Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States.
Department of Immunology, Microbiology, and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Leioa, Spain.
Front Cell Infect Microbiol. 2024 Jan 26;14:1327299. doi: 10.3389/fcimb.2024.1327299. eCollection 2024.
In this study, two distinct infection models of , using murine macrophages (RAW264.7) and human lung epithelial cells (A549), were employed to identify the genes important for fungal adaptation during infection. Transcriptomic analyses of co-incubated uncovered 140 fungal genes up-regulated in common between both models that, when compared with a previously published transcriptomic study, allowed the identification of 13 genes consistently up-regulated in all three infection conditions. Among them, the gene, responsible for a critical step in the L-phenylalanine degradation pathway, was identified. Disruption of resulted in a mutant strain unable to complete the Phe degradation pathway, leading to an excessive production of pyomelanin when this amino acid served as the sole carbon source. Moreover, the disruption mutant exhibited noticeable cell wall abnormalities, with reduced levels of β-glucans within the cell wall but did not show lack of chitin or mannans. The mutant strain induced reduced inflammation in primary macrophages and displayed significantly lower virulence in a neutropenic mouse model of infection. This is the first study linking the gene to fungal cell wall homeostasis and virulence.
在这项研究中,我们使用了两种不同的感染模型,即鼠源巨噬细胞(RAW264.7)和人肺上皮细胞(A549),以鉴定在感染过程中真菌适应所必需的基因。共同孵育的真菌转录组分析揭示了 140 个在两种模型中均上调的真菌基因,与之前发表的转录组研究相比,这些基因鉴定出了 13 个在所有三种感染条件下均持续上调的基因。其中,负责 L-苯丙氨酸降解途径关键步骤的 基因被鉴定出来。该基因的破坏导致突变株无法完成苯丙氨酸降解途径,当这种氨基酸作为唯一碳源时,会导致大量的焦黑素过度产生。此外,该突变株还表现出明显的细胞壁异常,细胞壁内的β-葡聚糖水平降低,但没有发现壳聚糖或甘露聚糖缺失。突变株在原代巨噬细胞中引起的炎症减少,在中性粒细胞减少的感染小鼠模型中显示出明显较低的毒力。这是首次将 基因与真菌细胞壁动态平衡和毒力联系起来的研究。