Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
Department of Medicine V, Hematology, Oncology and Rheumatology, Heidelberg University Hospital, Heidelberg, Germany, and.
Blood Adv. 2022 Apr 12;6(7):2081-2091. doi: 10.1182/bloodadvances.2021005097.
Neutrophils transit through megakaryocytes in a process termed emperipolesis, but it is unknown whether this interaction is a single type of cell-in-cell interaction or a set of distinct processes. Using a murine in vitro model, we characterized emperipolesis by live-cell spinning disk microscopy and electron microscopy. Approximately half of neutrophils exited the megakaryocyte rapidly, typically in 10 minutes or less, displaying ameboid morphology as they passed through the host cell (fast emperipolesis). The remaining neutrophils assumed a sessile morphology, most remaining within the megakaryocyte for at least 60 minutes (slow emperipolesis). These neutrophils typically localized near the megakaryocyte nucleus. By ultrastructural assessment, all internalized neutrophils remained morphologically intact. Most neutrophils resided within emperisomes, but some could be visualized exiting the emperisome to enter the cell cytoplasm. Neutrophils in the cytoplasm assumed close contact with the platelet-forming demarcation membrane system or the perinuclear endoplasmic reticulum. These findings reveal that megakaryocyte emperipolesis reflects at least 2 distinct processes differing in transit time and morphology, fast and slow emperipolesis, suggesting divergent physiologic functions.
中性粒细胞通过巨核细胞的过程称为“有丝分裂”，但尚不清楚这种相互作用是单一类型的细胞内相互作用还是一组不同的过程。我们使用一种小鼠的体外模型，通过活细胞旋转盘显微镜和电子显微镜来描述有丝分裂。大约一半的中性粒细胞迅速离开巨核细胞，通常在 10 分钟或更短的时间内，当它们穿过宿主细胞时呈现阿米巴样形态（快速有丝分裂）。其余的中性粒细胞则呈静止状态，其中大多数至少在巨核细胞内停留 60 分钟（缓慢有丝分裂）。这些中性粒细胞通常定位于巨核细胞核附近。通过超微结构评估，所有内化的中性粒细胞形态保持完整。大多数中性粒细胞位于有丝分裂体内，但有些可以观察到从有丝分裂体中出来进入细胞质。细胞质中的中性粒细胞与形成血小板的界膜系统或核周内质网密切接触。这些发现表明，巨核细胞有丝分裂反映了至少两种不同的过程，它们在转运时间和形态上存在差异，即快速和缓慢有丝分裂，提示存在不同的生理功能。
