ラット正常歯髄におけるLYVE-1陽性マクロファージはCD163を発現する

抄録

Abstract : Lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) is widely used as a lymphatic marker, but it is also expressed in some specific macrophage populations. The aim of this study was to examine the phenotype of LYVE-1-expressing cells in rat normal molar pulp tissue. The maxilla, gingiva, small intestine, and spleen were collected from male SD rats (8-9 weeks old, n=4) and fixed with 4% paraformaldehyde. The maxilla specimens were demineralized with 17% EDTA. Cryostat sections (10μm thick) were subjected to immunohistochemistry using anti-LYVE-1, anti-CD68, anti-CD163, and anti-MHC class II antibodies. LYVE-1^＋ cells with polygonal shape were ubiquitously distributed throughout the coronal pulp tissue. Double immunofluorescence staining revealed that 94.7, 94.0 and 4.7% of LYVE-1^＋ cells in the pulp co-expressed CD68, CD163 and MHC class II, respectively. In gingiva and spleen, LYVE-1^＋ cells co-expressing macrophage markers were not detected, while CD68^＋ and CD163^＋ cells were observed. LYVE-1^＋ tubular structures, representing lymphatic vessels, were observed in gingiva, small intestine, but not in dental pulp. This study demonstrated that the majority of LYVE-1^＋ cells in rat molar pulp co-expressed CD163, suggesting that they are mostly composed of tissue resident M2 macrophages.