Understanding the ways in which pathogens infect host cells is essential to improve and develop new treatment strategies. This study aimed to generate a novel in vitro infection model by establishing a reproducible 3D spheroid cell culture system that may lead to a reduced need for animals in fish disease research. 2D models (commonly cell lines) cannot replicate many key conditions of in vivo infections, but 3D spheroids have the potential to provide bridging technology between in vivo and in vitro systems. 3D spheroids were generated using cells from rainbow trout (Oncorhynchus mykiss) cell lines, RTG‐2 and RTS‐11. The RTG‐2 spheroids were tested for their potential to be infected upon exposure to Saprolegnia parasitica spores. Positive infiltration of mycelia into the spheroids was verified by confocal microscopy. As a closer analogue of in vivo conditions encountered during infection, the straightforward model developed in this study shows promise as an additional tool that can be used to further our understanding of host–pathogen interactions for Saprolegnia and possibly a variety of other fish pathogens.

中文翻译：

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从鱼细胞系中开发用于体外感染研究的3D球状细胞培养系统：用腐烂腐烂霉进行评估

了解病原体感染宿主细胞的方式对于改善和开发新的治疗策略至关重要。这项研究旨在通过建立可重现的3D球形细胞培养系统来生成新颖的体外感染模型，从而减少鱼类疾病研究中对动物的需求。2D模型（通常是细胞系）无法复制体内感染的许多关键条件，但3D椭球体有可能在体内和体外系统之间提供桥接技术。使用虹鳟（Oncorhynchus mykiss）细胞系RTG-2和RTS-11的细胞生成3D球体。测试了RTG-2球状体在暴露于腐烂腐烂霉菌后被感染的可能性孢子。共聚焦显微镜检查证实了菌丝体向球体中的阳性浸润。作为感染过程中遇到的体内条件的更接近的模拟，本研究开发的简单模型显示出有望作为一种额外的工具，可用于进一步了解腐烂症和可能的其他鱼类病原体的宿主-病原体相互作用。