Transcript expression analysis of putative Trypanosoma brucei GPI-anchored surface proteins during development in the tsetse and mammalian hosts.
Transcript expression analysis of putative Trypanosoma brucei GPI-anchored surface proteins during development in the tsetse and mammalian hosts.
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DOI：
10.1371/journal.pntd.0001708
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发表时间：
2012
影响因子：
3.8
通讯作者：
Aksoy S
中科院分区：
文献类型：
--
作者：
Savage AF;Cerqueira GC;Regmi S;Wu Y;El Sayed NM;Aksoy S
人类非洲锥虫病是一种由布氏锥虫寄生虫引起的毁灭性疾病。锥虫生活在采采蝇和哺乳动物的细胞外。锥虫体表面蛋白可以直接与宿主环境相互作用，使寄生虫能够有效地建立和维持感染。糖基磷脂酰肌醇（GPI）锚定是真核生物表面蛋白的一种常见的翻译后修饰。于T.在布鲁氏菌中，已经鉴定了三种GPI锚定的主要表面蛋白：变体表面糖蛋白（VSG）、前环酸性重复蛋白（PARP或原环蛋白）和布鲁氏菌富含丙氨酸的蛋白（BARP）。本研究的目的是从T.布氏杆菌基因组，并表征在采采蝇和哺乳动物宿主的周期性发育过程中的一个子集的表达谱。对假定的T.通过Big PI算法对布氏杆菌蛋白质进行分析，共鉴定出163个GPI锚定蛋白，其中106个未知功能。第二GPI锚预测算法（FragAnchor），信号肽和跨膜结构域预测软件的应用导致25个推定的假设蛋白质的鉴定。使用半定量RT-PCR分析了具有假设功能的81个基因产物的阶段调控表达。这些基因的表达大多被发现是上调锥虫感染采采蝇唾液腺和腺胃组织中，38%的特异性表达，只有寄生虫感染唾液腺组织。在哺乳动物感染性亚循环锥鞭毛体中也检测到唾液腺特异性表达的所有基因的转录物，这表明这些推定的蛋白质在哺乳动物宿主中的入侵和/或建立过程中可能起作用。这些结果代表了第一个大规模的报告的差异表达的未知基因编码的预测T。布鲁氏菌表面蛋白在整个发育周期。这些知识可能会形成未来新的传输阻断策略，对亚循环寄生虫的发展的基础。人类非洲锥虫病（HAT）是一种由非洲锥虫引起的致命疾病，由受感染的采采蝇传播。目前，还没有预防哺乳动物感染的疫苗。在锥虫表面上表达的蛋白质可以影响宿主环境并允许其传播。这些蛋白质可能被脊椎动物宿主的适应性免疫系统所利用，可以作为未来的疫苗靶点。这些目前未知的蛋白质的鉴定和表征可以帮助我们制定改变宿主环境的策略，使其不适合寄生虫，从而减少疾病传播。虽然有广泛的知识锥虫在哺乳动物宿主的发展，少知采采蝇的分子事件，特别是唾液腺阶段。我们使用了一种计算机模拟的方法来确定推定的表面蛋白从已知的布氏锥虫基因组序列，我们描述了这些基因在采采蝇和哺乳动物宿主的发展过程中的阶段特异性表达。我们的研究结果表明，大多数未知的转录本编码预测的表面蛋白表达的寄生虫感染采采蝇唾液腺。这些数据将有助于集中在未来的调查传播阻断的方法，针对锥虫感染采采蝇唾液腺的表达抗原。
Human African Trypanosomiasis is a devastating disease caused by the parasite Trypanosoma brucei. Trypanosomes live extracellularly in both the tsetse fly and the mammal. Trypanosome surface proteins can directly interact with the host environment, allowing parasites to effectively establish and maintain infections. Glycosylphosphatidylinositol (GPI) anchoring is a common posttranslational modification associated with eukaryotic surface proteins. In T. brucei, three GPI-anchored major surface proteins have been identified: variant surface glycoproteins (VSGs), procyclic acidic repetitive protein (PARP or procyclins), and brucei alanine rich proteins (BARP). The objective of this study was to select genes encoding predicted GPI-anchored proteins with unknown function(s) from the T. brucei genome and characterize the expression profile of a subset during cyclical development in the tsetse and mammalian hosts. An initial in silico screen of putative T. brucei proteins by Big PI algorithm identified 163 predicted GPI-anchored proteins, 106 of which had no known functions. Application of a second GPI-anchor prediction algorithm (FragAnchor), signal peptide and trans-membrane domain prediction software resulted in the identification of 25 putative hypothetical proteins. Eighty-one gene products with hypothetical functions were analyzed for stage-regulated expression using semi-quantitative RT-PCR. The expression of most of these genes were found to be upregulated in trypanosomes infecting tsetse salivary gland and proventriculus tissues, and 38% were specifically expressed only by parasites infecting salivary gland tissues. Transcripts for all of the genes specifically expressed in salivary glands were also detected in mammalian infective metacyclic trypomastigotes, suggesting a possible role for these putative proteins in invasion and/or establishment processes in the mammalian host. These results represent the first large-scale report of the differential expression of unknown genes encoding predicted T. brucei surface proteins during the complete developmental cycle. This knowledge may form the foundation for the development of future novel transmission blocking strategies against metacyclic parasites. Human African Trypanosomiasis (HAT) is a fatal disease caused by African trypanosomes and transmitted by an infected tsetse fly. Presently, there are no vaccines to prevent mammalian infections. Proteins expressed on the trypanosome surface can influence the host environment and allow for their transmission. Potentially accessible to the adaptive immune systems of vertebrate hosts, these proteins could serve as future vaccine targets. Identification and characterization of these currently unknown proteins can help us develop strategies to alter the host environment, making it inhospitable for the parasite, thereby reducing disease transmission. While there is extensive knowledge about trypanosome development in the mammalian host, less is known about the molecular events in the tsetse fly, particularly the salivary gland stages. We used an in silico approach to identify putative surface proteins from the known genome sequence of Trypanosoma brucei, and we describe the stage specific expression of these genes during development in the tsetse fly and mammalian host. Our findings show that a majority of unknown transcripts encoding predicted surface proteins are expressed by the parasites infecting tsetse salivary glands. These data will help focus future investigations into transmission-blocking approaches targeting the expressed antigens of trypanosomes infecting tsetse salivary glands.
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影响因子：
2.1
作者：
LANHAM, SM;GODFREY, DG
通讯作者：
GODFREY, DG
影响因子：
56.9
作者：
Ivens, AC;Peacock, CS;Myler, PJ
通讯作者：
Myler, PJ
影响因子：
9.9
作者：
Nakayasu, Ernesto S.;Yashunsky, Dmitry V.;Almeida, Igor C.
通讯作者：
Almeida, Igor C.
影响因子：
30.8
作者：
通讯作者：
--
DOI：
10.1093/protein/10.6.673
发表时间：
1997-06-01
期刊：
PROTEIN ENGINEERING
影响因子：
--
作者：
Cserzo, M;Wallin, E;Elofsson, A
通讯作者：
Elofsson, A