| Herpes simplex virus type 1(HSV-1)is a member of the alpha subfamily of human herpesviruses.The main feature of HSV-1 is that it can infect the body and form pathological damage to the epithelial tissue.HSV-1 has the long-term latent capacity in the trigeminal ganglion to form a lifelong infection.When the body is subjected to nonspecific stimuli,such as fever,cold,low immunity,etc.,the reactivation of the latent state of HSV-1 will be achieved.The latent process of establishment,maintenance,and reactivation caused by HSV-1 infection is a series of biological system strategies based on the necessity of the infection process.Therefore it also shows that HSV-1 is very effective in the evolution of infection strategy.The HSV-1 specific pathological effects of latent infection and recurrent attacks are closely related to the multi-level and different types of interactions between the complex structure and the immune system in the body.In a sense,the body’s immune response generated in this interaction and lack of protective effect indicate the success of the HSV-1 infection strategy.Meanwhile it is also the reason why the clinical treatment and prevention of HSV-1 infection is ineffective.In the past,HSV1 vaccine strategies have focused on envelope glycoproteins,such as gB,gD,and gE.However,one of the structural features of HSV-1 is that it encodes more than 80 proteins,of which the viral envelope glycoprotein is only a small subset.Therefore,in addition to viral glycoproteins,what kind of immune interactions exist between other HSV-1-encoded proteins(such as a variety of nucleocapsid molecules that form three different forms of A,B,and C)and the body’s immune system?Furthermore,how the interaction affects the development and phenotypic characterization of the antiviral immune response throughout the organism has not been clearly identified.Therefore,the research on the immunogenicity of nucleocapsid protein with important structural significance and its interaction with the immune system of the host infected by HSV-1 will help us to have a deeper understanding of the immunological characteristics of HSV-1 nucleocapsid protein and its relationship with the anti-virus immunity of the host.Based on the above facts,in the first part of this study,10 major capsid proteins were cloned using the pET32a vector,and purified proteins were obtained by prokaryotic expression.Moreover,cell-specific responses were detected by ELISpot’s method 35 days after the intranasal challenge of BALB/c mice with three different virulence HSV-1.The detection results showed that these 10 capsid proteins can be used as target molecules of the corresponding specific CTL response,thereby inducing a significantly enhanced T cell immune response.Further immunoprecipitation was used to co-incubated the 35-day serum with 10 purified capsid proteins,and it was found that specific antibodies against UL25 and UL26.5 were produced in the serum.These results and our other related work togeth er indicate that these two proteins may be the predominant antigens to stimulate the body to produce antibodies after HSV-1 infection.Then we analyzed the expression characteristics and immunological characteristics of HSV-1 dominant antigens UL25 and UL26.5.The analysis results suggest that the dominant nucleocapsid proteins UL25 and UL26.5 can promote the expression of specific antibodies in the body.However,due to the complexity of the virus structure and its multiple potential immune escape mechanisms,specific antibodies against these capsid proteins alone are not enough to form the body’s immune defense against HSV-1.Therefore,on this basis,in the second part of the experiment,firstly,we used TMT protein omics method to make a preliminary analysis of the action characteristics of two antigen proteins,UL25 and UL26.5,on the innate immune response system in epithelial cells.We found that p62/SQSTM1,BCL-10,STAT3,IFI16,etc.all decreased significantly after transfection of UL25 and UL26.5 genes into Vero cells,suggesting that the dominant antigens of UL25 and UL26.5 may be involved in the immune escape of HSV-1.Subsequently,mice were immunized three times by intraperitoneal injection of 10μg/mice with these two predominant encoded proteins of the virus,and then intranasally challenged with wild strains.The results showed that the clinical symptoms of HSV-1 in mice were significantly alleviated.Interestingly,mice showed a decrease in the number of CD4+T cells and an increase in CD8+T cells on day 14 post-infection.Analysis of the mRNA transcription profiling of T cells revealed that the elevated CD8+T cell subsets were mainly killer T cells.Subsequent ELISpot assay found that UL26.5 and UL25+UL26.5 recombinant proteins could specifically stimulate T cells of HSV-1-infected mice to produce IFN-y.The above analysis indicated that UL25 and UL26.5 immunization may induce a highly specific T cell immune response in mice.Next,we examined the role of T cell responses in the protective cellular immune responses induced by proteins encoded by UL25 and UL26.5.To further verify the role of T cells IFN-y the protective immune response induced by the proteins encoded by UL25 and UL26.5,this study then collected the T cells of mice immunized with UL25,UL26.5 and UL25+UL26.5,and passively reinfused them to blank BALB/c mice.After 48 hours,they were infected with HSV-1 through nose.The results showed that the virus antigen-specific T cell response of the proteins encoded by UL25 and UL26.5 was still unique.However,the existing results show that these two structural proteins,as immunogens,can not provide complete protection for the body.Therefore,the research on antiviral immunity against two dominant antigens,HSV-1 UL25 and UL26.5,suggests that HSV-1 consumes antibody resources in the immune response during the infection process,and can induce the organism to produce obvious cellular immune response.Although we don’t fully understand the molecular mechanism of virus strategy,it can theoretically strengthen the immunogenicity of the target antigen by using HSV-1 UL25 and UL26.5’ s specific antibody reaction and cellular immunity as bait to stimulate the immune system function of the organism.In our preliminary experiment,we linked these two dominant antigens with COVID-19 S1 antigen,and explored whether S antigen could stimulate the corresponding immune response through the function of dominant antigen.The preliminary results suggest that the dominant antigen can synergistically enhance the cellular immunity and antibody reaction of COVID-19’s mRNA vaccine antigen without considering the 5’-UTR and 3’-UTR elements of mRNA molecules.Therefore,the results of this work provide a new theoretical clue for the interaction between HSV-1 nucleocapsid dominant antigen and immune system,and put forward a new technical strategy for constructing mRNA vaccine. |
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