An engineered innate immune defense protects grapevines from Pierce disease
An engineered innate immune defense protects grapevines from Pierce disease
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DOI：
10.1073/pnas.1116027109
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发表时间：
2012-03-06
影响因子：
11.1
通讯作者：
Gupta, Goutam
中科院分区：
文献类型：
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作者：
Dandekar, Abhaya M.;Gouran, Hossein;Gupta, Goutam
我们假设，在蛋白质嵌合体中，两种先天免疫功能（病原体表面识别和裂解）的协同组合将导致一类强大的工程抗菌治疗药物，用于保护病原体。为了支持我们的假设，我们设计了这样一个嵌合体来防止革兰氏阴性苛养木杆菌（Xf），这种细菌会在多种具有经济意义的植物中引起疾病。在这里，我们报告了这种嵌合体的设计和交付，目标是Xf亚种fastidiosa (Xff)，它导致葡萄的皮尔斯病，对加利福尼亚的葡萄酒产区构成了巨大的威胁。这个嵌合体的一个结构域是一个弹性蛋白酶，它可以识别和切割Xff的保守外膜蛋白MopB。第二个结构域是一种裂解肽，cecropin B，它以保守的脂质部分为目标，并在Xff外膜上形成孔。一个灵活的连接体连接识别和裂解结构域，从而确保单个结构域的正确折叠和它们功能的协同组合。嵌合体转基因与氨基末端信号序列融合，以促进嵌合体传递到植物木质部，这是Xff定植的部位。我们发现木质部中表达的蛋白嵌合体能够直接靶向Xff，抑制Xff的生长，并显著减少与葡萄刺病相关的叶片烧焦和木质部堵塞。我们相信，涉及蛋白质嵌合体的类似策略可以开发出来，以防止由人类和植物病原体引起的许多疾病。
We postulated that a synergistic combination of two innate immune functions, pathogen surface recognition and lysis, in a protein chimera would lead to a robust class of engineered antimicrobial therapeutics for protection against pathogens. In support of our hypothesis, we have engineered such a chimera to protect against the Gram-negative Xylella fastidiosa (Xf), which causes diseases in multiple plants of economic importance. Here we report the design and delivery of this chimera to target the Xf subspecies fastidiosa (Xff), which causes Pierce disease in grapevines and poses a great threat to the wine-growing regions of California. One domain of this chimera is an elastase that recognizes and cleaves MopB, a conserved outer membrane protein of Xff. The second domain is a lytic peptide, cecropin B, which targets conserved lipid moieties and creates pores in the Xff outer membrane. A flexible linker joins the recognition and lysis domains, thereby ensuring correct folding of the individual domains and synergistic combination of their functions. The chimera transgene is fused with an amino-terminal signal sequence to facilitate delivery of the chimera to the plant xylem, the site of Xff colonization. We demonstrate that the protein chimera expressed in the xylem is able to directly target Xff, suppress its growth, and significantly decrease the leaf scorching and xylem clogging commonly associated with Pierce disease in grapevines. We believe that similar strategies involving protein chimeras can be developed to protect against many diseases caused by human and plant pathogens.