RESUMEN
Essentials The immunogenesis of Heparin-induced thrombocytopenia (HIT) is not well understood. Immunization to platelet factor 4 (PF4)-heparin occurs early in life, before any heparin exposure. PF4 and PF4-heparin complexes induce the proliferation of CD14+ cells. Reduced levels of regulatory cytokines contribute to immune dysregulation in HIT. SUMMARY: Background Heparin-induced thrombocytopenia (HIT) is an adverse reaction to heparin characterized by thrombocytopenia and thrombotic complications. HIT is caused by pathogenic antibodies that bind to complexes of platelet factor 4 (PF4) and heparin, leading to platelet activation and inducing a hypercoagulable state. Previous studies have shown immunity to PF4-heparin complexes occurs early in life, even before heparin exposure; however, the immunogenesis of HIT is not well characterized. Objectives To investigate cellular proliferation in response to PF4-heparin complexes in patients with HIT. Patients/Methods Peripheral blood mononuclear cells (PBMCs) from healthy controls (n = 30), postoperative cardiac surgery patients who had undergone cardiopulmonary bypass (CPB) (n = 17) and patients with confirmed HIT (n = 41) were cultured with PF4 and PF4-heparin complexes. Cellular proliferation was assessed by [3 H]thymidine uptake and 5-ethynyl-2'-deoxyuridine detection. Results and Conclusions PBMCs proliferated in the presence of PF4, and this was enhanced by the addition of heparin in all study groups. CPB and HIT patients showed significantly greater proliferative responses than healthy controls. PBMC proliferation was antigen-specific, depended on the presence of platelets, and only CD14+ cells were identified as proliferating cells. Culture supernatants were tested for the levels of regulatory cytokines, and both CPB and HIT patients produced significantly lower levels of interleukin-10 and transforming growth factor-ß1 than healthy controls. These findings further demonstrate cellular immune sensitization to PF4-heparin complexes occurs before heparin exposure, and suggests immune dysregulation can contribute to HIT.
Asunto(s)
Anticoagulantes/efectos adversos , Anticoagulantes/inmunología , Proliferación Celular , Heparina/efectos adversos , Heparina/inmunología , Inmunidad Celular , Leucocitos Mononucleares/inmunología , Factor Plaquetario 4/inmunología , Trombocitopenia/inducido químicamente , Trombocitopenia/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Células Cultivadas , Femenino , Humanos , Interleucina-10/sangre , Interleucina-10/inmunología , Leucocitos Mononucleares/metabolismo , Receptores de Lipopolisacáridos/sangre , Receptores de Lipopolisacáridos/inmunología , Masculino , Persona de Mediana Edad , Factor Plaquetario 4/sangre , Trombocitopenia/sangre , Factor de Crecimiento Transformador beta1/sangre , Factor de Crecimiento Transformador beta1/inmunología , Adulto JovenRESUMEN
The Future of the Allergists and Specific Immunotherapy (FASIT) workshop provides a regular platform for global experts from academia, allergy clinics, regulatory authorities and industry to review developments in the field of allergen immunotherapy (AIT). The most recent meeting, held in February 2017, had two main themes: advances in AIT and hot topics in AIT from the regulatory point of view. The first theme covered opportunities for personalized AIT, advances in adjuvants and delivery systems, and the development of new molecules and future vaccines for AIT. Key topics in the second part of the meeting were the effects of the enactment of European Directive 2001/83 on the availability of allergens for therapy and diagnosis across the EU, the challenges of conducting Phase 3 studies in the field, the future role of allergen exposure chambers in AIT studies and specific considerations in performing AIT studies in the paediatric population. Finally, the group highlighted the forthcoming EAACI guidelines and their particular importance for the standardization of practice in the treatment of allergies. This review presents a comprehensive insight into those panel discussions and highlights unmet needs and also possible solutions to them for the future.
Asunto(s)
Desensibilización Inmunológica/normas , Desensibilización Inmunológica/tendencias , Hipersensibilidad/diagnóstico , Hipersensibilidad/terapia , Medicina de Precisión/métodos , Vacunología/métodos , Adyuvantes Inmunológicos/uso terapéutico , Adolescente , Adulto , Biomarcadores , Niño , Preescolar , Sistemas de Liberación de Medicamentos/métodos , Descubrimiento de Drogas , Humanos , Terminología como Asunto , Resultado del TratamientoRESUMEN
In this review, we report on relevant current topics in allergen immunotherapy (AIT) which were broadly discussed during the first Aarhus Immunotherapy Symposium (Aarhus, Denmark) in December 2015 by leading clinicians, scientists and industry representatives in the field. The aim of this symposium was to highlight AIT-related aspects of public health, clinical efficacy evaluation, mechanisms, development of new biomarkers and an overview of novel therapeutic approaches. Allergy is a public health issue of high socioeconomic relevance, and development of evidence-based action plans to address allergy as a public health issue ought to be on national and regional agendas. The underlying mechanisms are in the focus of current research that lays the ground for innovative therapies. Standardization and harmonization of clinical endpoints in AIT trials as well as current knowledge about potential biomarkers have substantiated proof of effectiveness of this disease-modifying therapeutic option. Novel treatments such as peptide immunotherapy, intralymphatic immunotherapy and use of recombinant allergens herald a new age in which AIT may address treatment of allergy as a public health issue by reaching a large fraction of patients.
Asunto(s)
Alérgenos/inmunología , Desensibilización Inmunológica , Hipersensibilidad/inmunología , Hipersensibilidad/terapia , Biomarcadores , Ensayos Clínicos como Asunto , Desensibilización Inmunológica/efectos adversos , Desensibilización Inmunológica/métodos , Manejo de la Enfermedad , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/prevención & control , Tolerancia Inmunológica , Resultado del TratamientoRESUMEN
BACKGROUND: Allergen exposure chambers (AECs) are clinical facilities allowing for controlled exposure of subjects to allergens in an enclosed environment. AECs have contributed towards characterizing the pathophysiology of respiratory allergic diseases and the pharmacological properties of new therapies. In addition, they are complementary to and offer some advantages over traditional multicentre field trials for evaluation of novel therapeutics. To date, AEC studies conducted have been monocentric and have followed protocols unique to each centre. Because there are technical differences among AECs, it may be necessary to define parameters to standardize the AECs so that studies may be extrapolated for driving basic immunological research and for marketing authorization purposes by regulatory authorities. METHODS: For this task force initiative of the European Academy of Allergy and Clinical Immunology (EAACI), experts from academia and regulatory agencies met with chamber operators to list technical, clinical and regulatory unmet needs as well as the prerequisites for clinical validation. RESULTS: The latter covered the validation process, standardization of challenges and outcomes, intra- and interchamber variability and reproducibility, in addition to comparability with field trials and specifics of paediatric trials and regulatory issues. CONCLUSION: This EAACI Position Paper aims to harmonize current concepts in AECs and to project unmet needs with the intent to enhance progress towards use of these facilities in determining safety and efficacy of new therapeutics in the future.
Asunto(s)
Alérgenos/inmunología , Desensibilización Inmunológica/métodos , Ambiente Controlado , Exposición por Inhalación , Desensibilización Inmunológica/normas , Desensibilización Inmunológica/tendencias , Política de Salud , Humanos , Hipersensibilidad/inmunología , Hipersensibilidad/terapia , Exposición por Inhalación/efectos adversos , Reproducibilidad de los ResultadosAsunto(s)
Rechazo de Injerto/prevención & control , Fallo Renal Crónico , Trasplante de Riñón/métodos , Ácido Micofenólico , Espondiloartropatías , Tacrolimus , Adulto , Disponibilidad Biológica , Antígeno HLA-B27/análisis , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/farmacocinética , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/cirugía , Masculino , Ácido Micofenólico/administración & dosificación , Ácido Micofenólico/farmacocinética , Espondiloartropatías/complicaciones , Espondiloartropatías/diagnóstico , Espondiloartropatías/tratamiento farmacológico , Espondiloartropatías/inmunología , Linfocitos T/inmunología , Linfocitos T/patología , Tacrolimus/administración & dosificación , Tacrolimus/farmacocinética , Resultado del TratamientoAsunto(s)
Anticuerpos Monoclonales/metabolismo , Anticuerpos Monoclonales/farmacología , Citocinas/antagonistas & inhibidores , Citocinas/metabolismo , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Neutralizantes/farmacología , Complejo Antígeno-Anticuerpo/metabolismo , Citocinas/agonistas , HumanosRESUMEN
BACKGROUND: An unresolved issue in T regulatory cells' cell biology is the lack of consensus on phenotypic markers that accurately define the natural Treg (nTreg) population. OBJECTIVES: To examine nTreg frequency and functional capacity in healthy controls and their frequency in asthmatic subjects using three different phenotypic strategies. We hypothesized that phenotypically different nTreg are quantitatively and functionally different. METHODS: Thirty-four healthy, non-asthmatic and 17 asthmatic subjects were studied. Three nTreg phenotypes were defined as follows: nTreg1 (CD4(+) CD25(+) Foxp3(+) ), nTreg2 (CD4(+) CD25(+) CD127(low) Foxp3(+) ), and nTreg3 (CD4(+) CD25(high) Foxp3(+) ). The flow cytometric determination of nTreg frequency in peripheral blood (PB) and bronchoalveolar lavage (BAL) was performed using fluorescently labelled antibodies. Peripheral blood nTreg functional capacity was assessed using a CFSE-based suppression assay. RESULTS: There was a significantly lower frequency of PB nTreg3 compared to nTreg2 and nTreg1 (P < 0.05). Both nTreg2 and nTreg3 had a significantly greater suppressive capacity than nTreg1 at T responder (Tresp) to nTreg ratios of 16 : 1 up to 1 : 1 (P < 0.01). Asthmatics exhibited a significantly lower PB nTreg3 and nTreg1 frequency than healthy controls (P < 0.05). There were no differences between healthy controls and asthmatic subjects when comparing BAL nTreg frequency. CONCLUSIONS AND CLINICAL RELEVANCE: Phenotypically different nTreg subsets are quantitatively and functionally different and are variably observed in asthma. The CD4(+) CD25(high) Foxp3(+) phenotype was the least frequent, but demonstrated the greatest suppression, and was significantly lower in PB of asthmatic subjects. Consequently, it is imperative that nTreg phenotypes be clearly defined and that the interpretation of their frequency and function be phenotype specific.
Asunto(s)
Asma/inmunología , Asma/metabolismo , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Fenotipo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Adulto , Antígenos de Superficie/metabolismo , Asma/fisiopatología , Recuento de Linfocito CD4 , Estudios de Casos y Controles , Femenino , Factores de Transcripción Forkhead/metabolismo , Humanos , Inmunofenotipificación , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Food allergy, in particular peanut allergy, is a growing concern in Western countries. The prevalence of allergy to peanut, which currently stands at 1.4%, nearly tripled between 1997 and 2008. Allergic sensitization is a particularly difficult process to study as it is clinically silent. We sought to identify key pathways and mediators critically involved in the induction of allergic sensitization to peanut. METHODS: Comprehensive metabolomics analysis with liquid chromatography-mass spectrometry was used to detect metabolite changes in mice (C57BL/6) undergoing sensitization. Loss-of-function and gain-of-function studies were performed in mice subjected to two models of peanut sensitization and anaphylaxis that involved either oral or epicutaneous sensitization. Flow cytometric analyses on dendritic cells (DCs) in vitro and in vivo were used to investigate the mechanisms of immune activation. RESULTS: Elevated levels of uric acid (UA) were detected in mice undergoing sensitization as well as in peanut-allergic children who were not challenged with peanut. In mice, the depletion of UA during sensitization prevented the development of peanut-specific immunoglobulins IgE and IgG1 as well as anaphylaxis while exogenous delivery of UA crystals (monosodium urate, MSU) restored the allergic phenotype. Monosodium urate enhanced CD86 and OX40L expression on DCs, independent of Toll-like receptors 2 and 4, the NLRP3 inflammasome, and IL-1ß, via a PI3K signaling pathway. CONCLUSION: Overproduction of the UA alarmin in the local microenvironment plays a critical role in the induction of peanut-allergic sensitization, likely due to its ability to activate DCs. These finding suggest that cellular damage or tissue injury may be an essential requisite for the development of allergic sensitization to foods.
Asunto(s)
Alarminas/inmunología , Hipersensibilidad al Cacahuete/inmunología , Ácido Úrico/inmunología , Alarminas/metabolismo , Animales , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Metabolómica , Ratones , Ratones Endogámicos C57BL , Hipersensibilidad al Cacahuete/metabolismo , Ácido Úrico/metabolismoRESUMEN
BACKGROUND: Cat-PAD, the first in a new class of synthetic peptide immuno-regulatory epitopes (SPIREs), was shown to significantly improve rhinoconjunctivitis symptoms in subjects with cat allergy up to 1 year after the start of a short course of treatment. OBJECTIVE: To evaluate the long-term effects of Cat-PAD on rhinoconjunctivitis symptoms following standardized allergen challenge 2 years after treatment. METHODS: In a randomized, double-blind, placebo-controlled, parallel group study, subjects were exposed to cat allergen in an environmental exposure chamber (EEC) before and after treatment with two regimens of Cat-PAD (either eight doses of 3 nmol or four doses of 6 nmol) given intradermally over a 3-month period. In this follow-up study, changes from baseline in rhinoconjunctivitis symptoms were reassessed 2 years after the start of treatment. RESULTS: The primary endpoint showed a mean reduction in total rhinoconjunctivitis symptom scores of 3.85 units in the 4 × 6 nmol Cat-PAD group compared to placebo 2 years after the start of treatment (P = 0.13), and this difference was statistically significant in the secondary endpoint at the end of day 4 when the cumulative allergen challenge was greatest (P = 0.02). Consistent reductions in nasal symptoms of between 2 and 3 units were observed for 4 × 6 nmol Cat-PAD compared to placebo between the 2 and 3 h time points on days 1-4 of EEC challenge at 2 years (P < 0.05). The 8 × 3 nmol dose did not show a meaningful effect in this study. CONCLUSION AND CLINICAL RELEVANCE: A persistent, clinically meaningful reduction in rhinoconjunctivitis symptoms was observed on EEC challenge 2 years after the start of a short course of treatment with 4 × 6 nmol Cat-PAD. This study is the first to provide evidence of a long-term therapeutic effect with this new class of SPIREs.
Asunto(s)
Desensibilización Inmunológica , Epítopos/administración & dosificación , Epítopos/inmunología , Glicoproteínas/inmunología , Hipersensibilidad/inmunología , Hipersensibilidad/terapia , Péptidos/administración & dosificación , Péptidos/inmunología , Adolescente , Adulto , Anciano , Alérgenos/administración & dosificación , Alérgenos/inmunología , Animales , Gatos , Conjuntivitis Alérgica/diagnóstico , Conjuntivitis Alérgica/tratamiento farmacológico , Conjuntivitis Alérgica/inmunología , Desensibilización Inmunológica/efectos adversos , Femenino , Estudios de Seguimiento , Glicoproteínas/química , Humanos , Hipersensibilidad/diagnóstico , Masculino , Persona de Mediana Edad , Péptidos/síntesis química , Rinitis Alérgica/diagnóstico , Rinitis Alérgica/tratamiento farmacológico , Rinitis Alérgica/inmunología , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Inhaled peptide challenge has been shown to induce T cell-mediated, isolated late asthmatic reaction (LAR), characterized by recruitment of CD4(+) T cells and increased levels of thymus and activation-regulated chemokine (TARC; CCL17). Epithelial-derived thymic stromal lymphopoietin (TSLP) has been shown to modulate dendritic cell function to promote TH 2 responses via CCL17 production. OBJECTIVES: To elucidate the mechanisms involved in allergen-specific T cell-induced LAR and recruitment of CD4(+) T cells by examining the effects of T cell-derived factors on the induction of TSLP in primary bronchial epithelial cells (PBEC). METHODS: PBEC grown at air-liquid interface from healthy individuals and patients with asthma were stimulated with double-stranded RNA (dsRNA) or supernatants from activated allergen-specific T cells. TSLP was measured in PBEC culture supernatants. Neutralizing antibodies and signalling inhibitors were used to examine the mechanisms responsible for the induction of epithelial-derived TSLP. The functional activity of PBEC-derived TSLP was measured using a bioassay involving the induction of CCL17 production from monocyte-derived dendritic cells (moDC). RESULTS: Both dsRNA and allergen-specific T cells induced enhanced TSLP secretion from asthmatic PBEC compared to healthy PBEC. Activated PBEC culture supernatant induced TSLP-dependent CCL17 production from moDC in a manner related to clinical asthmatic status. IL-1ß, IL-6, and CXCL8, rather than TH 2 cytokines (IL-4/5/13), appeared to be the principle mediators of allergen-specific T cell-dependent induction of epithelial-derived TSLP, which was regulated by the MEK, MAPK, and NFκB pathways. CONCLUSION AND CLINICAL RELEVANCE: Our data reveal a novel effect of allergen-specific T cells as a positive regulator of TSLP production by epithelial cells, suggesting T cell-airway epithelium interactions that may lead to maintenance and amplification of allergic inflammation. TSLP is currently a candidate for therapeutic intervention in asthma, but the factors that drive TSLP expression (T cell-derived factors) may be equally relevant in the treatment of allergic inflammation.
Asunto(s)
Citocinas/metabolismo , Células Epiteliales/metabolismo , Mucosa Respiratoria/inmunología , Subgrupos de Linfocitos T/inmunología , Adulto , Alérgenos/inmunología , Animales , Asma/genética , Asma/inmunología , Asma/metabolismo , Asma/fisiopatología , Bronquios/inmunología , Bronquios/metabolismo , Gatos , Diferenciación Celular , Células Cultivadas , Citocinas/genética , Células Dendríticas/inmunología , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Femenino , Expresión Génica , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Mediadores de Inflamación/metabolismo , Ligandos , Sistema de Señalización de MAP Quinasas , Masculino , Persona de Mediana Edad , FN-kappa B/metabolismo , Poli I-C/farmacología , Mucosa Respiratoria/metabolismo , Transducción de Señal , Especificidad del Receptor de Antígeno de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Receptor Toll-Like 3/metabolismo , Adulto Joven , Linfopoyetina del Estroma TímicoRESUMEN
In the present study, we show therapeutic amelioration of established ovalbumin (OVA)-induced allergic airway disease following house dust mite (HDM) peptide therapy. Mice were sensitized and challenged with OVA and HDM protein extract (Dermatophagoides species) to induce dual allergen sensitization and allergic airway disease. Treatment of allergic mice with peptides derived from the major allergen Der p 1 suppressed OVA-induced airway hyperresponsiveness, tissue eosinophilia, and goblet cell hyperplasia upon rechallenge with allergen. Peptide treatment also suppressed OVA-specific T-cell proliferation. Resolution of airway pathophysiology was associated with a reduction in recruitment, proliferation, and effector function of T(H)2 cells and decreased interleukin (IL)-17⺠T cells. Furthermore, peptide immunotherapy induced the regulatory cytokine IL-10 and increased the proportion of Fox p3⺠cells among those expressing IL-10. Tolerance to OVA was not associated with increased IL-35. In conclusion, our results provide in vivo evidence for the creation of a tolerogenic environment following HDM peptide immunotherapy, leading to the therapeutic amelioration of established OVA-induced allergic airway disease.
Asunto(s)
Alérgenos/inmunología , Antígenos Dermatofagoides/inmunología , Proteínas de Artrópodos/inmunología , Cisteína Endopeptidasas/inmunología , Interleucinas/biosíntesis , Ovalbúmina/efectos adversos , Hipersensibilidad Respiratoria/inmunología , Hipersensibilidad Respiratoria/metabolismo , Animales , Antígenos Dermatofagoides/administración & dosificación , Proteínas de Artrópodos/administración & dosificación , Cisteína Endopeptidasas/administración & dosificación , Desensibilización Inmunológica , Modelos Animales de Enfermedad , Epítopos de Linfocito T/inmunología , Femenino , Factores de Transcripción Forkhead/metabolismo , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Interleucina-5/biosíntesis , Activación de Linfocitos/inmunología , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/metabolismo , Ratones , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/inmunología , Neumonía/inmunología , Neumonía/metabolismo , Neumonía/patología , Hipersensibilidad Respiratoria/terapiaRESUMEN
BACKGROUND: The OX40/OX40L interaction contributes to an optimal T cell response following allergic stimuli and plays an important role in the maintenance and reactivation of memory T effector cells. OBJECTIVE: We tested whether treatment with an anti-OX40L monoclonal antibody (MAb) would inhibit allergen-induced responses in subjects with asthma. METHODS: Twenty-eight mild, atopic asthmatic subjects were recruited for a double-blind, randomized, placebo-controlled, parallel-group trial (ClinicalTrials.gov identifier NCT00983658) to compare blockade of OX40L using a humanized anti-OX40L MAb to placebo-administered intravenously in 4 doses over 3 months. Allergen inhalation challenges were carried out 56 and 113 days after the first dose of study drug. The primary outcome variable was the late-phase asthmatic response. Other outcomes included the early-phase asthmatic response, airway hyperresponsiveness, serum IgE levels, blood and sputum eosinophils, safety and tolerability. RESULTS: Treatment with anti-OX40L MAb did not attenuate the early- or late-phase asthmatic responses at days 56 or 113 compared with placebo. In the anti-OX40L MAb treatment group, total IgE was reduced 17% from pre-dosing levels, and sputum eosinophils decreased 75% by day 113 (both P = 0.04). There was no effect of anti-OX40L MAb on airway hyperresponsiveness or blood eosinophils. The frequency of AEs was similar in both groups. CONCLUSION AND CLINICAL RELEVANCE: Pharmacological activity of anti-OX40L MAb was observed by decreases in serum total IgE and airway eosinophils at 16 weeks post-dosing, but there was no effect on allergen-induced airway responses. It is possible that the treatment duration or dose of antibody was insufficient to impact the airway responses.
Asunto(s)
Alérgenos/inmunología , Antiasmáticos/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Asma/tratamiento farmacológico , Asma/inmunología , Ligando de CD40/antagonistas & inhibidores , Adulto , Antiasmáticos/efectos adversos , Antiasmáticos/farmacología , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/farmacología , Asma/metabolismo , Antígenos CD40/metabolismo , Ligando de CD40/metabolismo , Células Dendríticas/inmunología , Eosinófilos , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Transducción de Señal/efectos de los fármacos , Linfocitos T/inmunología , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Asthmatic patients are often differentiated based on their atopic status (atopic or nonatopic) and type of bronchitis (eosinophilic, neutrophilic, both, or neither). There is evidence supporting a central role for the T cell in asthma, but the role of allergen-induced T cell cytokines in driving disease in different asthma phenotypes remains unclear. OBJECTIVE: To investigate the hypothesis that peripheral blood mononuclear cells (PBMCs) from asthma patients with different phenotypes would react characteristically to a panel of common aeroallergens. METHODS: We incubated PBMCs from 41 asthma patients and 8 healthy controls with allergen and assessed PBMC proliferation by (3) H-thymidine incorporation and the production of the cytokines IL-5, IL-17A, IL-23, IL-10, and IFN-γ by ELISA. RESULTS: No differences in PBMC proliferation or cytokine production were found in patients with asthma, compared with healthy controls, or between patients with different asthma phenotypes. CONCLUSIONS AND CLINICAL RELEVANCE: Peripheral blood mononuclear cell cytokine responses to allergen are not able to assist in the discrimination between disease state, atopic status, or type of bronchitis in asthma.
Asunto(s)
Alérgenos/inmunología , Asma/inmunología , Asma/metabolismo , Citocinas/metabolismo , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Adulto , Asma/diagnóstico , Estudios de Casos y Controles , Femenino , Humanos , Hipersensibilidad Inmediata/inmunología , Hipersensibilidad Inmediata/metabolismo , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Fenotipo , Factores de RiesgoRESUMEN
BACKGROUND: Induction of allergen-specific IgG(4) antibodies is the most consistent immunological finding in immunotherapy trials. However, quantitative assessments of IgG(4) antibodies have not proven beneficial in evaluating clinical changes during or after immunotherapy. In the current study, we investigated the relationship between clinical outcome and allergen-specific IgG(4) titres or functional antibody responses following immunotherapy. We hypothesized that functional assays of serum IgG-associated inhibitory activity such as inhibition of IgE-allergen interactions (IgE-blocking factor) and inhibition of CD23-dependent IgE-facilitated allergen binding (IgE-FAB) correlate more closely with clinical outcome and may be biomarkers of clinical response. METHODS: In an 8-month dose-response randomized double-blind placebo-controlled study, 221 polysensitized subjects with severe seasonal rhinitis received Alutard SQ, Phleum pratense 100,000 SQ-U, 10,000 SQ-U or placebo injections. Serum specimens were collected before treatment, after up-dosing, during the peak season and at the end of the study. Allergen-specific IgG(4) titres and IgG-associated inhibitory activity were evaluated. RESULTS: A time- and dose-dependent increase in serum inhibitory activity for both the IgE-blocking factor and IgE-FAB was observed, which paralleled increases in grass pollen-specific IgG(4) antibodies. A modest but significant inverse relationship was demonstrated between postimmunotherapy serum inhibitory activity and combined symptom-rescue medication scores (IgE-FAB: r = -0.25, P = 0.0002; IgE-blocking factor: r = -0.28, P < 0.0001), whereas this was not observed for immunoreactive IgG(4) levels (r = -0.11, P = 0.12). CONCLUSIONS: Functional assays of inhibitory IgG(4) and IgE-blocking factor may be more useful surrogates of clinical response than IgG(4). Whether these antibody effects may serve as predictive biomarkers of clinical efficacy in individual patients requires further investigation.
Asunto(s)
Alérgenos/inmunología , Desensibilización Inmunológica , Inmunoglobulina G/inmunología , Phleum/inmunología , Polen/inmunología , Rinitis Alérgica Estacional/inmunología , Rinitis Alérgica Estacional/terapia , Alérgenos/administración & dosificación , Relación Dosis-Respuesta Inmunológica , Glicoproteínas/sangre , Glicoproteínas/inmunología , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inyecciones Subcutáneas , Proteínas de Neoplasias , Resultado del TratamientoRESUMEN
A well-recognized characteristic of the autoimmune disease, systemic lupus erythematosus (SLE), is the high level of activated T cells present in the blood. Because of the increased size and granularity of activated T cells, in flow cytometry one might expect to find increased numbers of cells falling outside a standard light-scatter lymphocyte gate, and indeed we now report that the percentage of T lymphocytes in the gate (% TiG) was below the normal range in 23 of 58 (40%) female patients because of increased scatter values. However, the surprising additional observation was made that 18 of 30 (60%) female first-degree relatives of the patients also fell below the normal % TiG range, suggesting the presence of T cell activation in these relatives. This view is strengthened by the strong inverse correlation between plasma total immunoglobulin G(IgG), which was raised in some relatives, and % TiG, as T cell activation is a requirement for IgG production. Conversely, there was no correlation with IgM, which has no comparable link with T cell activation. While a definitive interpretation must await the demonstration of activation antigen expression in relatives, these findings suggest the existence of a T cell activation trait, not harmful in itself, which, however, contributes to the development of disease in patients with SLE.
Asunto(s)
Lupus Eritematoso Sistémico/inmunología , Hermanos , Linfocitos T/inmunología , Adulto , Autoinmunidad , Biomarcadores/sangre , Complejo CD3/análisis , Estudios de Casos y Controles , Femenino , Citometría de Flujo , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Lupus Eritematoso Sistémico/genética , Activación de Linfocitos , Masculino , Distribución por Sexo , Estadísticas no ParamétricasAsunto(s)
Epítopos de Linfocito T/inmunología , Antígenos HLA-DP/inmunología , Antígenos HLA-DQ/inmunología , Hipersensibilidad/inmunología , Epítopos Inmunodominantes/inmunología , Glicoproteínas de Membrana/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Gatos , Citocinas/metabolismo , Dermatitis Atópica/inmunología , Desensibilización Inmunológica , Mapeo Epitopo , Epítopos de Linfocito T/uso terapéutico , Glicoproteínas/inmunología , Cadenas beta de HLA-DP , Cadenas beta de HLA-DQ , Humanos , Hipersensibilidad/terapia , Epítopos Inmunodominantes/uso terapéuticoRESUMEN
BACKGROUND: The mechanisms of late asthmatic reactions provoked in atopic asthmatics by allergen-derived T-cell peptide epitopes remain unclear. Previous studies showed no changes in airway eosinophils or mast cell products after peptide challenge. In the present study our aim was to measure calcitonin gene-related peptide (CGRP), neurokinin (NK)-A, and substance P (SP) in bronchoalveolar lavage fluid and bronchial biopsies (BB) after inhalation of allergen-derived T-cell peptide epitopes since these neuropeptides (NP) had not previously been evaluated in this chronic asthma model. METHODS: Bronchoscopy, with BB and bronchoalveolar lavage (BAL), was performed in 24 cat-allergic subjects 6 h after inhalation of Fel d 1-derived peptides. Neuropeptides were measured in BAL by enzyme-linked immunosorbent assay and CGRP expression in the airways was assessed by immunohistochemistry and confocal microscopy. RESULTS: Twelve subjects (termed 'responders') developed isolated late reactions. Calcitonin gene-related peptide, but not NK-A or SP, was significantly elevated in BAL in responders only. Biopsy studies showed that in virtually all responders peptide challenge induced marked increases in CGRP immunoreactivity in bronchial epithelial cells, infiltrating submucosal cells and in association with airway smooth muscle. Double immunostaining indicated that CGRP colocalized predominantly to CD3+/CD4+ and CD68+ submucosal inflammatory cells. CONCLUSION: Calcitonin gene-related peptide, a potent vasodilator, is markedly up-regulated in the airways of atopic asthmatics during late-phase reactions provoked by inhalation of allergen-derived T-cell peptides.
Asunto(s)
Péptido Relacionado con Gen de Calcitonina/biosíntesis , Hipersensibilidad Inmediata/metabolismo , Péptidos/metabolismo , Sistema Respiratorio/metabolismo , Linfocitos T/inmunología , Adulto , Femenino , Humanos , Hipersensibilidad Inmediata/inmunología , Masculino , Péptidos/inmunología , Sistema Respiratorio/inmunologíaRESUMEN
Indirect allorecognition has been implicated in the mechanism of chronic rejection and alloantibody formation but precise definition of the epitopes involved has been limited. We have undertaken a detailed assessment of the antigenic properties of peptides derived from HLA-A2. Candidate epitopes were identified in vitro by assessment of MHC class II binding. The immune response to these epitopes was determined in patients awaiting a renal transplant by the assessment of PBMC activation using gamma-interferon ELISPOT. Twenty-two of fifty-five patients responded to peptides from HLA-A2 and this was associated with but not confined to those who had made antibody to HLA-A2 (14/18). Nineteen of twenty-two patients responded to peptides derived from the hypervariable alpha1 and alpha2 domains and 18/22 responded to peptides from the alpha 3 and transmembrane domain, the sequences of which show little polymorphism. In six patients, the sequence of these peptides was identical to self, that is, the response was autoimmune. The finding of indirect epitopes derived from regions of MHC class I that exhibit little polymorphism provides a novel perspective on the immune response to alloantigen and has potential implications for the development of specific therapies.
Asunto(s)
Regiones Determinantes de Complementariedad/genética , Epítopos de Linfocito T/genética , Antígeno HLA-A2/genética , Trasplante de Riñón/inmunología , Adolescente , Adulto , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Proliferación Celular , Regiones Determinantes de Complementariedad/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Genes MHC Clase II/inmunología , Rechazo de Injerto/genética , Rechazo de Injerto/inmunología , Antígeno HLA-A2/inmunología , Antígenos HLA-DR/genética , Antígenos HLA-DR/inmunología , Humanos , Inmunoglobulina G/inmunología , Interferón gamma/metabolismo , Isoanticuerpos/inmunología , Masculino , Persona de Mediana Edad , Polimorfismo Genético/genéticaRESUMEN
Specific allergen immunotherapy has been widely practised for almost 100 years. Whilst this approach is disease-modifying and efficacious, the use of whole allergen preparations is associated with an unacceptably high prevalence of allergic adverse events during treatment. Many approaches to reduce the allergenicity of immunotherapy preparations whilst maintaining immunogenicity are under development. One such approach is the use of short synthetic peptides which represent major T-cell epitopes of the allergen. Major potential advantages of this approach include markedly reduced capacity to cross-link immunoglobulin-E and activate mast cells and basophils, and ease of manufacture and standardization. Promising results in preclinical studies have led to the translation of this approach to clinical studies in humans. Peptide immunotherapy is currently under development for allergic and autoimmune diseases.