BIOCHEMICAL CYTOLOGY OF HOST-PARASITE INTERACTIONS IN PARASITIC PROTOZOA

利什曼原虫和弓形虫的细胞和分子生物学 作为细胞内寄生的模型被研究。重点放在 关于生物化学功能和基因结构的表征 它们的表膜(SM)和分泌的蛋白质来定义 这些成分在寄生虫生存和发育中的作用。 编码锥虫表面膜独特酶3‘-的基因。 核苷酸酶已被鉴定、克隆和部分测序。 多诺瓦尼。同样，杜氏乳杆菌的全长基因组克隆 分泌型酸性磷酸酶基因正在测序中。这件事的命运 受感染的巨噬细胞内的酶也在研究中。方法 是为大量连续体外培养而设计的 来自多诺瓦尼乳杆菌和其他几种细菌的传染性无鞭毛体(Am-) 物种。这些AM-是关于他们的细胞的特征的 生物学和生物化学。在分子水平上，有几个基因已经 由am-和以唯一或不同的方式表示的标识 这些都被用作研究寄生虫基因调控的探针。 分化和细胞周期发育。更进一步，生理学研究 已经证明利什曼原虫和克里西迪亚都使用甲基化作为 一种对其表面进行快速和可逆改性的方法 膜蛋白原位表达。最后，一种独特的5‘-核苷酸酶 在弓形虫速殖子表膜和 一种由五氯苯酚产生的探针正被用来鉴定这一基因 蛋白。 目前的结果已经确定了潜在的目标，即 与开发新的/改进的诊断有关， 针对这些重要疾病的化疗和免疫预防药物 人类病原体。

The cell and molecular biology of both Leishmania and Toxoplasma are investigated as models of intracellular parasitism. Emphasis is placed on characterizing both the biochemical functions and gene structure of their surface membrane (SM) and secreted proteins toward defining the roles of these constituents in parasite survival and development. A gene encoding the unique, trypanosomatid surface membrane enzyme, 3'- nucleotidase has been identified, cloned and partially sequenced from L. donovani. Similarly, full length genomic clones of an L. donovani secretory acid phosphatase gene are being sequenced. The fate of this enzyme within infected macrophages is also being investigated. Methods were devised for the continuous in vitro cultivation of large quantities of infectious amastigotes (Am-) from L. donovani and several other species. These Am- are being characterized with regard to their cell biology and biochemistry. At the molecular level, several genes have been identified which are uniquely or differentially expressed by Am- and these are being used as probes to study parasite-gene-regulated differentiation and cell cycle development. Further, physiologic studies have demonstrated that both Leishmania and Crithidia use methylation as a means for the rapid and reversible modification of their surface membrane proteins in situ. Finally, a unique 5'-nucleotidase was identified in the surface membrane of Toxoplasma gondii tachyzoites and a PCP-generated probe is being used to identify the gene for this protein. The current result have identified potential targets which are of relevance toward the development of new/improved diagnostic, chemotherapeutic and immunoprophylactic agents against these important human pathogens.