DEVELOPMENTAL BIOLOGY OF LEISHMANIA PROMASTIGOTES

利什曼原虫前鞭毛体的发育生物学

• 批准号: 3768760
• 负责人: D L SACKS
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3768760
• 关键词: Leishmania; Leishmania major; Psychodidae; antimicroorganism antibody; biological polymorphism; glycolipids; leishmaniasis; life cycle; monoclonal antibody; posttranslational modifications

During growth within the sandfly and within axenic, Leishmania promastigotes undergo differentiation from a dividing noninfective stage to a resting infective or metacyclic stage which is uniquely adapted for life in the vertebrate. This development is accompanied by a substantial modification of the surface lipophosphoglycan (LPG) which is the major surface glycoconjugate of these cells. In the case of L. major and L. donovani promastigotes derived from culture, the structural polymorphism is expressed as a loss of terminal galactose residues on the LPG. Using stage specific monoclonal antibodies against L. major LPG, identical structural changes in LPG have now been demonstrated for metacyclics found within the natural vector, P. papatasi, and in particular those metacyclics found to emerge from the proboscis during force feeding experiments. The substitution or capping of terminally exposed sugars with other sugars with other sugar residues was shown to be the molecular mechanism underlying the attachment and release of promastigotes from midgut epithelial cells during metacyclogenesis in the fly. The interspecific polymorphisms of these terminal sugars appears to influence the species specificity of vectorial competence observed in nature. Thus, the ability of procyclic promastigotes of the purified procyclic LPG of various Leishmania species to bind to midgut epithelial cells of various sandfly species forcibly predicts vectorial competence.

在白蛉和无菌环境中生长期间，利什曼原虫 前鞭毛体从分裂的非感染阶段分化 到静息感染或后循环阶段，该阶段特别适合 脊椎动物的生命。 这一发展伴随着巨大的 表面脂磷酸聚糖（LPG）的修饰是主要的 这些细胞的表面糖缀合物。以 L. Major 和 L. 杜诺瓦尼前鞭毛体来源于培养物，结构多态性 表示为 LPG 上末端半乳糖残基的损失。使用 针对 L. Major LPG 的阶段特异性单克隆抗体，相同 液化石油气的结构变化现已被证明适用于后环化合物 在自然媒介 P. papatasi 中发现，特别是那些 在强制喂食期间发现从长鼻中出现后环物质 实验。末端暴露糖的取代或封端 与其他糖和其他糖残基的结合被证明是分子 前鞭毛体附着和释放的机制 果蝇后生过程中的中肠上皮细胞。 这 这些末端糖的种间多态性似乎影响 在自然界中观察到的矢量能力的物种特异性。因此， 纯化的原环LPG的原环前鞭毛体的能力 各种利什曼原虫种类与各种中肠上皮细胞结合 白蛉物种强制预测矢量能力。