Non-permissive CHO cells; A rapid approach for purification of recombinant Herpes Simplex Virus-1

Abstract Exploiting herpes simplex virus type 1 (HSV-1) has recently emerged as a new strategy to improve the treatment of patients with various cancers resistant to chemotherapy and associated with a poor prognosis due to its ability to infect tumor cells without causing harm to healthy cells. It has been suggested as a new platform for cancer therapy. Gene-modification techniques such as conventional homologous recombination or CRISPR/Cas9 system are utilized to introduce site-specific mutations in targeted viral genes. Although, the CRISPR-Cas9 system could significantly increase the efficiency of homologous recombination; nevertheless the process of purifying recombinant variants can be tedious. Here we present a rapid, innovative method using non-permissive hamster ovary (CHO) cells which is a remarkable improvement on the previously mentioned tedious process. Using this strategy, only 1–2 rounds of plaque purification would suffice. Our proposed protocol demonstrated high potential as a worthy alternative way for the current approaches of the isolation and purification of the fluorescent reporter genes-expressing recombinant HSV-1 by plaque assay using CHO cells.