Transcriptional networks governing A. fumigatus virulence

摘要 由烟曲霉引起的侵袭性感染正在增加，而且仍然与令人无法接受的高水平有关 死亡率，即使使用新的治疗方法也是如此。我们对烟曲霉菌感染生物学的了解是有限的。在10,180人中 在烟曲霉菌基因组中预测的基因中，超过95%是未表征的，只有不到100个基因具有 在致死性方面发挥了重要作用。确定控制毒力的基因和致病途径是至关重要的 他们采取行动是因为他们可以指出治疗和诊断开发的高度优先目标。我们有 在烟曲霉菌中发现了一种转录调控因子WrpA，它与白色念珠菌有有限的同源性 Wor1和组织胞浆菌Ryp1。我们的初步数据表明，WrpA支配A的能力。 烟曲霉能抵抗巨噬细胞的杀伤，在低氧条件下生长，并侵袭和破坏肺部 体外培养的细胞。ΔWrpA缺失突变体在侵袭性小鼠模型中的毒力高度减弱 曲霉病。利用rna-seq，我们发现WrpA控制着烟曲霉菌中~15%的基因的表达。 基因组，包括多个转录因子基因。我们的前提是WRPA是一个主要的监管机构， 控制宿主细胞的相互作用和毒力。为了支持这一前提，我们对WrpA的初步调查 调节子已经揭示了三种依赖WrpA的转录的新的致病相关功能 因子、SrbB、Fcr1和Ndt80。我们的目标是鉴定烟曲霉菌中的WrpA调节子，并鉴定 下游效应基因，其产物通过：1)鉴定转录因子 直接受WrpA调控，并确定它们在致病中的作用；2)分析选定的WrpA- 依赖转录因子及其下游靶基因的确定；3)功能的确定 WrpA调节子控制的效应基因及其在毒力中的作用。评选结果 这项提案中描述的实验将使我们能够表征一种关键的转录调节因子，它调控 致病性，然后利用这一信息来鉴定下游效应基因，其产物 它们调节宿主细胞的相互作用和毒力。这项工作的成果不仅将为 了解烟曲霉的毒力机制，也有望发现新的诊断方法， 治疗和疫苗靶标。

Abstract Invasive infections due to Aspergillus fumigatus are increasing and are still associated with unacceptably high mortality, even with new therapies. Our understanding of A. fumigatus infection biology is limited. Among 10,180 predicted genes in the A. fumigatus genome, over 95% are uncharacterized, and fewer than 100 genes have demonstrated roles in virulence. It is critical to identify genes that govern virulence and the pathways in which they act because they can point to high priority targets for therapeutic and diagnostic development. We have identified a transcriptional regulator in A. fumigatus, WrpA, that shares limited homology with Candida albicans Wor1 and Histoplasma capsulatum Ryp1. Our preliminary data indicate that WrpA governs the capacity of A. fumigatus to withstand macrophage killing, grow under hypoxic conditions, and invade and damage pulmonary cells in vitro. ΔwrpA deletion mutants have highly attenuated virulence in the mouse model of invasive aspergillosis. Using RNA-seq, we found that WrpA governs the expression of ~15% of genes in the A. fumigatus genome, including multiple transcription factor genes. Our premise is that the WrpA is a master regulator that governs host cell interactions and virulence. In support of this premise, our initial investigations of the WrpA regulon have already revealed novel pathogenicity-related functions of three WrpA-dependent transcription factors, SrbB, Fcr1, and Ndt80. Our goal is to characterize the WrpA regulon in A. fumigatus and to identify downstream effector genes whose products mediate pathogenicity by: 1) identifying the transcription factors that are directly regulated by WrpA and determining their roles in pathogenicity; 2) analyzing selected WrpA- dependent transcription factors and identifying their downstream target genes; and 3) determining the function of effector genes controlled by the WrpA regulon and investigating their roles in virulence. The results of the experiments described in this proposal will enable us to characterize a key transcriptional regulator that governs A. fumigatus pathogenicity and then use this information to identify downstream effector genes, the products of which mediate host cell interactions and virulence. The results of this work will not only provide foundational understanding of A. fumigatus virulence mechanisms, but also hold promise to identify new diagnostic, therapeutic, and vaccine targets.