Single Amino Acid Modification of Adeno-Associated Virus Capsid Changes Transduction and Humoral Immune Profiles
Single Amino Acid Modification of Adeno-Associated Virus Capsid Changes Transduction and Humoral Immune Profiles
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DOI：
10.1128/jvi.00675-12
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发表时间：
2012-08-01
影响因子：
5.4
通讯作者：
Samulski, R. Jude
中科院分区：
文献类型：
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作者：
Li, Chengwen;Diprimio, Nina;Samulski, R. Jude
腺相关病毒（AAV）载体具有促进长期基因表达的潜力。不幸的是，体液免疫限制了患者的治疗，此外，还为矢量读取的潜在选择提供了障碍。在这项研究中，我们描述了通过体外和体内AAV5对AAV类型1（AAV1）的中和抗体（NAB）反应的全面表征。这些结果表明，一种由一种AAV类型产生的NAB无法中和其他类型的转导。我们通过证明了一个合理设计的，肌肉 - 循环的AAV2突变体，该突变体包含来自AAV1的5个氨基酸取代的NAB曲线，与父母AAV2和AAV1不同。在这里，我们发现，在残基265保留的高肌肉转导下，将THR从AAV1插入AAV2 CAPSID，同时也会改变免疫轮廓。为了更好地理解THR插入在265位的作用，我们替换了所有20种氨基酸，并评估了肌肉转导和NAB反应。在这些变体中，有8个突变体诱导比AAV2更高的肌肉转导。此外，根据抑制AAV2或突变体转导的能力来定义三类的衣壳NAB免疫谱。尽管在转导，氨基酸特性和NAB滴度或其交叉反应性之间没有发现任何关系，但这些研究绘制了参与AAV感染性所有步骤的关键衣壳基序。我们的结果表明，AAV类型不仅可以用作模板来生成具有提高转导效率的突变体，而且还可以用作重复给药的底物。
Adeno-associated virus (AAV) vectors have the potential to promote long-term gene expression. Unfortunately, humoral immunity restricts patient treatment and in addition provides an obstacle to the potential option of vector readministration. In this study, we describe a comprehensive characterization of the neutralizing antibody (NAb) response to AAV type 1 (AAV1) through AAV5 both in vitro and in vivo. These results demonstrated that NAbs generated from one AAV type are unable to neutralize the transduction of other types. We extended this observation by demonstrating that a rationally engineered, muscle-tropic AAV2 mutant containing 5 amino acid substitutions from AAV1 displayed a NAb profile different from those of parental AAV2 and AAV1. Here we found that a single insertion of Thr from AAV1 into AAV2 capsid at residue 265 preserved high muscle transduction, while also changing the immune profile. To better understand the role of Thr insertion at position 265, we replaced all 20 amino acids and evaluated both muscle transduction and the NAb response. Of these variants, 8 mutants induced higher muscle transduction than AAV2. Additionally, three classes of capsid NAb immune profile were defined based on the ability to inhibit transduction from AAV2 or mutants. While no relationship was found between transduction, amino acid properties, and NAb titer or its cross-reactivity, these studies map a critical capsid motif involved in all steps of AAV infectivity. Our results suggest that AAV types can be utilized not only as templates to generate mutants with enhanced transduction efficiency but also as substrates for repeat administration.