Mining slime mold for susceptibility genes to fungi

描述(申请人提供)：真菌疾病是当前医疗实践中的一个主要临床问题。寄主遗传学与寄主易感性之间的关系是医学真菌学领域中一个尚未解决的主要问题。虽然有间接证据表明真菌疾病的易感性是由宿主遗传因素决定的，但这一领域相对来说还没有被探索。目前用于识别哺乳动物抗性和易感基因的技术繁琐、缓慢且效率低下，迫切需要新的方法。对于人类霉菌病来说，许多类型的真菌疾病在人类人群中发生的频率相对较低，这使得使用标准遗传方法的困难变得更加复杂。我们实验室最近证实，人类致病真菌新生隐球菌与变形虫捕食性动物棘阿米巴和盘状鞭毛虫的相互作用与哺乳动物巨噬细胞的相互作用非常相似。我们的团队已经证明，新生隐孢子虫可以感染盘状芽孢杆菌，在细胞内复制，并杀死阿米巴细胞。盘状芽孢杆菌是一种黏菌，已被证明是研究趋化和细胞间信号转导等细胞过程的一种非常有用的系统。盘状芽孢杆菌可以作为新生隐形芽孢杆菌的宿主，这一事实为利用这种可遗传延展的变形体宿主来剖析简单真核生物中宿主与病原体的相互作用提供了机会。这项应用建议利用这个系统来鉴定盘状芽孢杆菌的敏感性和抗性基因，从而在巨噬细胞中鉴定出同源的哺乳动物基因。我们预计，这种方法的新颖性与盘状芽孢杆菌系统实验的多功能性相结合，将导致识别从标准真菌-巨噬细胞实验中不立即明显的遗传途径。

DESCRIPTION (provided by applicant): Fungal diseases are a major clinical problem in current medical practice. A major unsolved problem in the field of medical mycology is the relationship between host genetics and host susceptibility. Although there is circumstantial evidence that susceptibility to fungal diseases is determined by host genetic factors, this area is relatively unexplored. Current technologies for identifying resistance and susceptibility genes in mammals are cumbersome, slow, and inefficient and, new approaches are urgently needed. For human mycoses the difficulties in using standard genetic approaches are compounded by the fact that many types of fungal diseases occur at relatively low frequency in human populations. Our laboratory has recently established that the interactions of the human pathogenic fungus Cryptococcus neoformans with the ameboid predators Acanthamoeba castellani and Dictostylium discoideum are very similar to that observed with mammalian macrophages. Our group has shown that C. neoformans can infect D. discoideum, replicate intracellularly, and kill the amoeboid cells. D. discoideum is a slime mold, which has proven to be an extremely useful system for the studying such cellular processes as chemotaxis and cell-to-cell signaling. The fact that D. discoideum can be host for C. neoformans provides the opportunity to use this genetically malleable ameboid host to dissect host-pathogen interactions in a simple eukaryote. This application proposes to exploit this system to identify D. discoideum susceptibility and resistance genes that can lead to the identification of homologous mammalian genes in macrophages. We anticipate that the novelty of this approach combined with the experimental versatility of the D. discoideum system will lead to the identification of genetic pathways that are not immediately obvious from standard fungal-macrophage experiments.