肠道病毒71型中和表位肽SP55、SP70及VP2-28在人血清中的抗体滴度特征研究

Antibody TitersofEnterovirus 71 Neutral Epitope Peptide SP55,SP70 and VP2-28 in Patient Serum

目的:通过肠道病毒71型(EV71)阳性患者抗血清对动物模型的中和表位肽SP55、SP70及VP2-28进行评价,研究动物中确定的表位肽与人抗血清的反应特征。方法:采用体外微量中和实验的方法,筛选高中和抗体滴度的患儿血清共13个样本,其中2 048倍样本8个,4 096倍样本4个,8 192倍样本1个。使用MEGA5. 0软件对目标中和表位肽SP55、SP70和VP2-28进行序列比对,确定最终使用序列。ELISA分析3个中和表位肽分别在N端和C端偶联BSA的情况下,其在抗血清中的抗体滴度。结果:EV71的中和抗体水平会随着EV71总抗体水平的升高而升高。SP55肽无论在N端还是C端偶联牛血清白蛋白BSA都具体较高的抗体滴度,但SP55肽C端偶联BSA的抗体滴度随着抗血清的中和滴度的升高而升高。VP2-28肽N端偶联BSA的抗体滴度普遍高于C端偶联。SP70肽在人抗血清中的抗体滴度普遍不高,其中N端偶联的SP70肽好于C端偶联。结论:SP55肽和VP2-28肽在人抗血清中具有较高的抗体滴度,而不同方向的偶联对于中和表位肽具有很大影响。

Objective The neutralizing epitope peptides SP55,SP70 and VP2-28 screenedfrom animal model were evaluated by Enterovirus 71 positive patient’s antisera to investigate the response characteristics of the epitope peptides identified in the animals to human antisera. Method In this study,we used in vitro micro-neutralization assay to screen a total of 13 serum samples from EV71 positivepatients with highneutralizingantibodytiters,of which 8 samples were 2 048 times,4 samples were 4 096 times and 1 sample was 8 192 times. The targeted neutralizing epitope peptides,SP55,SP70 and VP2-28,were aligned using MEGA5. 0 software to determine the end-use sequence. ELISA was used to analyze the antibody titers of 3 neutralizing epitope peptides coupled with BSAat N-terminal or C-terminal in EV71 positivepatient’ s antiserum. Results EV71 antibody titers were increased with the neutralizing antibody titers of EV71 positive patient’ s antisera. Antibody titers ofpeptide SP55 * with BSA coupled in N-terminus and C-terminus,both had high antibody titers,whereas SP55*-B antibody titers increased with neutralizing antibody titers. B-VP2-28 * antibody titer was generally higher than VP2-28 *-B. B-SP70 * antibody titershigher than SP70*-B,but both were not high. Conclusion Neutralizing epitope SP55 * and VP2-28 * peptides have higher antibody titers in EV71 positivepatient’s antisera,whereas BSA coupling in different terminator has a great influence on neutralizing epitope peptides.