日本血吸虫大陆株副肌球蛋白全基因核酸疫苗诱生免疫应答的实验研究

Preliminary study on the immune response in C_(57) BL/6 mice vaccinated by nucleic acid encoding paramyosin of Chinese S. japonicum

目的初步研究日本血吸虫大陆株副肌球蛋白核酸疫苗在C57BL／6小鼠诱生的免疫应答特征。方法利用TRIzol方法抽提日本血吸虫大陆株成虫总RNA，并通过逆转录聚合酶链反应；扩增编码日本血吸虫大陆株副肌球蛋白（SjC97）的全基因cDNA，将其克隆入质粒表达载体（pcDNA／Amp）构建成日本血吸虫大陆株副肌球蛋白全基因核酸疫苗（pCMV－SjC97）；将其通过后腿胫前肌免疫C57BL／6小鼠，共免疫3次，每次间隔3周；利用酶联免疫吸附试验（ELISA）分析pCMV－SjC97免疫所诱生的特异性抗体IgG及IgG亚类，以及特异性抗体IgM及IgE。并初步分析了pCMV－SjC97免疫C57BL／6小鼠脾淋巴细胞抗原特异性体外增殖能力。结果pCMV－SjC97免疫能够诱生特异性抗体IgG及IgM；pCMV－SjC97诱生的抗体滴度与注射的DNA间存在一定的量-效关系；IgG亚类分析显示，pCMV-SjC97免疫主要诱生IgG2a和IgG2b亚类，未测到IgG1及IgG3亚类。PCMV-SjC97免疫能够诱导小鼠Th细胞激活。结论pCMV-SjC97核酸疫苗能够在C57BL／6小鼠诱生较强的体液免疫应答；pCMV-SjC97免疫主要诱生Th1型细胞免疫应答。

Objective To study the characteristics of immune response in C57BL/6 mice by nucleic acid encoding full-length paramyosin of Chinese S. japonicum. Methods Total RNA was isolatal from adult Chinese S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of Chinese S. japonicum was amplified by RT-PCR and cloned into expression vector pcDNA/Amp (pCMV-SjC97), which was intramuscularly injected into C57 BL/6 mice. The mice were vaccinated with DNA the three-week interval for a total of three inoculations. The specific anti-SjC97 IgM, IgG and IgE antibodies and IgG subclasses were determined by ELISA test. Results The pCMV-SjC97 vaccine induced specific anti-SjC97 IgM and IgG antibodies. The antibody resporise correlated well with the administered amount of pCMV-SjC97. The IgG subclasses, predominantly IgG2a and IgG2b, were observed in the mice vaccinated with pCMV-SjC97, but no IgG1 and IgG3 responses were seen.Conclusion The strong immune response, especially Th1 type, can be induced in the mice with pCMV-SjC97 vaccine.