Ag85B表位多肽对体外单核细胞增殖影响的研究

Effect of Epitope Peptides of Ag85B on the Proliferation of Human Peripheral Blood Mononuclear Cell

目的通过观察Ag85B不同表位多肽对人外周血单个核细胞(PBMC)增殖的影响,筛选出增殖活性较强的Ag85B表位多肽,为制备结核新疫苗提供理论基础。方法采用的实验方法为人工预测Ag85B的表位,并合成多肽。将不同表位多肽体外刺激人外周血单个核细胞,利用CCK-8法测定单核细胞同一时相的吸光值,计算各自的增殖指数,并与BCG、Ag85B抗原等作对比。结果①Ag85B表位多肽组的OD450值及增殖指数均高于阴性对照组,且高于传统抗原BCG;②5条多肽中,28aa多肽的OD450值及增殖指数最高,且显著高于BCG(POD450=0.001<0.01,P增殖指数=0.013<0.05),但低于PHA;③28aa多肽的OD450值及增殖指数明显低于Ag85B,差异有统计学意义(POD450=P增殖指数=0.000<0.01)。结论预测的Ag85B表位多肽抗原具有一定的免疫原性,其中28aa多肽可作为优势表位多肽,但是否可用于表位多肽疫苗候选抗原还需进一步研究。

Objective To explore the effect of epitope peptides of Ag85B on in vitro proliferation of human peripheral blood mononuclear cell（PBMC） and to provide theoretical basis for preparation of new tuberculosis vaccines.Methods The epitope of Ag85B was artificially predicted,and polypeptide of Ag85B was then synthesized.After activated by different antigens at the same hours,the proliferation activity of PBMC was analyzed by CCK-8,and compared with those of stimulated by BCG and Ag85B.Results The all five epitope polypeptides of Ag85B activated PBMC proliferation,their OD450 values and proliferation index were higher than that of the control group and traditional BCG antigen.The OD450 value and proliferation index of 28aa epitope peptide was the best in five epitope polypeptides of Ag85B.The OD450 value and proliferation index of peptide of Ag85B were significantly higher than that of BCG（POD4500.01,PPI0.05）,but less than that of PHA.The OD450 value and proliferation index of peptide 28aa were significantly lower than that of Ag85B（P0.01）.Conclusion The predicted antigens of epitope polypeptides of Ag85B have certain immunogenicity,of which 28aa peptides can be used as an advantage peptide.The further research would be needed to confirm Ag85 as a candidate for epitope polypeptide vaccine.