Investigation on Replicative aging in Cryptococcus neoformans populations

这项申请是一项研究提案的竞争性更新，该提案调查了 新型隐球菌，一种人类致病真菌，是艾滋病发病和死亡的主要原因 患者复制老化导致老C。新形细胞，其对宿主的清除更有抵抗力 细胞，以及抗真菌治疗。拟议的研究重点是继续我们以前的研究， 建立机制，传达这些老C的弹性。新生细胞总体 一种假说是，观察到的对吞噬细胞攻击和抗真菌药物的抗性是由一种组合引起的， 在C.复制老化过程中的新生细胞。这些变化 发生在复制寿命的早期，它们协同作用，进一步选择和积累旧的C。 新生细胞在过去的资助期间，我们取得了重大进展，包括开发了一个高- 通量微流控芯片装置，现在使我们能够研究形态和蛋白质表达的C。 neoformans人口。在上一个资助周期中获得的其他发现包括关于细胞壁的知识 重塑，改变线粒体功能，克隆一个新的外排泵，在旧的C。 新生细胞这些发现现在指导所提出的实验方法。四个目标，每个目标都得到支持 通过全面的初步和公布的数据，提出。目标1将建立C. 新生细胞被巨噬细胞选择。目标2将试图确定线粒体功能的改变是如何 在老C。neoformans细胞影响抗真菌药物的耐受性。在目标3中，我们建议克隆母亲 富集突变体目的4探讨老年人C.新生儿细胞影响耐受性 抗真菌药物

This application is a competitive renewal of a research proposal that investigated replicative aging in Cryptococcus neoformans, a human pathogenic fungus that is a major cause of mortality and morbidity in AIDS patients. Replicative aging leads to old C. neoformans cells, which are more resistant to clearing by the host cells, as well as antifungal treatment. The proposed studies are focused on continuing our prior studies by establishing mechanisms that convey the resilience of these old C. neoformans cells. The overarching hypothesis is that the observed resistance to phagocytic attack and antifungal drugs results from a combination of several physiological changes that occur in C. neoformans cells during replicative aging. These changes occur early in the replicative lifespan, and they synergize to further the selection and accumulation of old C. neoformans cells. In the past funding period, we made significant progress, including developing a high- throughput microfluidic chip device, which now enabled us to study morphology and protein expression in C. neoformans populations. Other discoveries obtained in the last funding cycle include knowledge about cell wall remodeling, altered mitochondrial function, and cloning of a novel efflux pump that is expressed in old C. neoformans cells. These findings now guide the proposed experimental approach. Four aims, each supported by comprehensive preliminary and published data, are proposed. Aim 1 will establish mechanisms how old C. neoformans cells are selected by macrophages. Aim 2 will seek to establish how altered mitochondrial function in old C. neoformans cells affects tolerance to antifungal drugs. In Aim 3, we propose to clone a mother enrichment mutant. Aim 4 will establish how vacuolar function of old C. neoformans cells affects tolerance to antifungal drugs.