| Rabies is a zoonotic central nervous system infectious disease,caused by rabies virus(RABV),still poses a serious threat to the public health and safety of the world,especially in developing countries and regions.China's annual incidence of rabies were nearly 1,000 cases,the pathogenesis of rabies is still unclear,and there is no effective treatment,which makes the mortality rate close to 100%.When RABV infects the host cells,the viral genomic RNA or transcriptional leader RNA can be recognized by RIG-I,thereby induces the type I interferon pathway(IFN-?)and plays a role of resistance to RABV.It has been found that RABV phosphoprotein(P)can inhibit the host interferon pathway.The viral virulence can be affected by changing the ability of phosphoproteins.,The virulence of RABV can be reduced by changing the amino acid composition of nucleoprotein,which can also affect the activation of interferoncan reduce.However,whether the G protein,which plays a critical role in viral pathogenicity,plays a role in regulating the IFN-? pathway? Does it play an important role in resisting the antiviral process of IFN-?? More research is needed on these issues..We selected three rabies virus,attenuated Hep-Flury,immobilized CVS-11 strain and recombinant virus HepG obtained by replacing G gene of Hep-Flury with the G gene of CVS-11.Hep-Flury,HepG,CVS-11 were infected in vivo and in vitro,respectively,and the differences in activation and regulation of type I interferon pathway were investigated.And the differences in the ability of replication and the antagonism against the antiviral effect of type I interferon were compared in rabies virus with different G genes.Firstly,the effect of rabies virus attenuated G gene on the pathogenicity of neonatal mice was determined.The mortality of HepG was significantly higher than that ofHep-Flury,which was close to that of CVS-11.After qPCR detection,we found that Hep-Flury could activate the interferon pathway earlier after infection of the central nervous system,whereas CVS-11 and HepG strongly stimulated the expression of interferon pathway related genes on the 7th day after infection,indicating that the level of activation in late stage of infection.NA cellswere infected withHep-Flury,HepG,CVS-11,and the expression of IFN-? pathway-related factors was detected.Hep-Flury activates interferon levels higher than that of HepG and CVS-11,in the late Hep-Flury slow down to close to HepG and CVS-11.In vitro infection,HepG and CVS-11 do not significantly activate IFN-? responses in later stages unlike in vivo infection.In addition,rHep-shP,rHep-shM,rHep-shG,three rabies viruses were rescued by replace P MG genes of GD-SH-01 with Hep-Flury and the template,respectively,and compared with the parents strain The effect of Hep-Flury and GD-SH-01 on NA cell infection on the activation of interferon pathway-related factors found that G gene had an effect on activation of interferon,but there was no significant effect on P gene.The growth curves of Hep-Flury,HepG,CVS-11 on 3T3 cells,NA cells and SK cells were detected.In 3T3 cells,the viral replication level is very low.On SK cells,the overall titer of the virus is higher and the virus titer is stable on NA cells.Overall,HepG and CVS-11 showed a relatively similar replication trend,indicating that strong and weak carriers carrying different G gene on the replication of the virus have an impact.After the addition of PolyI: C on the NA cells and SK cells,IFN-? was added to stimulate the effect of interferon on viral replication.Thereby comparing the ability of different rabies virus strains against interferon,Study of G protein in the fight against interferon,the study found:In the early stage of infection,IFN inhibits Hep-Flury replication significantly.CVS-11 on the contrary,after the infection of the early impact of small,long after infection,the inhibitory effect is obvious,indicating that the virus in the late activation of interferon pathway. |
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