融合蛋白CAC免疫的小鼠血清可抑制β-淀粉样肽的纤维形成  

Sera of the mice immunized with fusion protein CAC inhibit fibrous formation of β-amyloid peptide

作　　者：冯改丰[1] 胡海涛[1] 靳辉[1] 王全颖 杨广笑 

机构地区：[1]西安交通大学医学院人体解剖与组织胚胎学系,陕西西安710061 [2]西安华广生物工程公司

出　　处：《中国老年学杂志》2005年第10期1187-1189,共3页Chinese Journal of Gerontology

基　　金：陕西省自然科学基金(No.2001SM57);西安交通大学科学研究基金(No.2002003)

摘　　要：目的观察融合蛋白CAC(HBcAg与β-淀粉样肽基因重组的原核表达产物)免疫的小鼠血清对β-淀粉样肽(Aβ)纤维形成的抑制作用。方法用融合蛋白CAC免疫BALB/C小鼠,通过ELISA方法检测其血清中抗-Aβ抗体的滴度。当滴度大于1∶10 000时,经小鼠眼球采血分离血清。以不同稀释度的血清与终浓度为0.5 mg/m l的Aβ混合,37℃孵育(老化)5 d后,透射电镜观察Aβ的聚集和纤维形成。结果融合蛋白免疫3次后,小鼠血清中抗-Aβ抗体的滴度达到了1∶16 000。电镜观察可见,加未免疫的对照鼠血清时,经过5 d的老化,Aβ聚集成空心管状纤维,纤维密集,呈网状,几乎充斥于整个视野。当加入稀释度为1∶2 000的高滴度免疫血清时,开始出现明显的抑制作用,随着血清浓度的增加,形成的Aβ纤维逐渐减少;到1∶500时,镜下见不到Aβ纤维的存在。结论CAC免疫的小鼠血清可抑制Aβ的纤维形成。Objective To study the inhibition effects of sera of the mice immunized with fusion protein CAC [ prokaryotic expression production of recombinant genes of HBcAg and β-amyloid peptide （Aβ） ] on fibrous formation of Aβ. Methods The titers of anti-Aβ antibody of BALB/C mice immunized with fusion protein CAC were evaluated by ELISA. When the titers of anti-Aβ antibody reached to 1：10 000, the sera were separated from the blood sampled via mice＇s eyeball. The mixture of variant diluted sera and Aβ （end concentration： 0.5 mg/ml） were incubated at 37℃ for 5 days aging to observe the aggregation and fibrous formation of Aβ by transmission electron microscopy （TEM）. Results The titer of serum anti-Aβ antibody reached to 1 ： 16 000 after immunization of 3 times. After 5 days incubation, the sera of control mice without immunization aggregated and showed dense hollow fibers full＇of visual field. When the sera concentration of immunized mice reached to 1：2 000, the fibrous formation of Aβ was inhibited obviously. The higher concentration of the sera, the less fibril formation could be seen. Till the concentration was 1 ： 500, no fibril formation existed. Conclusions Sera of the mice immunized by fusion protein CAC can inhibit the aggregation and fibrous formation of Aβ.

关 键 词：β-淀粉样肽(Aβ) 融合蛋白 血清 抗体 

分 类 号：R749.1[医药卫生—神经病学与精神病学]