RESUMO
Advances in immunostimulatory and anti-immunosuppressive therapeutics have revolutionized cancer treatment. However, novel immunotherapeutics with these dual functions are not frequently reported. Here we describe the creation of a heterodimeric bifunctional fusion molecule, HCW9218, constructed using our soluble tissue factor (TF)-based scaffold technology. This complex comprises extracellular domains of the human transforming growth factor-ß (TGF-ß) receptor II and a human interleukin-15 (IL-15)/IL-15 receptor α complex. HCW9218 can be readily expressed in CHO cells and purified using antibody-based affinity chromatography in a large-scale manufacturing setting. HCW9218 potently activates mouse natural killer (NK) cells and CD8+ T cells in vitro and in vivo to enhance cell proliferation, metabolism, and antitumor cytotoxic activities. Similarly, human immune cells become activated with increased cytotoxicity following incubation with HCW9218. This fusion complex also exhibits TGF-ß neutralizing activity in vitro and sequesters plasma TGF-ß in vivo. In a syngeneic B16F10 melanoma model, HCW9218 displayed strong antitumor activity mediated by NK cells and CD8+ T cells and increased their infiltration into tumors. Repeat-dose subcutaneous administration of HCW9218 was well tolerated by mice, with a half-life sufficient to provide long-lasting biological activity. Thus, HCW9218 may serve as a novel therapeutic to simultaneously provide immunostimulation and lessen immunosuppression associated with tumors.
Assuntos
Linfócitos T CD8-Positivos/metabolismo , Interleucina-15/genética , Células Matadoras Naturais/metabolismo , Melanoma Experimental/tratamento farmacológico , Receptor do Fator de Crescimento Transformador beta Tipo II/química , Receptores de Interleucina-15/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Injeções Subcutâneas , Interleucina-15/metabolismo , Melanoma Experimental/imunologia , Camundongos , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Receptores de Interleucina-15/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Fator de Crescimento Transformador beta/sangue , Fator de Crescimento Transformador beta/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several antigen epitopes were designed according to the sequences of Swine influenza virus hemagglutinin (HA) genes and lined with the interval. The gene was amplified by PCR and sub cloned into pET30a (+) vector. The fusion protein was expressed in E. coli BL21 (DE3) by induced with IPTG and purified by affinity chromatography. The molecular weight of the protein was about 20 kD in SDS-PAGE. Immunological activity of the fusion protein was analyzed by Western blot. The results showed that the fusion protein could interact with anti-His antibody and the rabbit antiserum against SIV. The immunized mouse can produced antibodies against the target peptide and HI antibody against SIV H1N1 or H3N2. This study provides a new vaccine candidate for SIV.