CpG对乙肝核酸疫苗及基因重组（CHO细胞）疫苗免疫效果的影响

发布时间：2018-02-24 02:32

本文关键词： CpG佐剂乙肝核酸疫苗(DNA疫苗) 基因重组(CHO)乙肝疫苗　出处：《吉林大学》2007年硕士论文　论文类型：学位论文

【摘要】： 接种乙肝疫苗是预防和控制乙肝病毒传播的重要措施。血源乙肝疫苗由于潜在安全性问题,现在已由基因工程疫苗所替代,但是,基因工程乙肝疫苗应用过程中也存在一些问题,其中酵母苗成本低,母婴阻断效果好,但体液免疫水平较低,所以GMT水平低,造成许多接种者产生低滴度抗体(〈10IU/L〉或不产生抗体,平均发生率在20%左右;重组CHO细胞疫苗糖基化水平较好,但细胞免疫水平较低,生产成本高,同样在全程免疫人群中,约有5%-10%的人不产生保护性抗体或抗体水平很低,老年人群比例尤高。现有疫苗也不能打破乙肝患者或乙肝病毒携带者机体的免疫耐受使之清除病毒,另外,对有可能逃避现有疫苗保护作用的HBsAg突变株存在争议。本文在构建出乙肝核酸疫苗的基础上,考察了CpG对乙肝核酸疫苗及基因重组乙肝疫苗免疫效果的影响。CpG- ODN作为佐剂可促进HBV基因疫苗诱导Balb/c小鼠产生的细胞免疫应答,其佐剂效应主要由于CpG基序的存在。乙肝疫苗用量减少三倍时,诱导抗体产生水平和小鼠阳转数量皆无明显改变,说明CpG对诱导体液免疫具有较好的增强作用。这可能是由于其增强了机体对乙肝基因重组疫苗的反应敏感性,从而降低疫苗的ED50,减少了疫苗的用量CpG与基因重组(CHO)乙肝疫苗联合免疫小鼠的实验中,无论从小鼠的阳转率还是小鼠的阳转时间均高于或早于CpG与乙肝核酸疫苗联合免疫的实验。应用CpG-寡聚脱氧核苷酸(CpG-ODN)与不同剂量HBV疫苗配伍分别免疫小鼠后抗-HBs阳转率及抗-HBs水平分别较单用核酸疫苗的对照组高3倍和2倍。而CpG和重组HBV疫苗配伍免疫后抗-HBs阳转率和阳转时间均高于和早于CpG与核酸疫苗组。加入CpG-ODN后,即使重组HBV疫苗用量减少3倍,其诱导抗-HBs阳转率和水平亦无改变。这样有望在人类应用上更有效、经济。
[Abstract]:Vaccination of hepatitis B vaccine is an important measure to prevent and control the spread of hepatitis B. due to potential safety problems, blood source hepatitis B vaccine has now been replaced by genetic engineering vaccine, but, There are also some problems in the application of genetically engineered hepatitis B vaccine, including low cost of yeast vaccine, good blocking effect of mother and child, but low level of humoral immunity, so the level of GMT is low, resulting in low titer antibody (< 10 IUP / L > or no antibody) produced by many inoculators. The average incidence was about 20%, the glycosylation level of recombinant CHO cell vaccine was good, but the level of cellular immunity was lower and the production cost was high. In the same population, about 5- 10% of the whole immune population did not produce protective antibody or antibody level was very low. The existing vaccine can not break the immune tolerance of hepatitis B patients or hepatitis B carriers to clear the virus. In addition, there is controversy about the HBsAg mutants that may escape the protective effect of the existing vaccine. Based on the construction of hepatitis B nucleic acid vaccine, the effect of CpG on the immune effect of hepatitis B nucleic acid vaccine and recombinant hepatitis B vaccine. CpG- ODN as adjuvant can promote the cellular immune response of Balb/c mice induced by HBV gene vaccine. The adjuvant effect was mainly due to the existence of CpG motif. When the dosage of hepatitis B vaccine decreased by three times, the level of antibody production and the number of positive transformation in mice did not change obviously. It is suggested that CpG can enhance humoral immunity, which may be due to its enhanced sensitivity to recombinant hepatitis B vaccine. Thus reducing the ED50 of the vaccine and reducing the dosage of the vaccine CpG and recombinant hepatitis B vaccine co-immunized mice, Both the positive conversion rate of mice and the positive transition time of mice were higher or earlier than that of CpG combined with hepatitis B nucleic acid vaccine. Anti-HBs were immunized with CpG- oligodeoxynucleotides (CpG-ODN) and different doses of HBV vaccine respectively. The positive conversion rate and anti-HBs level of CpG and recombinant HBV vaccine were 3 and 2 times higher than those of the control group, respectively, and the positive conversion rate and time of CpG and recombinant HBV vaccine were higher than and earlier than those of CpG and nucleic acid vaccine group. After the addition of CpG-ODN, the positive conversion rate and time of anti-HBs positive transformation were higher than those of CpG and nucleic acid vaccine group. Even if the dosage of recombinant HBV vaccine is reduced threefold, the positive conversion rate and level of anti-HBs induced by recombinant HBV vaccine will not change, which is expected to be more effective and economical in human application.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R392

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