Swine-origin virus infection spreading widely could cause significant economic loss to porcine industry. Novel antiviral agents need to be developed to control this situation. In this study, we evaluated the activities of five broad-spectrum antimicrobial peptides (AMPs) against several important swine-origin pathogenic viruses by TCID50 assay. Plaque reduction assay and cell apoptosis assay were also used to test the activity of the peptides. Protection effect of piscidin against pseudorabies virus (PRV) was also examined in mouse model. Piscidin (piscidin 1), caerin (caerin 1.1) and maculatin (maculatin 1.1) could inhibit PRV by direct interaction with the virus particles in a dose-dependent manner and they could also protect the cells from PRV-induced apoptosis. Among the peptides tested, piscidin showed the strongest activity against PRV. Moreover, in vivo assay showed that piscidin can reduce the mortality of mice infected with PRV. In vitro and in vivo experiments indicate that piscidin has antiviral activity against PRV.

Background: Selectively replicating herpes simplex virus-2 (HSV-2) vector is a promising treatment for cancer therapy. The insertion of multiple transgenes into the viral genome has been performed to improve its oncolytic activity.Methods: Herein, we simultaneously constructed five “armed” oncolytic viruses (OVs), designated oHSV2-IL12, -IL15, GM-CSF, -PD1v, and IL7 × CCL19. These OVs delete theICP34.5andICP47genes with the insertion of transgenes into the deletedICP34.5locus. The anti-tumor efficacy in vivo was tested in the syngeneic 4T1 and CT26 tumor-bearing mice model.Results: The OVs showed comparable oncolytic capability in vitro. The combination therapy of oHSV2-IL12, -IL15, GM-CSF, -PD1v, and IL7 × CCL19 exhibited the highest tumor inhibition efficacy compared with the treatment of single OV or two OVs combination.Conclusions: The OVs armed with different transgenes combination therapy also named 5-valent oHSV2 (also called cocktail therapy) might be an effective therapeutic strategy for solid tumors.

Background: OH2 is an oncolytic virus derived from herpes simplex virus type 2. A phase Ia/Ib clinical trial in China was conducted in patients with unresected stage III–IV melanoma, the majority of whom had the acral type, to assess the safety and preliminary efficacy of OH2. Methods: The trial enrolled patients with histologically confirmed unresectable stage III or advanced stage IV melanoma. In phase Ia, nine patients received OH2 single-dose treatment across three dose levels (10⁶, 10⁷, and 10⁸ CCID₅₀/mL, where CCID₅₀ represents cell culture infectious dose 50%) while six patients underwent multidose therapy. Phase Ib expanded the proposed dose. Antitumor efficacy was evaluated using the Response Evaluation Criteria in Solid Tumors and immune-RECIST guidelines. NCT04386967 is the clinical trial identifier. Results: All 44 patients were enrolled. OH2 was well tolerated without serious adverse events (AEs) or deaths reported. No Grade 3 or higher treatment-related AEs occurred. In phase Ia, the 1-year survival rate was 92.9% (95% CI, 59.1% to 99.0%), with a median overall survival of 28.9 months (95% CI, 12.7 to not reached). In phase Ib, 10 patients achieved immune-partial response (iPR)/partial response (PR), yielding an objective response rate (ORR) of 37.0% (95% CI, 19.4% to 57.6%), with 6 patients still responding. The rate of the durable response (PR or complete response lasting at least 6 months) was at least 29.6% (8/27). Notably, 7 of 12 III–IVM1a patients who previously received programmed cell death protein-1 (PD-1) therapy achieved iPR/PR, with an ORR of 58.3% (95% CI, 27.7% to 84.8%) and a disease control rate of 75.0% (95% CI, 42.8% to 94.5%). Biomarker analysis indicated that elevated baseline neutrophil activation state correlated with poorer clinical outcomes. A phase III clinical trial is ongoing in China (NCT05868707). Conclusions: OH2 oncolytic virotherapy exhibited a favorable safety profile without dose-limiting toxicities (DLTs) and demonstrated durable antitumor efficacy in patients with melanoma, especially in those who had progressed on anti-PD-1 treatment. Trial registration number: ClinicalTrials.gov identifier NCT04386967.

Hu H, et al. J Vet Sci. 2021 Jul;22(5):e59. https://doi.org/10.4142/jvs.2021.22.e59