Annulate lamellae (AL) have been observed many times over the years on electron micrographs of rapidly dividing cells, but little is known about these unusual organelles consisting of stacked sheets of endoplasmic reticulum-derived membranes with nuclear pore complexes (NPCs). Evidence is growing for a role of AL in viral infection. AL have been observed early in the life cycles of the hepatitis C virus (HCV) and, more recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), suggesting a specific induction of mechanisms potentially useful to these pathogens. Like other positive-strand RNA viruses, these viruses induce host cells membranes rearrangements. The NPCs of AL could potentially mediate exchanges between these partially sealed compartments and the cytoplasm. AL may also be involved in regulating Ca²⁺ homeostasis or cell cycle control. They were recently observed in cells infected with Theileria annulata, an intracellular protozoan parasite inducing cell proliferation. Further studies are required to clarify their role in intracellular pathogen/host-cell interactions.

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环状薄片和细胞内病原体

多年来，在快速分裂细胞的电子显微照片上多次观察到环状薄片 (AL)，但对这些不寻常的细胞器知之甚少，这些细胞器由具有核孔复合物 (NPC) 的内质网衍生膜的堆叠片组成。越来越多的证据表明 AL 在病毒感染中的作用。在丙型肝炎病毒 (HCV) 和最近的严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 生命周期的早期已经观察到 AL，这表明对这些病原体可能有用的机制的特定诱导。像其他正链 RNA 病毒一样，这些病毒会诱导宿主细胞膜重排。AL 的 NPC 可能会介导这些部分密封的隔室和细胞质之间的交换。AL 也可能参与调节 Ca ²⁺稳态或细胞周期控制。最近在感染环状泰勒虫的细胞中观察到它们，这是一种诱导细胞增殖的细胞内原生动物寄生虫。需要进一步的研究来阐明它们在细胞内病原体/宿主细胞相互作用中的作用。