Pimenta P F, Turco S J, McConville M J, Lawyer P G, Perkins P V, Sacks D L
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Science. 1992 Jun 26;256(5065):1812-5. doi: 10.1126/science.1615326.
Although leishmaniasis is transmitted to humans almost exclusively by the bite of infected phlebotomine sandflies, little is known about the molecules controlling the survival and development of Leishmania parasites in their insect vectors. Adhesion of Leishmania promastigotes to the midgut epithelial cells of the sandfly was found to be an inherent property of noninfective-stage promastigotes, which was lost during their transformation to metacyclic forms, thus permitting the selective release of infective-stage parasites for subsequent transmission by bite. Midgut attachment and release was found to be controlled by specific developmental modifications in terminally exposed saccharides on lipophosphoglycan, the major surface molecule on Leishmania promastigotes.
虽然利什曼病几乎完全是通过受感染的白蛉叮咬传播给人类的，但对于控制利什曼原虫在其昆虫媒介中生存和发育的分子却知之甚少。研究发现，利什曼原鞭毛体与白蛉中肠上皮细胞的黏附是未感染阶段原鞭毛体的固有特性，在其转变为循环后期形式的过程中这种黏附特性会丧失，从而使得感染阶段的寄生虫能够选择性释放，以便随后通过叮咬进行传播。研究发现，中肠的附着和释放是由利什曼原鞭毛体主要表面分子脂磷酸聚糖末端暴露的糖类的特定发育修饰所控制的。
