THE ROLE OF THE LIPOPHOSPHOGLYCAN OF LEISHMANIA IN VECTOR COMPETENCE
THE ROLE OF THE LIPOPHOSPHOGLYCAN OF LEISHMANIA IN VECTOR COMPETENCE
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DOI：
10.1017/s0031182000075727
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发表时间：
1994-01-01
期刊：
影响因子：
2.4
通讯作者：
PIMENTA, PF
中科院分区：
文献类型：
--
作者：
SACKS, DL;SARAIVA, EM;PIMENTA, PF
利什曼原虫前鞭毛体表面脂多糖(LPG)表达阶段和物种特有的多态，这种多态是由磷酸化低聚糖重复序列的类型和数量的变化所定义的。我们研究了这些多态结构如何控制沙蝇媒介中可传播感染的发展，以及媒介能力的物种特异性。原环前鞭毛体显示出与有能力的载体的中肠上皮细胞结合的固有能力。这一能力在它们转变为后环前鞭毛虫的过程中丧失，允许感染期寄生虫选择性地释放和向前迁移，以便随后通过叮咬传播。中肠附着和释放是由LPG上末端暴露的糖的发育修饰控制的，这取决于利什曼原虫的种类，涉及末端侧链糖的替代或封顶，末端侧链糖的丢失，中性封顶糖的替代或丢失。在某些情况下，参与中肠黏附的阶段特定的末端糖也是物种特有的，这些差异对中肠黏附的影响程度强烈地预测了载体的能力。
The surface lipophosphoglycans (LPG) of Leishmania promastigotes express stage- and species-specific polymorphisms that are defined by variations in the type and number of phosphorylated oligosaccharide repeats. We have studied how these polymorphic structures control the development of transmissible infections in the sandfly vector as well as the species-specificity of vectorial competence. Procyclic promastigotes displayed an inherent capacity to bind to midgut epithelial cells of a competent vector. This capacity was lost during their transformation to metacyclic promastigotes, permitting the selective release and anterior migration of infective-stage parasites for subsequent transmission by bite. Midgut attachment and release were found to be controlled by developmental modifications in terminally exposed saccharides on LPG, which, depending on the species of Leishmania, involved either substitution or capping of terminal side-chain sugars, loss of terminal side-chain sugars, substitution or loss of neutral capping sugars. The stage-specific terminal sugars involved in midgut adhesion are, in some cases, also species-specific, and the extent to which these differences affect midgut attachment, forcefully predicted vectorial competence.