Combinatorial resurfacing of Dengue envelope protein domain III antigens selectively ablates epitopes associated with serotype-specific or infection-enhancing antibody responses.
Combinatorial resurfacing of Dengue envelope protein domain III antigens selectively ablates epitopes associated with serotype-specific or infection-enhancing antibody responses.
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DOI：
10.1021/acscombsci.0c00073
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发表时间：
2020-06
影响因子：
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通讯作者：
Jennifer L Remmel;K. Beauchemin;Akaash K. Mishra;Julia C. Frei;J. Lai;C. Bailey-Kellogg;M. Ackerman
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文献类型：
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作者：
Jennifer L Remmel;K. Beauchemin;Akaash K. Mishra;Julia C. Frei;J. Lai;C. Bailey-Kellogg;M. Ackerman
表面暴露残基的诱变或“表面重塑”是可用于调节抗体识别或蛋白质引发抗体应答的能力的蛋白质工程化策略。我们应用表面重塑来工程化登革病毒包膜蛋白结构域III（DENV DIII）抗原，目标是通过选择性消融不相关和不需要的表位来将体液识别集中在感兴趣的表位上。交叉反应性但非中和性抗体有可能通过称为抗体依赖性增强的过程增强DENV感染，该过程被认为与严重的继发性异型感染相关。因此，关注与广泛交叉反应性和中和性抗体相关的表位对于理解针对DENV的人抗体应答和开发成功的DENV疫苗都是重要的。为了工程化集中于与广泛中和抗体应答相关的AG链表位的DENV DIII抗原，我们产生了DENV 2 DIII的酵母表面展示文库，其中AB环（与交叉反应性但非中和抗体应答相关）和FG环（与表型特异性抗体应答相关）被诱变以允许所有可能的氨基酸取代。保持AG链表位并同时破坏AB和FG环表位的环变体表现出高且多样的突变负荷，其适合于环交换和移植到DENV4 DIII背景中。因此，无论血清型背景如何，几种环变体均符合该抗原性标准。所得表面重构的DIII抗原可用作AG链表位聚焦探针或免疫原候选物。
Mutagenesis of surface-exposed residues, or "resurfacing", is a protein engineering strategy that can be utilized to modulate antibody recognition or the capacity of a protein to elicit antibody responses. We apply resurfacing to engineer Dengue virus envelope protein domain III (DENV DIII) antigens with the goal of focusing humoral recognition on epitopes of interest by selective ablation of irrelevant and undesired epitopes. Cross-reactive but non-neutralizing antibodies have the potential to enhance DENV infection by a process called antibody-dependent enhancement, thought to be associated with severe secondary heterotypic infection. Thus, a focus on epitopes associated with broadly cross-reactive and neutralizing antibodies is important both for understanding human antibody responses against DENV and for development of a successful DENV vaccine. To engineer DENV DIII antigens focusing on the AG strand epitope associated with broadly neutralizing antibody responses, we generated yeast surface display libraries of DENV2 DIII where the AB loop (associated with cross-reactive but non-neutralizing antibody responses) and FG loop (associated with serotype-specific antibody responses) were mutagenized to allow for all possible amino acid substitutions. Loop variants that maintained the AG strand epitope and simultaneously disrupted the AB and FG loop epitopes exhibited high and diverse mutational loads that were amenable to loop exchange and transplantation into a DENV4 DIII background. Thus, several loop variants fulfill this antigenicity criteria regardless of serotype context. The resulting resurfaced DIII antigens may be utilized as AG strand epitope-focusing probes or immunogen candidates.