An oncolytic herpes simplex virus type 1 strain expressing a single-chain variable region antibody fragment against PD-1 and a PI3K inhibitor synergize to elicit antitumor immunity in ovarian cancer

• Published in: Archives of virology Vol. 168; no. 4; p. 128
• Main Authors: Huang, Shanying, Hu, Haiyan, Tang, Guoling, Liu, Kai, Luo, Zhihua, Zeng, Weiwei
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.04.2023; Springer Nature B.V
• Subjects: 1-Phosphatidylinositol 3-kinase; AKT protein; Animals; Apoptosis; Biomedical and Life Sciences; Biomedicine; Caspase; Cell death; Cell Line, Tumor; Chemotherapy; Cytotoxicity; Enzyme-linked immunosorbent assay; Female; Herpes simplex; Herpes viruses; Herpesvirus 1, Human; Humans; Immunity; Infectious Diseases; Kinases; Medical Microbiology; Medical prognosis; Mice; Oncolysis; Oncolytic Virotherapy - methods; Oncolytic Viruses - genetics; Original Article; Ovarian cancer; Ovarian Neoplasms - pathology; Ovarian Neoplasms - therapy; PD-1 protein; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Programmed Cell Death 1 Receptor; Signal transduction; Single-Chain Antibodies - genetics; Synergism; Variable region; Virology; Antitumor immunity; Oncolytic herpes simplex virus; PI3K/AKT; Ovarian cancer
• ISSN: 0304-8608; 1432-8798
• DOI: 10.1007/s00705-023-05754-1

Due to recurrence and resistance to chemotherapy, the current standard therapeutics are not fully effective against ovarian cancer. Therefore, we aimed to find an effective approach to improve the prognosis and therapy of ovarian cancer. NG34ScFvPD-1 is a modified oncolytic herpes simplex virus NG34 strain that expresses a single-chain antibody against programmed cell death protein 1 (PD-1) (ScFvPD-1). We assessed its efficacy and its regulatory mechanism in a mouse model of ovarian cancer. Enzyme-linked immunosorbent assay and western blot techniques were used to measure protein expression. Oncolysis caused by NG34ScFvPD-1 was examined using cytotoxicity and replication assays. The mechanism by which NG34ScFvPD-1 regulates apoptosis of ovarian cancer cells in vitro was also evaluated. We assessed the antitumor immunity and therapeutic potency of NG34ScFvPD-1 in combination with a phosphoinositide 3-kinase (PI3K) inhibitor. We found that NG34ScFvPD-1-infected ovarian cancer cells expressed and secreted ScFvPD-1, which bound mouse PD-1. The insertion of the ScFvPD-1 sequence did not inhibit the oncolytic activity of NG34ScFvPD-1, which induced apoptosis of ovarian cancer cells via the caspase-dependent pathway in vitro and activated the PI3K/AKT signaling pathway. Synergy was observed between NG34ScFvPD-1 and a PI3K inhibitor, and the combination was able to suppress tumor development, to prolong survival, and to elicit potent antitumor immunity. Thus, inhibition of PI3K enhanced the potent antitumor immunity induced by NG34ScFvPD-1 against ovarian cancer.