日前,，國際學(xué)術(shù)期刊《疫苗學(xué)》Vaccine在線發(fā)表了上海巴斯德所黃忠研究組題為“Identification of conserved neutralizing linear epitopes within the VP1 protein of coxsackievirus A16”的研究論文,。該論文首次報道了柯薩奇A16型病毒(CA16)的保守線性中和表位,，為設(shè)計針對CA16的廣譜性多肽疫苗奠定了基礎(chǔ),。
CA16是引起手足口病的主要病原之一,。該疾病是五歲以下兒童常見傳染病,，有可能導(dǎo)致嚴(yán)重的神經(jīng)系統(tǒng)損傷甚至死亡,。僅今年1月至2月,，我國內(nèi)地報告94,，693個病例，其中20例死亡,。然而,，到目前為止，仍無有效疫苗和治療藥物,。
上海巴斯德所黃忠研究組的前期工作發(fā)現(xiàn),，CA16滅活病毒疫苗和CA16病毒樣顆粒新型疫苗均能在小鼠體內(nèi)誘導(dǎo)產(chǎn)生中和性抗血清，所產(chǎn)生的抗血清能夠有效保護(hù)CA16病毒感染的小鼠,，說明中和抗體在體內(nèi)可以抵抗CA16病毒感染,。
基于病毒中和抗體表位的多肽疫苗是一種新型疫苗策略，由免疫原性和保護(hù)活性位點明確鑒定的多肽構(gòu)成,，避免了滅活全病毒疫苗中病毒核酸或其它非保護(hù)性蛋白可能引起的副作用,。然而，截至目前,，能夠誘導(dǎo)中和抗體產(chǎn)生的CA16中和表位尚未被鑒定出來,，限制了CA16多肽疫苗的研發(fā)。
上海巴斯德所博士研究生石金平等在黃忠研究員指導(dǎo)下,，利用該課題組前期研究獲得的CA16的病毒樣顆粒中和性抗血清,，首先評價了CA16衣殼蛋白重疊多肽與中和性抗血清的結(jié)合能力及其中和抑制作用，篩選出候選的CA16的線性中和表位肽,；然后用候選多肽免疫動物并進(jìn)行了抗血清中和效果評價，確定了位于VP1蛋白上的六個線性中和表位PEP32、PEP37,、PEP55,、PEP63、PEP71和PEP91,；通過分析獲得的CA16中和表位的序列保守性和空間位置,，發(fā)現(xiàn)這六個中和表位在CA16的不同亞型中高度保守。
本研究的完成不僅加深了我們對CA16抗原結(jié)構(gòu)的認(rèn)識,，而且為研發(fā)安全有效的CA16廣譜疫苗打下基礎(chǔ),。
該研究工作得到中國科學(xué)院“百人計劃”的經(jīng)費支持。（生物谷Bioon.com）
doi:10.1016/j.vaccine.2013.02.051
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PMID:
Identification of conserved neutralizing linear epitopes within the VP1 protein of coxsackievirus A16
Jinping Shi, Xulin Huang, Qingwei Liu, Zhong Huang,
Coxsackievirus A16 (CA16) is a major causative agent of hand, foot, and mouth disease. Immunization with inactivated whole-virus or recombinant virus-like particles (VLP) of CA16 elicits neutralizing antibodies that protect mice against lethal challenge. However, the epitope/s responsible for this induction has not been determined. In this investigation, we identified six neutralizing linear epitopes of CA16. A panel of 95 synthetic peptides spanning the entire VP1 protein of CA16 were screened by ELISA for reactivity with neutralizing antisera against CA16 VLPs, which were generated in a previous study (Vaccine 30:6642–6648). Fifteen high-binding peptides were selected and further examined for their inhibitory effect on neutralization by anti-VLP sera. Among them, six peptides with no overlap significantly inhibited neutralization. Mice immunized with these six peptides generated peptide-specific serum antibodies. The anti-peptide antisera positively detected CA16 via immunofluorescent staining and Western blot assays. More importantly, they neutralized both homologous and heterologous CA16 strains, indicating that these six peptides represented neutralizing epitopes. Sequence alignment also showed that these epitopes are extremely conserved among CA16 strains of different genotypes. These findings have important implications for the development of peptide-based broadly protective CA16 vaccines.
