title: Gamma-retroviral vectors enveloped with an antibody and an engineered fusogenic protein achieved antigen-specific targeting.
abstract: Development of methods to engineer gamma-retroviral vectors capable of transducing target cells in a cell-specific manner could impact the future of the clinical application of gene therapy as well as the understanding of the biology of transfer gene vectors. Two molecular events are critical for controlling the entry of gamma-retroviral vectors to target cells: binding to cell-surface receptors and the subsequent fusion of viral vector membrane and cellular membrane. In this report, we evaluated a method to incorporate a membrane-bound antibody and a fusogenic molecule to provide binding and fusion functions respectively, into gamma-retroviral vectors for targeted gene delivery. An anti-CD20 antibody and a fusogenic protein derived from Sindbis virus glycoprotein could be efficiently co-displayed on the surface of viral vectors. Vectors bearing anti-CD20 antibody conferred their binding specificity to cells expressing CD20. Enhanced in vitro transduction towards CD20-expressing cells was observed for gamma-retroviral vectors displaying both an antibody and a fusogen. We found that the biological activity of the fusogen played an important role on the efficiency of such a targeting strategy and were able to engineer several mutant forms of the fusogen exhibiting elevated fusion function to improve the overall efficiency of targeted transduction. We devised an animal model to show that subcutaneous injection of such engineered vectors to the areas xenografted with target cells could achieve targeted gene delivery in vivo. Taken together, we demonstrated as proof-of-principle a flexible and modular two-molecule strategy for engineering targeting gamma-retroviral vectors.
authors.affiliation: Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Haiguang
authors.initials: H
authors.lastname: Yang
authors.forename: Leslie
authors.initials: L
authors.lastname: Ziegler
authors.forename: Kye-Il
authors.initials: KI
authors.lastname: Joo
authors.forename: Taehoon
authors.initials: T
authors.lastname: Cho
authors.forename: Yuning
authors.initials: Y
authors.lastname: Lei
authors.forename: Pin
authors.initials: P
authors.lastname: Wang
mesh_terms: D000818:Animals; D000906:Antibodies / Q000235:genetics* / Q000276:immunology; D018951:Antigens, CD20 / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D005260:Female; D017988:Gammaretrovirus / Q000235:genetics* / Q000276:immunology; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000276:immunology; D012845:Sindbis Virus / Q000235:genetics; D014161:Transduction, Genetic; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D000906:Antibodies; D018951:Antigens, CD20; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; C064950:glycoprotein E2, Sindbis virus