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1.
Osteoporos Int ; 25(11): 2591-7, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25011985

RESUMEN

UNLABELLED: The effect of patient characteristics and organizational and system factors on time to surgery were studied using Emilia Romagna Region database and hospital survey. The results showed that the implementation of a Hip Fracture Program significantly increased the probability of early surgery while single intervention had only slight effect INTRODUCTION: The purpose of this study is to evaluate the effect of formal Hip Fracture Program (HFP) on timing of surgery in hip fracture older patients. METHODS: This is a retrospective cohort study based on Emilia Romagna administrative databases. Data on organizational and system factor were also obtained through a hospital survey. A multilevel logistic regression analysis was carried out to assess the effect of covariates on early surgery, taking into account patient level, hospital level, and trust level variability. RESULTS: From 1 January to 31 December 2011, 5,520 subjects over 65 years old underwent surgical repair for hip fracture in Emilia Romagna. The mean waiting time to surgery was 3.4 ± 12.3 days, and the overall percentage of patients operated within 2 days was 52.2%. In the adjusted multilevel logistic model, significant risk factors affecting the timing of surgical intervention at patient level were age, comorbidity, day of admission, and antiplatelet or warfarin therapy while no significant single variables were found at hospital level including dedicated operation theater, hospital volume, dedicated orthogeriatric beds, and geriatrician involvement. The most significant variable was the implementation of HFP at trust level that increased three times the probability of early surgery after adjusting for confounding variables (OR 3.216, 95% CI 0.582-6.539). CONCLUSIONS: Several modifiable organizational factors may affect the proportion of patients with hip fracture undergoing early surgery. This study suggests that the development and the implementation of an evidence-based HFP at trust level are a key point of the strategy of quality of care.


Asunto(s)
Prestación Integrada de Atención de Salud/organización & administración , Fracturas de Cadera/cirugía , Fracturas Osteoporóticas/cirugía , Grupo de Atención al Paciente/organización & administración , Anciano , Anciano de 80 o más Años , Comorbilidad , Prestación Integrada de Atención de Salud/normas , Femenino , Hospitalización , Humanos , Italia , Masculino , Evaluación de Programas y Proyectos de Salud , Mejoramiento de la Calidad , Indicadores de Calidad de la Atención de Salud , Estudios Retrospectivos , Tiempo de Tratamiento/estadística & datos numéricos
2.
Br J Cancer ; 106(10): 1648-59, 2012 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-22569000

RESUMEN

BACKGROUND: MEK is activated in ∼40% colorectal cancer (CRC) and 20-30% non-small cell lung cancer (NSCLC). Selumetinib is a selective inhibitor of MEK1/2, which is currently in clinical development. METHODS: We evaluated the effects of selumetinib in vitro and in vivo in CRC and NSCLC cell lines to identify cancer cell characteristics correlating with sensitivity to MEK inhibition. RESULTS: Five NSCLC and six CRC cell lines were treated with selumetinib and classified according to the median inhibitory concentration (IC(50)) values as sensitive (≤1 µM) or resistant (>1 µM). In selumetinib-sensitive cancer cell lines, selumetinib treatment induced G1 cell-cycle arrest and apoptosis and suppression of tumour growth as xenografts in immunodeficient mice. Evaluation of intracellular effector proteins and analysis of gene mutations showed no correlation with selumetinib sensitivity. Microarray gene expression profiles revealed that the activation of cAMP-dependent protein kinase A (PKA) was associated with MEK inhibitor resistance. Combined targeting of both MEK and PKA resulted in cancer cell growth inhibition of MEK inhibitor-resistant cancer cell lines in vitro and in vivo. CONCLUSION: This study provides molecular insights to explain resistance to an MEK inhibitor in human cancer cell lines.


Asunto(s)
Bencimidazoles/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Proteínas Quinasas Dependientes de AMP Cíclico/fisiología , Neoplasias Pulmonares/tratamiento farmacológico , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular , Neoplasias Colorrectales/patología , Resistencia a Antineoplásicos , Activación Enzimática/efectos de los fármacos , Perfilación de la Expresión Génica , Humanos , Neoplasias Pulmonares/patología , Mutación , Ensayos Antitumor por Modelo de Xenoinjerto
3.
Br J Cancer ; 105(3): 382-92, 2011 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-21750552

RESUMEN

BACKGROUND: To study the molecular mechanisms regulating cancer cell resistance to four different tyrosine kinase inhibitors (TKIs): erlotinib, gefitinib, vandetanib and sorafenib. METHODS: An in vitro model of acquired resistance to these TKIs was developed by continuously treating the human lung adenocarcinoma cell line CALU-3 with escalating doses of each drug. Transcriptional profiling was performed with Agilent whole genome microarrays. Western blot analysis, enzyme-linked immunosorbent (ELISA), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation, migration, invasion and anchorage-independent colony growth assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in parental (P) and TKI-resistant (R) CALU-3 cell lines. RESULTS: As compared with P-CALU-3 cells, in TKI-R CALU-3 cell lines a significant increase in the expression of activated, phosphorylated MET, IGF-1R, AKT, MEK, MAPK and of survivin was observed. Downregulation of E-cadherin and amphiregulin mRNAs and upregulation of vimentin, VE-cadherin, HIF-1α and vascular endothelial growth factor receptor-1 mRNAs were observed in all four TKI-R CALU-3 cell lines. All four TKI-R CALU-3 cells showed increased invasion, migration and anchorage-independent growth. Together, these data suggest epithelial to mesenchymal transition (EMT) in TKI-R CALU-3 cells. Treatment with several agents that target AKT, MET or IGF-1R did not affect TKI-R CALU-3 cell proliferation. In contrast, treatment with MSC19363669B and selumetinib, two selective MEK inhibitors, caused inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumour growth in vivo of all four TKI-R CALU-3 cell lines. CONCLUSION: These data suggest that resistance to four different TKIs is characterised by EMT, which is MEK-inhibitor sensitive in human CALU-3 lung adenocarcinoma.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Resistencia a Antineoplásicos , Neoplasias Pulmonares/tratamiento farmacológico , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/uso terapéutico , Adenocarcinoma del Pulmón , Animales , Bencenosulfonatos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Clorhidrato de Erlotinib , Gefitinib , Perfilación de la Expresión Génica , Humanos , Ratones , Ratones Desnudos , Niacinamida/análogos & derivados , Compuestos de Fenilurea , Piperidinas/farmacología , Piridinas/farmacología , Quinazolinas/farmacología , Sorafenib , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Oncogene ; 30(24): 2707-17, 2011 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-21278794

RESUMEN

Induction of a senescent phenotype in tumor cells has been linked to anticancer immune response, however, the molecular mechanisms mediating these phenomenon have not yet been determined. In this study, we present evidence that induction of premature senescence in human cancer cell lines induces Fas expression, and loss of resistance to Fas-induced apoptosis. Triggering of Fas by using the agonistic antibody CH11 or the recombinant ligand APO010, activates an apoptotic pathway responsible for cell death. Secretion of pro-inflammatory cytokines by the senescent cells, particularly TNF-α and IFN-γ, mediates Fas upregulation. Indeed, treatment of proliferating cancer cell lines with TNF-α and IFN-γ, upregulates Fas expression, while blocking TNF-α and IFN-γ by using neutralizing antibodies, decreases Fas expression in senescent cells. We also demonstrate that NF-κB has a central role in controlling the senescence-associated secretory phenotype (SASP) by the premature senescent cells, and that TNF-α and IFN-γ, transcriptionally controlled by NF-κB, are the main mediators of Fas upregulation. Our data suggest the existence of an NF-κB-dependent autocrine loop, mediated by TNF-α and IFN-γ, responsible for expression of Fas on the surface of senescent cells, and for their killing.


Asunto(s)
Antineoplásicos/farmacología , Senescencia Celular/efectos de los fármacos , Interferón gamma/fisiología , FN-kappa B/fisiología , Neoplasias/patología , Factor de Necrosis Tumoral alfa/fisiología , Receptor fas/fisiología , Apoptosis , Línea Celular Tumoral , Humanos , Receptor fas/análisis
5.
Ann Oncol ; 22(1): 188-194, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20605933

RESUMEN

BACKGROUND: clinical guidelines can improve quality of care summarising available knowledge and proposing recommendations for health care decisions. Being up to date is one of their quality requisites. Little experience is available on when and how guidelines should be updated. We report on the update process of evidence-based clinical recommendations on anticancer drugs. METHODS: three multidisciplinary panels, supported by methodology experts, updated the recommendations. The methodologists were in charge of the qualitative and quantitative synthesis of the evidence. The panels were responsible for the final decision about risk/benefit profile of the drugs and strength of the recommendations. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used. RESULTS: six recommendations out of 15 were completely updated in 8 months time. In four cases, the strength of the recommendation changed; in two of them, we moved from a weak to a strong positive one. Despite the increased certainty about the positive risk/benefit profile, this was translated in a change in the strength of the recommendation only in one case out of three. Three recommendations were refined making them more clinically specific. CONCLUSIONS: accumulation of evidence is an opportunity for guideline panels to refine methodological rigour, clinical relevance and to foster consensus on recommendations. This requires time and resource investments.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias Colorrectales/tratamiento farmacológico , Guías como Asunto , Neoplasias Pulmonares/tratamiento farmacológico , Oncología Médica/normas , Quimioterapia/métodos , Quimioterapia/normas , Medicina Basada en la Evidencia , Femenino , Humanos , Oncología Médica/métodos
6.
Int J Immunopathol Pharmacol ; 23(1): 307-16, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20378017

RESUMEN

Thymomas are rare tumours that sustain T-lymphopoiesis and trigger a variety of autoimmune diseases and immunodeficiencies, including a fatal hypogammaglobulinemia, namely Goods Syndrome (GS). Due to its rarity, GS has been poorly investigated and immunological features, as well as pathogenetic mechanisms underlying this syndrome, are unclear. We studied 30 thymoma patients by performing an immunological assessment, including immunophenotype and analysis of T cell repertoire (TCR). Development of GS was characterized by a progressive decrease in B, CD4 T and NK lymphocytes. These alterations paired with accumulation of CD8+CD45RA+ T cells that showed a polyclonal repertoire without expansions of specific clonotypes. GS is defined as hypogammaglobulinemia with thymoma. Here, we show for the first time that this syndrome is characterized by a severe loss of CD4+, NK and B cells. Furthermore, the accumulation of CD8+CD45RA+ T lymphocytes parallels these changes; this accumulation may have a role in determining the disease and can be used to monitor clinical stages of immunodeficiency in thymoma.


Asunto(s)
Agammaglobulinemia/inmunología , Linfocitos B/inmunología , Linfocitos T CD8-positivos/inmunología , Células Asesinas Naturales/inmunología , Timoma/inmunología , Neoplasias del Timo/inmunología , Adulto , Anciano , Regiones Determinantes de Complementariedad , Femenino , Estudios de Seguimiento , Humanos , Antígenos Comunes de Leucocito/análisis , Recuento de Linfocitos , Masculino , Persona de Mediana Edad
7.
Clin Exp Immunol ; 158(1): 1-9, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19737224

RESUMEN

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor involved in the proliferation and survival of cancer cells. EGFR is the first molecular target against which monoclonal antibodies (mAb) have been developed for cancer therapy. Here we review the mechanisms underlying the effects of EGFR-specific mAb in cancer therapy. The efficacy of EGFR-specific mAb in cancer occurs thanks to inhibition of EGFR-generated signalling; furthermore, the effects of antibodies on the immune system seem to play an important role in determining the overall anti-tumour response. In this review, attention is focused on cetuximab and panitumumab, two mAb introduced recently into clinical practice for treatment of metastatic colorectal and head and neck cancer which target the external part of EGFR.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Receptores ErbB/antagonistas & inhibidores , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados , Cetuximab , Neoplasias Colorrectales/inmunología , Resistencia a Antineoplásicos , Receptores ErbB/inmunología , Neoplasias de Cabeza y Cuello/inmunología , Humanos , Panitumumab , Ensayos Clínicos Controlados Aleatorios como Asunto , Transducción de Señal/efectos de los fármacos , Resultado del Tratamiento
9.
Clin Exp Allergy ; 37(10): 1436-43, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17883723

RESUMEN

BACKGROUND: Proteinase-activated receptors (PAR)-2 are members of the family of G-protein-coupled receptors activated by proteases. These receptors are widely expressed in several tissues and in virtually all cells involved in rhinitis and asthma. In particular, proteinases activating PAR-2 may affect airway functions and play a role in human diseases. OBJECTIVE: Assessment of the role of PAR-2 in bronchoconstriction, airway responsiveness and immune response after allergic challenge, in rabbits sensitized to Par j 1, the major allergen of Parietaria judaica pollen. METHODS: Evaluation of antigen challenge in rabbits treated with PAR-2-activating peptide (PAR-2AP) (SLIGRL) or the scrambled peptide LSIGRL or vehicle immediately before allergen exposure measuring airway responsiveness. Characterization of bronchoalveolar lavage (BAL) following histamine challenge and phenotype analysis of cells by flow cytometry and analysis of cytokine production by quantitative PCR. RESULTS: PAR-2AP pre-treatment, but not the scrambled peptide, was able to significantly inhibit bronchoconstriction, airway hyper-responsiveness and to modulate the immune response induced by allergic challenge in sensitized rabbits. The phenotype analysis of the cells recovered from BAL showed an increase in RLA-DR-positive cells while RTLA-positive cells were unchanged. IFN-gamma and IL-2 production were inhibited, with a concomitant increase in IL-10 of about 10-fold over the control values. CONCLUSIONS: In this experimental model, PAR-2 modulates bronchoconstriction interfering with antigen challenge-induced immune response in rabbits sensitized and challenged to Par j 1.


Asunto(s)
Asma/inmunología , Broncoconstricción/inmunología , Pulmón/inmunología , Receptor PAR-2/agonistas , Hipersensibilidad Respiratoria/inmunología , Alérgenos/inmunología , Animales , Asma/patología , Líquido del Lavado Bronquioalveolar/inmunología , Femenino , Histamina/farmacología , Interferón gamma/metabolismo , Interleucina-2/metabolismo , Pulmón/efectos de los fármacos , Masculino , Oligopéptidos/farmacología , Péptidos/farmacología , Proteínas de Plantas/inmunología , Conejos , Receptor PAR-2/fisiología , Hipersensibilidad Respiratoria/patología
10.
Ann Oncol ; 15(1): 113-7, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14679129

RESUMEN

BACKGROUND: The outcome of patients with nasopharyngeal carcinoma (NPC) presenting as advanced-stage disease or failing conventional radio-chemotherapy is poor. Thus, additional forms of effective, low-toxicity treatment are warranted to improve NPC prognosis. Since NPC is almost universally associated with Epstein-Barr virus (EBV), cellular immunotherapy with EBV-specific cytotoxic T lymphocytes (CTLs) may prove a successful treatment strategy. Patient and methods A patient with relapsed NPC, refractory to conventional treatments, received salvage adoptive immunotherapy with EBV-specific CTLs reactivated ex vivo from a human leukocyte antigen-identical sibling. EBV-specific immunity, as well as T-cell repertoire in the tumor, before and after immunotherapy, was evaluated. RESULTS: CTL transfer was well tolerated, and a temporary stabilization of disease was obtained. Moreover, notwithstanding the short in-vivo duration of allogeneic CTLs, immunotherapy induced a marked increase of endogenous tumor-infiltrating CD8+ T lymphocytes, and a long-term increase of latent membrane protein 2-specific immunity. CONCLUSIONS: Preliminary data obtained in this patient indicate that EBV-specific CTLs are safe, may exert specific killing of NPC tumor cells in vitro, and induce antitumor effect in vivo.


Asunto(s)
Antígenos Virales/inmunología , Herpesvirus Humano 4/inmunología , Inmunoterapia Adoptiva , Neoplasias Nasofaríngeas/inmunología , Neoplasias Nasofaríngeas/terapia , Neoplasias Glandulares y Epiteliales/inmunología , Neoplasias Glandulares y Epiteliales/terapia , Linfocitos T Citotóxicos/inmunología , Proteínas de la Matriz Viral/inmunología , Adulto , Humanos , Inmunohistoquímica , Masculino , Neoplasias Nasofaríngeas/patología , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Glandulares y Epiteliales/virología , Linfocitos T Citotóxicos/trasplante , Trasplante Homólogo , Latencia del Virus
11.
Immunol Lett ; 79(1-2): 85-91, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11595293

RESUMEN

In addition to HIV infection, several acquired immunodeficiencies lead to depletion of CD4 lymphocytes. These include immunosuppression resulting from high dose cancer chemotherapy or induced to control graft rejection, as well as in autoimmune diseases. The consequence of this depletion is an increased susceptibility to opportunistic infections or the inability to control primary infection in the case of HIV infection. In all instances a full or partial immunoreconstitution is desirable. In order to monitor the cellular immune state of a patient, rational information cannot be simply derived from phenotypic quantification of T lymphocytes. Instead loss or recovery of CD4 cells should be monitored by defining the specificity, the function and the clonality of the relevant cell population. Several methods are now available for this type of investigation. Here we describe an approach for the definition of clonal heterogeneity of antigen specific CD4 lymphocytes, a parameter that may help monitor loss or reconstitution in acquired immunodeficiencies. As examples of antigen specific CD4 T cell responses we focused on Pneumocystis carinii and on cytomegalovirus, as prototypic opportunistic pathogens which are responsible for severe infections in AIDS and in other immunosuppressive conditions which arise for instance following transplantation. Specific CD4 T cell lines were generated from normal controls and from seropositives in order to select antigen specific lymphocytes. The cells were subsequently analyzed for clonal diversity according to TCR BV gene family usage and according to TCR CDR3 size heterogeneity (spectratyping).


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Variación Antigénica , Antígenos Fúngicos , Antígenos Virales , Estudios de Casos y Controles , Células Clonales , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/inmunología , Humanos , Técnicas In Vitro , Activación de Linfocitos , Pneumocystis/inmunología , Neumonía por Pneumocystis/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/genética
12.
Allergy ; 55 Suppl 61: 56-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10919509

RESUMEN

Allergies are dramatically increasing in prevalence, and the management of these diseases is a heavy burden on the health-care systems of developed countries. In recent years, many efforts have been made to improve the therapy of allergies and to develop new approaches for immunotherapy. Here we briefly review the use of peptides to modulate T-cell responses to allergens. We focus mainly on the possibility of using altered peptide ligands (APLs), i.e., peptides tailored on immunodominant T epitopes and bearing a single amino-acid substitution, as a tool to modulate immune responses to allergens. These peptides may be recognized by the specific T cells triggered by the agonist peptides, but they are unable to elicit T-cell responses; thus, they could be ideal candidates to modulate immune responses to allergens. The availability of these peptides could allow new approaches for immunotherapies.


Asunto(s)
Desensibilización Inmunológica , Hipersensibilidad/inmunología , Hipersensibilidad/terapia , Péptidos/química , Péptidos/inmunología , Animales , Humanos , Ligandos
13.
Acta Chir Belg ; 100(3): 100-3, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11280170

RESUMEN

Lipodermatosclerosis and chronic ulceration have been longstanding and vexing problems caused by chronic venous insufficiency (CVI). While traditional approaches have been mainly medical with the use of compression, bedrest, and elevation; operative therapy for CVI has now been shown to cause earlier healing with fewer ulcer recurrences. The development of subfascial endoscopic surgery (SEPS) promises a more elegant approach applicable to outpatient or day surgery. However, in a recent trial, early results showed a 22% ulcer recurrence at 30 months, which did not compare favorably with traditional approaches. We have used extrafascial perforator interruption for SEPS recurrence and have now modified our SEPS approach particularly for low-lying ulcers. This overview suggests use of a combination of SEPS with an extrafascial perforator division when skin change relates to retro or submalleolar perforating veins. Several procedures, rather than one intervention may be required in CVI to prevent or divert transmission of venous hypertension to areas of affected skin, including saphenous stripping, staged valveplasty and treatment of iliac occlusions.


Asunto(s)
Endoscopía , Insuficiencia Venosa/cirugía , Endoscopía/métodos , Fasciotomía , Humanos , Procedimientos Quirúrgicos Vasculares/métodos , Cicatrización de Heridas
14.
Blood ; 94(10): 3432-8, 1999 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-10552953

RESUMEN

Bone marrow transplantation (BMT) from an HLA-identical donor is an established therapy to cure homozygous beta-thalassemia. Approximately 10% of thalassemic patients developed a persistent mixed chimerism (PMC) after BMT characterized by stable coexistence of host and donor cells in all hematopoietic compartments. Interestingly, in the erythrocytic lineage, close to normal levels of hemoglobin can be observed in the absence of complete donor engraftment. In the lymphocytic lineage, the striking feature is the coexistence of immune cells. This implies a state of tolerance or anergy, raising the issue of immunocompetence of the host. To understand the state of the T cells in PMC, repertoire analysis and functional studies were performed on cells from 3 ex-thalassemics. Repertoire analysis showed a profound skewing. This was due to an expansion of some T cells and not to a collapse of the repertoire, because phytohemagglutinin stimulation showed the presence of a complex repertoire. The immunocompetence of the chimeric immune systems was further established by showing responses to alloantigens and recall antigens in vitro. Both host and donor lymphocytes were observed in the cultures. These data suggest that the expanded T cells play a role in specific tolerance while allowing a normal immune status in these patients.


Asunto(s)
Trasplante de Médula Ósea , Linfocitos T/inmunología , Talasemia/inmunología , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Hibridación Fluorescente in Situ , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Masculino , Fitohemaglutininas/farmacología , Receptores de Antígenos de Linfocitos T/inmunología , Talasemia/terapia , Quimera por Trasplante
15.
J Immunol ; 162(4): 1982-7, 1999 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9973468

RESUMEN

Antigenic peptides with substituted side chains inhibit immune responses to a number of recall Ags from infectious agents in vitro. Here we show that the same strategy can be applied to peptides derived from a pollen protein, the major allergen of Parietaria judaica(Par j1), a plant responsible for most allergenic sensitization in the southern Mediterranean area. Three T cell lines responding to Par j1 protein were used to identify a stimulatory peptide. Two different monosubstituted altered peptide ligands (APL) were identified that bound to the HLA-DR of the responders, did not stimulate the T cell lines on their own, and decreased the response to subsaturating amounts of the unmodified stimulatory peptide. Most important, these APL were able to inhibit the response of these cell lines to intact Par j1 protein. A third monosubstituted peptide bound to the HLA-DR but did not show inhibitory activity. The two APL had a lower affinity than the unsubstituted peptide for the HLA-DR. The last two observations make MHC blockade an unlikely explanation for the observed effect. These results indicate the action of a specific peptide-mediated antagonism that may be useful in controlling the T cell component of an allergic response.


Asunto(s)
Alérgenos/inmunología , Glicoproteínas/inmunología , Inmunosupresores/farmacología , Péptidos/inmunología , Proteínas de Plantas , Polen/inmunología , Linfocitos T/inmunología , Secuencia de Aminoácidos , Sustitución de Aminoácidos/inmunología , Antígenos/inmunología , Unión Competitiva/inmunología , Línea Celular , Glicoproteínas/antagonistas & inhibidores , Antígenos HLA-DR/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Inmunosupresores/metabolismo , Activación de Linfocitos/efectos de los fármacos , Datos de Secuencia Molecular , Péptidos/metabolismo , Péptidos/farmacología , Unión Proteica/inmunología
18.
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