CB-Aβ抗体偶联物抑制痴呆小鼠脑内Aβ纤维斑块形成

The inhibition of brain amyloid Aβ burden with cholera toxin B subunit and anti-Aβ monoclonal antibody conjugate in senile dementia mice

目的研究CB-Aβ多肽抗体(IgG)是否能高效的进入痴呆小鼠脑内,发挥抑制Aβ纤维斑块形成的作用。方法用改良过碘酸钠法制备CB-IgG偶联物;鼻腔给予C57小鼠CB-IgG后用间接ELISA法测定脑内抗体量;给予C57小鼠抗体3 h后用间接ELISA测血清和脑区抗体量;5XFAD小鼠分为CB-IgG IN组,IgG IN组,IgG IV组,阳性对照组和阴性对照组,抗体干预14周后,双抗夹心ELISA检测脑内Aβ水平,免疫组化染色观察Aβ沉积和老年斑。结果鼻腔给予CB-IgG 0.3 h时在脑内即可检测到Aβ抗体的存在(P<0.05),3 h后达峰值(P<0.01);抗体给予3 h后,CB-IgG IN组海马区的抗体量高于IgG IN组和IgG IV组10倍以上(P<0.05),IgG IV组与IgG IN组脑内的抗体量接近;CB-IgG IN组小鼠脑内Aβ水平比阳性对照组显著降低(P<0.05);CB-IgG IN组海马和皮层区的老年斑面积与阳性对照组相比分别减少了80%以上(P<0.05)。结论鼻腔给予CB-IgG的方式,在提高抗体入脑量、抑制痴呆鼠脑内Aβ纤维斑块形成等方面均优于其他途径和措施。

Objective To study the inhibition effect of anti-Aβ monoclonal antibody（IgG） conjugated with cholera toxin B subnnit（CB） on brain Aβ burden in senile dementia mice. Methods IgG was conjugated with CB by im- proved sodium metaperiodate method. CB-IgG amount that accessed into the brain of mice was measured by indirect ELISA, which was also employed to measure IgG amount of brain different regions and blood sample after 3 hours of IgG administration. Transgenic mice were used to study the role of CB-IgG in inhibition of Aβ burden compared with IgG IN group, IgG IV group and wild type mice, after 14 weeks of IgG administration, AI3 level of brain was assessed by sandwich ELISA and Aβ deposits and senile plaques were observed by immunostaining. Results The trace of IgG in brain could be detected after 0. 3 hours of CB-IgG intranasal administration （ P 〈 0.05 ） and IgG amount achieved to peak at 3 hours （ P 〈 0. 01 ） when the amount of IgG in hippocampus was 10-fold higher in CB-IgG group than IgG IN group or IgG IV group （P 〈 0.05） ,and IgG quantity in brain was similar between IgGIN aud IgG IV group. Compared with positive control group, the duced （P〈0.05）, percent Aβ load in hippocampus and cortex （ P 〈0. 05 ）. Conclusions CB-IgG heatment via intranasal was a promising approach that can effectively penetrate into brain,decrease Aβ deposits and senile plaques.