Molecular Cloning, Biochemical Characterization, and Partial Protective Immunity of the Heme-Binding Glutathione S-Transferases from the Human Hookworm Necator americanus
Molecular Cloning, Biochemical Characterization, and Partial Protective Immunity of the Heme-Binding Glutathione S-Transferases from the Human Hookworm Necator americanus
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DOI：
10.1128/iai.00848-09
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发表时间：
2010-04-01
影响因子：
3.1
通讯作者：
Hotez, Peter
中科院分区：
文献类型：
--
作者：
Zhan, Bin;Perally, Samirah;Hotez, Peter
钩虫谷胱甘肽S-转移酶（GST）对寄生虫的吸血和存活至关重要，并代表了疫苗接种的潜在靶点。基于它们与Ac-GST-1（来自犬钩虫Ancylostoma caninum的GST）的序列相似性，从cDNA中分离了三个cDNA，每个cDNA编码来自人钩虫美洲钩虫Necator americanus的全长GST蛋白（分别命名为Na-GST-1、Na-GST-2和Na-GST-3）。三个N.美洲GST各自含有206个氨基酸，彼此与Ac-GST-1之间具有51%至69%的序列同一性。与其他生物的GST序列比对表明，这三个Na-GST属于线虫特异性nu-类GST家族。所有三个钠GST，在毕赤酵母中表达时，表现出低脂质过氧化物酶和谷胱甘肽结合酶活性，但高血红素结合能力，他们可能参与解毒和/或运输血红素。在两个单独的疫苗试验中，用铝胶配制的重组Na-GST-1在N.与单独用Alhydrogel免疫的组的结果相比，相比之下，在Na-GST-2或Na-GST-3的疫苗试验中没有观察到保护作用。基于这些和其他临床前数据，Na-GST-1可能被考虑用于进一步的疫苗开发。
Hookworm glutathione S-transferases (GSTs) are critical for parasite blood feeding and survival and represent potential targets for vaccination. Three cDNAs, each encoding a full-length GST protein from the human hookworm Necator americanus (and designated Na-GST-1, Na-GST-2, and Na-GST-3, respectively) were isolated from cDNA based on their sequence similarity to Ac-GST-1, a GST from the dog hookworm Ancylostoma caninum. The open reading frames of the three N. americanus GSTs each contain 206 amino acids with 51% to 69% sequence identity between each other and Ac-GST-1. Sequence alignment with GSTs from other organisms shows that the three Na-GSTs belong to a nematode-specific nu-class GST family. All three Na-GSTs, when expressed in Pichia pastoris, exhibited low lipid peroxidase and glutathione-conjugating enzymatic activities but high heme-binding capacities, and they may be involved in the detoxification and/or transport of heme. In two separate vaccine trials, recombinant Na-GST-1 formulated with Alhydrogel elicited 32 and 39% reductions in adult hookworm burdens (P < 0.05) following N. americanus larval challenge relative to the results for a group immunized with Alhydrogel alone. In contrast, no protection was observed in vaccine trials with Na-GST-2 or Na-GST-3. On the basis of these and other preclinical data, Na-GST-1 is under possible consideration for further vaccine development.