Leukocyte trafficking in experimental autoimmune uveitis: Breakdown of blood-retinal barrier and upregulation of cellular adhesion molecules
Leukocyte trafficking in experimental autoimmune uveitis: Breakdown of blood-retinal barrier and upregulation of cellular adhesion molecules
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DOI：
10.1167/iovs.01-1202
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发表时间：
2003-01-01
影响因子：
4.4
通讯作者：
Crane, IJ
中科院分区：
文献类型：
--
作者：
Xu, HP;Forrester, JV;Crane, IJ
目的。阐明实验性自身免疫性葡萄膜视网膜炎 (EAU) 中血视网膜屏障 (BRB) 破坏发生的事件顺序，特别是研究 EAU 期间血管通透性增加、内皮细胞粘附分子上调以及白细胞粘附和浸润之间的关系。用人光感受器间视黄醇结合蛋白(IRBP)肽161-180对B10.RIII小鼠进行免疫。在免疫后（pi）第3、6、7、8、9、10、16和21天检查视网膜微脉管系统的变化。静脉注射伊文思蓝染料以评估血管通透性。通过体内施用抗体和随后对视网膜整体进行免疫染色来评估细胞间粘附分子（ICAM）-1、血管细胞粘附分子（VCAM）-1、P-选择素、E-选择素和血小板内皮细胞粘附分子（PECAM）-1的表达。感染后第 5、6、7、8 和 15 天，来自正常和鸡卵清蛋白 (OVA) 或 IRBP 肽免疫小鼠腹股沟淋巴结的淋巴细胞在体外用钙黄绿素-AM (C-AM) 标记，并静脉注射到在相同相应时间点用肽免疫的同基因受体小鼠中。 24小时后用共聚焦显微镜观察视网膜整体制备物以确定淋巴细胞的粘附和浸润。结果。第一次观察到血管通透性增加发生在感染后第 7 天，并且仅限于内血管丛的视网膜毛细血管后微静脉的焦点区域。在感染后第 9 天，这逐渐延伸到外血管丛。在注射后第 6 天首次观察到白细胞对内血管丛视网膜小静脉内皮的特异性粘附。白细胞在感染后第 8 天开始从这些血管外渗到视网膜实质，并在感染后第 9 天延伸到外血管丛。在 EAU 的发育过程中，粘附分子的表达逐渐增加。特别是，从感染后第 7 天开始，粘附分子 ICAM-1、P-选择素和 E-选择素主要在视网膜小静脉、BRB 分解、细胞粘附和外渗部位表达。 ICAM-1 和 P-选择素表达的增加在空间和时间上与 BRB 的破坏、细胞粘附和外渗相关。在 EAU 小鼠的肠系膜血管或 OVA 免疫小鼠的视网膜血管中均未观察到 P-选择素和 ICAM-1 表达的增加。结论。 EAU 中的事件顺序似乎是白细胞粘附到毛细血管后微静脉上的离散位点，随后粘附分子（尤其是 ICAM-1 和 P-选择素）上调，以及 BRB 分解，导致白细胞跨内皮迁移并将大量细胞募集到视网膜实质。这些变化在注射后 6 至 9 天的短时间内发生，并在接下来的 2 至 3 周内引发组织损伤过程。
PURPOSE. To clarify the order of events occurring in the breakdown of the blood-retinal barrier (BRB) in experimental autoimmune uveoretinitis (EAU) and in particular to study the relationships between increased vascular permeability, upregulation of endothelial cell adhesion molecules, and leukocyte adhesion and infiltration during EAU.METHODs. B10.RIII mice were immunized with human interphotoreceptor retinoid binding protein (IRBP) peptide 161-180. Changes in the retinal microvasculature were examined on days 3, 6, 7, 8, 9, 10, 16, and 21 postimmunization (pi). Evans blue dye was administered intravenously to assess vascular permeability. Expression of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, P-selectin, E-selectin, and platelet endothelial cell adhesion molecule (PECAM)-1 was evaluated by in vivo administration of antibody and subsequent immunostaining of retinal whole-mounts. Lymphocytes from inguinal lymph nodes of normal and chicken ovalbumin (OVA)- or IRBP peptide-immunized mice at day 5, 6, 7, 8, and 15 pi were labeled in vitro with calcein-AM (C-AM) and infused intravenously into syngeneic recipient mice, which had been immunized with peptide at the same corresponding time point. Wholemount preparations of retinas were observed 24 hours later by confocal microscopy to determine the adhesion and infiltration of lymphocytes.RESULTS. The first observation of an increase in vascular permeability occurred at day 7 pi and was restricted to focal areas of the retinal postcapillary venules of the inner vascular plexus. This progressively extended to the outer vascular plexus at day 9 pi. Specific adhesion of leukocytes to the endothelium of retinal venules of the inner vascular plexus was first observed at day 6 pi. Leukocyte extravasation into the retinal parenchyma from these vessels began at day 8 pi and extended to the outer vascular plexus at day 9 pi. The expression of adhesion molecules increased progressively during the development of EAU. In particular, the adhesion molecules ICAM-1, P-selectin, and E-selectin were expressed predominately in retinal venules, the sites of BRB breakdown, cell adhesion, and extravasation, from day 7 pi. The increases in expression of ICAM-1 and P-selectin were associated both spatially and temporally with breakdown of the BRB, cell adhesion, and extravasation. No increase in expression of P-selectin and ICAM-1 was observed in either the mesenteric vessels of EAU mice or the retinal vessels of OVA-immunized mice.CONCLUSIONS. The sequence of events in EAU appears to be focal adhesion of leukocytes to discrete sites on postcapillary venules, followed by upregulation of adhesion molecules, especially ICAM-1 and P-selectin, and breakdown of the BRB, leading to transendothelial migration of leukocytes and recruitment of large numbers of cells to the retinal parenchyma. These changes occur over a short period of 6 to 9 days pi and initiate the process of tissue damage during the following 2 to 3 weeks.