Study On The Inhibitory Effect Of Novel Oncolytic Virus OVV-HYAL1 Combined With PD-1 Antibody On Malignant Melanoma

ObjectiveThe study of this project can improve the therapeutic effect of anti-PD-1 on malignant melanoma(MM).To investigate the inhibitory effect of the new oncolytic virus OVV-HYAL1 on MM cells in vitro,and whether the combination with anti-PD-1 can enhance the inhibitory effect.To further study the inhibition mechanism of the novel oncolytic virus combined with PD-1 antibody on MM in vivo.Explore new methods and drugs to improve the cure rate of MM,and provide new treatment options for advanced MM patients.Methods1.The full-length gene sequence of HYAL1 was synthesized by gene synthesis technique and cloned into the shuttle plasmid p CB of vaccinia virus with TK deletion.Homologous recombination was used to construct the novel recombinant oncolytic vaccinia virus OVV-HYAL1;2.Green fluorescent protein(GFP)was used to label OVV-HYAL1 and OVV,and then reconstructed into OVV-GFP-HYAL1 and OVV-GFP;3.To study the cytotoxic effects of OVV-HYAL1 and OVV on malignant melanoma(MM)cell lines.A357 and B16-F10 from MM cell lines were selected to infect OVV-HYAL1 and OVV with corresponding titers,and 24 hours later,FACS was used to detect the infection ability of oncolytic viruses on cells.CCK-8 assay was used to detect the killing effect of OVV-HYAL1 and OVV on A357 and B16-F10 cell lines 48 hours later.4.The tumor-bearing mouse model of murine melanoma cells B16-F10 was established,and the mice were intraperitoneally injected with OVV-GFP,OVV-GFP-HYAL1,OVV-GFP+ anti-PD-1,OVV-GFP-HYAL1 + anti-PD-1,anti-PD-1 and PBS,respectively.Tumor size and survival time of mice were measured every 2 days.Results1.OVV-GFP、OVV-GFP-HYAL1 can infiltrate melanoma cells;2.HYAL1 protein secreted by A357 cells and B16-F10 cells was significantly increased after OVV-GFP-HYAL1 infection(P<0.05);3.OVV-GFP-HYAL1 induced apoptosis of A357 cells;4.OVV-GFP-HYAL1 combined with PD-1 antibody can effectively inhibit the tumor growth of malignant melanoma bearing mice(P<0.05).ConclusionOncolytic virus OVV-GFP-HYAL1 combined with PD-1 antibody has inhibitory effect on malignant melanoma.