柯萨奇病毒A组16型(Coxsackievirus A16，CV-A16)是手足口病(Hand, foot and mouth disease, HFMD)的重要病原体之一，其疫苗研发正在深入开展。前期我们用一株CV-A16疫苗候选株免疫恒河猴，发现其能够诱导高水平抗体应答，但并不能完全抵御感染。推测其诱导的优势抗体并非保护性抗体或其广谱中和活性不佳，因此期望从单个分子水平评估该疫苗诱导的抗体应答。前期运用Ig-seq技术对免疫前后BCR进行分析，已获得大量抗体序列信息，但尚不明确疫苗诱导的优势抗体的序列特征及功能。本研究拟进行：①将前期发现的超高频重轻链序列进行配对后经转染获得全抗体分子；②通过中和、ELISA和SPR等验证其功能，并评估其体内保护效果；③根据功能挖掘优势抗体的序列特征，分析其与疫苗保护效力不佳的潜在关联性。本研究可为CV-A16疫苗免疫保护机理研究及免疫原优化提供参考。

Coxsackievirus A16 (CV-A16) is one of the major pathogens causing hand, foot and mouth disease (HFMD).Vaccines against CV-A16 are in development. In our previous study, rhesus macaques were immunized with a CV-A16 vaccine candidate, and it can elicit high level of serum antibody responses but is not completely effective against CV-A16 challenge. We speculate that dominant antibodies induced by this candidate were insufficient to afford complete protection due to its poor broad-spectrum neutralizing activity. Therefore, exploration at the single antibody molecule level is expected to evaluate antibody responses induced by this vaccine candidate. Ig-seq technology was applied to analyze BCR sequences before and after vaccination with this candidate in rhesus monkeys in our prior studies, and quantitative sequences information was obtained. However, sequence characteristics and functional properties of the predominant antibodies elicited by the vaccine prepared by whole virus is not clear yet. This study intends to construct full-size antibodies by pairing of the ultrahigh frequency(UHF) heavy chains with UHF light chains obtained from previous studies, and to verify their function through neutralizing assays, ELISA,SPR, in vivo effectiveness tests etc., then further deep-mine the sequence characteristics based on these clear-cut functional antibodies and analyze the potential association of the properties of predominant antibodies elicited by this vaccine with the vaccine efficacy.. This study may aid in provide a reference in the investigation on protective mechanisms of CV-A16 vaccine and further optimization of the CV-A16 immunogen.