Transcriptional networks governing A. fumigatus virulence

摘要 由于烟曲霉引起的侵袭性感染正在增加，并且仍然与不可接受的高感染率相关。 死亡率，即使有新的疗法。我们对A.烟曲霉感染生物学是有限的。在10 180人中 预测基因在A.烟曲霉基因组中，超过95%是未表征的，只有不到100个基因具有 在毒力方面的作用。关键是要确定控制毒力的基因和其中的途径， 它们之所以采取行动，是因为它们可以为治疗和诊断的发展指明高度优先的目标。我们有 在A.与白色念珠菌具有有限的同源性 Wor 1和荚膜组织胞浆菌Ryp 1。我们的初步数据表明，A. 烟曲霉抵抗巨噬细胞杀伤，在缺氧条件下生长，并侵入和损害肺 体外细胞ΔwrpA缺失突变体在侵袭性肺转移小鼠模型中的毒力高度减弱 曲霉病使用RNA-seq，我们发现ApopA控制了A中约15%的基因的表达。烟曲霉 基因组，包括多个转录因子基因。我们的前提是，AFPA是一个主调节器， 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ACPA的初步调查 调节子已经揭示了三种与致病性相关的转录调控功能， 因子SrbB、Fcr 1和Ndt 80。我们的目标是描述A.烟曲霉，并确定 其产物通过以下方式介导致病性的下游效应基因：1）鉴定转录因子， 直接受BMPA调节，并决定其在致病性中的作用; 2）分析选择的BMPA- 依赖性转录因子并鉴定其下游靶基因;和3）确定功能 的效应基因的控制下，调节子和调查他们的作用，毒力。的结果 在这个提议中描述的实验将使我们能够描述一个关键的转录调节因子， A.烟曲霉致病性，然后使用这些信息来确定下游效应基因， 其介导宿主细胞相互作用和毒力。这项工作的结果不仅将提供基础 理解A。烟曲霉毒力机制，但也有希望确定新的诊断， 治疗和疫苗靶点。

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.