In this study, we developed a new recombinant virus rHVT-F using a Turkey herpesvirus (HVT) vector, expressing the fusion (F) protein of the genotype XII Newcastle disease virus (NDV) circulating in Peru. We evaluated the viral shedding and efficacy against the NDV genotype XII challenge in specific pathogen-free (SPF) chickens. The F protein expression cassette was inserted in the unique long (UL) UL45–UL46 intergenic locus of the HVT genome by utilizing a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 gene-editing technology via a non-homologous end joining (NHEJ) repair pathway. The rHVT-F virus, which expressed the F protein stably in vitro and in vivo, showed similar growth kinetics to the wild-type HVT (wtHVT) virus. The F protein expression of the rHVT-F virus was detected by an indirect immunofluorescence assay (IFA), Western blotting, and a flow cytometry assay. The presence of an NDV-specific IgY antibody was detected in serum samples by an enzyme-linked immunosorbent assay (ELISA) in SPF chickens vaccinated with the rHVT-F virus. In the challenge experiment, the rHVT-F vaccine fully protects a high, and significantly reduced, virus shedding in oral at 5 days post-challenge (dpc). In conclusion, this new rHVT-F vaccine candidate is capable of fully protecting SPF chickens against the genotype XII challenge.

Introduction. Oncolytic virotherapy has emerged as a novel method for treating cancer. The newcastle disease virus (ndv) exhibits oncolytic potential and selectively replicates in tumor cells. Human prostate and renal cancer are the leading causes of death worldwide. Objective. To evaluate the oncolytic activity of the rLS1 viral construct on prostate carcinoma (DU-145) and renal cancer (786-O) cell lines, as well as its selective replication in both tumor lines and the non-tumoral madin-darby canine kidney (MDCK) cell line. Methods. The oncolytic effectiveness was determined by reducing cell viability and apoptosis using the (3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2h-tetrazolium) MTS colorimetric assay and by labeling with annexin v/anxa5-pe/sytox blue dead cell, respectively. The viral replicative selectivity in cells was evaluated by crystal violet staining. Results. The MTS assay determined that rls1 significantly reduced viability (p < 0,001) in both tumor cell lines without causing a significant reduction in the viability of MDCK cells compared to uninfected cells. A significant increase (p < 0,001) in the percentage of apoptotic cells was observed in 786-O and DU-145 cells infected with rLS1 compared to uninfected cells. Conclusion. The results indicate that rLS1 demonstrated selective oncolytic potential in human prostate and renal cancer cells, suggesting its potential as an antitumoral agent.

Background/Objectives: Prostate cancer is the second most common type of cancer diagnosed in men. Various treatments for this cancer, such as radiation therapy, surgery, and systemic therapy, can cause side effects in patients; therefore, there is a need to develop new treatment alternatives. One promising approach is virotherapy, which involves using oncolytic viruses (OVs), such as the recombinant Newcastle disease virus (rNDV). Methods: We used the lentogenic rNDV rLS1 strain (the control virus) as our backbone to develop two highly fusogenic rNDVs: rFLCF5nt (the parental virus) and rFLCF5nt-IFN-γ (rFLCF5nt expressing human interferon-gamma (IFN-γ)). We evaluated their oncolytic properties in a prostate cancer cell line (DU145). Results: The results showed the expression and stability of the IFN-γ protein, as confirmed using Western blotting after ten passages in specific pathogen-free chicken embryo eggs using the IFN-γ-expressing virus. Additionally, we detected a significantly high oncolytic activity in DU145 cells infected with the parental virus or the IFN-γ-expressing virus using MTS (a cell viability assay) and Annexin V-PE assays compared with the control virus (p < 0.0001 for both). Conclusions: In conclusion, our data show that IFN-γ-expressing virus can decrease cell viability and induce apoptosis in human prostate cancer in vitro.