Dermatology hospital, Southern Medical University, Guangzhou, China.
Department of Clinical Laboratory, Zhuhai People's Hospital, Zhuhai Clinical Medical College of Jinan University, Zhuhai, China.
Fly (Austin). 2024 Dec;18(1):2398300. doi: 10.1080/19336934.2024.2398300. Epub 2024 Sep 6.
Talaromycosis, caused by (, formerly known as ), is an opportunistic invasive mycosis endemic in tropical and subtropical areas of Asia with high mortality rate. Despite various infection models established to study the immunological interaction between and the host, the pathogenicity of this fungus is not yet fully understood. So far, , a well-established genetic model organism to study innate immunity, has not been used in related research on . In this study, we provide the initial characterization of a systemic infection model of in the host. Survival curves and fungal loads were tested as well as Toll pathway activation was quantified by RT-qPCR of several antimicrobial peptide (AMP) genes including , , and . We discovered that whereas most wild-type flies were able to overcome the infection, or mutant flies failed to prevent fungal dissemination and proliferation and ultimately succumbed to this challenge. Unexpectedly, the induction of classical Toll pathway activation readouts, and , by live or killed was quite limited in wild-type flies, suggesting that the fungus largely escapes detection by the systemic immune system. This unusual situation of a poor systemic activation of the Toll pathway and a strong susceptibility phenotype of / might be accounted for by a requirement for this host defence in only specific tissues, a hypothesis that remains to be rigorously tested.
枝孢霉病由（以前称为）引起，是一种机会性侵袭性真菌感染，流行于亚洲热带和亚热带地区，死亡率很高。尽管已经建立了各种感染模型来研究和宿主之间的免疫相互作用，但这种真菌的致病性仍未完全了解。到目前为止，作为研究先天免疫的成熟遗传模式生物，尚未用于相关的研究。在这项研究中，我们初步描述了在宿主中建立的系统性感染模型。我们检测了生存曲线和真菌负荷，并通过 RT-qPCR 定量检测了几种抗菌肽 (AMP) 基因的 Toll 途径激活情况，包括 、 和 。我们发现，大多数野生型果蝇能够克服感染，而 或 突变体果蝇无法阻止真菌的传播和增殖，最终因此而死亡。出乎意料的是，野生型果蝇中活的或死的对经典 Toll 途径激活的检测，如 、 和 ，激活程度相当有限，这表明真菌在很大程度上逃避了系统性免疫系统的检测。这种 Toll 途径系统性激活不良和/或易感性强的不寻常情况可能归因于这种宿主防御仅在特定组织中起作用，这一假设仍有待严格检验。
