Innate Antiviral Mechanisms Of Mouse Prostate Epithelial Cells And Human Prostatic Fluids

Background and objectives:A large spectrum of viruses can infect the male reproductive system and cause local inflammation.However,viral infection of the prostate has been rarely reported,suggesting that the prostate may possess sufficient antiviral ability.In the present thesis,we investigated pattern recognition receptors(PRRs)-mediated innate antiviral responses in mouse prostate epithelial cells(PECs)after infection with mumps virus(MuV).We also analyzed the antiviral role of human prostatic fluid(PF).Materials and methods:Primary prostate epithelial cells(PECs)were isolated from C57BL/6J or gene knockout mice(Ifnar-/-).The expression of PRRs in PECs were detected.Human PF were obtained from healthy donors,and the antiviral activity of PF was examined using MuV infection of HeLa cells.The mRNA and protein levels were detected by real-time qRT-PCR and Western blot,the levels of cytokines were measured using ELISA,the cellular distributions of proteins were analyzed by immunofluorescence,and the cell viabilities were assessed by CCK-8 assay.Results:PECs expressed various PRRs,including viral RNA sensors Toll-like receptors 3(TLR3),melanoma differentiation-associated gene 5(MDA5)and retinoic acid inducible gene-1(RIG-I).MuV activated these RNA sensors and induced the expression of proinflammatory cytokines TNF-α and IL-6,chemokines MCP-1 and CXCL10,interferons IFN-α and IFN-β,and major antiviral proteins MX1,OSA1 and ISG15,thereby suppressing MuV replication within PECs.This suppression of MuV replication was significantly reduced in Ifnar-/-PECs.MuV can infect HeLa cells and replicate within the cells.PF potently inhibited the MuV infection.The antiviral property of PF was not affected by boiling and enzymatic hydrolysis.Antiviral factor in PF belongs to small molecules less than 10 kDa.PF broadly inhibited herpes simplex virus type 1(HSV-1),adenovirus type 5(AV-5)and dengue virus type 2(DeV-2)infection of HeLa cells.Moreover,PF inhibited MuV infection of mouse epididymal epithelial cells,human prostate epithelial cell line(RWPE-1),mouse Sertoli cell line(15P1)and human T-lymphocyte tumor cells(Jurkat).These results suggest that PF possesses a broad-spectrum of antiviral activities.Conclusions:Primary mouse PECs constitutively express various PRRs.These PRRs mediate the innate antiviral responses in PECs after MuV infection,which inhibits MuV replication by activating the interferon pathway.PF secreted by PEC exhibits a broadspectrum of antiviral activities.These antiviral abilities of the prostate should play roles in the defense against viral infection of the prostate and the inhibition of sexual transmission of viruses via semen.