully integrated ECG-SoC consumes 6.14 µ A including 1.28- µA non-volatile MCU and 0.7- µA heartbeat detector.
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Electrocardiografía/instrumentación , Frecuencia Cardíaca/fisiología , Procesamiento de Señales Asistido por Computador , Telemedicina/instrumentación , Algoritmos , Ingeniería Biomédica/instrumentación , Electrocardiografía/métodos , Diseño de Equipo , Humanos , Telemedicina/métodosRESUMEN
To prevent lifestyle diseases, wearable bio-signal monitoring systems for daily life monitoring have attracted attention. Wearable systems have strict size and weight constraints, which impose significant limitations of the battery capacity and the signal-to-noise ratio of bio-signals. This report describes an electrocardiograph (ECG) processor for use with a wearable healthcare system. It comprises an analog front end, a 12-bit ADC, a robust Instantaneous Heart Rate (IHR) monitor, a 32-bit Cortex-M0 core, and 64 Kbyte Ferroelectric Random Access Memory (FeRAM). The IHR monitor uses a short-term autocorrelation (STAC) algorithm to improve the heart-rate detection accuracy despite its use in noisy conditions. The ECG processor chip consumes 13.7 µA for heart rate logging application.
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Electrocardiografía Ambulatoria/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Telemedicina/instrumentación , Adulto , Algoritmos , Vestuario , Diseño de Equipo , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Adulto JovenRESUMEN
Bone marrow-derived mesenchymal stem cells (MSCs) could exert a potent immunosuppressive effect, and therefore may have a therapeutic potential in T-cell-dependent pathologies. In the present study, we aimed to determine whether MSCs could be used to control graft-versus-host disease (GvHD), a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). MSCs were isolated from Lewis rat bone morrow and then cultured in 10% FBS DMEM at 37°C for 4 weeks. The enriched conventional MSCs and macrophages were purified by auto-MACS. Cloned MSCs were obtained by cloning using the limiting dilution method and expanded up to more than 6 months. The identity of MSCs was confirmed by their typical spindle-shaped morphology and immunophenotypic criteria, based on the absence of expression of CD45 and CD11b/c molecules. Both types of MSCs were also tested for their ability to differentiate into adipocytes. We showed that MSCs, like macrophages, exhibit immunomodulatory properties capable of inhibiting T-cell proliferation stimulated by alloantigens, anti-CD3e/CD28 mAbs, and ConA in a dose-dependent manner in vitro. After performing adoptive transfer, MSCs suppressed systemic Lewis to (Lewis × DA)F1 rat GvHD. In contrast to the immunosuppressive activities of conventional MSCs, the cloned MSCs enhanced T-cell proliferation in vitro and yielded no clinical benefit in regard to the incidence or severity of GvHD. Therefore, these rat models have shown intriguing differences in the suppression effects of lymphocyte proliferation and GvHD prevention between short-term cultured conventional MSCs and cloned MSCs.
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Células de la Médula Ósea/citología , Enfermedad Injerto contra Huésped/prevención & control , Células Madre Mesenquimatosas/citología , Linfocitos T/citología , Adipocitos/citología , Animales , Antígenos CD11/metabolismo , Diferenciación Celular , Proliferación Celular/efectos de los fármacos , Tratamiento Basado en Trasplante de Células y Tejidos , Células Cultivadas , Modelos Animales de Enfermedad , Rayos gamma , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/mortalidad , Trasplante de Células Madre Hematopoyéticas , Inmunofenotipificación , Terapia de Inmunosupresión , Isoantígenos/farmacología , Antígenos Comunes de Leucocito/metabolismo , Masculino , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/patología , Ratas , Ratas Endogámicas Lew , Tasa de Supervivencia , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunologíaRESUMEN
UNLABELLED: The aim of this study was to investigate the trafficking patterns, radiation sensitivities, and functions of conventional dendritic cell (DC) subsets in the rat liver in an allotransplantation setting. We examined DCs in the liver, hepatic lymph, and graft tissues and recipient secondary lymphoid organs after liver transplantation from rats treated or untreated by sublethal irradiation. We identified two distinct immunogenic DC subsets. One was a previously reported population that underwent blood-borne migration to the recipient's secondary lymphoid organs, inducing systemic CD8(+) T-cell responses; these DCs are a radiosensitive class II major histocompatibility complex (MHCII)(+) CD103(+) CD172a(+) CD11b(-) CD86(+) subset. Another was a relatively radioresistant MHCII(+) CD103(+) CD172a(+) CD11b(+) CD86(+) subset that steadily appeared in the hepatic lymph. After transplantation, the second subset migrated to the parathymic lymph nodes (LNs), regional peritoneal cavity nodes, or persisted in the graft. Irradiation completely eliminated the migration and immunogenicity of the first subset, but only partly suppressed the migration of the second subset and the CD8(+) T-cell response in the parathymic LNs. The grafts were acutely rejected, and intragraft CD8(+) T-cell and FoxP3(+) regulatory T-cell responses were unchanged. The radioresistant second subset up-regulated CD25 and had high allostimulating activity in the mixed leukocyte reaction, suggesting that this subset induced CD8(+) T-cell responses in the parathymic LNs and in the graft by the direct allorecognition pathway, leading to the rejection. CONCLUSION: Conventional rat liver DCs contain at least two distinct immunogenic passenger subsets: a radiosensitive blood-borne migrant and a relatively radioresistant lymph-borne migrant. LNs draining the peritoneal cavity should be recognized as a major site of the intrahost T-cell response by the lymph-borne migrant. This study provides key insights into liver graft rejection and highlights the clinical implications of immunogenic DC subsets.
Asunto(s)
Movimiento Celular/efectos de la radiación , Células Dendríticas/inmunología , Trasplante de Hígado/inmunología , Hígado/efectos de la radiación , Tolerancia a Radiación/inmunología , Animales , Movimiento Celular/genética , Movimiento Celular/fisiología , Células Cultivadas , Células Dendríticas/fisiología , Modelos Animales de Enfermedad , Rechazo de Injerto/inmunología , Inmunohistoquímica , Hígado/patología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/efectos de la radiación , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Distribución Aleatoria , Ratas , Ratas Endogámicas Lew , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To elucidate the significance of early expression of CC-chemokine ligand motif 8 (CCL8) in mice with graft-vs.-host disease (GVHD), we investigated its induction mechanisms and correlation with overall survival rate in GVHD mice. Plasma CCL8 increases on day 5 of allogeneic transplantation, when signs of GVHD are barely detectable. Increase of allogeneic splenocytes in grafts exacerbates GVHD and leads to upregulation of plasma CCL8 on day 5. Overall survival is the gold standard in determining the severity of acute GVHD in mice, but the absence of clinical and/or pathological manifestations in the early phase make it difficult to estimate vital outcomes at this stage of allogeneic marrow transplantation. MATERIALS AND METHODS: After lethal irradiation, BALB/c mice received bone marrow transplantation from C57BL/6 mice. Survival rate was monitored and clinical and pathological scores of GVHD were examined. Coculture of BALB/c-derived dendritic cells and C57BL/6-derived splenocytes was performed. CCL8 was measured by immunoassay. RESULTS: The plasma CCL8 level at day 5 of transplantation was closely correlated with survival rate and clinical/pathological scores on day 14. In vitro study revealed that the BALB/c-derived dendritic cells expressed CCL8 upon stimulation of C57BL/6 CD4(+) T cells by cell interactions through major histocompatibility complex class II molecules. CONCLUSIONS: These investigations indicate that early and preclinical expression of CCL8 in plasma predicts overall survival of GVHD mice. Together with an involvement of allo-recognition in CCL8 expression, it suggests that CCL8 plays an important role in GVHD pathology.
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Quimiocina CCL8/biosíntesis , Quimiocina CCL8/sangre , Enfermedad Injerto contra Huésped/mortalidad , Enfermedad Aguda , Animales , Trasplante de Médula Ósea/efectos adversos , Trasplante de Médula Ósea/mortalidad , Comunicación Celular/inmunología , Células Dendríticas/química , Células Dendríticas/inmunología , Ratones , Modelos Animales , Pronóstico , Tasa de Supervivencia , Linfocitos T/inmunología , Factores de Tiempo , Activación Transcripcional , Trasplante HomólogoRESUMEN
La(3)Ta(0.5)Ga(5.5)O(14) (LTG) single crystals, which have no phase transition up to the melting point, were heat-treated in air at temperatures from 1000°C to 1450°C for 10 h. LaTaO(4) (LT) and LaGaO(3) (LG), which coexist with LTG in the three-phase region on the Ga-poor side, precipitated on the surface of the crystal for heat treatments above 1300°C because of Ga evaporation during the heat treatment. The Ga-poor state near the surface of the 1450°C heat-treated specimen was confirmed by electron probe micro-analysis measurements. The electrical resistivity of LTG single crystals decreased by heat treatment in the range of 1000°C to 1200°C for 10 h in air, where no precipitation was observed, whereas the resistivity increased with heat treatment over 1400°C for 10 h in air. The electrical resistivity of the Ga-poor surface region was higher than that of the interior.
RESUMEN
Naturally occurring CD4(+)CD25(+) Treg cells (nTregs) can be exploited to establish an immunologic tolerance to non-self-antigens. The in vivo administration of a single superagonistic CD28-specific monoclonal antibody (supCD28mAb) to naive rat preferentially expanded the nTregs, which induced a potent inhibition of lethality of the graft-versus-host (GvH) diseases. The appearance of increased Foxp3 molecules was accompanied with a polarization towards a Th2 cytokine profile with a decreased production of IFN-γ and increased production of IL-4 and IL-10 in the serum of the antibody-treated rat. The peripheral Foxp3 nTregs are decreased in acute GvHD, while supCD28mAb administration showed that nTregs were preferentially proliferating in vivo, thus resulting in the significant prevention of the GvH disease. Furthermore, antigen-specific nTregs could suppress conventional T-cell proliferation stimulated with alloantigen in vitro. Taken together, our findings demonstrate that the potent regulatory functions of the Tregs for the treatment of GvHD are antigen specific. These data also provide evidence that GvHD is associated with decrease of Tregs in the periphery of the host. The determination of the Foxp3 Tregs can be a helpful tool to discriminate GvHD severity and lethality after allogeneic stem cell transplantation.
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Anticuerpos Monoclonales/uso terapéutico , Antígenos CD28/inmunología , Epítopos/inmunología , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/prevención & control , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/inmunología , Animales , Proliferación Celular , Citocinas/sangre , Factores de Transcripción Forkhead/metabolismo , Enfermedad Injerto contra Huésped/sangre , Enfermedad Injerto contra Huésped/inmunología , Subunidad alfa del Receptor de Interleucina-2/inmunología , Cinética , Ratas , Ratas Endogámicas Lew , Bazo/citologíaRESUMEN
Regulatory lymphocytes play a pivotal role in preventing organ-specific autoimmune disease and in induction and maintenance of tolerance in various experimental transplantation models. The enhancement of the number and activity of peripheral CD4(+)CD25(+) Treg cells is an obvious goal for the treatment of autoimmunity and for the suppression of alloreactions. The present study demonstrates that naturally occurring CD4(+)CD25(+) Treg (nTreg) cells preferentially proliferate to a fourfold increase within 3 days in response to the administration of a single superagonistic CD28-specific monoclonal antibody (supCD28 mAb). The appearance of increased Foxp3 molecules was accompanied with polarization toward a Th2 cytokine profile with decreased production of IFN-gamma and increased production of IL-4 and IL-10 in the expanded Treg subset. Adoptive transfer of supCD28 mAb-expanded cells in a graft-versus-host disease (GvHD) model induced a potent inhibition of lethality. These results suggest that this therapeutic effect is mediated by the in vivo expansion of nTreg cells. Taken together, these data demonstrate that supCD28-mAb may target nTreg cells in vivo and maintain and enhance their potent regulatory functions for the treatment GvHD.
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Anticuerpos Monoclonales/farmacología , Antígenos CD28/inmunología , Factores de Transcripción Forkhead/metabolismo , Enfermedad Injerto contra Huésped/prevención & control , Linfocitos T Reguladores/inmunología , Animales , Proliferación Celular , Factores de Transcripción Forkhead/genética , Enfermedad Injerto contra Huésped/inmunología , Interferón gamma/genética , Interferón gamma/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Masculino , Ratas , Linfocitos T Reguladores/metabolismoRESUMEN
Experimental autoimmune encephalomylitis (EAE), an animal mode of multiple sclerosis (MS), was previously considered that be mediated by Th1 cells. However, a number of recent studies provided strong evidence that T helper cells that produce IL-17 play a dominant role in the pathogenesis of EAE. Curcumin (1,7-Bis 94-hydroxy-3-methoxyphenyl)-1,6 heptadiene-3, 5-di-one) is a naturally occurring polyphenolic phytochemical isolated from the rhizome of the medicinal plant Curcuma longa. It has been strongly implicated as an anti-inflammatory agent, but the precise mechanisms of its action are largely unknown. In the present study, we have investigated the efficacy and mechanism of curcumin against EAE. The treatment of Lewis rats with curcumin significantly reduced the clinical severity of EAE, and had a dramatic reduction in the number of inflammatory cells infiltration in the spinal cord. The proliferation of the MBP-reaction lymphocyte also was reduced in a curcumin dose-dependent manner. Furthermore, the mRNA expression of the cytokine profiles was assessed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), revealing the dramatic decrease of IL-17, TGF-beta, IL-6, IL-21, STAT3, and RORgammat expression in curcumin-treated groups and STAT3-phosphorylation also was inhibited. These findings indicated that curcumin amelioration EAE was, to a large extent, due to inhibit differentiation and development of Th17 cells depends on down-regulating expression of IL-6, IL-21, RORgammat signaling and inhibition STAT3-phosphorylation, suggests it is useful in the treatment of MS and other Th17 cell-mediated inflammatory diseases.
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Curcumina/uso terapéutico , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/inmunología , Interleucina-17/metabolismo , Fitoterapia , Linfocitos T Colaboradores-Inductores/metabolismo , Animales , Proliferación Celular/efectos de los fármacos , Curcuma , Progresión de la Enfermedad , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Encefalomielitis Autoinmune Experimental/patología , Encefalomielitis Autoinmune Experimental/fisiopatología , Femenino , Adyuvante de Freund , Cobayas , Humanos , Inmunización , Interleucina-17/genética , Interleucina-17/inmunología , Interleucina-6/genética , Interleucina-6/inmunología , Interleucina-6/metabolismo , Interleucinas/genética , Interleucinas/inmunología , Interleucinas/metabolismo , Células Jurkat , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/terapia , Proteína Básica de Mielina/administración & dosificación , Proteína Básica de Mielina/química , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/inmunología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Péptidos/administración & dosificación , Péptidos/química , Fosforilación , Ratas , Ratas Endogámicas Lew , Rizoma , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/inmunología , Factor de Transcripción STAT3/metabolismo , Médula Espinal/patología , Médula Espinal/fisiopatología , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/patología , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/inmunología , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Although enhanced green fluorescent protein (EGFP) is widely used as a molecular tag in cell biology, it has become evident that immunogenicity of transgenic or transduced EGFP is important when it applies to transplantation model. Indeed, it appears that applications of EGFP-expressing cells, tissues and organ transplantation are limited in vivo due to the ultimate rejection of the graft. Nevertheless, the immunological behavior of transduced EGFP, in particular, as a minor histocompatibility antigen is not fully understood. Thus employing two strains of EGFP transgenic (Tg) rats generated by the same vector construct, e.g., EGFP-F344 Tg (RT11) and EGFP-DA Tg (RT1a), and its F(1) hybrid with a non-transgenic rat, behavior of EGFP-transgenic antigen(s) was examined by in vivo assays, such as EGFP-transgenic test skin grafts or regulation of EGFP-transgenic lymphocytes. In the latter system, EGFP-specific, T-cell-mediated immune regulation of local graft-versus-host reaction (GvHR) was further investigated with a special reference of in vivo cytotoxic assay, i.e., elimination of colored lymphocytes with either EGFP-incompatible or CFSE-labeled sex-mismatched lymphocytes. We provide evidence that differential immunological behavior of EGFP-transgenic minor histocompatibility antigen was observed in vivo. Thus, immune responses to EGFP-minor histocompatibility antigen(s) were not always accompanied with the rejection of test skin isograft. It only becomes apparent for EGFP-specific elimination and suppression of both systemic and local GvHR induced by EGFP-transgenic T lymphocytes after EGFP-specific sensitization. However, this was not the case where test skin isografting was applied even under extensive sensitization protocols. These findings demonstrate that minor histocompatibility antigen specific immune elimination of EGFP-transgenic T lymphocytes or regulation of local GvHR provides more sensitive and better immune assay systems in vivo than classical test skin isograft systems.
Asunto(s)
Reacción Injerto-Huésped/inmunología , Proteínas Fluorescentes Verdes/inmunología , Antígenos de Histocompatibilidad Menor/inmunología , Trasplante de Piel/inmunología , Animales , Femenino , Supervivencia de Injerto/inmunología , Masculino , Ratas , Ratas Transgénicas , Piel/inmunología , Piel/metabolismo , Trasplante Isogénico/inmunologíaRESUMEN
BACKGROUND: It has been suggested that pregnancy-related hormones play a critical role in mediating selective immune tolerance during pregnancy. An understanding of why a woman's body normally does not reject the fetus is highly relevant to the prevention of transplant rejection. METHODS: The hearts of female inbred F344 rats (RT-1(lvl)) were transplanted into naive Lewis (RT-1(l); nLewis) or pregnant (pLewis; Day 6, 12 and 18 of pregnancy) rats. The mean survival time (MST) of the cardiac allografts between the nLewis and pLewis rats was compared. We determined the rate of proliferation of the T cells isolated from nLewis and pLewis rats in response to concanavalin A (ConA), anti-CD3 and -CD28 antibody and alloantigen stimulation ex vivo. mRNA expression of several cytokines in these T cells was analyzed using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, the effect of estriol on the cardiac allograft was tested. RESULTS: The pLewis rats with transplant on Day 12 of pregnancy had the most significantly prolonged F344 cardiac graft survival (MST 13.3 days) as compared with nLewis recipients (MST 8 days). pLewis T-cell proliferation was stimulated by alloantigen and antibody but ConA was reduced, whereas Th1/Th2 cytokine mRNA profiles in the T cells were similar for nLewis and pLewis rats. Likewise, estriol also significantly prolonged survival of cardiac allografts. CONCLUSIONS: The results of this study demonstrate that pregnancy hormones not only appear to play a critical role in maternal acceptance of the fetus, but also have therapeutic potential for prolonging the survival of major histocompatibility complex (MHC)-compatible allografts during pregnancy.
Asunto(s)
Trasplante de Corazón/inmunología , Complejo Mayor de Histocompatibilidad , Preñez/inmunología , Animales , Concanavalina A/farmacología , Citocinas/genética , Estriol/uso terapéutico , Femenino , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón/patología , Activación de Linfocitos/efectos de los fármacos , Masculino , Embarazo , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificación , Ratas , Ratas Endogámicas F344 , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Supervivencia , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Trasplante Heterotópico/inmunología , Trasplante Heterotópico/patología , Trasplante Homólogo/patologíaRESUMEN
PURPOSE: To study the effect of B7-CD28 costimulatory signal blockade by adenovirus-mediated cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin (AdCTLA-4Ig) on cardiac allograft survival in DA (RT1(a)) to LEW (Lewis RT1(l)) rat combinations. METHODS: We evaluated the effect of combined AdCTLA-4Ig and anti-inducible costimulator (ICOS) antibody immunotherapy on rat cardiac allograft acceptance. RESULTS: Unlike AdCTLA-4Ig alone, anti-ICOS immunotherapy combined with AdCTLA-4Ig induced stable tolerance without causing chronic rejection. The combined immunotherapy also prevented the accelerated cardiac rejection caused by donor-type test skin grafting. Immunohistochemical analyses revealed remarkable inflammatory mononuclear cell infiltration with typical vasculopathy, especially ICOS-positive cells in the grafts, in recipients treated with AdCTLA-4Ig alone. In contrast, anti-ICOS therapy combined with AdCTLA-4Ig reduced the ICOS-positive inflammatory cell infiltration of the graft significantly. The most important finding is that possible cardiac arrest caused by secondary donor-type skin graft was prevented by combined immunotherapy of AdCTLA-4Ig and anti-ICOS antibody, despite skin graft rejection. CONCLUSIONS: Our results identified a major role played by the ICOS-ICOSL pathway in chronic and accelerated cardiac allograft rejection, providing a novel approach to preventing the chronic rejection of vascularized organ allografts.
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Anticuerpos Monoclonales/farmacología , Antígenos de Diferenciación de Linfocitos T/inmunología , Rechazo de Injerto/inmunología , Trasplante de Corazón/inmunología , Tolerancia Inmunológica/efectos de los fármacos , Inmunosupresores/farmacología , Inmunoterapia , Abatacept , Adenoviridae , Animales , Antígenos de Diferenciación de Linfocitos T/sangre , Vectores Genéticos , Supervivencia de Injerto/efectos de los fármacos , Supervivencia de Injerto/inmunología , Trasplante de Corazón/patología , Inmunoconjugados/farmacología , Proteína Coestimuladora de Linfocitos T Inducibles , Masculino , Ratas , Ratas Endogámicas Lew , Trasplante de Piel/inmunología , Trasplante HeterotópicoRESUMEN
BACKGROUND: It is well known that CD4(+)CD25(+) regulatory T (Treg) cells play a central role in the suppression of autoimmunity, inflammation and allograft rejection. Therefore, therapeutic agents that capable of enhancing the number and activity of this T-cell subset are highly desirable. METHODS: The present study was designed to investigate the effects of superagonistic CD28-specific monoclonal antibody (supCD28 MAb) on preferentially expanded rat naturally occurring CD4(+)CD25(+) Treg (nTreg) cells and its applicability in cardiac transplantation. RESULTS: A single administration of supCD28 MAb preferentially proliferated nTreg cells. The increase of Foxp3 expression and polarization toward a Th2 cytokine profile correlated with decreased production of interferon-gamma and increased production of interleukin-4 and -10 in the expanded CD4(+)CD25(+) Treg subset, which was capable of suppressing CD4(+)CD25(-) T-cell proliferation after purification. Furthermore, supCD28 MAb administration revealed that nTreg cells were preferentially proliferating in vivo and recruited into the grafts, resulting in significant prolongation of full MHC-mismatch cardiac graft survival. CONCLUSIONS: Our data demonstrate that supCD28 MAb targets expansion of nTreg cells in vivo and maintains and enhances their regulatory functions, which represents a major advance toward the therapeutic use of polyclonally activated Treg cells as cellular therapy for treatment of allograft rejection.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Antígenos CD28/inmunología , Factores de Transcripción Forkhead/metabolismo , Rechazo de Injerto/prevención & control , Trasplante de Corazón , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/patología , Animales , Células Sanguíneas/metabolismo , Proliferación Celular/efectos de los fármacos , Concanavalina A/farmacología , Supervivencia de Injerto/efectos de los fármacos , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Interleucinas/metabolismo , Isoantígenos/farmacología , Masculino , Miocardio/metabolismo , Miocardio/patología , Periodo Posoperatorio , Ratas , Ratas Endogámicas , Linfocitos T Reguladores/efectos de los fármacos , Factores de Tiempo , Trasplante HeterotópicoRESUMEN
Ras is a guanine nucleotide-binding protein that plays a major role in regulating the proliferation of T cells. To investigate the mechanism of the Ras/mitogen-activated protein kinase pathway, one of the downstream signal-transduction pathways of T-cell receptors, in the response to alloantigen, we performed full-thickness skin grafting in the major histocompatibility complex (MHC) incompatible strain BALB/c (H-2Kd) (donor) and T-cell-specific H-Ras dominant-negative (dnRas) transgenic (tg) C57BL/6 (H-2Kb) (recipient) male mice. In vitro and in vivo dnRas tg mouse T-cell proliferation and cytotoxic T lymphocyte (CTL) activity assay were also performed. The median graft survival time in control B6/wild type (wt) mouse allografts was seven days. Conversely, the dnRas tg mouse group exhibited a significant (p<0.01) prolongation of graft survival to 15 days. However, all grafts were eventually rejected after one month. Mixed lymphocyte reaction and popliteal lymph node assay revealed that T-cell proliferation was decreased in response to alloantigen, but CTL activity was not changed in the dnRas tg mice. These results suggested that Ras is essential for peripheral T lymphocytes to respond to allo-MHC antigens, and Ras may be a molecular target for controlling transplant rejection.
Asunto(s)
Genes Dominantes , Genes ras , Rechazo de Injerto/inmunología , Supervivencia de Injerto/inmunología , Trasplante de Piel/inmunología , Proteínas ras/genética , Animales , Rechazo de Injerto/genética , Supervivencia de Injerto/genética , Sistema de Señalización de MAP Quinasas/genética , Sistema de Señalización de MAP Quinasas/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Trasplante HomólogoRESUMEN
Enhanced green fluorescence protein (EGFP) has been widely applied to gene transduction in cellular and molecular biology as a reporter element. When applied to cell transplantation, it raises fundamental issues concerning cell-associated antigens, in particular, a model of minor histocompatibility antigen(s). Although it is well known that immunological behavior of minor histocompatibility antigens mimic tumor associated antigens (TAA), identified genes coding minor histocompatibility antigens are few and far between. Inasmuch as immunity and tolerance to TAA are provided by immunological behavior of minor histocompatibility antigen such as histocompatibility antigen of the Y chromosome, H-Y, it occurs to us that transgenic as well as transduced EGFP provides a useful model system to be applied to tumor immunology. In this respect, genetic modification of specialized antigen-presenting cells (APC), i.e., dendritic cells (DC), such as gene transduction of EGFP into DC, would provide one of the most important strategies in transplantation as well as tumor immunology inasmuch as DC play a key role in initiating primary immune responses, As far as gene transduction into DC is concerned, others have reported that successful gene transduction occurs in DC by adenoviral vector systems. However, our previous studies concerning EGFP transduction into DC suggested that this view should be carefully examined and interpreted. Employing adenoviral and lentiviral vector systems as well as specialized APC of rat DC and peritoneal exudate macrophages (PEM), EGFP-transduced APC were examined to determine whether and to what extent the EGFP-transduced APC were able to sensitize non-transgenic littermates against transgenic EGFP as antigen(s). Thus EGFP-transgenic cardiac isografts were transplanted to non-transgenic littermates and examined to determine if sensitization of non-transgenic littermate recipients with the EGFP-transduced APC was able to reject the test grafts in an accelerated manner. In this study, we examined this and provide further evidence that widely used viral vector systems are unable to transfer the reporter gene EGFP into mature rat DC generated from bone marrow cells (BMC), driven by Flt3/Flk2 ligand and IL-6. Nevertheless, successful gene transduction was obtained by either applying a lentiviral vector system to the developing DC progenitor cells during a long-term culture of rat BMC or by applying an adenoviral vector system to PEM. Thus, successful gene transduction into specialized APC was verified by in vivo priming of non-transgenic littermates with the EGFP-transduced APC, followed by accelerated rejection of EGFP-transgenic cardiac isografts.
Asunto(s)
Células Dendríticas/fisiología , Proteínas Fluorescentes Verdes/inmunología , Trasplante de Corazón/inmunología , Macrófagos Peritoneales/fisiología , Antígenos de Histocompatibilidad Menor/genética , Transducción Genética/métodos , Adenoviridae/genética , Animales , Animales Modificados Genéticamente , Antígenos de Neoplasias/inmunología , Antígenos de Superficie/inmunología , Células de la Médula Ósea/inmunología , Células Dendríticas/inmunología , Células Dendríticas/trasplante , Vectores Genéticos/genética , Proteínas Fluorescentes Verdes/genética , VIH-1/genética , Humanos , Interleucina-6/inmunología , Lectinas Tipo C/inmunología , Lentivirus/genética , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/trasplante , Masculino , Proteínas de la Membrana/inmunología , Proteínas de la Membrana/metabolismo , Antígenos de Histocompatibilidad Menor/inmunología , Subfamilia B de Receptores Similares a Lectina de Células NK , Ratas , Ratas EndogámicasRESUMEN
The liver contains significant numbers of invariant natural killer T (iNKT) cells, which have an invariant T cell receptor-alpha chain and are activated in a CD1d-restricted manner. We examined the role of iNKT cells in the spontaneous tolerance of the major histocompatibility antigen complex-mismatched liver allograft model using Jalpha18 knockout mice that lack iNKT cells. Liver allografts lacking iNKT cells manifested not only infiltration but also hemorrhage and necrosis with significant reduction of graft survival and much less induction of tolerance compared with wild type (WT) liver allograft. In addition, allografts lacking iNKT cells grafted into iNKT-deficient recipients result in more severe inflammation than when grafted into WT recipients, while there was no significant difference with respect to induction of tolerance and graft survival. These results demonstrated that iNKT cells, especially donor-residual iNKT cells, constitute immune regulatory cells that play an important role in induction of allograft tolerance.
Asunto(s)
Tolerancia Inmunológica/inmunología , Células Asesinas Naturales/inmunología , Trasplante de Hígado/inmunología , Linfocitos T/trasplante , Animales , Supervivencia de Injerto/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: There is great interest in the recently developed immunosuppressant NK026680, which is a derivative of triazolopyrimidine. Its unique chemical structure and action mechanism are completely different from those of conventional immunosuppressants. METHODS: The present study was designed to investigate the effects of NK026680 on rat bone-marrow-derived dendritic cell (BMDC) differentiation and maturation in an in vitro culture system and its applicability in liver transplantation. RESULTS: NK026680 inhibited T-cell proliferation stimulated by alloantigen in a dose-dependent manner, but did not inhibit concanavalin A. The populations of OX6+CD161a cells and CD86+CD161a cells were suppressed in NK026680-treated dendritic cells (DCs). Exposure of DCs to NK026680 downregulated the interleukin (IL)-12 (p40, p35), interferon-gamma mRNA expression and upregulated IL-10, transforming growth factor-beta, in which impaired the ability of DC to stimulate T cell proliferation. Furthermore, oral administration of NK026680 for 14 days significantly prolonged liver allograft survival and limitation of T-cell responses and polarization toward a Th2 cytokine profile. CONCLUSIONS: These results demonstrate that NK026680 may have therapeutic potential for preventing allo-rejection in organ transplantation, acting at the step of immune response through inhibiting BMDC differentiation and maturation into potent antigen-presenting cells.
Asunto(s)
Células Dendríticas/efectos de los fármacos , Células Dendríticas/fisiología , Supervivencia de Injerto/fisiología , Inmunosupresores/farmacología , Trasplante de Hígado/fisiología , Pirimidinas/farmacología , Triazoles/farmacología , Animales , Antígeno B7-2/genética , Antígeno B7-2/metabolismo , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Concanavalina A/farmacología , Células Dendríticas/citología , Relación Dosis-Respuesta a Droga , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Isoantígenos/farmacología , Trasplante de Hígado/patología , Masculino , Mitógenos/farmacología , Ratas , Ratas Endogámicas Lew , Linfocitos T/efectos de los fármacos , Linfocitos T/patología , Linfocitos T/fisiologíaRESUMEN
BACKGROUND: Immune regulatory CD4+CD25+ T (regulatory T; Treg) cells play a vital role in the induction and maintenance of self-tolerance. They are essential for the homeostasis of T cells, the prevention of autoimmunity, and the induction of tolerance to allogeneic donor grafts. However, the underlying mechanism of their functions remains mostly elusive. Therefore, we investigated here a crucial role of Treg cells in their response to alloantigen via the programmed death (PD)-1/PD-1 ligand (PD-L1) pathway. METHODS: In vitro mixed lymphocyte reaction (MLR) assay, graft-versus-host disease (GvHD) and a skin transplantation model were used to evaluate the mechanisms of PD-1/PD-L1 pathway. RESULTS: Blockade of the PD-1/PD-L1 pathway using anti-PD-L1 monoclonal antibodies (mAb) is found to inhibit Treg cell's ability to suppress and restore CD4+CD25-T-cell proliferation in vitro. GvHD was lethal after adoptive transfer of allogeneic C57BL/6 (H-2K) spleen cells to NOD/SCID (H-2K) mice unless CD25+ T cells were also included. Strikingly, the suppression of GvHD by CD25+ cells was abrogated by anti-PD-L1 mAb administration. The abrogation of Treg-cell-mediated suppression could also be demonstrated in a Balb/c (H-2K) to B6/Rag-2KO (H-2K) skin-allograft model. CONCLUSIONS: The blockade of the PD-1/PD-L1 pathway abrogates Treg-mediated immunoregulation, thus suggesting that the PD-1/PD-L1 pathway is required for Treg suppression of the alloreactive responses of CD4+CD25-T cells. This finding has important implications for clarifying the mechanisms of allograft rejection and GvHD.
Asunto(s)
Antígenos de Superficie/fisiología , Proteínas Reguladoras de la Apoptosis/fisiología , Autoinmunidad/inmunología , Transducción de Señal/fisiología , Linfocitos T Reguladores/fisiología , Tolerancia al Trasplante/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Antígenos de Superficie/inmunología , Proteínas Reguladoras de la Apoptosis/inmunología , Autoinmunidad/fisiología , Antígeno CD24 , Rechazo de Injerto/inmunología , Enfermedad Injerto contra Huésped/inmunología , Subunidad alfa del Receptor de Interleucina-2 , Isoantígenos/inmunología , Ligandos , Prueba de Cultivo Mixto de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Receptor de Muerte Celular Programada 1 , Trasplante de Piel/inmunología , Linfocitos T Reguladores/inmunología , Tolerancia al Trasplante/fisiologíaRESUMEN
Induction of transplant tolerance is a clinically desirable goal. To provide unbiased insight into transplant tolerance, we analyzed gene expression profiling in peripheral blood mononuclear cells from recipients of living-donor liver transplants (LDLTs) who had retained an immune tolerance with a well-functioning graft for several years using cDNA microarray. The comparative analyses with nontransplanted normal healthy volunteers showed that the majority of reliable detected genes were similar, and 5.6% of the genes in the tested genome (of which 627 up-regulated and 90 down-regulated) were significantly regulated and specific to tolerant LDLT recipients, indicating a significant genetic feature for inducing and maintaining immune tolerance. Moreover, the expression of several selected genes was confirmed by semiquantitative reverse transcriptase-polymerase chain reaction, which correlated to microarray data. Our data indicated that cDNA microarray technology was useful for this application and provided many informative insights into transplant tolerance mechanism.