Aβ42及亚单位疫苗诱导小鼠抗体产生及其中和Aβ42的细胞毒性

目的 :探讨Aβ4 2 及其亚单位肽疫苗接种小鼠后特异性抗Aβ4 2抗体的产生情况。方法 :75只 6wk龄雄性BALB/c小鼠 ,随机分为 5组 :即对照组、Aβ4 2 组 ,Aβ3 6 - 42 组、Aβ1- 15 组和FAβ1- 15组。分别用PBS MF59佐剂 ,Aβ4 2 MF59,Aβ36～ 4 2 七聚赖氨酸 (MAP) MF59,Aβ1- 15 MAP MF59,Aβ1- 15 MAP 福氏佐剂 ,免疫BALB/c小鼠 4次。用间接ELISA法 ,检测各组免疫小鼠血清和脑组织匀浆上清液中特异性抗体的滴度。将Aβ42 、Aβ3 6 - 42 和Aβ1- 15 与培养的PC12细胞共同培养 7d ,用MTT比色法检测 3种抗原肽对PC12细胞的毒性。将各组免疫小鼠的血清加入到含 2 0mg/LAβ4 2 的培养基中 ,再与培养的PC12细胞一起培养 7d ,用MTT比色法测定PC12细胞的存活率。结果 :第 2次免疫后 ,各实验组小鼠的免疫血清均有抗Aβ42 抗体产生 ,且抗体滴度随接种次数的增多而增高。同时 ,在脑组织匀浆上清液中也可检测出低滴度的抗Aβ4 2 抗体。Aβ42 可降低PC12细胞的存活率 ;而不同浓度的Aβ3 6 - 42 和Aβ1- 15 则对PC12细胞的存活率无显著影响。将 4组疫苗免疫血清和 2 0mg/LAβ42 同时加入培养基中培养PC12细胞时 ,可显著提高其存活率。结论 :Aβ42 及其亚单位疫苗 (Aβ1- 15 及Aβ36～ 4 2 )结合MF59佐剂免疫B

Antibody production and its neutralization of Aβ42'S cytoxicity in BALB/c mice induced by Aβ42 and its subunit vaccines

AIM: To explore the production of anti-Abeta42 antibody after immunization with Abeta42 and its subunit peptide vaccines. METHODS: Seventy five male BALB/c with the age of 6 weeks were randomly divided into 5 groups, namely, control group, Abeta42 group, Abeta(36-42) group, Abeta(1-15)group and F Abeta(1-15) group. The BALB/c mice were immunized four times with PBS+MF59 adjuvant, Abeta42+MF59, Abeta(36-42)+heptalysine (MAP)+MF59, Abeta(1-15)+MAP+MF59 and Abeta(1-15)+MAP+Freud's adjuvant, respectively. The titers of specific antibodies in sera and supernatants of brain tissue homogenates from the immunized mice in every group were detected by indirect ELISA. After Abeta42, Abeta(36-42), Abeta(1-15) and F Abeta(1-15) were co-cultured together with cultured PC12 cells for 7 days, the cytotoxicity of the 3 antigen peptides to PC12 cells were determined by MTT colorimetry. In addition, after immune sera from each group were added to culture medium containing 20 mg/L Abeta42 and co-cultured with PC12 cells for 7 days, the survival rate of PC12 cells were examined by MTT assay. RESULTS: The production of anti-Abeta42 antibodies was detected in sera of each experimental group after the second time immunization, and the titer of antibody rose with the increase of immunizing times. In addition, the anti-Abeta42 antibody with low titer was also detected in supernatants of brain tissue homogenates. The Abeta42 could reduce the survival rate of PC12 cells, whereas Abeta(36-42) and Abeta(1-15) had no obvious effect on survival rate of PC12 cells. After immune sera from 4 experimental groups and Abeta42 were co-cultured with PC12 cells, their survival rate was found improved. CONCLUSION: Combination of Abeta42 and its subunit (Abeta(36-42) and Abeta(1-15)) vaccines with MF59 adjuvant can induce BALB/c mice to produce anti-Abeta42 antibody. The antibody may neutralize the cytotoxicity of Abeta42.