Study On Host Immune Responses To Porcine Hemagglutinating Encephalomyelitis Virus Acute And Chronic Infection Of Mice

Porcine Hemagglutinating Encephalomyelitisis caused by the pathogen of PigsHemagglutinating Encephalomyelitis Virus（PHEV）. It mainly affects young pigswith acute and highly contagious disease, showed vomiting and failure as clinicalsymptoms or neurological symptoms, the mortality rate is up to20%～100%.Neutralization test and hemagglutination inhibition survey showed that PHEVinfection was widely distributed. It is a serious threat to the development of the pigindustry in the world.At present, foreign and domestic scholars carried out the work of PHEV fromdifferent angles, they found that PHEV infection can led to the central nervous systemnon-suppurative encephalomyelitis lesions. The most direct and effective way tocontrol livestock epidemic spread is vaccinated and stimulate the body specificimmune response. However it is not clear for PHEV infection pathogenic and immunemechanisms, especially on the animal’s immune response mechanisms of PHEVinfection is still blank. Therefore, it is particularly important to seek effectivetreatment measures and defensive strategies to fundamentally control the disease.PHEV natural host is the pig, but the virus has been confirmed to adapt in themouse and rat models, and neurotropic performance in a mouse model. So this studytaking mice as experimental animals, PHEV inoculat mice by two ways (intranasaland oral), successfully established PHEV acute and chronic infection model: In theacute infection model of PHEV, mice rapidly onset with short incubation period,allmice died within5days after inoculation and associated with typical clinicalsymptoms;model of chionic infection in mice after inoculation,the mortality rate waszero and no obvious symptoms appear. Mice of two models were monitored the body organs PHEV content and humoral、cellular immune response related indicators indifferent infection periods. The results show that PHEV performed neurotropicproperties in both model，extended time with chronic infection，immune functionrecovered，and the content of PHEV in the various organs reduced significantly. In theacute infection model, The immune indicators mostly increased first and thendecreased, indicating that the early stage of infection, the body is actively mobilizethe immune response, The immune indicators mostly increased first and thendecreased, indicating that the early stage of infection the body is actively mobilize theimmune response,but the immune cells and antibody content is limited, they can notprotect the body from resisting the ongoing replication of the virus, immunity of micedeclined sharply, eventually leading to the death of the hosts; In the chronic infectionmodel, much of immune indicators appeared down and then up, indicating that theearly stage of infection, the immune system was damaged by PHEV, in the late ofinfection, the body mobilized the adaptive immune response, which is the majorsignificance of disease control and host outcomes. This research laided down certainexperimental basis on the immunity、pathogenesis and prevention strategy of PHEV.