Maximizing antigen targeting to the proteasome for gene-based vaccines
Maximizing antigen targeting to the proteasome for gene-based vaccines
复制标题
DOI：
10.1016/j.ymthe.2004.05.035
复制
发表时间：
2004-09-01
影响因子：
12.4
通讯作者：
Barry, MA
中科院分区：
文献类型：
--
作者：
Andersson, HA;Barry, MA
在基于基因的疫苗接种期间，野生型或免疫逃避性抗原可以驱动针对显性和次显性表位的弱CD8（+）T细胞应答。对于许多抗原，融合到泛素（Ub），使其靶向蛋白酶体规避这个问题。尽管这种方法在大多数情况下有效，但对于一个抗原子集，Ub融合并不能改善免疫应答。为了确定这些失败发生的原因，我们详细评估了蛋白酶体靶向的“规则”，这些规则已应用于哺乳动物疫苗研究，但实际上是在酵母系统中定义的。为此，我们将一系列工程化的Ub基因与绿色荧光蛋白（GFP）融合，并测试了它们将GFP靶向蛋白酶体以增强抗原加工和CD8（+）T细胞应答的能力。在这里，我们证明，Ub融合介导的蛋白酶体靶向增强CD8（+）的反应，而不是通过增强蛋白质翻译。我们还发现，几种酵母定义的Ub结构未能靶向哺乳动物细胞中的蛋白酶体，同样未能增强小鼠中转基因特异性CD8（+）T细胞应答。相比之下，当将优化的构建体应用于靶向流感病毒核蛋白时，小鼠中针对其难治性亚显性表位的CD8（+）应答增强。这项工作表明，Ub融合具有增强CD8（+）应答的功效，特别是针对亚显性抗原表位，只要构建体被优化用于哺乳动物使用。
Wild-type or immunoevasive antigens can drive weak CD8(+) T-cell responses against both dominant and subdominant epitopes during gene-based vaccination. For many antigens, fusion to ubiquitin (Ub) to target them to the proteasome circumvents this problem. Although this procedure works in most cases, for one subset of antigens, Ub fusion does not improve immune responses. To determine why these failures occur, we have evaluated in detail the 'rules' for proteasome targeting that have been applied in mammalian vaccine studies, but that were actually defined in yeast systems. To do this, we fused a series of engineered Ub genes to green fluorescent protein (GFP) and tested their ability to target GFP to the proteasome for enhanced antigen processing and CD8(+) T-cell responses. Here we demonstrate that Ub fusion mediates enhanced CD8(+) responses by proteasome targeting rather than by enhancing protein translation. We also show that several of the yeast-defined Ub constructs failed to target the proteasome in mammalian cells and likewise failed to enhance transgene-specific CD8(+) T-cell responses in mice. In contrast, when mammalian-optimized constructs were applied to target the influenza virus nucleoprotein, CD8(+) responses were enhanced against its refractory subdominant epitope in mice. This work demonstrates that Ub fusion has efficacy to enhance CD8(+) responses, especially against subdominant antigen epitopes, provided constructs are optimized for mammalian use.