Antiviral effect of rhuIFN-α2b on enterovirus 71 in vitro and its mechanism

PU Qiaohong; CHEN Zhili; YANG Tong; ZHOU Ying; ZHANG Shaojun; LIU Jie; LIN Shujian; PENG Tuohua

doi:10.3969/j.issn.1002-266X.2025.10.006

Abstract：Objective To observe the antiviral effect of recombinant human interferon α2b(rhuIFN-α2b)on entero-virus 71(EV71)in vitro and to explore its mechanism.Methods Human rhabdomyosarcoma(RD)cells were seeded at 1.0×104/well in a 96-well plate.After reaching full confluence,the cells were divided into blocking effect group,di-rect antiviral group,and inhibitory effect group,with a virus control group(only virus infection)and a cell control group(untreated)set up simultaneously.The blocking effect group was co-infected with 100 TCID50 of EV71 virus and rhuIFN-α 2b at different concentrations(2.5×104,1.25×104,6.25×103,3.125×103,1.563×103,781.25,and 390.625 IU/mL);the direct antiviral group was infected with a mixture of 100 TCID50 EV71 and rhuIFN-α2b at different concentra-tions;the inhibitory effect group was first infected with 100 TCID50 EV71,followed by the addition of rhuIFN-α2b at differ-ent concentrations.After 48 h of continued culture,cytopathic effect(CPE)was observed under a microscope,cell viabili-ty was measured using the MTT assay,and the half-maximal effective concentration(EC50)and half-maximal cytotoxic concentration(CC50)were calculated based on the dose-response curve to determine the selectivity index(SI).RD cells were co-infected with 100 TCID50 of EV71 virus and rhuIFN-α2b at concentrations of 2.5×104,1.25×104,and 6.25×103 IU/mL,and after 48 h of culture,EV71 viral VP1 mRNA was detected by real-time quantitative PCR.RD cells were co-infected with 100 TCID50 of EV71 virus and 2.5×104 IU/mL of rhuIFN-α2b,and after 48 h of culture,IL-6 and TNF-α mRNA levels were detected using real-time quantitative PCR.Results CPE was observed in the blocking effect group,direct antiviral group,and inhibitory effect group after the addition of 2.5×104 IU/mL rhuIFN-α2b.The cell survival rates in the blocking effect group with rhuIFN-α2b concentrations of 781.25-2.5×104 IU/mL were all higher than those in the virus control group(all P<0.05).The cell survival rates in both the direct antiviral group and the inhibito-ry effect group with rhuIFN-α2b concentrations of 1.563×103-2.5×104 IU/mL were also higher than those in the vi-rus control group(all P<0.05).The SI for the blocking effect group,direct antiviral group,and inhibitory effect group were 25.43,16.73,and 20.90,respectively.After adding rhuIFN-α2b at concentrations of 2.5×104,1.25×104,and 6.25×103 IU/mL,the relative expression levels of EV71 virus VP1 mRNA were all reduced(all P<0.05).After adding 2.5×104 IU/mL rhuIFN-α2b,the relative expression levels of IL-6 and TNF-α mRNA in cells decreased(both P<0.05).Conclusion RhuIFN-α2b has blocking,inhibitory,and direct antiviral effects on EV71 in vitro,and its mechanism may be related to the inhibition of EV71 virus VP1 gene expression and the inhibition of inflammatory factors IL-6 and TNF-α expression.