Valid and relevant models are critical for research to have biological relevance or proceed in the right path. As well-established 2D cell cultures lack niches and cues and rodent models differ in species, 3D organoids emerged as a powerful platform for research. Cultured in vitro from stem cells, organoids are heterogeneous in cells and closely resemble the in vivo settings. Organoids also recapitulate the unique human features if cultured from a human source and are subject to genetic modification. However, one type of organoid possesses only a limited selection of cells. In particular, the absence of vasculature and immune cells restricts the organoids from nutrition, cues, or critical interactions, undermining the validity of organoids as physiological or pathological models. To fill the current gap, there is an urgent need to provide organoids with vasculature and immune cells. In this paper, we review the methods to generate physiological and pathological organoid models and summarize ways to vascularize or immunize them. Our discussion continues with some advantages and disadvantages of each method and some emerging solutions to current problems.


中文翻译：

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给他们脉管系统和免疫细胞——如何填补类器官的空白

有效且相关的模型对于研究具有生物学相关性或在正确的道路上进行至关重要。由于成熟的 2D 细胞培养物缺乏生态位和线索，并且啮齿动物模型因物种而异，因此 3D 类器官成为了一个强大的研究平台。从干细胞体外培养的类器官在细胞中是异质的，与体内环境非常相似。如果从人类来源培养并进行基因改造，类器官也概括了独特的人类特征。然而，一种类型的类器官仅拥有有限的细胞选择。特别是，脉管系统和免疫细胞的缺乏限制了类器官的营养、线索或关键相互作用，破坏了类器官作为生理或病理模型的有效性。为了填补目前的空白，迫切需要提供具有脉管系统和免疫细胞的类器官。在本文中，我们回顾了生成生理和病理类器官模型的方法，并总结了血管化或免疫它们的方法。我们继续讨论每种方法的一些优点和缺点以及针对当前问题的一些新兴解决方案。