van Niel G, Raposo G, Candalh C, Boussac M, Hershberg R, Cerf-Bensussan N, Heyman M
INSERM E9925, Faculté Necker-Enfants Malades, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
Gastroenterology. 2001 Aug;121(2):337-49. doi: 10.1053/gast.2001.26263.
BACKGROUND & AIMS: Given the observations that intestinal epithelial cells (IECs) can present antigens to CD4(+) T lymphocytes and that professional antigen-presenting cells secrete exosomes (antigen-presenting vesicles), we hypothesized that IECs may secrete exosomes carrying molecules implicated in antigen presentation, which may be able to cross the basement membrane and convey immune information to noncontiguous immune cells.
Human IEC lines HT29-19A and T84-DRB1*0401/CIITA were grown on microporous filters. Release of exosomes under basal or inflammatory conditions was evaluated in conditioned apical and basolateral media after differential ultracentrifugations. Morphologic and biochemical characterization of exosomes was performed using immunoelectron microscopy, Western blotting, and matrix-assisted laser desorption ionization-time of flight mass spectrometry.
The intestinal cell lines released 30-90-nm-diameter vesicles from the apical and basolateral sides, and this release was significantly increased in the presence of interferon gamma. MHC class I, MHC class II, CD63, CD26/dipeptidyl-peptidase IV, and A33 antigen were present in epithelial-derived exosomes. CONCLUSIONS; Human IEC lines secrete exosomes bearing accessory molecules that may be involved in antigen presentation. These data are consistent with a model in which IECs may influence antigen presentation in the mucosal or systemic immune system independent of direct cellular contact with effector cells.
鉴于观察到肠上皮细胞（IECs）可将抗原呈递给CD4(+) T淋巴细胞，且专职抗原呈递细胞分泌外泌体（抗原呈递囊泡），我们推测IECs可能分泌携带与抗原呈递相关分子的外泌体，这些外泌体可能能够穿过基底膜并将免疫信息传递给非相邻的免疫细胞。
人IEC系HT29 - 19A和T84 - DRB1*0401/CIITA在微孔滤膜上培养。在不同条件下进行超速离心后，在条件性顶端和基底外侧培养基中评估基础或炎症条件下外泌体的释放情况。使用免疫电子显微镜、蛋白质印迹法和基质辅助激光解吸电离飞行时间质谱法对外泌体进行形态学和生化特征分析。
肠细胞系从顶端和基底外侧释放直径为30 - 90nm的囊泡，在存在γ干扰素的情况下这种释放显著增加。上皮来源的外泌体中存在MHC I类、MHC II类、CD63、CD26/二肽基肽酶IV和A33抗原。结论：人IEC系分泌携带可能参与抗原呈递的辅助分子的外泌体。这些数据与一个模型一致，即IECs可能在不与效应细胞直接细胞接触的情况下影响黏膜或全身免疫系统中的抗原呈递。
