RESUMO
Targeting angiogenesis is a promising approach to the treatment of solid tumors and age-related macular degeneration (AMD). Inhibition of vascularization has been validated by the successful marketing of monoclonal antibodies (mAbs) that target specific growth factors or their receptors, but there is considerable room for improvement in existing therapies. Combination of mAbs targeting both the VEGF and PDGF pathways has the potential to increase the efficacy of anti-angiogenic therapy without the accompanying toxicities of tyrosine kinase inhibitors and the inability to combine efficiently with traditional chemotherapeutics. However, development costs and regulatory issues have limited the use of combinatorial approaches for the generation of more efficacious treatments. The concept of mediating disease pathology by targeting two antigens with one therapeutic was proposed over two decades ago. While mAbs are particularly suitable candidates for a dual-targeting approach, engineering bispecificity into one molecule can be difficult due to issues with expression and stability, which play a significant role in manufacturability. Here, we address these issues upstream in the process of developing a bispecific antibody (bsAb). Single-chain antibody fragments (scFvs) targeting PDGFRbeta and VEGF-A were selected for superior stability. The scFvs were fused to both termini of human Fc to generate a bispecific, tetravalent molecule. The resulting molecule displays potent activity, binds both targets simultaneously, and is stable in serum. The assembly of a bsAb using stable monomeric units allowed development of an anti-PDGFRB/VEGF-A antibody capable of attenuating angiogenesis through two distinct pathways and represents an efficient method for rapid engineering of dual-targeting molecules.
Assuntos
Inibidores da Angiogênese/farmacologia , Anticorpos Biespecíficos/farmacologia , Imunoterapia , Neoplasias Experimentais/tratamento farmacológico , Proteínas Recombinantes de Fusão/metabolismo , Anticorpos de Cadeia Única/metabolismo , Sequência de Aminoácidos , Inibidores da Angiogênese/administração & dosagem , Animais , Anticorpos Biespecíficos/administração & dosagem , Linhagem Celular Tumoral , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Feminino , Humanos , Camundongos , Camundongos SCID , Dados de Sequência Molecular , Neoplasias Experimentais/imunologia , Neovascularização Fisiológica/efeitos dos fármacos , Ligação Proteica , Engenharia de Proteínas , Estabilidade Proteica , Receptor beta de Fator de Crescimento Derivado de Plaquetas/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Carga Tumoral/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/imunologiaRESUMO
T cell-derived cytokines are important in the development of an effective immune response, but when dysregulated they can promote disease. Here we identify a four-helix bundle cytokine we have called interleukin 31 (IL-31), which is preferentially produced by T helper type 2 cells. IL-31 signals through a receptor composed of IL-31 receptor A and oncostatin M receptor. Expression of IL-31 receptor A and oncostatin M receptor mRNA was induced in activated monocytes, whereas epithelial cells expressed both mRNAs constitutively. Transgenic mice overexpressing IL-31 developed severe pruritus, alopecia and skin lesions. Furthermore, IL-31 receptor expression was increased in diseased tissues derived from an animal model of airway hypersensitivity. These data indicate that IL-31 may be involved in promoting the dermatitis and epithelial responses that characterize allergic and non-allergic diseases.
