RESUMEN
Deciphering the initial steps of SARS-CoV-2 infection, that influence COVID-19 outcomes, is challenging because animal models do not always reproduce human biological processes and in vitro systems do not recapitulate the histoarchitecture and cellular composition of respiratory tissues. To address this, we developed an innovative ex vivo model of whole human lung infection with SARS-CoV-2, leveraging a lung transplantation technique. Through single-cell RNA-seq, we identified that alveolar and monocyte-derived macrophages (AMs and MoMacs) were initial targets of the virus. Exposure of isolated lung AMs, MoMacs, classical monocytes and non-classical monocytes (ncMos) to SARS-CoV-2 variants revealed that while all subsets responded, MoMacs produced higher levels of inflammatory cytokines than AMs, and ncMos contributed the least. A Wuhan lineage appeared to be more potent than a D614G virus, in a dose-dependent manner. Amidst the ambiguity in the literature regarding the initial SARS-CoV-2 cell target, our study reveals that AMs and MoMacs are dominant primary entry points for the virus, and suggests that their responses may conduct subsequent injury, depending on their abundance, the viral strain and dose. Interfering on virus interaction with lung macrophages should be considered in prophylactic strategies.
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COVID-19 , Citocinas , Pulmón , Macrófagos Alveolares , Macrófagos , SARS-CoV-2 , Humanos , COVID-19/virología , COVID-19/inmunología , SARS-CoV-2/fisiología , Pulmón/virología , Pulmón/inmunología , Pulmón/patología , Macrófagos/virología , Macrófagos/metabolismo , Macrófagos/inmunología , Macrófagos Alveolares/virología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Citocinas/metabolismo , Monocitos/virología , Monocitos/metabolismo , Monocitos/inmunología , Masculino , Femenino , Análisis de la Célula Individual , Persona de Mediana EdadRESUMEN
Conventional immunosuppressants are ineffective for the management of EGPA-related asthma. Tezepelumab is a human monoclonal antibody that inhibits thymic stromal lymphopoietin (TLSP) that has proven efficacy in several phase 3 studies for the treatment of asthma. We treated with off-label tezepelumab the first two patients with severe refractory EPGA-related asthma. These preliminary findings suggest that targeting upstream signaling of the T2 inflammatory pathway can improve symptoms, reduce BVAS and increase Asthma Control Test scores, even in patients with refractory asthma who have failed several previous lines of treatment. Nevertheless, by analogy with dupilumab-induced IL-4/13 blockade, the persistence of sputum eosinophilia (reported in both patients) raises questions as to whether TSLP inhibition could lead to a rebound of eosinophilia and potentially to eosinophil-related symptoms in patients with EGPA.
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Anticuerpos Monoclonales Humanizados , Asma , Humanos , Asma/tratamiento farmacológico , Asma/diagnóstico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Persona de Mediana Edad , Femenino , Masculino , Resultado del Tratamiento , Antiasmáticos/uso terapéutico , Síndrome de Churg-Strauss/tratamiento farmacológico , Síndrome de Churg-Strauss/diagnóstico , Granulomatosis con Poliangitis/tratamiento farmacológico , Granulomatosis con Poliangitis/diagnósticoRESUMEN
BACKGROUND: Long-term outcomes of lung transplantation (LTx) remain hampered by chronic lung allograft dysfunction (CLAD). Matrix metalloproteinase 9 (MMP-9) is a secretory endopeptidase identified as a key mediator in fibrosis processes associated with CLAD. The objective of this study was to investigate whether plasma MMP9 levels may be prognostic of CLAD development. METHODS: Participants were selected from the Cohort in Lung Transplantation (COLT) for which a biocollection was associated. We considered two time points, year 1 (Y1) and year 2 (Y2) post-transplantation, for plasma MMP-9 measurements. We analysed stable recipients at those time points, comparing those who would develop a CLAD within the 2 years following the measurement to those who would remain stable 2 years after. RESULTS: MMP-9 levels at Y1 were not significantly different between the CLAD and stable groups (230 ng/ml vs. 160 ng/ml, p = 0.4). For the Y2 analysis, 129 recipients were included, of whom 50 developed CLAD within 2 years and 79 remained stable within 2 years. MMP-9 plasma median concentrations were higher in recipients who then developed CLAD than in the stable group (230 ng/ml vs. 118 ng/ml, p = 0.003). In the multivariate analysis, the Y2 MMP-9 level was independently associated with CLAD, with an average increase of 150 ng/ml (95% CI [0-253], p = 0.05) compared to that in the stable group. The Y2 ROC curve revealed a discriminating capacity of blood MMP-9 with an area under the curve of 66%. CONCLUSION: Plasmatic MMP-9 levels measured 2 years after lung transplantation have prognostic value for CLAD.
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Trasplante de Pulmón , Metaloproteinasa 9 de la Matriz , Humanos , Pronóstico , Aloinjertos , Trasplante de Pulmón/efectos adversos , Pulmón , Biomarcadores , Estudios RetrospectivosRESUMEN
Immunoglobulin E is the latest discovered of immunoglobulin family and has been long associated with anaphylaxis and worm expulsion. Immunoglobulin E, along with mast cells, basophils, and eosinophils, is also a hallmark of type 2 immunity which is dysregulated in numerous diseases such as asthma, rhinitis, atopic dermatitis, and eosinophilic esophagitis in addition to anaphylaxis as aforementioned. However, recent advances have shed light on IgE regulation and memory explaining the low level of free IgE, the scarcity of IgE plasma cells that are mainly short live and the absence of IgE memory B cells in homeostatic conditions. Furthermore, IgE was implicated in inflammatory conditions beyond allergic disorders where IgE-mediated facilitated antigen presentation can enhance cellular and humoral response against autoantigens in systemic lupus or chronic urticaria leading to more severe disease and even against neoantigen facilitating tumor cell lysis. At last, IgE was unexpectedly associated with allograft rejection or atheromatous cardiovascular diseases where precise mechanisms remain to be deciphered. The purpose of this review is to summarize these recent advances in IgE regulation, biology, and physiopathology beyond allergic diseases opening whole new fields of IgE biology to explore.
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Anafilaxia , Receptores de IgE , Basófilos , Humanos , Inmunoglobulina E , MastocitosRESUMEN
BACKGROUND: Regulatory T cells (Tregs) are known to protect against allergies. Moreover, the decrease in the frequency and efficiency of Tregs amplifies allergic symptoms. AIM: This study investigated whether expanding Tregs in vivo with an IL-2/IL-2 antibody complex could be safe, well tolerated and efficient in a therapeutic setting in allergies. METHODS: We produced an anti-IL-2 antibody (1C6) and demonstrated that when it is complexed to human IL-2, it increases IL-2 efficiency to induce Tregs in vivo without any detectable side effects. Furthermore, the IL-2/1C6 complex induces an increase in Helios expression by Tregs, suggesting that it not only elevated Treg numbers but also boosted their functions. Using mouse models of house-dust-mite-induced airway inflammation and wheat-gliadin-induced food allergies, we investigated the therapeutic potential of the IL-2/1C6 complex in allergies. RESULTS: IL-2/1C6 treatment significantly reduced allergic symptoms, specific IgE production, the adaptive immune response and tissue damage. Interestingly, IL-2/1C6 treatment modulated innate lymphoid cells by increasing ILC2s in asthma and decreasing ILC3s in food allergies. CONCLUSION: In conclusion,complexed IL-2/anti-IL-2 may restore Treg numbers and function in respiratory and food allergies, thereby improving allergic markers and symptoms. Our IL-2/anti-IL-2 complex offers new hope for reestablishing immune tolerance in patients with allergies.
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Asma , Hipersensibilidad a los Alimentos , Animales , Modelos Animales de Enfermedad , Humanos , Inmunidad Innata , Interleucina-2 , Linfocitos , Ratones , Linfocitos T ReguladoresRESUMEN
BACKGROUND: Voltage-gated calcium (Cav 1) channels contribute to T-lymphocyte activation. Cav 1.2 and Cav 1.3 channels are expressed in Th2 cells but their respective roles are unknown, which is investigated herein. METHODS: We generated mice deleted for Cav 1.2 in T cells or Cav 1.3 and analyzed TCR-driven signaling. In this line, we developed original fast calcium imaging to measure early elementary calcium events (ECE). We also tested the impact of Cav 1.2 or Cav 1.3 deletion in models of type 2 airway inflammation. Finally, we checked whether the expression of both Cav 1.2 and Cav 1.3 in T cells from asthmatic children correlates with Th2-cytokine expression. RESULTS: We demonstrated non-redundant and synergistic functions of Cav 1.2 and Cav 1.3 in Th2 cells. Indeed, the deficiency of only one channel in Th2 cells triggers TCR-driven hyporesponsiveness with weakened tyrosine phosphorylation profile, a strong decrease in initial ECE and subsequent reduction in the global calcium response. Moreover, Cav 1.3 has a particular role in calcium homeostasis. In accordance with the singular roles of Cav 1.2 and Cav 1.3 in Th2 cells, deficiency in either one of these channels was sufficient to inhibit cardinal features of type 2 airway inflammation. Furthermore, Cav 1.2 and Cav 1.3 must be co-expressed within the same CD4+ T cell to trigger allergic airway inflammation. Accordingly with the concerted roles of Cav 1.2 and Cav 1.3, the expression of both channels by activated CD4+ T cells from asthmatic children was associated with increased Th2-cytokine transcription. CONCLUSIONS: Thus, Cav 1.2 and Cav 1.3 act as a duo, and targeting only one of these channels would be efficient in allergy treatment.
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Asma , Canales de Calcio , Animales , Asma/metabolismo , Calcio/metabolismo , Canales de Calcio/metabolismo , Citocinas/metabolismo , Humanos , Inflamación/metabolismo , Ratones , Receptores de Antígenos de Linfocitos T/metabolismo , Células Th2/metabolismoRESUMEN
Objective: This exploratory cross-sectional study aimed to evaluate the associations between the chemokine ligand 18 (CCL18) blood level and phenotypic characteristics of asthma.Methods: We evaluated in a sample of 173 asthmatic adult patients from the Cohort of Bronchial obstruction and Asthma (63.4% women; median age 50 ± interquartile range 27.5 years; median level of CCL18 was 44.1 ± interquartile range 27.5 ng/mL) the association between CCL18 blood level and allergic features of asthma using a multivariate analysis.Results: We found an association between the log-transformed value of blood CCL18 and age (+0.7% [0.1; 1.3] per 1-year increase, p = 0.033), gender (-25.1% [-42; -3.2] in women, p = 0.029), and nasal polyposis (+38.1% [11.6; 70.9], p = 0.004). No association was observed between CCL18 level and the other main phenotypic characteristics of asthma.Conclusions: Our exploratory study suggests that CCL18 is not an effective biomarker of allergic asthma endotype but may rather be a biomarker of tissue eosinophilia as supported by its association with nasal polyposis.
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Asma , Pólipos Nasales , Adulto , Asma/diagnóstico , Biomarcadores , Quimiocinas , Quimiocinas CC , Estudios Transversales , Femenino , Humanos , Ligandos , MasculinoRESUMEN
BACKGROUND: Severe asthma is a chronic lung disease characterised by inflammation, airway hyperresponsiveness (AHR) and airway remodelling. The molecular mechanisms underlying uncontrolled airway smooth muscle cell (aSMC) proliferation involved in pulmonary remodelling are still largely unknown. Small G proteins of the Rho family (RhoA, Rac1 and Cdc42) are key regulators of smooth muscle functions and we recently demonstrated that Rac1 is activated in aSMC from allergic mice. The objective of this study was to assess the role of Rac1 in severe asthma-associated airway remodelling. METHODS AND RESULTS: Immunofluorescence analysis in human bronchial biopsies revealed an increased Rac1 activity in aSMC from patients with severe asthma compared with control subjects. Inhibition of Rac1 by EHT1864 showed that Rac1 signalling controlled human aSMC proliferation induced by mitogenic stimuli through the signal transducer and activator of transcription 3 (STAT3) signalling pathway. In vivo, specific deletion of Rac1 in SMC or pharmacological inhibition of Rac1 by nebulisation of NSC23766 prevented AHR and aSMC hyperplasia in a mouse model of severe asthma. Moreover, the Rac1 inhibitor prevented goblet cell hyperplasia and epithelial cell hypertrophy whereas treatment with corticosteroids had less effect. Nebulisation of NSC23766 also decreased eosinophil accumulation in the bronchoalveolar lavage of asthmatic mice. CONCLUSION: This study demonstrates that Rac1 is overactive in the airways of patients with severe asthma and is essential for aSMC proliferation. It also provides evidence that Rac1 is causally involved in AHR and airway remodelling. Rac1 may represent as an interesting target for treating both AHR and airway remodelling of patients with severe asthma.
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Remodelación de las Vías Aéreas (Respiratorias) , Asma/metabolismo , Miocitos del Músculo Liso/metabolismo , Hipersensibilidad Respiratoria , Proteína de Unión al GTP rac1/metabolismo , Corticoesteroides/farmacología , Aminoquinolinas/administración & dosificación , Aminoquinolinas/farmacología , Animales , Biopsia , Líquido del Lavado Bronquioalveolar/citología , Estudios de Casos y Controles , Proliferación Celular , Modelos Animales de Enfermedad , Eosinófilos/metabolismo , Células Caliciformes/metabolismo , Humanos , Ratones , Pirimidinas/administración & dosificación , Pirimidinas/farmacología , Factor de Transcripción STAT3/metabolismo , Transducción de SeñalRESUMEN
Asthma, atopic dermatitis and chronic rhinoconjunctivitis are highly heterogeneous. However, epidemiologic associations exist between phenotypic groups of patients. Atopic march is one such association but is not the only common point. Indeed, beyond such phenotypes, hallmarks of type 2 immunity have been found in these diseases involving immune dysregulation as well as environmental triggers and epithelial dysfunction. From the canonical Th2 cytokines (IL-4, IL-5, IL-13), new cellular and molecular actors arise, from the epithelium's alarmins to new innate immune cells. Their interactions are now better understood across the different environmental barriers, and slight differences appeared. In parallel, the development of type 2-targeting biotherapies not only raised hope to treat those diseases but also raised new questions regarding their true pathophysiological involvement. Here, we review the place of type 2 immunity in the different phenotypes of asthma, chronic rhinitis, chronic rhinosinusitis and atopic dermatitis, highlighting nuances between them. New hypotheses rising from the use of biotherapies will be discussed along with the uncertainties and unmet needs of this field.
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Asma , Dermatitis Atópica , Eccema , Asma/epidemiología , Asma/etiología , Asma/terapia , Citocinas , Dermatitis Atópica/epidemiología , Dermatitis Atópica/etiología , Dermatitis Atópica/terapia , Humanos , Inmunidad InnataRESUMEN
BACKGROUND: Interleukin-7 (IL-7) is the most important cytokine for T-cell homeostasis. IL-7 signals through the IL-7 receptor (IL-7R) which is composed of an alpha chain (IL-7Rα), also called CD127 and a common gamma chain. T lymphocytes, especially T helper type 2, play a crucial role in the pathobiology of allergic asthma. OBJECTIVE: To study the effects of an anti-CD127 monoclonal antibody (mAb) in a murine model of allergic airway inflammation induced by house dust mite (HDM). METHODS: Allergic airway inflammation was induced in mice using a protocol comprising 4 weekly percutaneous sensitizations followed by 2 weekly intranasal challenges with total HDM extracts and treated by intraperitoneal injections of an anti-CD127 mAb. Because CD127 is shared by both IL-7R and the receptor for thymic stromal lymphopoietin (TSLP), a group of mice was also treated with an anti-IL-7 mAb to block only the IL-7 signalling pathway. RESULTS: Anti-CD127 mAb-treated mice showed significantly lower airway resistance in response to methacholine and improvement in lung histology compared with isotype mAb-treated animals. Anti-CD127 mAb treatment significantly decreased the mRNA expression of Th2 cytokines (IL-4, IL-5, and IL-13) and chemokines (CCL5/RANTES) in lung tissue, decreased the secretion of Th2 cytokines (IL-4, IL-5, and IL-13) and chemokines (CXCL1 and CCL11/eotaxin) in bronchoalveolar lavage fluid (BALF), decreased serum HDM-specific IgE, and reduced the number of total leucocytes and leucocyte subpopulations such as eosinophils, macrophages, lymphocytes, T lymphocytes, and ILC2 in BALF and lung tissue. Mice treated with anti-IL-7 mAb also showed less allergic airway inflammation as evidenced by significantly lower airway resistance and fewer leucocytes in BALF and lung tissue compared to mice treated with the corresponding isotype control mAb. CONCLUSION AND CLINICAL RELEVANCE: Targeting the IL-7Rα by an anti-CD127 mAb improves allergic airway inflammation in mice and presents as a potential therapeutic approach for allergic asthma.
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Anticuerpos Monoclonales/farmacología , Asma , Subunidad alfa del Receptor de Interleucina-7 , Transducción de Señal/efectos de los fármacos , Células Th2/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Asma/tratamiento farmacológico , Asma/inmunología , Femenino , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Subunidad alfa del Receptor de Interleucina-7/antagonistas & inhibidores , Subunidad alfa del Receptor de Interleucina-7/inmunología , Ratones Endogámicos BALB C , Pyroglyphidae/inmunología , Transducción de Señal/inmunologíaRESUMEN
BACKGROUND: Interleukin 15 (IL-15) is a growth and modulating factor for B, T lymphocytes and natural killer cells (NK). Its action on innate and adaptive immunity is modulated by its alpha chain receptor (IL-15Rα). The IL-15/sIL-15Rα complex (IL-15Cx) increases the bioavailability and activity of the cytokine in vivo. IL-15Cx has been used in diseases to dampen IL-15 inflammation by the use of soluble IL-15Ralpha specificity. Here, we aim to evaluate the interest of IL-15Cx in a mouse model of asthma. METHODS: Using a mouse model of asthma consisting in percutaneous sensitization and intranasal challenge with total house dust mite extract, we evaluated the effect of IL-15Cx injected intraperitoneally four times after a first nasal challenge. Respiratory function was assessed by the technique of forced oscillations (Flexivent®). The effect on bronchial remodeling was evaluated by lung histology. The inflammatory status was analyzed by flow cytometry. RESULTS: We observed that the IL-15Cx modulates lung and systemic inflammation by increasing NK cells, CD8+ memory T cells and regulatory cells. However, IL-15Cx displays no effect on bronchial hyperreactivity, bronchial remodeling nor cellular bronchial infiltrate, but limits the secretion of bronchial mucus and modulates only inflammatory response in a HDM-allergic asthma murine model. CONCLUSIONS: IL-15Cx has a limited effect on immune response in asthma and has no effect on lung function in mice. Thus, it limits its therapeutic potential but might suggest a combinatory potential with other therapeutics.
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Inmunidad Adaptativa/inmunología , Asma/inmunología , Inmunidad Celular/inmunología , Interleucina-15/inmunología , Receptores de Interleucina-15/inmunología , Inmunidad Adaptativa/efectos de los fármacos , Alérgenos/inmunología , Alérgenos/toxicidad , Animales , Asma/inducido químicamente , Asma/metabolismo , Femenino , Humanos , Inmunidad Celular/efectos de los fármacos , Interleucina-15/metabolismo , Ratones , Ratones Endogámicos BALB C , Receptores de Interleucina-15/metabolismoRESUMEN
Our main objective was to demonstrate that, in smoker patients hospitalised for Chronic Obstructive Pulmonary Disease (COPD) exacerbation, early initiation of varenicline during 12 weeks, combined with an intensive counselling, is associated with a higher continuous abstainers rate (CAR) at one year as compared to intensive counselling alone. In this multicenter, prospective, double-blind, randomised study, 81 smoking COPD patients hospitalised for an acute exacerbation for at least 24 h were allocated to receive either varenicline (n = 42) or placebo (n = 39) for 12 weeks, in association with an intensive counselling in the 2 groups, and followed up for 40 weeks. The primary outcome was CAR at week 52. Secondary outcomes included CAR at week 12 and 26, partial abstinence rate (PAR) at week 12, 26 and 52, nicotinic substitute consumption and adverse events. At week 52, CAR was not different in placebo and varenicline groups (25.6%). At week 12, CAR was significantly higher in the varenicline group (50%) as compared to placebo group (27%) (p = 0.041). Nicotine consumption was significantly higher at week 52 in the placebo group (55.3%) as compared to the varenicline group (24.4%) (p = 0.005). There was no significant difference in PAR at week 12, 26 and 52; the frequency of adverse events was similar between the two groups. Among active smoker COPD patients with exacerbation, 12-week varenicline associated with intensive counselling for smoking cessation increased the rate of continuous abstainers as compared to placebo. However, benefit was not maintained after varenicline discontinuation.Clinical Trials Registration: URL: http://www.controlled-trials.com. Unique identifier: NCT01694732.
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Consejo/métodos , Enfermedad Pulmonar Obstructiva Crónica/terapia , Agentes para el Cese del Hábito de Fumar/uso terapéutico , Cese del Hábito de Fumar/métodos , Tabaquismo/terapia , Vareniclina/uso terapéutico , Anciano , Progresión de la Enfermedad , Intervención Médica Temprana , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Tabaquismo/complicaciones , Resultado del TratamientoRESUMEN
Bronchiolitis obliterans syndrome is the main limitation for long-term survival after lung transplantation. Some specific B cell populations are associated with long-term graft acceptance. We aimed to monitor the B cell profile during early development of bronchiolitis obliterans syndrome after lung transplantation. The B cell longitudinal profile was analyzed in peripheral blood mononuclear cells from patients with bronchiolitis obliterans syndrome and patients who remained stable over 3 years of follow-up. CD24hi CD38hi transitional B cells were increased in stable patients only, and reached a peak 24 months after transplantation, whereas they remained unchanged in patients who developed a bronchiolitis obliterans syndrome. These CD24hi CD38hi transitional B cells specifically secrete IL-10 and express CD9. Thus, patients with a total CD9+ B cell frequency below 6.6% displayed significantly higher incidence of bronchiolitis obliterans syndrome (AUC = 0.836, PPV = 0.75, NPV = 1). These data are the first to associate IL-10-secreting CD24hi CD38hi transitional B cells expressing CD9 with better allograft outcome in lung transplant recipients. CD9-expressing B cells appear as a contributor to a favorable environment essential for the maintenance of long-term stable graft function and as a new predictive biomarker of bronchiolitis obliterans syndrome-free survival.
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Linfocitos B/metabolismo , Biomarcadores/metabolismo , Bronquiolitis Obliterante/diagnóstico , Rechazo de Injerto/diagnóstico , Trasplante de Pulmón/efectos adversos , Complicaciones Posoperatorias/diagnóstico , Tetraspanina 29/metabolismo , Adolescente , Adulto , Anciano , Bronquiolitis Obliterante/etiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Rechazo de Injerto/etiología , Supervivencia de Injerto , Humanos , Leucocitos Mononucleares , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Pronóstico , Factores de Riesgo , Tasa de Supervivencia , Síndrome , Trasplante Homólogo , Adulto JovenRESUMEN
Long-term oral corticosteroid (OCS) use in patients with severe asthma is associated with significant adverse effects.This 40-week, randomised, double-blind trial evaluated the OCS-sparing potential of tralokinumab in patients with severe, uncontrolled asthma requiring maintenance OCS treatment plus inhaled corticosteroids/long-acting ß2-agonists. Overall, 140 patients were randomised to tralokinumab 300â mg or placebo (n=70 in each group) administered subcutaneously every 2â weeks. The primary end-point was percentage change from baseline in average OCS dose at week 40, while maintaining asthma control. Secondary end-points included proportion of patients with a prescribed maintenance OCS dose of ≤5â mg, those with a ≥50% reduction in prescribed maintenance OCS dose and asthma exacerbation rate. Safety was also assessed.At week 40, the percentage reduction from baseline in the final daily average OCS dose was not significantly different between tralokinumab and placebo (37.62% versus 29.85%; p=0.271). There were no significant between-treatment differences for any secondary end-point. Overall, reporting of adverse events and serious adverse events were similar for the tralokinumab and placebo groups. Although a greater proportion of tralokinumab-treated patients reported upper respiratory tract infections (35.7% versus 14.3%), there were no reported cases of pneumonia.Overall, tralokinumab did not demonstrate an OCS-sparing effect in patients with severe asthma.
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Corticoesteroides/administración & dosificación , Anticuerpos Monoclonales/uso terapéutico , Asma/tratamiento farmacológico , Administración por Inhalación , Administración Oral , Adulto , Anciano , Antiasmáticos/uso terapéutico , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
BACKGROUND: The molecular mechanisms responsible for airway smooth muscle cells' (aSMCs) contraction and proliferation in airway hyperresponsiveness (AHR) associated with asthma are still largely unknown. The small GTPases of the Rho family (RhoA, Rac1, and Cdc42) play a central role in SMC functions including migration, proliferation, and contraction. OBJECTIVE: The objective of this study was to identify the role of Rac1 in aSMC contraction and to investigate its involvement in AHR associated with allergic asthma. METHODS: To define the role of Rac1 in aSMC, ex and in vitro analyses of bronchial reactivity were performed on bronchi from smooth muscle (SM)-specific Rac1 knockout mice and human individuals. In addition, this murine model was exposed to allergens (ovalbumin or house dust mite extract) to decipher in vivo the implication of Rac1 in AHR. RESULTS: The specific SMC deletion or pharmacological inhibition of Rac1 in mice prevented the bronchoconstrictor response to methacholine. In human bronchi, a similar role of Rac1 was observed during bronchoconstriction. We further demonstrated that Rac1 activation is responsible for bronchoconstrictor-induced increase in intracellular Ca2+ concentration and contraction both in murine and in human bronchial aSMCs, through its association with phospholipase C ß2 and the stimulation of inositol 1,4,5-trisphosphate production. In vivo, Rac1 deletion in SMCs or pharmacological Rac1 inhibition by nebulization of NSC23766 prevented AHR in murine models of allergic asthma. Moreover, nebulization of NSC23766 decreased eosinophil and neutrophil populations in bronchoalveolar lavages from mice with asthma. CONCLUSIONS: Our data reveal an unexpected and essential role of Rac1 in the regulation of intracellular Ca2+ and contraction of aSMCs, and the development of AHR. Rac1 thus appears as an attractive therapeutic target in asthma, with a combined beneficial action on both bronchoconstriction and pulmonary inflammation.
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Broncoconstricción/fisiología , Miocitos del Músculo Liso/fisiología , Neuropéptidos/fisiología , Hipersensibilidad Respiratoria/fisiopatología , Proteína de Unión al GTP rac1/fisiología , Aminoquinolinas/farmacología , Animales , Bronquios/fisiología , Calcio/fisiología , Células Cultivadas , Humanos , Masculino , Ratones Noqueados , Contracción Muscular , Músculo Liso/fisiología , Neuropéptidos/antagonistas & inhibidores , Pirimidinas/farmacología , Tráquea/fisiología , Proteína de Unión al GTP rac1/antagonistas & inhibidoresRESUMEN
BACKGROUND: T lymphocytes express not only cell membrane ORAI calcium release-activated calcium modulator 1 but also voltage-gated calcium channel (Cav) 1 channels. In excitable cells these channels are composed of the ion-forming pore α1 and auxiliary subunits (ß and α2δ) needed for proper trafficking and activation of the channel. Previously, we disclosed the role of Cav1.2 α1 in mouse and human TH2 but not TH1 cell functions and showed that knocking down Cav1 α1 prevents experimental asthma. OBJECTIVE: We investigated the role of ß and α2δ auxiliary subunits on Cav1 α1 function in TH2 lymphocytes and on the development of acute allergic airway inflammation. METHODS: We used Cavß antisense oligonucleotides to knock down Cavß and gabapentin, a drug that binds to and inhibits α2δ1 and α2δ2, to test their effects on TH2 functions and their capacity to reduce allergic airway inflammation. RESULTS: Mouse and human TH2 cells express mainly Cavß1, ß3, and α2δ2 subunits. Cavß antisense reduces T-cell receptor-driven calcium responses and cytokine production by mouse and human TH2 cells with no effect on TH1 cells. Cavß is mainly involved in restraining Cav1.2 α1 degradation through the proteasome because a proteasome inhibitor partially restores the α1 protein level. Gabapentin impairs the T-cell receptor-driven calcium response and cytokine production associated with the loss of α2δ2 protein in TH2 cells. CONCLUSIONS: These results stress the role of Cavß and α2δ2 auxiliary subunits in the stability and activation of Cav1.2 channels in TH2 lymphocytes both in vitro and in vivo, as demonstrated by the beneficial effect of Cavß antisense and gabapentin in allergic airway inflammation.
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Canales de Calcio Tipo L/inmunología , Hipersensibilidad/inmunología , Subunidades de Proteína/inmunología , Linfocitos T/inmunología , Enfermedad Aguda , Alérgenos , Animales , Femenino , Inflamación/inmunología , Ratones Endogámicos BALB C , Ratones Transgénicos , OvalbúminaRESUMEN
BACKGROUND: Homeostatic turnover of the extracellular matrix conditions the structure and function of the healthy lung. In lung transplantation, long-term management remains limited by chronic lung allograft dysfunction, an umbrella term used for a heterogeneous entity ultimately associated with pathological airway and/or parenchyma remodeling. OBJECTIVE: This study assessed whether the local cross-talk between the pulmonary microbiota and host cells is a key determinant in the control of lower airway remodeling posttransplantation. METHODS: Microbiota DNA and host total RNA were isolated from 189 bronchoalveolar lavages obtained from 116 patients post lung transplantation. Expression of a set of 11 genes encoding either matrix components or factors involved in matrix synthesis or degradation (anabolic and catabolic remodeling, respectively) was quantified by real-time quantitative PCR. Microbiota composition was characterized using 16S ribosomal RNA gene sequencing and culture. RESULTS: We identified 4 host gene expression profiles, among which catabolic remodeling, associated with high expression of metallopeptidase-7, -9, and -12, diverged from anabolic remodeling linked to maximal thrombospondin and platelet-derived growth factor D expression. While catabolic remodeling aligned with a microbiota dominated by proinflammatory bacteria (eg, Staphylococcus, Pseudomonas, and Corynebacterium), anabolic remodeling was linked to typical members of the healthy steady state (eg, Prevotella, Streptococcus, and Veillonella). Mechanistic assays provided direct evidence that these bacteria can impact host macrophage-fibroblast activation and matrix deposition. CONCLUSIONS: Host-microbes interplay potentially determines remodeling activities in the transplanted lung, highlighting new therapeutic opportunities to ultimately improve long-term lung transplant outcome.
Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias)/inmunología , Bacterias , Trasplante de Pulmón , Pulmón , Microbiota/inmunología , Transducción de Señal/inmunología , Adulto , Bacterias/clasificación , Bacterias/inmunología , Matriz Extracelular/inmunología , Matriz Extracelular/patología , Femenino , Fibroblastos/inmunología , Fibroblastos/patología , Humanos , Pulmón/inmunología , Pulmón/microbiología , Pulmón/patología , Macrófagos/inmunología , Macrófagos/patología , Masculino , Persona de Mediana EdadRESUMEN
Experimental models are critical for the understanding of lung health and disease and are indispensable for drug development. However, the pathogenetic and clinical relevance of the models is often unclear. Further, the use of animals in biomedical research is controversial from an ethical perspective.The objective of this task force was to issue a statement with research recommendations about lung disease models by facilitating in-depth discussions between respiratory scientists, and to provide an overview of the literature on the available models. Focus was put on their specific benefits and limitations. This will result in more efficient use of resources and greater reduction in the numbers of animals employed, thereby enhancing the ethical standards and translational capacity of experimental research.The task force statement addresses general issues of experimental research (ethics, species, sex, age, ex vivo and in vitro models, gene editing). The statement also includes research recommendations on modelling asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, lung infections, acute lung injury and pulmonary hypertension.The task force stressed the importance of using multiple models to strengthen validity of results, the need to increase the availability of human tissues and the importance of standard operating procedures and data quality.
Asunto(s)
Experimentación Animal/ética , Investigación Biomédica/normas , Modelos Animales de Enfermedad , Trastornos Respiratorios , Comités Consultivos , Animales , Europa (Continente) , Humanos , Sociedades MédicasRESUMEN
An irreversible loss in lung function limits the long-term success in lung transplantation. We evaluated the role of chronic exposure to ambient air pollution on lung function levels in lung transplant recipients (LTRs).The lung function of 520 LTRs from the Cohort in Lung Transplantation (COLT) study was measured every 6â months. The levels of air pollutants (nitrogen dioxide (NO2), particulate matter with an aerodynamic cut-off diameter of x µm (PMx) and ozone (O3)) at the patients' home address were averaged in the 12â months before each spirometry test. The effects of air pollutants on forced expiratory volume in 1â s (FEV1) and forced vital capacity (FVC) in % predicted were estimated using mixed linear regressions. We assessed the effect modification of macrolide antibiotics in this relationship.Increased 12-month levels of pollutants were associated with lower levels of FVC % pred (-2.56%, 95% CI -3.86--1.25 for 5â µg·m-3 of PM10; -0.75%, 95% CI -1.38--0.12 for 2â µg·m-3 of PM2.5 and -2.58%, 95% CI -4.63--0.53 for 10â µg·m-3 of NO2). In patients not taking macrolides, the deleterious association between PM and FVC tended to be stronger and PM10 was associated with lower FEV1Our study suggests a deleterious effect of chronic exposure to air pollutants on lung function levels in LTRs, which might be modified with macrolides.
Asunto(s)
Contaminación del Aire/efectos adversos , Trasplante de Pulmón , Pulmón/fisiopatología , Material Particulado/análisis , Disfunción Primaria del Injerto/fisiopatología , Adolescente , Adulto , Anciano , Aloinjertos , Bronquiolitis Obliterante/etiología , Bronquiolitis Obliterante/fisiopatología , Enfermedad Crónica , Exposición a Riesgos Ambientales , Femenino , Volumen Espiratorio Forzado , Francia , Humanos , Modelos Lineales , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Dióxido de Nitrógeno/análisis , Ozono/análisis , Espirometría , Capacidad Vital , Adulto JovenRESUMEN
Mesenchymal stem cell (MSC) immunosuppressive functions make them attractive candidates for anti-inflammatory therapy in allergic asthma. However, the mechanisms by which they ensure therapeutic effects remain to be elucidated. In an acute mouse model of house dust mite (Der f)-induced asthma, one i.v. MSC injection was sufficient to normalize and stabilize lung function in Der f-sensitized mice as compared to control mice. MSC injection decreased in vivo airway responsiveness and decreased ex vivo carbachol-induced bronchial contraction, maintaining bronchial expression of the inhibitory type 2 muscarinic receptor. To evaluate in vivo MSC survival, MSCs were labeled with PKH26 fluorescent marker prior to i.v. injection, and 1 to 10 days later total lungs were digested to obtain single-cell suspensions. 91.5 ± 2.3% and 86.6 ± 6.3% of the recovered PKH26(+) lung cells expressed specific macrophage markers in control and Der f mice, respectively, suggesting that macrophages had phagocyted in vivo the injected MSCs. Interestingly, only PKH26(+) macrophages expressed M2 phenotype, while the innate PKH26(-) macrophages expressed M1 phenotype. Finally, the remaining 0.5% PKH26(+) MSCs expressed 10- to 100-fold more COX-2 than before injection, suggesting in vivo MSC phenotype modification. Together, the results of this study indicate that MSCs attenuate asthma by being phagocyted by lung macrophages, which in turn acquire a M2 suppressive phenotype. Stem Cells 2016;34:1836-1845.