阿尔茨海默病重组4Aβ15-TF亚单位疫苗的免疫原性研究

摘要

Objective:The immunogenicity of the recombinant chimeric antigen 4Aβ15-TF was studied to assess its feasibility as a subunit vaccine.Methods:The gene of the recombinant chimeric protein 4Aβ15-TF was synthesized and inserted into the prokaryotic expression vector pTIG-Trx.Then the 4Aβ15-TF protein was expressed and purified in E.coli.And C57BL/6 mice were immunized with 4Aβ15-TF formulated with aluminum hydroxide adjuvant to study its immunogenicity.Results:The recombinant chimeric antigen 4Aβ15-TF could stimulated mice to produce anti-Aβ42-specific antibodies with a high antibody titer after four immunizations.The antibody subtype was mainly IgG1 type accompanied by a small amount of IgG2b type.And T-cell immune responses against the auxiliary of T cell epitope were detected in mice after immunization by T-lymphocyte proliferation experiments,while T-cell immune responses against β-amyloid(Aβ) 42 was not detected.Conclusion:The recombinant chimeric antigen 4Aβ15-TF expressed in E.coli have a functional active conformation and is capable of stimulating the production of high-titer anti-Aβ42 antibody.The immune response generated in mice was mainly Th2 type without Aβ42-specific T lymphocyte proliferation.These results suggest that this protein can be used as a vaccine candidate for the prevention and immunotherapy of Alzheimer's disease.%目的:研究重组嵌合抗原4Aβ15-TF的免疫原性,评估其作为亚单位疫苗的可行性.方法:设计合成了重组融合蛋白4Aβ15-TF的基因序列,插入原核表达载体pTIG-Trx中,用大肠杆菌表达并纯化重组嵌合抗原4Aβ15-TF,与铝佐剂配制成亚单位疫苗免疫C57BL/6小鼠以研究其免疫原性.结果:重组嵌合抗原4Aβ15-TF免疫小鼠后刺激其产生了抗β淀粉样蛋白(Aβ)42的特异性抗体,抗体滴度4次免疫后达到较高水平,抗体亚型主要为IgG1型,并且伴随着少量的IgG2b,T淋巴细胞增殖实验证明免疫后产生了针对辅助性T细胞表位的T细胞免疫反应,不产生针对Aβ42的T细胞免疫反应.结论:大肠杆菌表达的重组嵌合抗原4Aβ15-TF具有良好的免疫原性,能够刺激产生高滴度的抗Aβ42抗体,并且产生的免疫反应主要为Th2型,无Aβ42特异的T淋巴细胞增殖反应.提示它可作为候选疫苗用于预防或免疫治疗阿尔茨海默病.