Intestinal epithelium functions as a barrier to protect multicellular organisms from the outside world. It consists of epithelial cells closely connected by intercellular junctions, selective gates which control paracellular diffusion of solutes, ions and macromolecules across the epithelium and keep out pathogens. Rotavirus is one of the major enteric viruses causing severe diarrhea in humans and animals. It specifically infects the enterocytes on villi of small intestines. The polarity of rotavirus replication in their target enterocytes and the role of intestinal epithelial integrity were examined in the present study. Treatment with EGTA, a drug that chelates calcium and disrupts the intercellular junctions, (i) significantly enhanced the infection of rotavirus in primary enterocytes, (ii) increased the binding of rotavirus to enterocytes, but (iii) considerably blocked internalization of rotavirus. After internalization, rotavirus was resistant to EGTA treatment. To investigate the polarity of rotavirus infection, the primary enterocytes were cultured in a transwell system and infected with rotavirus at either the apical or the basolateral surface. Rotavirus preferentially infected enterocytes at the basolateral surface. Restriction of infection through apical inoculation was overcome by EGTA treatment. Overall, our findings demonstrate that integrity of the intestinal epithelium is crucial in the host's innate defense against rotavirus infection. In addition, the intercellular receptor is located basolaterally and disruption of intercellular junctions facilitates the binding of rotavirus to their receptor at the basolateral surface.

中文翻译：

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猪轮状病毒主要感染基底外侧表面的原代猪肠上皮细胞。

肠上皮是保护多细胞生物免受外界侵害的屏障。它由通过细胞间连接紧密相连的上皮细胞，控制溶质，离子和大分子在上皮细胞旁扩散并阻止病原体的选择性门组成。轮状病毒是引起人类和动物严重腹泻的主要肠病毒之一。它特异性感染小肠绒毛上的肠上皮细胞。在本研究中检查了轮状病毒在其靶肠上皮细胞中复制的极性和肠上皮完整性的作用。EGTA是一种螯合钙并破坏细胞间连接的药物，（i）显着增强了轮状病毒在原代肠上皮细胞中的感染，（ii）增强了轮状病毒与肠上皮细胞的结合，但是（iii）大大阻止了轮状病毒的内在化。内化后，轮状病毒对EGTA治疗具有抗性。为了研究轮状病毒感染的极性，在transwell系统中培养原代肠上皮细胞，并在根尖或基底外侧表面用轮状病毒感染。轮状病毒在基底外侧表面优先感染肠上皮细胞。EGTA治疗克服了通过根尖接种引起的感染限制。总体而言，我们的发现表明，肠上皮的完整性在宿主抵抗轮状病毒感染的先天防御中至关重要。另外，细胞间受体位于基底外侧，并且细胞间连接的破坏促进轮状病毒与其在基底外侧表面上的受体的结合。