Yang Ning, Li Yang, Cai Yifei, Liu Yuanyuan, Zhang Yunhang, Fu Yuguang, Tan Chen, Willems Luc, Liu Guangliang
State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liege, Liège, Belgium.
BMC Biol. 2024 Dec 23;22(1):297. doi: 10.1186/s12915-024-02094-7.
The mucus layer provides the first defense that keeps the epithelium free from microorganisms. However, the effect of the small intestinal mucus layer on pathogen invasion is still poorly understood, especially for swine enteric coronavirus. To better understand virus‒mucus layer‒intestinal epithelium interactions, here, we developed a porcine intestinal organoid mucus‒monolayer model under air‒liquid interface (ALI) conditions.
We successfully established a differentiated intestinal organoid monolayer model comprising various differentiated epithelial cell types and a mucus layer under ALI conditions. Mass spectrometry analysis revealed that the mucus derived from the ALI monolayer shared a similar composition to that of the native small intestinal mucus. Importantly, our results demonstrated that the ALI monolayer exhibited lower infectivity of both TGEV and PEDV than did the submerged monolayer. To further confirm the impact of ALI mucus on coronavirus infection, mucus was collected from the ALI monolayer culture system and incubated with the viruses. These results indicated that ALI mucus treatment effectively reduced the infectivity of TGEV and PEDV. Additionally, Mucin 2 (Muc2), a major component of native small intestinal mucus, was found to be abundant in the mucus derived from the ALI monolayer, as determined by mass spectrometry analysis. Our study confirmed the potent antiviral activity of Muc2 against TGEV and PEDV infection. Considering the sialylation of Muc2 and the known sialic acid-binding activity of coronavirus, further investigations revealed that the sialic acid residues of Muc2 play a potential role in inhibiting coronavirus infection.
We established the porcine intestinal organoid mucus monolayer as a novel and valuable model for confirming the pivotal role of the small intestinal mucus layer in combating pathogen invasion. In addition, our findings highlight the significance of sialic acid modification of Muc2 in blocking coronavirus infections. This discovery opens promising avenues for the development of tailor-made drugs aimed at preventing porcine enteric coronavirus invasion.
黏液层提供了使上皮免受微生物侵害的第一道防线。然而，小肠黏液层对病原体入侵的影响仍知之甚少，尤其是对于猪肠道冠状病毒。为了更好地理解病毒-黏液层-肠上皮之间的相互作用，在此，我们在气液界面（ALI）条件下建立了猪肠道类器官黏液单层模型。
我们成功建立了一个分化的肠道类器官单层模型，该模型在ALI条件下包含各种分化的上皮细胞类型和一层黏液。质谱分析表明，ALI单层产生的黏液与天然小肠黏液的组成相似。重要的是，我们的结果表明，与浸没单层相比，ALI单层对传染性胃肠炎病毒（TGEV）和猪流行性腹泻病毒（PEDV）的感染性更低。为了进一步证实ALI黏液对冠状病毒感染的影响，从ALI单层培养系统中收集黏液并与病毒一起孵育。这些结果表明，ALI黏液处理有效降低了TGEV和PEDV的感染性。此外，通过质谱分析确定，天然小肠黏液的主要成分黏蛋白2（Muc2）在ALI单层产生的黏液中含量丰富。我们的研究证实了Muc2对TGEV和PEDV感染具有强大的抗病毒活性。考虑到Muc2的唾液酸化以及冠状病毒已知的唾液酸结合活性，进一步研究发现，Muc2的唾液酸残基在抑制冠状病毒感染中发挥潜在作用。
我们建立了猪肠道类器官黏液单层模型，作为一种新型且有价值的模型，用于证实小肠黏液层在抵抗病原体入侵中的关键作用。此外，我们的研究结果突出了Muc2的唾液酸修饰在阻断冠状病毒感染中的重要性。这一发现为开发旨在预防猪肠道冠状病毒入侵的定制药物开辟了广阔前景。
