Bacteria-Derived Recombinant Interferon-Gamma: Production and In Vitro Activity in Equine Herpesvirus-1 Cell Culture Models

Equine herpesvirus type 1 (EHV-1) is a major viral pathogen of horses, causing respiratory disease, abortion, and neurological disorders, while current vaccines provide only limited protection. This study aimed to evaluate the in vitro cytoprotective potential of recombinant human interferon-gamma (rhIFN-γ) and its capacity for the reduction of cytopathic damage in equine dermal cells. The human IFN-γ gene was cloned into a bacterial expression vector, expressed in Escherichia coli, and purified using affinity chromatography. Equine dermal (ED) cells were treated with different concentrations of rhIFN-γ prior to viral challenge. Cytotoxicity was assessed using the MTT assay, and cytoprotective activity was evaluated through cytopathic effect (CPE) observations and TCID50 titration. The results demonstrated that rhIFN-γ reduced EHV-1-induced cytopathic effects in a dose-dependent manner, with the most pronounced protective activity observed at 200 and 400 ng/mL. Additionally, treated cells showed significantly higher viability compared to infected controls (p < 0.05). These findings indicate that bacterially produced rhIFN-γ exhibits both antiviral and cytoprotective effects against EHV-1 in vitro and may represent a promising candidate for the development of alternative potential antiviral strategies targeting EHV-1 infections in horses. These findings indicate that bacterially produced rhIFN-γ exhibits notable cytoprotective activity in vitro by mitigating cellular injury following EHV-1 exposure.