The Chinese herbal prescription JieZe-1 inhibits caspase-1-dependent pyroptosis induced by herpes simplex virus-2 infection in vitro

Objective:JieZe-1(JZ-1),a Chinese herbal prescription,has an obvious effect on genital herpes,which is mainly caused by herpes simplex virus type 2(HSV-2).Our study aimed to address whether HSV-2 induces pyroptosis of VK2/E6E7 cells and to investigate the anti-HSV-2 activity of JZ-1 and the effect of JZ-1 on caspase-1-dependent pyroptosis.Methods:HSV-2-infected VK2/E6E7 cells and culture supernate were harvested at different time points after the infection.Cells were co-treated with HSV-2 and penciclovir(0.078125 mg/mL)or caspase-1 inhibitor VX-765(24 h pretreatment with 100μmol/L)or JZ-1(0.078125-50 mg/mL).Cell counting kit-8 assay and viral load analysis were used to evaluate the antiviral activity of JZ-1.Inflammasome activation and pyroptosis of VK2/E6E7 cells were analyzed using microscopy,Hoechst 33342/propidium iodide staining,lactate dehydrogenase release assay,gene and protein expression,coimmunoprecipitation,immunofluorescence,and enzyme-linked immunosorbent assay.Results:HSV-2 induced pyroptosis of VK2/E6E7 cells,with the most significant increase observed 24 h after the infection.JZ-1 effectively inhibited HSV-2(the 50%inhibitory concentration=1.709 mg/mL),with the 6.25 mg/mL dose showing the highest efficacy(95.76%).JZ-1(6.25 mg/mL)suppressed pyroptosis of VK2/E6E7 cells.It downregulated the inflammasome activation and pyroptosis via inhibiting the expression of nucleotide-binding oligomerization domain-like receptor family pyrin domaincontaining protein 3(P<0.001)and interferon-γ-inducible protein 16(P<0.001),and their interactions with apoptosis-associated speck-like protein containing a caspase recruitment domain,and reducing cleaved caspase-1 p20(P<0.01),gasdermin D-N(P<0.01),interleukin(IL)-1β(P<0.001),and IL-18 levels(P<0.001).Conclusion:JZ-1 exerts an excellent anti-HSV-2 effect in VK2/E6E7 cells,and it inhibits caspase-1-dependent pyroptosis induced by HSV-2 infection.These data enrich our understanding of the pathologic basis of HSV-2 infection and provide experimental evidence for the anti-HSV-2 activity of JZ-1.