HIV-1膜抗原部分糖基化位点改造对免疫原性及假病毒形成的影响

The impact of site-dlrected deglycosylation of the HIV-1 envelope （Env） on its immunogenicity and assembly of functional pseudovirus

目的研究HIV-1膜蛋白（Env）特定糖基化位点改造对Env免疫原性及功能性假病毒形成能力的影响。方法采用环形诱变，DpnⅠ筛选的方法对Env进行定点突变，单周期感染试验检测功能性假病毒形成能力，免疫小鼠，利用假病毒中和试验与ELISPOT分别检测突变对中和抗体和T细胞分泌Env特异的IFN-γ的影响。结果N197Q突变体使Env诱导中和抗体的能力提高而诱导T细胞分泌Env特异的IFN-γ的能力降低，并使Env不能形成功能性假病毒；G2突变体（N624Q，N637Q）诱导的中和抗体能更好地中和假病毒74-2，但中和假病毒Wt的能力下降，对Env诱导T细胞分泌Env特异的IFN-γ的能力和功能性假病毒形成无明显影响。结论特定糖基化位点的改造影响假病毒的形成及Env的免疫原性。

Objective To study the influence of site-directed deglycosylation of the HIV-1 envelope （Env） on its immunogenicity and assembly of functional pseudovirus. Methods Site-directed deglycosylation were performed using cycling mutagenesis and selection of mutants with Dpn Ⅰ. Single-cycle infection assay was employed to analyze the effect of the mutations on the ability of functional pseudovirus assembly. The influence of deglycosylations on the immunodeficiency of Env was evaluated using pseudovirusbased neutralization assay and ELISPOT assay. Results Mutant N197Q induced higher neutralization activities for both pseudoviruses, but lower Env-specific T-cell response. And N197Q rendered the Env to lose the ability of functional pseudovirus assembly. Mutant G2 induced higher neutralization activities for pseudovirus 74-2 but lower for pseudovirus Wt, and had almost no influence on Env-specific T-cell response and functional pseudovirus forming. Conclusion The site-directed deglycosylation of the HIV-1 Env affects the pseudovirus forming and its immunogenicity.