RESUMEN
The sphingosine-1-phosphate receptor-1 (S1P1) agonist ozanimod ameliorates ulcerative colitis, yet its mechanism of action is unknown. Here, we examine the cell subsets that express S1P1 in intestine using S1P1-eGFP mice, the regulation of S1P1 expression in lymphocytes after administration of dextran sulfate sodium (DSS), after colitis induced by transfer of CD4+CD45RBhi cells, and by crossing a mouse with TNF-driven ileitis with S1P1-eGFP mice. We then assayed the expression of enzymes that regulate intestinal S1P levels, and the effect of FTY720 on lymphocyte behavior and S1P1 expression. We found that not only T and B cells express S1P1, but also dendritic (DC) and endothelial cells. Furthermore, chronic but not acute inflammatory signals increased S1P1 expression, while the enzymes that control tissue S1P levels in mice and humans with inflammatory bowel disease (IBD) were uniformly dysregulated, favoring synthesis over degradation. Finally, we observed that FTY720 reduced T-cell velocity and induced S1P1 degradation and retention of Naïve but not effector T cells. Our data demonstrate that chronic inflammation modulates S1P1 expression and tissue S1P levels and suggests that the anti-inflammatory properties of S1PR agonists might not be solely due to their lymphopenic effects, but also due to potential effects on DC migration and vascular barrier function.
Asunto(s)
Colitis/inmunología , Células Dendríticas/inmunología , Endotelio/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Intestinos/fisiología , Linfocitos/inmunología , Receptores de Lisoesfingolípidos/metabolismo , Animales , Movimiento Celular , Células Cultivadas , Sulfato de Dextran , Modelos Animales de Enfermedad , Clorhidrato de Fingolimod/farmacología , Humanos , Factores Inmunológicos/uso terapéutico , Memoria Inmunológica , Indanos/farmacología , Indanos/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Oxadiazoles/farmacología , Oxadiazoles/uso terapéutico , Receptores de Lisoesfingolípidos/agonistas , Receptores de Lisoesfingolípidos/genéticaRESUMEN
BACKGROUND: Periostin is highly expressed in eosinophilic oesophagitis (EoE), but has not been extensively studied as a non-invasive biomarker. AIM: To assess whether serum periostin distinguished EoE from controls at baseline, had utility for monitoring treatment response, or was associated with IL-13 levels. METHODS: This was a sub-analysis of a prospective cohort study of adults undergoing out-patient upper endoscopy. Incident cases of EoE were diagnosed per consensus guidelines. Controls were subjects with either GERD or dysphagia without EoE. EoE patients were treated with swallowed/topical steroids and had repeat endoscopy/biopsy. Serum periostin levels for cases and controls were compared at baseline, and pre/post-treatment levels were compared for cases. Serum IL-13 and tissue expression of periostin were also assessed. RESULTS: A total of 61 incident EoE cases and 87 controls were analysed. Despite a marked increase in tissue periostin expression in cases, the median baseline serum periostin level was only slightly higher in cases than controls (22.1 ng/mL vs. 20.7; P = 0.04); there was no change in post-treatment levels. There was also no difference in serum periostin for cases by histologic response or atopic status. There was a strong trend towards higher serum IL-13 levels in cases in the highest periostin quartile (57.1 pg/mL vs. 2.6; P = 0.07). CONCLUSIONS: Serum periostin levels were similar in cases and controls, and there were no changes post-treatment. Given elevated IL-13 levels in the EoE patients with the highest periostin levels, future studies could explore periostin as a biomarker in EoE, perhaps in the setting of anti-IL-13 therapy.
Asunto(s)
Moléculas de Adhesión Celular/sangre , Esofagitis Eosinofílica/diagnóstico , Interleucina-13/sangre , Adulto , Biomarcadores/sangre , Biopsia , Trastornos de Deglución/diagnóstico , Endoscopía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Estudios ProspectivosRESUMEN
BACKGROUND AND PURPOSE: Sphingosine1-phosphate (S1P) receptors mediate multiple events including lymphocyte trafficking, cardiac function, and endothelial barrier integrity. Stimulation of S1P1 receptors sequesters lymphocyte subsets in peripheral lymphoid organs, preventing their trafficking to inflamed tissue sites, modulating immunity. Targeting S1P receptors for treating autoimmune disease has been established in clinical studies with the non-selective S1P modulator, FTY720 (fingolimod, Gilenya™). The purpose of this study was to assess RPC1063 for its therapeutic utility in autoimmune diseases. EXPERIMENTAL APPROACH: The specificity and potency of RPC1063 (ozanimod) was evaluated for all five S1P receptors, and its effect on cell surface S1P1 receptor expression, was characterized in vitro. The oral pharmacokinetic (PK) parameters and pharmacodynamic effects were established in rodents, and its activity in three models of autoimmune disease (experimental autoimmune encephalitis, 2,4,6-trinitrobenzenesulfonic acid colitis and CD4(+) CD45RB(hi) T cell adoptive transfer colitis) was assessed. KEY RESULTS: RPC1063 was specific for S1P1 and S1P5 receptors, induced S1P1 receptor internalization and induced a reversible reduction in circulating B and CCR7(+) T lymphocytes in vivo. RPC1063 showed high oral bioavailability and volume of distribution, and a circulatory half-life that supports once daily dosing. Oral RPC1063 reduced inflammation and disease parameters in all three autoimmune disease models. CONCLUSIONS AND IMPLICATIONS: S1P receptor selectivity, favourable PK properties and efficacy in three distinct disease models supports the clinical development of RPC1063 for the treatment of relapsing multiple sclerosis and inflammatory bowel disease, differentiates RPC1063 from other S1P receptor agonists, and could result in improved safety outcomes in the clinic.
Asunto(s)
Enfermedades Autoinmunes/tratamiento farmacológico , Indanos/farmacología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Oxadiazoles/farmacología , Receptores de Lisoesfingolípidos/agonistas , Animales , Enfermedades Autoinmunes/inducido químicamente , Modelos Animales de Enfermedad , Femenino , Enfermedades Inflamatorias del Intestino/inducido químicamente , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Glicoproteína Mielina-Oligodendrócito/inmunología , Ratas , Ratas Sprague-Dawley , Ácido TrinitrobencenosulfónicoRESUMEN
We report our experimental results for linear analog optical links that use phase or frequency modulation and optical discrimination. The discriminators are based on two architectures: a cascaded MZI FIR lattice filter and a ring assisted MZI (RAMZI) IIR filter. For both types of discriminators, we demonstrate > 6 dB improvement in the link's third-order output intercept point (OIP3) over a MZM link. We show that the links have low second-order distortion when using balanced detection. Using high optical power, we demonstrate an OIP3 of 39.2 dBm. We also demonstrate 4.3dB improvement in signal compression.
Asunto(s)
Amplificadores Electrónicos , Diseño Asistido por Computadora , Modelos Teóricos , Dispositivos Ópticos , Oscilometría/instrumentación , Fotones , Procesamiento de Señales Asistido por Computador , Simulación por Computador , Diseño de Equipo , HumanosAsunto(s)
Antígenos CD40/fisiología , Ligando de CD40/fisiología , Supervivencia de Injerto/inmunología , Terapia de Inmunosupresión/métodos , Sirolimus/uso terapéutico , Trasplante de Piel/inmunología , Trasplante Homólogo/inmunología , Animales , Supervivencia de Injerto/efectos de los fármacos , Masculino , Ratas , Ratas Endogámicas Lew , Factores de TiempoRESUMEN
The existence of surface waves on anisotropic materials was proven under fairly general conditions by Lothe and Barnett in 1976 [1]. But, until now, the status of surface waves on piezoelectric materials has remained unresolved. This paper presents general existence theorems for surface waves on piezoelectric substrates. It is demonstrated that for short circuit boundary conditions a surface wave solution must exist under virtually any circumstances. However, for a free surface, comparatively stringent existence conditions are required. Numerical examples are given for both free and shorted surfaces, and it is demonstrated that, in some situations, a surface wave solution may not exist for free surface propagation. The existence proofs were developed as a result of theoretical work on Green function modeling, which is now the preferred technique for rigorous SAW and pseudo-SAW device analysis. The mechanisms of the existence proofs and the associated mathematical results give great insight into the structure and properties of the Green functions and include many results that are directly relevant to device analysis.
RESUMEN
The CD28 ligands CD80 and CD86 are expressed on APC, and both provide costimulatory function. However, the reason for the expression of two separate CD28 ligands remains unclear. We have previously shown that blockade of CD80 costimulation by Y100F-Ig, a CTL-associated Ag-4 (CTLA4)-Ig mutant that does not bind CD86, inhibits the development of lung inflammatory immune responses, but does not affect blood eosinophilia or Ab production. Each of those responses was inhibited by treatment with CTLA4-Ig, which binds both CD80 and CD86. To clarify the mechanism underlying these observations we have developed a model of lung inflammation using adoptively transferred CD4(+) T cells expressing a Valpha11(+)Vbeta3(+) transgenic TCR specific for I-E(k) and moth cytochrome c. Treatment with Y100F-Ig inhibited the induction of lung eosinophilia in adoptively transferred mice. However, Y100F-Ig did not detectably affect the accumulation of Ag-specific T cells at the site of peptide deposit or in the draining lymphoid tissues. Acquisition of an activated phenotype and expression of adhesion molecules required for migration into the lung were modestly affected. Importantly, treatment with Y100F-Ig diminished the ability of T cells to produce the cytokines IL-4 and IL-5 following intranasal challenge with Ag. All the responses examined were severely inhibited by treatment with CTLA4-Ig. We conclude that T cells require CD80 costimulation for the optimal production of IL-5 following intranasal administration of Ag. Decreased IL-5 production is the most likely explanation for the diminished airway eosinophilia observed.
Asunto(s)
Antígeno B7-1/fisiología , Movimiento Celular/inmunología , Citocinas/biosíntesis , Epítopos de Linfocito T/inmunología , Inmunoconjugados , Pulmón/inmunología , Células Th2/inmunología , Células Th2/patología , Abatacept , Traslado Adoptivo , Animales , Antígenos CD , Antígenos de Diferenciación/administración & dosificación , Antígenos de Diferenciación/genética , Células CHO , Antígeno CTLA-4 , Cricetinae , Grupo Citocromo c/administración & dosificación , Grupo Citocromo c/antagonistas & inhibidores , Grupo Citocromo c/inmunología , Modelos Animales de Enfermedad , Eosinofilia/inmunología , Eosinofilia/prevención & control , Femenino , Humanos , Pulmón/metabolismo , Pulmón/patología , Activación de Linfocitos , Tejido Linfoide/inmunología , Tejido Linfoide/patología , Masculino , Ratones , Ratones Endogámicos A , Ratones Endogámicos C57BL , Ratones Transgénicos , Mariposas Nocturnas/inmunología , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/inmunología , Subgrupos de Linfocitos T/patología , Subgrupos de Linfocitos T/trasplante , Células Th2/metabolismo , TransfecciónAsunto(s)
Presentación de Antígeno/inmunología , Aorta Torácica/trasplante , Antígenos de Histocompatibilidad/inmunología , Túnica Íntima/patología , Animales , Aorta Torácica/patología , Antígeno B7-1/efectos de los fármacos , Antígeno B7-1/inmunología , Antígenos CD28/efectos de los fármacos , Antígenos CD28/inmunología , Antígenos CD40/efectos de los fármacos , Antígenos CD40/inmunología , Ligando de CD40/efectos de los fármacos , Ligando de CD40/inmunología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BLAsunto(s)
Aorta/trasplante , Antígenos CD28/inmunología , Antígenos CD40/inmunología , Rechazo de Injerto/prevención & control , Animales , Presentación de Antígeno , Aorta/patología , Antígeno B7-1/inmunología , Ligando de CD40/inmunología , Enfermedad Crónica , Rechazo de Injerto/inmunología , Rechazo de Injerto/patología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Transducción de Señal , Trasplante Homólogo , Túnica Íntima/patologíaRESUMEN
Provision of adequate T cell costimulation is critical for the development of acute and chronic allograft rejection. We have previously reported that early blockade of CD28-B7 T cell costimulation prevents the development of graft arteriosclerosis, in the LEW into F344 rat cardiac transplant model. In this study, we used the same model to examine the requirement for CD28-B7-mediated T cell costimulation in the progression of established chronic rejection and examined the individual roles of B7-1 (CD80) and B7-2 (CD86) costimulatory molecules. Late blockade of CD28-B7 T cell costimulation by the fusion protein CTLA4Ig, which binds both CD80 and CD86, attenuated the development of transplant arteriosclerosis, mononuclear cell infiltration, and parenchymal fibrosis in this model. Selective blockade of CD80 using the mutant fusion protein Y100F was as effective as CTLA4Ig in this regard. In contrast to CTLA4Ig, blockade of CD80 alone by Y100F was ineffective at preventing early graft loss and prolonging graft survival when given early after transplantation. This study is the first to demonstrate that late blockade of CD28-B7 T cell costimulation interrupts chronic cardiac allograft rejection, and it indicates the importance of continued T cell activation in this process. This study further defines functional differences between CD80 and CD86 costimulatory molecules in vivo.
Asunto(s)
Antígeno B7-1/inmunología , Antígenos CD28/inmunología , Linfocitos T CD4-Positivos/inmunología , Rechazo de Injerto/inmunología , Trasplante de Corazón/efectos adversos , Inmunoconjugados , Activación de Linfocitos , Abatacept , Animales , Antígenos CD , Antígenos de Diferenciación/administración & dosificación , Antígenos de Diferenciación/genética , Antígenos de Diferenciación/uso terapéutico , Linfocitos T CD4-Positivos/efectos de los fármacos , Antígeno CTLA-4 , Traumatismos de las Arterias Carótidas/etiología , Traumatismos de las Arterias Carótidas/patología , Cateterismo/efectos adversos , División Celular , Enfermedad de la Arteria Coronaria/etiología , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/patología , Esquema de Medicación , Fibrosis/patología , Rechazo de Injerto/tratamiento farmacológico , Rechazo de Injerto/patología , Supervivencia de Injerto , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Activación de Linfocitos/efectos de los fármacos , Masculino , Mutación , Miocardio/patología , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Trasplante Homólogo , Túnica Íntima/patologíaAsunto(s)
Trasplante de Médula Ósea/inmunología , Inmunoconjugados , Linfocitos T Citotóxicos/inmunología , Quimera por Trasplante/inmunología , Tolerancia al Trasplante/inmunología , Abatacept , Animales , Antígenos CD , Antígenos de Diferenciación/farmacología , Ligando de CD40/inmunología , Antígeno CTLA-4 , División Celular , Inmunidad Celular , Inmunosupresores/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Quimera por Radiación/inmunología , Linfocitos T Citotóxicos/efectos de los fármacos , Tolerancia al Trasplante/efectos de los fármacosAsunto(s)
Trasplante de Médula Ósea/inmunología , Antígenos CD28/efectos de los fármacos , Ligando de CD40/inmunología , Inmunoconjugados , Quimera por Trasplante/inmunología , Abatacept , Animales , Antígenos CD , Antígenos de Diferenciación/farmacología , Antígenos CD28/inmunología , Antígeno CTLA-4 , Enfermedad Injerto contra Huésped , Inmunosupresores/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBARESUMEN
The requirements for B7 costimulation during an in vivo humoral response to an intact extracellular bacteria have not been reported. In this study we immunized mice with Streptococcus pneumoniae (R36A) to determine the B7 requirements for induction of Ig, specific for two determinants on R36A, the phosphorylcholine (PC) determinant of C-polysaccharide and pneumococcal surface protein A (PspA). We show that the primary anti-PspA response, the development of PspA-specific memory, and the induction of the secondary anti-PspA response in primed mice were completely dependent upon B7 costimulation. Of note, costimulation was required only briefly after the secondary immunization compared with after the primary immunization for optimal induction of Ig. Blockade of B7 costimulation at the time of secondary immunization also completely abrogated the established state of memory, but did not induce tolerance. In contrast to the anti-PspA response, the primary anti-PC response involved only a very short period of B7 costimulation. Whereas B7-2 alone was required for induction of the primary anti-PspA and anti-PC responses, a redundant role for B7-1 and B7-2 was noted for the PspA-specific secondary response. CTLA4Ig blocked both the anti-PC and anti-PspA responses equally well over a wide range of bacterial doses. These studies demonstrate a critical, but variable, role for B7-dependent costimulation during an Ig response to an extracellular bacteria.
Asunto(s)
Antígenos CD/fisiología , Antígeno B7-1/fisiología , Inmunización Secundaria , Inmunoconjugados , Isotipos de Inmunoglobulinas/biosíntesis , Glicoproteínas de Membrana/fisiología , Polisacáridos Bacterianos/inmunología , Streptococcus pneumoniae/inmunología , Abatacept , Animales , Anticuerpos Bloqueadores/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígenos de Diferenciación/administración & dosificación , Antígeno B7-1/inmunología , Antígeno B7-1/metabolismo , Antígeno B7-2 , Proteínas Bacterianas/inmunología , Antígenos CD28/genética , Antígenos CD28/fisiología , Antígeno CTLA-4 , Relación Dosis-Respuesta Inmunológica , Epítopos/inmunología , Fragmentos Fc de Inmunoglobulinas/administración & dosificación , Inmunoglobulina G/biosíntesis , Isotipos de Inmunoglobulinas/sangre , Memoria Inmunológica , Inmunosupresores/administración & dosificación , Inyecciones Intraperitoneales , Cinética , Ligandos , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilcolina/inmunología , Polisacáridos Bacterianos/administración & dosificación , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/inmunologíaRESUMEN
Abscesses are a classic host response to infection by many pathogenic bacteria. The immunopathogenesis of this tissue response to infection has not been fully elucidated. Previous studies have suggested that T cells are involved in the pathologic process, but the role of these cells remains unclear. To delineate the mechanism by which T cells mediate abscess formation associated with intra-abdominal sepsis, the role of T-cell activation and the contribution of antigen-presenting cells via CD28-B7 costimulation were investigated. T cells activated in vitro by zwitterionic bacterial polysaccharides (Zps) known to induce abscess formation required CD28-B7 costimulation and, when adoptively transferred to the peritoneal cavity of naïve rats, promoted abscess formation. Blockade of T-cell activation via the CD28-B7 pathway in animals with CTLA4Ig prevented abscess formation following challenge with different bacterial pathogens, including Staphylococcus aureus, Bacteroides fragilis, and a combination of Enterococcus faecium and Bacteroides distasonis. In contrast, these animals had an increased abscess rate following in vivo T-cell activation via CD28 signaling. Abscess formation in vivo and T-cell activation in vitro required costimulation by B7-2 but not B7-1. These results demonstrate that abscess formation by pathogenic bacteria is under the control of a common effector mechanism that requires T-cell activation via the CD28-B7-2 pathway.
Asunto(s)
Absceso/etiología , Antígenos CD/fisiología , Antígenos CD28/fisiología , Linfocitos T CD4-Positivos/inmunología , Inmunoconjugados , Activación de Linfocitos , Glicoproteínas de Membrana/fisiología , Abatacept , Animales , Antígenos de Diferenciación/farmacología , Antígeno B7-1/fisiología , Antígeno B7-2 , Antígeno CTLA-4 , Humanos , Masculino , Ratas , Ratas WistarRESUMEN
CTLA-4 (CD152) is involved in T-lymphocyte co-stimulatory pathways modulating both humoral and cellular immune response. The membrane-external domain has been prepared and crystallized. The unit-cell parameters are a = b = 43, c = 143 A with the symmetry of space group P3(1)21 or its enantiomer and the crystals diffract to 2. 7 A resolution at synchrotron beamlines.
Asunto(s)
Antígenos de Diferenciación/química , Inmunoconjugados , Proteínas de la Membrana/química , Abatacept , Antígenos CD , Antígeno CTLA-4 , Cristalización , Cristalografía por Rayos X , Conformación ProteicaAsunto(s)
Antígenos de Diferenciación/uso terapéutico , Trasplante de Médula Ósea/inmunología , Enfermedad Injerto contra Huésped/prevención & control , Inmunoconjugados , Terapia de Inmunosupresión/métodos , Inmunosupresores/uso terapéutico , Trasplante Heterólogo/inmunología , Abatacept , Animales , Antígenos CD , Linfocitos B/inmunología , Antígeno CTLA-4 , Cricetinae , Enfermedad Injerto contra Huésped/inmunología , Activación de Linfocitos , Ratas , Ratas Endogámicas Lew , Esplenectomía , Linfocitos T/inmunología , Factores de Tiempo , Irradiación Corporal TotalRESUMEN
Previous studies have found that subjects diagnosed with verbal auditory agnosia (VAA) from bilateral brain lesions may experience difficulties at the prephonemic level of acoustic processing. In this case study, we administered a series of speech and nonspeech discrimination tests to an individual with unilateral VAA as a result of left-temporal-lobe damage. The results indicated that the subject's ability to perceive steady-state acoustic stimuli was relatively intact but his ability to perceive dynamic stimuli was drastically reduced. We conclude that this particular aspect of acoustic processing may be a major contributing factor that disables speech perception in subjects with unilateral VAA.
Asunto(s)
Trastornos de la Percepción Auditiva/diagnóstico , Trastornos de la Percepción Auditiva/fisiopatología , Encéfalo/fisiopatología , Lateralidad Funcional/fisiología , Percepción del Habla/fisiología , Adulto , Agnosia/diagnóstico , Agnosia/fisiopatología , Humanos , Masculino , Acústica del LenguajeRESUMEN
Interleukin-10 (IL-10) is associated with inhibition of cell-mediated immunity and downregulation of the expression of costimulatory molecules required for T-cell activation. When IL-10-deficient (IL-10KO) mice are infected with Toxoplasma gondii, they succumb to a T-cell-mediated shock-like reaction characterized by the overproduction of IL-12 and gamma interferon (IFN-gamma) associated with widespread necrosis of the liver. Since costimulation is critical for T-cell activation, we investigated the role of the CD28-B7 and CD40-CD40 ligand (CD40L) interactions in this infection-induced immunopathology. Our studies show that infection of mice with T. gondii resulted in increased expression of B7 and CD40 that was similar in wild-type and IL-10KO mice. In vivo blockade of the CD28-B7 or CD40-CD40L interactions following infection of IL-10KO mice with T. gondii did not affect serum levels of IFN-gamma or IL-12, nor did it prevent death in these mice. However, when both pathways were blocked, the IL-10KO mice survived the acute phase of infection and had reduced serum levels of IFN-gamma and alanine transaminase as well as decreased expression of inducible nitric oxide synthase in the liver and spleen. Analysis of parasite-specific recall responses from infected IL-10KO mice revealed that blockade of the CD40-CD40L interaction had minimal effects on cytokine production, whereas blockade of the CD28-B7 interaction resulted in decreased production of IFN-gamma but not IL-12. Further reduction of IFN-gamma production was observed when both costimulatory pathways were blocked. Together, these results demonstrate that the CD28-B7 and CD40-CD40L interactions are involved in the development of infection-induced immunopathology in the absence of IL-10.
Asunto(s)
Antígenos CD/inmunología , Antígeno B7-1/inmunología , Antígenos CD28/inmunología , Antígenos CD40/inmunología , Inmunoconjugados , Interleucina-10/inmunología , Glicoproteínas de Membrana/inmunología , Toxoplasmosis/inmunología , Abatacept , Animales , Antígenos CD/biosíntesis , Antígenos de Diferenciación/administración & dosificación , Antígenos de Diferenciación/inmunología , Antígeno B7-1/biosíntesis , Antígeno B7-2 , Antígenos CD40/biosíntesis , Ligando de CD40 , Antígeno CTLA-4 , Femenino , Interferón gamma/biosíntesis , Interleucina-10/genética , Interleucina-12/biosíntesis , Glicoproteínas de Membrana/biosíntesis , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Noqueados , Toxoplasma/inmunología , Toxoplasmosis/patologíaRESUMEN
Experimental autoimmune glomerulonephritis (EAG), an animal model of Goodpasture's disease, can be induced in Wistar Kyoto (WKY) rats by a single injection of rat glomerular basement membrane (GBM) in adjuvant. EAG is characterized by circulating and deposited anti-GBM antibodies, accompanied by focal necrotizing glomerulonephritis with crescent formation. The role of T cells in the pathogenesis of EAG remains unclear. T-cell costimulation is provided by ligation of CD28 with either B7.1 (CD80) or B7.2 (CD86) on antigen-presenting cells, and can be inhibited by a soluble form of CTLA4 (CTLA4-Ig) that binds to both B7.1 and B7.2. We examined the effect of CD28-B7 blockade on the development of EAG using native CTLA4-Ig or mutant CTLA4-Ig (Y100F-Ig), which selectively blocks B7.1. Native CTLA4-Ig treatment ameliorated EAG by several measures, including the levels of circulating anti-GBM antibodies, albuminuria, the deposition of IgG and fibrin in the glomeruli, the severity of glomerular abnormalities, and the numbers of infiltrating T cells and macrophages. Y100F-Ig resulted in a similar reduction in the severity of nephritis, but produced no overall reduction in circulating anti-GBM antibodies, although there was a reduction in IgG2a antibodies. We concluded that CD28-B7 blockade reduced autoantibody production and cellular infiltration of glomeruli, and prevented target organ injury. Our results suggest a key role for B7. 1 in costimulation of Th1-like autoimmune responses in the rat, and show that glomerular injury in EAG is largely dependent on cell-mediated mechanisms.