To explore the role of Toll-like receptors (TLRs) and interferon (IFN) in the innate immunity against porcine epidemic diarrhea virus (PEDV), we detected the expression of TLR genes in PEDV-infected IPEC-J2 cells by real-time PCR. We also detected the level of interferon α (IFN-α) and interferon γ (IFN-γ) by enzyme-linked immunosorbent assay (ELISA). Results showed that IPEC-J2 cells exhibited a clear pathological change after PEDV infection at 24 h. In addition, TLR7, TLR9 and TLR10 expressions were significantly upregulated in PEDV-infected IPEC-J2 cells at 24 h. Interestingly, the expression patterns of TLR2 and TLR4 were consistent at different stages of PEDV infection. The expression level of TLR3 decreased significantly with the increase of infection time, but the expression levels of TLR5 and TLR8 genes at 6 h and 12 h were significantly lower than those in the control group (p<0.01). There were significant correlations among the expression levels of TLR genes (p<0.05). Cytokine detection showed that the secretion level of IFN-α in the PEDV-infected group was significantly higher than that in the control group (p<0.01), and IFN-γ at 6 h and 12 h after PEDV infection was significantly higher than that in control group (p<0.01). Therefore, our results suggest that PEDV infection can induce innate immune responses in intestinal porcine jejunum epithelial cells, leading to changes in the expression of Toll-like receptors, and can regulate the resistance to virus infection by affecting the release levels of downstream cytokines.

Coronaviruses present a considerable concern for humans and animals. The current world- wide pandemic of SARS-CoV-2 virus showed many gaps in understanding of coronaviruses spread and transmission. Because of lack of effective vaccine against SARS-CoV-2 the only preventive measures are represented by wearing protective masks and gloves thus limiting potential risk of contact with the airborne virus. Inversely, the limited time of protective function of the masks presents another drawback of their use. Therefore, the application of disinfection agent dispersed on the surface of protective masks may enhance their effectivity and safety of their application. The aim of the study was to examine the virucidal efficacy of low-concentra- ted sodium hypochlorite dispersed using ultrasonic humidifier on the surface of surgery masks. The study was conducted using SARS-CoV-2 surrogate virus, namely porcine epidemic diarrhea virus (PEDV) representing a model with similar biophysical properties and genomic structure to human coronaviruses. Five different concentrations of the disinfectant with different content of sodium hypochlorite were selected for the study. A final concentration of 0.228 g/L sodium hypochlorite effectively inactivated the PED virus and may support the biosafety of masks usage.