Soares Rodrigo P, Margonari Carina, Secundino Nágila C, Macêdo Maria E, da Costa Simone M, Rangel Elizabeth F, Pimenta Paulo F, Turco Salvatore J
Laboratory of Medical Entomology, Centro de Pesquisas René Rachou/FIOCRUZ, 30190-002 Belo Horizonte, MG, Brazil.
J Biomed Biotechnol. 2010;2010:439174. doi: 10.1155/2010/439174.
The interaction between Leishmania and sand flies has been demonstrated in many Old and New World species. Besides the morphological differentiation from procyclic to infective metacyclic promastigotes, the parasite undergoes biochemical transformations in its major surface lipophosphoglycan (LPG). An upregulation of beta-glucose residues was previously shown in the LPG repeat units from procyclic to metacyclic phase in Leishmania (Viannia) braziliensis, which has not been reported in any Leishmania species. LPG has been implicated as an adhesion molecule that mediates the interaction with the midgut epithelium of the sand fly in the Subgenus Leishmania. These adaptations were explored for the first time in a species from the Subgenus Viannia, L. (V.) braziliensis with its natural vectors Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani. Using two in vitro binding techniques, phosphoglycans (PGs) derived from procyclic and metacyclic parasites were able to bind to the insect midgut and inhibit L. braziliensis attachment. Interestingly, L. braziliensis procyclic parasite attachment was approximately 11-fold greater in the midgut of L. whitmani than in L. intermedia. The epidemiological relevance of L. whitmani as a vector of American Cutaneous Leishmaniasis (ACL) in Brazil is discussed.
利什曼原虫与白蛉之间的相互作用已在许多新旧世界的物种中得到证实。除了从前循环型到感染性后循环型前鞭毛体的形态分化外，寄生虫的主要表面脂磷壁酸（LPG）还会发生生化转变。先前已表明，在巴西利什曼原虫（维氏亚属）中，LPG重复单元中的β-葡萄糖残基从前循环期到后循环期会上调，这在任何利什曼原虫物种中均未报道过。在利什曼原虫亚属中，LPG被认为是一种粘附分子，介导与白蛉中肠上皮的相互作用。首次在维氏亚属的一个物种巴西利什曼原虫及其天然载体中间罗蛉和惠氏罗蛉中探索了这些适应性变化。使用两种体外结合技术，从前循环型和后循环型寄生虫衍生的磷酸聚糖（PGs）能够与昆虫中肠结合并抑制巴西利什曼原虫的附着。有趣的是，巴西利什曼原虫前循环型寄生虫在惠氏罗蛉中肠的附着比在中间罗蛉中肠大约高11倍。本文讨论了惠氏罗蛉作为巴西美洲皮肤利什曼病（ACL）载体的流行病学相关性。
