Influences of glycosylation on antigenicity, immunogenicity, and protective efficacy of Ebola virus GP DNA vaccines
Influences of glycosylation on antigenicity, immunogenicity, and protective efficacy of Ebola virus GP DNA vaccines
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DOI：
10.1128/jvi.02098-06
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发表时间：
2007-02-01
影响因子：
5.4
通讯作者：
Schmaljohn, Connie
中科院分区：
文献类型：
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作者：
Dowling, William;Thompson, Elizabeth;Schmaljohn, Connie
埃博拉病毒（EBOV）包膜糖蛋白（GP）是保护性免疫的主要目标。成熟的GP由两个二硫化物连接的亚基GP1和膜结合的GP2组成。GP与N链和o链碳水化合物高度糖基化。我们测量了GP糖基化对抗原性、免疫原性和保护作用的影响，通过测试由缺失n链糖基化位点的GP基因或中央高变粘蛋白区缺失的GP基因组成的DNA疫苗。我们发现，两个n链GP2糖基化位点中的一个突变对GP的抗原性和免疫原性非常不利。我们的数据表明，这可能是由于GP2和GP1无法在细胞表面二聚化，并表明该位点的糖基化是实现GP2和GP1构象完整性所必需的。相比之下，GP1上的两个n -连锁位点（位于GP上先前定义的保护性抗体表位的侧面）的突变可能通过揭开表位来增强免疫原性。我们进一步发现，虽然在体外去除粘蛋白区域对抗原性没有明显影响，但它对小鼠保护性免疫的激发有负面影响。此外，我们证实了GP中先前鉴定的b细胞和t细胞表位的存在，但表明当单独分析时，它们既不是绝对需要的，也不是对EBOV产生保护性免疫的充分条件。最后，我们确定了GP的其他可能包含相关抗体或t细胞表位的潜在区域。
The Ebola virus (EBOV) envelope glycoprotein (GP) is the primary target of protective immunity. Mature GP consists of two disulfide-linked subunits, GP1 and membrane-bound GP2. GP is highly glycosylated with both N- and O-linked carbohydrates. We measured the influences of GP glycosylation on antigenicity, immunogenicity, and protection by testing DNA vaccines comprised of GP genes with deleted N-linked glycosylation sites or with deletions in the central hypervariable mucin region. We showed that mutation of one of the two N-linked GP2 glycosylation sites was highly detrimental to the antigenicity and immunogenicity of GP. Our data indicate that this is likely due to the inability of GP2 and GP1 to dimerize at the cell surface and suggest that glycosylation at this site is required for achieving the conformational integrity of GP2 and GP1. In contrast, mutation of two N-linked sites on GP1, which flank previously defined protective antibody epitopes on GP, may enhance immunogenicity, possibly by unmasking epitopes. We further showed that although deleting the mucin region apparently had no effect on antigenicity in vitro, it negatively impacted the elicitation of protective immunity in mice. In addition, we confirmed the presence of previously identified B-cell and T-cell epitopes in GP but show that when analyzed individually none of them were neither absolutely required nor sufficient for protective immunity to EBOV. Finally, we identified other potential regions of GP that may contain relevant antibody or T-cell epitopes.