在本氏烟植物中高效生产带有 M2e 流感表位的嵌合人乳头瘤病毒 16 L1 蛋白。

BACKGROUND

Human papillomavirus 16 (HPV-16) L1 protein has the capacity to self-assemble into capsomers or virus-like particles (VLPs) that are highly immunogenic, allowing their use in vaccine production. Successful expression of HPV-16 L1 protein has been reported in plants, and plant-produced VLPs have been shown to be immunogenic after administration to animals.

RESULTS

We investigated the potential of HPV-16 L1 to act as a carrier of two foreign epitopes from Influenza A virus: (i) M2e2-24, ectodomain of the M2 protein (M2e), that is highly conserved among all influenza A isolates, or (ii) M2e2-9, a shorter version of M2e containing the N-terminal highly conserved epitope, that is common for both M1 and M2 influenza proteins. A synthetic HPV-16 L1 gene optimized with human codon usage was used as a backbone gene to design four chimeric sequences containing either the M2e2-24 or the M2e2-9 epitope in two predicted surface-exposed L1 positions. All chimeric constructs were transiently expressed in plants using the Cowpea mosaic virus-derived expression vector, pEAQ-HT. Chimeras were recognized by a panel of linear and conformation-specific anti HPV-16 L1 MAbs, and two of them also reacted with the anti-influenza MAb. Electron microscopy showed that chimeric proteins made in plants spontaneously assembled in higher order structures, such as VLPs of T = 1 or T = 7 symmetry, or capsomers.

CONCLUSIONS

In this study, we report for the first time the transient expression and the self-assembly of a chimeric HPV-16 L1 bearing the M2e influenza epitope in plants, representing also the first record of a successful expression of chimeric HPV-16 L1 carrying an epitope of a heterologous virus in plants. This study further confirms the usefulness of human papillomavirus particles as carriers of exogenous epitopes and their potential relevance for the production in plants of monovalent or multivalent vaccines.

背景

人乳头瘤病毒 16 型（HPV-16）L1 蛋白具有自我组装成衣壳或病毒样颗粒（VLPs）的能力，这些颗粒具有高度的免疫原性，允许它们用于疫苗生产。HPV-16 L1 蛋白已在植物中成功表达，并且已经证明，在动物中给药后，植物产生的 VLPs 具有免疫原性。

结果

我们研究了 HPV-16 L1 作为两种来自甲型流感病毒的外源性表位载体的潜力：（i）M2e2-24，M2 蛋白（M2e）的外显子，它在所有甲型流感病毒分离株中高度保守，或（ii）M2e2-9，M2e 的较短版本，包含 N 端高度保守的表位，这在 M1 和 M2 流感蛋白中都很常见。使用经过优化的具有人类密码子使用的合成 HPV-16 L1 基因作为骨架基因，设计了四个嵌合序列，这些序列在两个预测的表面暴露的 L1 位置包含 M2e2-24 或 M2e2-9 表位。所有嵌合构建体均使用豇豆花叶病毒衍生的表达载体 pEAQ-HT 在植物中瞬时表达。嵌合体被一组线性和构象特异性抗 HPV-16 L1 MAbs 识别，其中两个也与抗流感 MAb 反应。电子显微镜显示，植物中产生的嵌合蛋白自发组装成更高阶的结构，例如 T = 1 或 T = 7 对称的 VLPs 或衣壳。