不同佐剂条件下Aβ多肽B细胞表位疫苗诱导产生抗体的免疫反应特性分析

The Immunological Character of Polypeptide B Cell Epitopes Vaccines of Alzheimer's Disease in Different Adjuvants

目的:研究阿尔茨海默病β淀粉样肽(Aβ)B细胞表位疫苗2Aβ1-15-PADRE(Aβ-T)诱导产生抗体的免疫反应特性,并探讨不同佐剂对该疫苗免疫反应效果的影响。方法:合成了含2个Aβ42的B细胞表位—Aβ1-15及1个辅助T细胞表位—PADRE的多肽2Aβ1-15-PADRE。采用Al(OH)3佐剂,弗氏佐剂,Abisco佐剂,MF59佐剂分别与多肽疫苗联合免疫小鼠,并另设3个对照组:无佐剂多肽免疫组(Mock),PBS免疫组(PBS),未免疫组(Native)。结果:5组多肽免疫组小鼠均产生了针对Aβ的特异性抗体,无佐剂多肽免疫组的IgG抗体滴度最低,Al(OH)3佐剂组,MF59佐剂组,Abisco佐剂组小鼠IgG抗体滴度较高,弗氏佐剂组IgG抗体滴度最高。斑点杂交实验结果显示5组小鼠免疫后血清与Aβ42单体反应较弱,与寡聚体反应最明显,与纤维状Aβ42几乎不反应。结论:4种佐剂均能提高多肽疫苗的免疫反应,产生高水平抗Aβ的特异性抗体。5组免疫小鼠产生的抗体均与Aβ寡聚体反应较强,与纤维状Aβ42反应较弱,表明该多肽疫苗具有良好的应用前景。

Objective：To evaluate the immune response of polypeptide vaccines Aβ1-15-PADRE（Aβ-T）against Alzheimer’s disease containing the immunodominant B cell epitope from β-amyloid and pan-DR helper T cell epitopes and determine whether various adjuvants could boost the efficacy or performance of the vaccine in mouse model.Methods：The polypeptides of 2Aβ1-15-PADRE containing two B cell epitopes Aβ1-15 and one pan-DR helper T cell epitope PADRE was be artificially synthesized as polypeptide vaccines Aβ1-15-PADRE.Compared to the PBS control or untreated control,the immunogenicity of polypeptide vaccines without adjuvant and with four different adjuvants（Aluminum,Freund’s adjuvant,MF59 adjuvant and Abisco adjuvant respectively）were evaluated in Balb/C mouse model.Results：All groups produced the specific antibody IgG against Aβ.But the four adjuvant groups were better to generate immune response than Mock group or negative control.Of these,the titer of antibodies produced by the Freund’s adjuvant group was highest.The results of dot blotting showed that the sera antibodies could bind to the oligomer of Aβ better than the monomer form.But the antibodies have not binding reaction to the fiber form.Conclusion：All of these adjuvants could enhance the effect of polypeptide vaccine against Alzheimer’s disease in mouse model.All of the sera antibodies bind to the oligomer form of Aβ.The immunological character shows that the polypeptide vaccine is potential in clinical trial.