title: Therapeutic expression of an anti-death receptor 5 single-chain fixed-variable region prevents tumor growth in mice.
abstract: The clinical use of the single-chain fixed-variable (scFv) fragments of recombinant monoclonal antibodies as credible alternatives for classic therapeutic antibodies has two limitations: rapid blood clearance and inefficient local expression of functional molecules. In attempt to address these issues, we have developed a novel gene therapy protocol in which the anti-death receptor 5 (DR5) scFv fragments were either in vitro expressed in several tumor cell lines, or in vivo expressed in mice, using recombinant adeno-associated virus (rAAV)-mediated gene transfer. Viral transduction using the rAAV-S3C construct, which encodes a scFv molecule (S3C scFv) specific to DR5, led to stable expression in tumor cell lines and showed apoptosis-inducing activity in vitro, which could be inhibited by recombinant DR5 but not by DR4. A single i.m. injection of rAAV-S3C virus in nude mice resulted in stable expression of DR5-binding S3C scFv proteins in mouse sera for at least 240 days. Moreover, the expression of S3C scFv was associated with significant suppression of tumor growth and the increase of tumor cell apoptosis in previously established s.c. human lung LTEP-sml and liver Hep3B tumor xenografts.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Shi
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zheng
authors.forename: Yabin
authors.initials: Y
authors.lastname: Guo
authors.forename: Jinchun
authors.initials: J
authors.lastname: Zhang
authors.forename: Pik-To
authors.initials: PT
authors.lastname: Cheung
authors.forename: Ruian
authors.initials: R
authors.lastname: Xu
authors.forename: Dexian
authors.initials: D
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D017209:Apoptosis; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D045744:Cell Line, Tumor; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000627:therapeutic use*; D008113:Liver Neoplasms / Q000276:immunology; D008175:Lung Neoplasms / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000276:immunology*; D011994:Recombinant Proteins / Q000627:therapeutic use; D014183:Transplantation, Heterologous
chemical_list: D000911:Antibodies, Monoclonal; D007135:Immunoglobulin Variable Region; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D011994:Recombinant Proteins; C505640:Tnfrsf10b protein, mouse