RESUMO
BACKGROUND: Interleukin 13 (IL13) is a T-helper type 2 (Th2) cytokine associated with inflammation and pathology in allergic diseases such as bronchial asthma. We have shown that treatment with lebrikizumab, an anti-IL13 monoclonal antibody, significantly improves prebronchodilator forced expiratory volume in 1 s (FEV(1)) in a subset of subjects with uncontrolled asthma. OBJECTIVE: To evaluate efficacy and safety of lebrikizumab in subjects with mild asthma who underwent bronchial allergen challenge. METHODS: Twenty-nine subjects were randomized 1 : 1-5 mg/kg lebrikizumab (n = 13) or placebo (n = 16) administered subcutaneously every 4 weeks over 12 weeks, a total of four doses. Primary efficacy outcome was late asthmatic response (LAR) at Week 13, defined as area under the curve of FEV1 measured 2-8 h following inhaled allergen challenge. Serum biomarkers were measured to verify IL13 pathway inhibition and identify patients with an increased response to lebrikizumab. RESULTS: At Week 13, the LAR in lebrikizumab subjects was reduced by 48% compared with placebo subjects, although this was not statistically significant (95% confidence interval, -19%, 90%). Exploratory analysis indicated that lebrikizumab-treated subjects with elevated baseline levels of peripheral blood eosinophils, serum IgE, or periostin exhibited a greater reduction in LAR compared with subjects with lower baseline levels of these biomarkers. Lebrikizumab exerted systemic effects on markers of Th2 inflammation, reducing serum immunoglobulin E (IgE), chemokine ligands 13 and 17 by approximately 25% (P < 0.01). Lebrikizumab was well tolerated. CONCLUSION AND CLINICAL RELEVANCE: Lebrikizumab reduced the LAR in subjects with mild asthma. Clinical trial number NCT00781443.
Assuntos
Alérgenos/imunologia , Antiasmáticos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Asma/tratamento farmacológico , Asma/imunologia , Adulto , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/farmacologia , Asma/sangue , Biomarcadores/sangue , Testes de Provocação Brônquica , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Interleucina-13 , Pulmão/imunologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Células Th2/imunologia , Células Th2/metabolismo , Resultado do Tratamento , Adulto JovemRESUMO
TRANCE, a TNF family member, and its receptor, TRANCE-R, are critical regulators of dendritic cell and osteoclast function. Here, we demonstrate that TRANCE activates the antiapoptotic serine/threonine kinase Akt/PKB through a signaling complex involving c-Src and TRAF6. A deficiency in c-Src or addition of Src family kinase inhibitors blocks TRANCE-mediated PKB activation in osteoclasts. c-Src and TRAF6 interact with each other and with TRANCE-R upon receptor engagement. TRAF6, in turn, enhances the kinase activity of c-Src leading to tyrosine phosphorylation of downstream signaling molecules such as c-Cbl. These results define a mechanism by which TRANCE activates Src family kinases and PKB and provide evidence of cross-talk between TRAF proteins and Src family kinases.
Assuntos
Proteínas de Transporte/fisiologia , Glicoproteínas de Membrana/fisiologia , Osteoclastos/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Tirosina Quinases/fisiologia , Proteínas/fisiologia , Proteínas Proto-Oncogênicas , Transdução de Sinais , Animais , Proteína Tirosina Quinase CSK , Células Cultivadas , Células Dendríticas/fisiologia , Proteínas Proto-Oncogênicas c-akt , Ligante RANK , Receptores do Fator de Necrose Tumoral/fisiologia , Fator 6 Associado a Receptor de TNF , Fator de Necrose Tumoral alfa/fisiologia , Quinases da Família srcRESUMO
Tumor necrosis factor (TNF)-related activation-induced cytokine (TRANCE) is a TNF family member essential for osteoclast differentiation, and it induces the activation and survival of osteoclasts and mature dendritic cells. We recently demonstrated that TRANCE activates Akt via a mechanism involving TRANCE receptor (TRANCE-R)/RANK, TRAF6, and c-Src. Here, we show that TRANCE-R and CD40 recruit TRAF6, Cbl family-scaffolding proteins, and the phospholipid kinase phosphatidylinositol 3-kinase in a ligand-dependent manner. The recruitment of Cbl-b and c-Cbl to TRANCE-R is dependent upon the activity of Src-family kinases. TRANCE and CD40L-mediated Akt activation is defective in Cbl-b -/- dendritic cells, and CD40L-mediated Akt activation is defective in c-Cbl -/- B cells. These findings implicate Cbl family proteins as not only negative regulators of signaling but as positive modulators of TNF receptor superfamily signaling as well.