Experimental Study Of Bama Miniature Pig Vaccinate By Typical Strains Of PRRS

Porcine reproductive and respiratory syndrome(PRRS) was caused by porcine reproductive and respiratorysyndrome virus(PRRSV),it belongs to the arteritis virus family arteritis virus.PRRS is a serious hazard raisepig industry of infectious diseases.The mainly cause of pregnancy reproductive disorders and respiratorysymptoms of piglets.PRRS was first described in North America in1987,rapidly throughout the world, thePRRSV was isolated firstly in China in1996.In2006, the highly pathogenic porcine reproductive andrespiratory syndrome (HP-PRRS) was broke out in the South of China,it is characterized by sustained highfever, diarrhea, decreased appetite, ataxia, the high morbidity and mortality, spreads rapidly. Suitableexperimental animal is essential for the study of disease including pathogenesis, immune mechanism, andrecognize the essence of disease, evaluation of vaccines, and develop control strategies. Currently,the mainlyexperimental animals of PRRS research is for domestic pigs.Due to the domestic pig have these shortcomingsincluding large size of body, genetic traits difficultly to control and difficult operation and others, for PRRSresearch has some limitations.However,the Bama miniature pigs have a stable genetic traits, high reproductiveperformance, docile, easy to operate, early sexual maturity,the ability of anti-stress, a strong resistance.So,Inthis study,we compared the cytokine homology between Bama miniature pigs and domestic pigs,and researchExperimental of Bama Miniature Pig Vaccination by Typical Strains of PRRS,Explore the feasibility of Bamaminiature pigs instead of domestic pigs as an ideal experimental animal.In this study, Amplification and cloning of gene sequence of Bama miniature pigs cytokines IL-2, IL-6,IL-10, IL-12, IFN-γ and TNF-α,their lengths were338bp,446bp,446bp,377bp,380bp,402bp,respectively.comparison gene sequence of cytokines to the known domestic pigs corresponding. The results showed thatthe homologies of nucleotide sequence were98.9%,100%,98.9%,99.5%,99.7%,100%, the homologies ofamino acid sequence were97.8%,100%,98.6%,100%,99.2%,100%.In this study, Bama miniature pigs as experimental animals, immunization variation PRRS attenuatedvaccine (HuN4-F112strain) and classic PRRS attenuated vaccine (CH-1R strain), after immunization21d,challenged with HuN4-F5strains of PRRS.we study the experiment of Bama Miniature Pig Vaccination byTypical Strains of PRRS by the changes of body temperature, clinical observations, pathological changes,mortality, detection of viral replication, evaluation of humoral immunity and cellular immunity.The resultsshowed that: after immunization, the fever ratio of HuN4-F112strain group was5/147(temperature≥40.5°C), the CH-1R strain group and the control group did not heat.In entire immune period, all Bama miniaturepigs were not show obvious clinical symptoms and pathological changes, all survived.post immunization21d,the PRRSV-specific antibodies can be detected in HuN4-F112strain group, and the CH-1R strain groupwas not detected.During immunized0~14d,the CD4+/CD8+ratio of HuN4-F112strain group and the CH-1Rstrain group were increased, but in14~21d, CH-1R strain group continues to rise, while HuN4-F112straingroup decreased.During immune period,in HuN4-F112strain group and the group CH-1R strain,the cytokinemRNA transcription levels of IL-10increase, but IL-6decreased.Post-challenge, the heat rate of HuN4-F112strain group, CH-1R strain and control groups were12/196,28/142and10/55,respectively.Control group had obvious clinical symptoms and pathological changes, HuN4-F112strain group and CH-1R strain groupshowed a transient slight changes. The mortality rates of HuN4-F112strain group, CH-1R strain group andcontrol group were0/7,4/7and5/5,respectively. The detection of tissue viral load in Bama miniature pigs,we found the replication of PRRSV mainly in the lung and lymphoid tissue,post-infection,viral load reachedthe peak in the control group was107copies/g, CH-1R strain group was105copies/g and HuN4-F112straingroup was104copies/g. After challenge of HuN4-F5strain, the level of PRRSV’s neutralizing antibodies inHuN4-F112strain group and CH-1R strain group were significantly increased, the mRNA transcript levels ofcytokines IL-10and IL-6were significantly increased,Description Both vaccines stimulate the body’s specificimmune response, and HuN4-F112strain attenuated vaccine makes the body to produce a more effectivehumoral immune response.study the cytokine gene sequences of Bama miniature pigs,not only enrich the Bama miniature pigsbioinformatic data, but also provide a basis for functional studies of cytokines and make foundation forquantitative detection of cytokines.The experiment of Bama Miniature Pig Vaccination by Typical Strains ofPRRS,by the changes of body temperature, clinical observations, pathological changes, mortality, detection ofviral replication, evaluation of humoral immunity and cellular immunity and other studies,it have shownMing Bama miniature pigs as experimental animal models of PRRS research, Bama miniature pigs are an idealexperimental animal studies PRRS.