Research On Activation Of Innate Immunity By The Chinese EIAV Vaccine Strain EIAV_FDDV13 And Its Infectious Molecular Clone

Equine infectious anemia virus (EIAV) is a lentivirus which causes severe injury to equids. Last century, RongXian Shen academician from Harbin Veterinary Research Institute had created the attenuated vaccine successfully through a special approach to attenuate the virulence of the EIAV. This attenuated vaccine could cause good immune protection, and it is the only one lentivirus vaccine which used widely around the world. The study on the mechanism of the protection caused by the attenuated vaccine enables investigation of the key factor of the induction of lentivirus immune protection. Previous study showed that the immune responses caused by EIAVFDDV13and EIAVFDDV-8were different from each other. Besides, the interaction between innate immunity and acquired immunity is close. Consequently, in this study, we choose EIAVFDDV13and EIAVFDDV3-8as model stains to compare the differences of the activation of innate immunity, and try to explain the reason of the difference of the induction of immune protection caused by the two strains.In our research, based on the study on the immune responses, we choose TLR-2\3\4, TLR-6\7\8、 TLR-9, INF-α, INF-β, IL-6and TNF-a as the indicators of the innate immune response differences. Scientific community believes that Toll-like receptors play vital roles in innate immune. Besides, EIAV has dsRNA structure and ssRNA in its reproduction process which could be the adaptors of TLR-3and TLR-7\8. Meanwhile, TLR-2. TLR-4and TLR-6are expressed on the surface of the cell, could recognize EIAV envelope and activate the responses of immunity. And the Intracellular pathways of TLRs have overlap with pathways of acquired immunity. Apart from TLRs, type I interferons (INF-α INF-β) and other inflammatory factor (TNF-α、 IL-6) as the Important downstream products of TLR-2\3\4,TLR-6\7\8, TLR-9play vital roles in the protection of the organism from the pathogens. On the other hand, they play as the regulatory molecules in the transition from innate immunity to acquired immunity, and are indispensable in the acquired immunity.After determining the indicators, we used same amount of EIAVFDDV13and EIAVFDDV3-8to infect eMDMs and took the eMDMs without infection as control cells. Extracting the RNA from infected eMDM in different time post infection of EIAVFDDV13and EIAVFDDV3-8, then reverse transcribed into cDNA. Next, through Real-time quantitative PCR we can analysis the expression of different TLRs and cytokines related to the innate immune. By ELISA analysis, we also gathered the expression data of the protein of type I interferons after infection. The result illustrates that EIAVFDDV13could increase the expression of TLR-3and IFN-β significantly. Moreover, after infection, the expression of IL-6and TNF-a showed some differences as well. Considering the function of IFN-β, TNF-a and IL-6in the form of acquired immunity, our findings of the differences expression of cytokines caused by EIAVFDDV13and EIAVFDDV3-8infection have close link with the differences of protective immunity.To sum up, our findings enable investigation of the differences of protective immunity caused by the two EIAV strains from the aspect of innate immunity. Further study will focus on the causes of the differences of innate immune induction, and provide us a new perspective to investigate the mechanism of protective immune responses induced by EIAVFDDV13.