Sueki H, Telegan B, Murphy G F
Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, USA.
J Invest Dermatol. 1995 Nov;105(5):704-8. doi: 10.1111/1523-1747.ep12324502.
We attempted to characterize the three-dimensional structure of dermal dendrocytes and to clarify the spatial relationships between dermal dendrocytes and mast cells, macrophages, and nerves. Normal human adult skin (breast, n = 2) was routinely processed for electron microscopy. Every other section (about 50 per data set) was collected at 80-nm intervals traversing about 8 microns of tissue. Grids showing the same cells were photographed by electron microscopy at a magnification of 4000x. Based on the 10-20 photographs per data set, cell outlines were digitized into the reconstruction program at appropriate layers and aligned. Thin, elongated cytoplasmic "dendrites" of dermal dendrocytes in two-dimensional micrographs proved to be thin, membrane-bound flaps in three-dimensional reconstruction. For dermal dendrocytes concentrated about superficial vessels (perivascular dendrocytes), the flaps enshrouded the vessel wall, and for dermal dendrocytes directly beneath the epidermis (subepidermal dendrocytes), these flaps were aligned parallel to the dermal-epidermal junction. The three-dimensional feature of dermal dendrocytes (perivascular and subepidermal) is quite similar to that of perivascular adventitial veil cells, suggesting ultrastructurally identified perivascular dendrocytes and veil cells must be identical cells. In conventional ultrathin sections, 20-40% of perivascular dendrocytes and occasional subepidermal dendrocytes were closely associated with mast cells. When viewed by computer-assisted three-dimensional reconstruction, membrane flaps of dermal dendrocytes consistently shrouded mast cell membranes for 50-90% of their perimeter; mast cells resembled a ball in a baseball glove (dermal dendrocytes). Occasional dermal dendrocytes surrounded non-myelinated nerves in the superficial dermis. Membrane flaps also enabled dermal dendrocytes to present extensive areas to the plasma membranes of adjacent monocyte/macrophages. These findings indicate that dermal dendrocytes are non-dendritic cells that are spatially related to mast cells, monocyte/macrophages, microvessels, and nerves by their membranous flaps. This suggests the need for further study of functional interactions between these cells.
我们试图描绘真皮树突状细胞的三维结构，并阐明真皮树突状细胞与肥大细胞、巨噬细胞和神经之间的空间关系。正常成人皮肤（乳房，n = 2）常规进行电子显微镜处理。每隔一张切片（每个数据集约50张）以80纳米的间隔收集，穿过约8微米的组织。通过电子显微镜以4000倍放大率拍摄显示相同细胞的网格。根据每个数据集的10 - 20张照片，将细胞轮廓在适当的层面数字化到重建程序中并对齐。二维显微照片中真皮树突状细胞细长的细胞质“树突”在三维重建中被证明是薄的、膜结合的片状物。对于集中在浅表血管周围的真皮树突状细胞（血管周围树突状细胞），这些片状物包裹着血管壁，而对于表皮正下方的真皮树突状细胞（表皮下树突状细胞），这些片状物与真皮 - 表皮交界处平行排列。真皮树突状细胞（血管周围和表皮下）的三维特征与血管周围外膜面纱细胞非常相似，这表明超微结构鉴定的血管周围树突状细胞和面纱细胞必定是相同的细胞。在传统超薄切片中，20 - 40%的血管周围树突状细胞和偶尔的表皮下树突状细胞与肥大细胞紧密相关。通过计算机辅助三维重建观察时，真皮树突状细胞的膜片状物在其周长的50 - 90%持续包裹着肥大细胞膜；肥大细胞就像棒球手套（真皮树突状细胞）里的球。偶尔有真皮树突状细胞围绕着浅表真皮中的无髓神经。膜片状物还使真皮树突状细胞能够向相邻单核细胞/巨噬细胞的质膜呈现广泛的区域。这些发现表明真皮树突状细胞是通过其膜片状物在空间上与肥大细胞、单核细胞/巨噬细胞、微血管和神经相关的非树突状细胞。这表明需要进一步研究这些细胞之间的功能相互作用。
