Construction of Various γ34.5 Deleted Fluorescent-Expressing Oncolytic herpes Simplex type 1 (oHSV) for Generation and Isolation of HSV-Based Vectors

Abdoli, Shahriyar; Roohvand, Farzin; Teimoori-Toolabi, Ladan; Shokrgozar, Mohammad  Ali; Bahrololoumi, Mina; Azadmanesh, Kayhan

doi:10.18869/acadpub.ibj.21.4.206

Construction of Various γ34.5 Deleted Fluorescent-Expressing Oncolytic herpes Simplex type 1 (oHSV) for Generation and Isolation of HSV-Based Vectors

Authors

Shahriyar Abdoli ¹

Farzin Roohvand ¹

Ladan Teimoori-Toolabi ²

Mohammad Ali Shokrgozar ³

Mina Bahrololoumi ¹

Kayhan Azadmanesh ¹

¹ Department of Virology, Pasteur Institute of Iran, Tehran, Iran

² Molecular Medicine Department, Biotechnology Research center, Pasteur institute of Iran, Tehran, Iran

³ National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran

10.18869/acadpub.ibj.21.4.206

Abstract

Background: Oncolytic herpes simplex virus (oHSV)-based vectors lacking γ34.5 gene, are considered as ideal templates to construct efficient vectors for (targeted) cancer gene therapy. Herein, we reported the construction of three single/dually-flourescence labeled and γ34.5-deleted, recombinant HSV-1 vectors for rapid generation and easy selection/isolation of different HSV-Based vectors. Methods: Generation of recombinant viruses was performed with conventional homologous recombination methods using green fluorescent protein (GFP) and BleCherry harboring shuttle vectors. Viruses were isolated by direct fluorescence observation and standard plaque purifying methods and confirmed by PCR and sequencing and flow cytometry. XTT and plaque assay titration were performed on Vero, U87MG, and T98 GBM cell lines. Results: We generated three recombinant viruses, HSV-GFP, HSV-GR (Green-Red), and HSV-Red. The HSV-GFP showed two log higher titer (1010 PFU) than wild type (108 PFU). In contrast, HSV-GR and HSV-Red showed one log lower titer (107 PFU) than parental HSV. Cytotoxicity analysis showed that HSV-GR and HSV-Red can lyse target tumor cells at multiplicity of infection of 10 and 1 (P<0.001). Moreover, HSV-GFP showed higher infection potency (98%) in comparison with HSV-GR (82%). Conclusion: Our oHSVs provide a simple and an efficient platform for construction and rapid isolation of 2^nd and 3^rd generation oHSVs by replacing the inserted dyes with transgenes and also for rapid identification via fluorescence activated cell sorting. These vectors can also be used for tracing the efficacy of therapeutic agents on target cells, imaging of neural or tumoral cells in vitro/in vivo and as oncolytic agents in cancer therapy.

Keywords

Oncolytic Viruses

Herpes simplex virus

Homologous Recombination

flow cytometry

Fluorescence microscopy