Immune Responses in Wild-type Mice Against Prion Proteins Induced Using a DNA Prime-Protein Boost Strategy  

作　　者：HAN YanLing LI Yuan SONG Juan WANG Ying SHI Qi CHEN Cao ZHANG BaoYun GUO Yan LI ChaoPing HAN Jun DONG XiaoPing 

机构地区：[1]State Key Laboratory for Infectious Disease Prevention and Control,National Institute for Viral Disease Control and Prevention,Chinese Center for Disease Control and Prevention,Beijing 102206,China [2]Medical School,Anhui University of Science and Technology,Huainan 231001,China

出　　处：《Biomedical and Environmental Sciences》2011年第5期523-529,共7页生物医学与环境科学（英文版）

基　　金：supported by Chinese National Natural Science Foundation Grants 30771914 and 30800975;Institution Technique R&D Grant (2008EG150300);National Basic Research Program of China (973 Program) (2007CB310505);China Mega-Project for Infectious Disease (2009ZX10004‐101, 2008ZX10004‐001, and 2008ZX10004‐002);the SKLID Development Grant (2008SKLID102 and 2008SKLID202)

摘　　要：Objective To break immune tolerance to prion （PrP） proteins using DNA vaccines.Methods Four different human prion DNA vaccine candidates were constructed based on the pcDNA3.1 vector：PrP‐WT expressing wild‐type PrP,Ubiq‐PrP expressing PrP fused to ubiquitin,PrP‐LII expressing PrP fused to the lysosomal integral membrane protein type II lysosome‐targeting signal,and PrP‐ER expressing PrP locating the ER.Using a prime‐boost strategy,three‐doses of DNA vaccine were injected intramuscularly into Balb/c mice,followed by two doses of PrP protein.Two weeks after the last immunization,sera and spleens were collected and PrP‐specific humoral and cellular immune responses evaluated by ELISA and ELISPOT tests.Results Higher levels of serum PrP antibodies were detected in mice vaccinated using the strategy of DNA priming followed by protein boosting.Of these,WT‐PrP,Ubiq‐PrP,and PrP‐LII induced significantly higher humoral responses.ELISPOT tests showed markedly increased numbers of IFN‐γ‐secreting T cells in mice vaccinated using the strategy of DNA priming followed by protein boosting after stimulation with recombinant PrP23‐90 and PrP23‐231.PrP‐ER inducedthe strongest T‐cell response.Conclusion Prion vaccines can break tolerance to PrP proteins and induce PrP‐specific humoral and cellular immune responses.Objective To break immune tolerance to prion （PrP） proteins using DNA vaccines.Methods Four different human prion DNA vaccine candidates were constructed based on the pcDNA3.1 vector：PrP‐WT expressing wild‐type PrP,Ubiq‐PrP expressing PrP fused to ubiquitin,PrP‐LII expressing PrP fused to the lysosomal integral membrane protein type II lysosome‐targeting signal,and PrP‐ER expressing PrP locating the ER.Using a prime‐boost strategy,three‐doses of DNA vaccine were injected intramuscularly into Balb/c mice,followed by two doses of PrP protein.Two weeks after the last immunization,sera and spleens were collected and PrP‐specific humoral and cellular immune responses evaluated by ELISA and ELISPOT tests.Results Higher levels of serum PrP antibodies were detected in mice vaccinated using the strategy of DNA priming followed by protein boosting.Of these,WT‐PrP,Ubiq‐PrP,and PrP‐LII induced significantly higher humoral responses.ELISPOT tests showed markedly increased numbers of IFN‐γ‐secreting T cells in mice vaccinated using the strategy of DNA priming followed by protein boosting after stimulation with recombinant PrP23‐90 and PrP23‐231.PrP‐ER inducedthe strongest T‐cell response.Conclusion Prion vaccines can break tolerance to PrP proteins and induce PrP‐specific humoral and cellular immune responses.

关 键 词：PRION DNA vaccine Humoral response T‐cell response Prime‐boosting regime. 

分 类 号：S942.5[农业科学—水产养殖] S852.659.7[农业科学—水产科学]