Yanagawa Yasuaki, Sharma Manu, Izumiyama Shinji, Singh Upinder
Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA.
AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan.
Microbiol Spectr. 2025 Jul;13(7):e0050625. doi: 10.1128/spectrum.00506-25. Epub 2025 Jun 9.
Amebiasis, caused by the protozoan , is a significant parasitic infection affecting millions of people worldwide, particularly in developing regions. Elucidating the mechanisms by which this parasite invades host tissues and circumvents immune defenses is essential for advancing therapeutic strategies. Key virulence factors such as Gal/GalNAc lectin, amebapore, and proteases enable the parasite to adhere to, invade, and destroy host tissues. This study aimed to identify novel virulence-related genes in clinical strains by analyzing their gene expression profiles. We collected clinical isolates from asymptomatic individuals and patients with amoebic liver abscesses to perform RNA sequencing and compare their gene expression profiles. The analysis identified 14 differentially expressed genes between high-virulence and low-virulence strains. Among these, four candidate genes exhibited significant upregulation in the virulent strains. Functional assays demonstrated that the overexpression of these genes contributed to key virulence traits, including increased adhesion, complement resistance, and enhanced starch phagocytosis. Significantly, two of the four candidate genes, EHI_124550 and EHI_107170, which encode hypothetical proteins, exhibited a strong correlation with both oxidative stress response and complement resistance. These findings suggest that specific genes play crucial roles in the parasite's ability to evade the host immune system and establish infection in extraintestinal sites like the liver.IMPORTANCEThis study focuses on understanding how , the parasite responsible for amebiasis, affects over 50 million people globally. Our research is the first study to examine various clinical strains of the parasite, identifying key genes that influence its ability to attach to host cells (adhesion) and ingest them (phagocytosis), both critical processes for its ability to cause disease. Additionally, we discovered that these genes play a role in helping the parasite withstand environmental stress, such as oxidative stress and heat shock, which are part of the body's defense mechanisms. These findings are significant because they reveal potential targets for future treatments aimed at reducing the parasite's virulence, or disease-causing potential. Understanding how adapts and survives under hostile conditions will help in developing better strategies to combat amebiasis. These results provide new insights into a unique immune evasion strategy employed by a pathogen.
由原生动物引起的阿米巴病是一种严重的寄生虫感染,影响着全球数百万人,尤其是在发展中地区。阐明这种寄生虫侵入宿主组织并规避免疫防御的机制对于推进治疗策略至关重要。诸如半乳糖/ N - 乙酰半乳糖胺凝集素、阿米巴穿孔素和蛋白酶等关键毒力因子使寄生虫能够黏附、侵入并破坏宿主组织。本研究旨在通过分析临床菌株的基因表达谱来鉴定新的毒力相关基因。我们从无症状个体和阿米巴肝脓肿患者中收集临床分离株,进行RNA测序并比较它们的基因表达谱。分析确定了高毒力和低毒力菌株之间的14个差异表达基因。其中,四个候选基因在毒力菌株中显著上调。功能测定表明,这些基因的过表达导致了关键毒力特征,包括增加黏附、补体抗性和增强淀粉吞噬作用。值得注意的是,四个候选基因中的两个,即编码假定蛋白的EHI_124550和EHI_107170,与氧化应激反应和补体抗性都有很强的相关性。这些发现表明特定基因在寄生虫逃避宿主免疫系统并在肝脏等肠外部位建立感染的能力中起关键作用。重要性本研究聚焦于了解引起阿米巴病的寄生虫如何影响全球超过5000万人。我们的研究是首次对该寄生虫的各种临床菌株进行研究,鉴定出影响其黏附宿主细胞(黏附)和摄取宿主细胞(吞噬作用)能力的关键基因,这两个过程对其致病能力至关重要。此外,我们发现这些基因在帮助寄生虫抵御环境应激方面发挥作用,如氧化应激和热休克,这些都是人体防御机制的一部分。这些发现意义重大,因为它们揭示了未来旨在降低寄生虫毒力或致病潜力的治疗潜在靶点。了解该寄生虫在恶劣条件下如何适应和存活将有助于制定更好的抗阿米巴病策略。这些结果为病原体采用独特的免疫逃避策略提供了新见解。