SCHISTOSOME-SNAIL COMPATIBILITY: UNDERLYING MECHANISMS

我们研究的广泛目标是了解细胞和 导致人类传播的分子机制 曼氏血吸虫在某些个体宿主钉螺中的血吸虫感染 (Biomphalaria Grarata)和在其他地方传播失败。 这需要对最终导致的事件有所了解 兼容性和导致不兼容性的那些。 具体地说，我们试图识别寄生虫传播的特征 调节感染性和宿主传播的特征，这些特征决定了 易感性或抵抗力。 为了描述涉及寄生虫的分子事件 中间宿主蜗牛对复合孢子囊的识别- 在体外发生的血细胞系统将被简化为 实验分析。将放置孢子囊表面组件 在激活的珠子上。血细胞对这些孢子囊的识别- 标记的微珠将在体外通过两者的联合进行评估。 将获得蜗牛血细胞的关联指数 它们对血吸虫和蜗牛易感 它们是有抵抗力的。幼虫和寄生虫的血细胞- 暴露的蜗牛将被比对。蜗牛血浆对人体的影响 将在实验中进行评估，在实验中，孢子囊标记的珠子 在被提供给血细胞之前暴露在血浆中。电浆 将来自敏感和耐药蜗牛品系， 以及来自幼稚的寄生虫暴露的个体。 血细胞表面和血浆中的识别因子 将研究它们对血细胞结局的影响- 孢子囊遇到使用一种久经考验的细胞毒性检测系统。

Broad objectives of our research are to understand the cellular and molecular mechanisms which result in transmission of the human blood fluke Schistosoma mansoni in certain individual host snails (Biomphalaria glabrata), and the failure of transmission in others. This requires knowledge of the events which culminate in compatibility and those that result in incompatibility. Specifically we seek to identify parasite-borne characters which modulate infectivity and host-borne characters which determine susceptibility or resistance. In order to describe molecular events involved in parasite recognition by the intermediate host snail, the complex sporocyst- hemocyte system which occurs in vitro will be simplified for experimental analysis. Sporocyst surface components will be placed on activated beads. Hemocyte recognition of these sporocyst- labelled beads will be assessed by association of the two in vitro. Association indices will be obtained for hemocytes from snails which are susceptible to the schistosome and those from snails which are resistant. Hemocytes from naive and from parasite- exposed snails will be compared. The influence of snail plasma will be evaluated in experiments where the sporocyst-labelled beads are exposed to plasma before they are offered to hemocytes. Plasma will be derived from both susceptible and resistant snail strains, and from naive parasite-exposed individuals. Recognition factors on hemocyte surfaces and those from the plasma will be studied for their influence on the outcome of hemocyte- sporocyst encounters using a well tried cytotoxicity assay system.