Sato J, Chida K, Suda T, Sato A, Nakamura H
Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Lung. 2000;178(5):295-308. doi: 10.1007/s004080000033.
Lymphocytes continuously circulate between the bloodstream and lymphoid organs, and their migration into lymphatic tissues presumably occurs through selective mechanisms. Although bronchus-associated lymphoid tissue (BALT) is known as an inductive tissue of the common mucosal immune system, little is known about how effectively the lymphocytes in the blood vessels migrate into the BALT, thereby enabling the BALT to act as an effector tissue in the immunologic responses of the lungs. To analyze whether or not thoracic duct lymphocytes (TDL) from immunized and nonimmunized rats possess different migratory patterns to the BALT, 5-(6)-carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled TDL were injected into rats with BALT hyperplasia that was produced by intratracheal administration of TNP-KLH, and then the number of labeled cells in the BALT were examined by immunohistochemical methods. We studied the following three groups at 12 h after the injection: group A, intraintestinally immunized donors and intratracheally immunized recipients; group B, nonimmunized donors and intratracheally immunized recipients; group C (control group), nonimmunized donors and nonimmunized recipients. Time course studies 0.5, 4, 12, and 24 h after the injection were done in groups A and C. In a cytokinetic study, larger numbers of CFSE-labeled lymphocytes were found at 12 h and 24 h in group A than in group C. At 12 h after the injection, the absolute number of CFSE-labeled lymphocytes per BALT was significantly higher in group A than in group B (p < 0.05), and was lowest in group C. Histologically, there was a marked proliferation of high endothelial venules (HEV), with findings of adhesion and influx of lymphocytes inside the HEV in group A. These observations indicate that the immunized BALT actively recruits immunized TDL through a specific mechanism of lymphocyte-endothelium recognition in HEV, which partially explains the process of BALT development as an effector tissue for local immunity.
淋巴细胞持续在血液循环和淋巴器官之间循环，它们迁移到淋巴组织中大概是通过选择性机制实现的。虽然支气管相关淋巴组织（BALT）是常见黏膜免疫系统的诱导组织，但关于血管中的淋巴细胞如何有效地迁移到BALT中，从而使BALT在肺部免疫反应中发挥效应组织的作用，人们了解甚少。为了分析免疫和未免疫大鼠的胸导管淋巴细胞（TDL）对BALT是否具有不同的迁移模式，将5-(6)-羧基荧光素二乙酸琥珀酰亚胺酯（CFSE）标记的TDL注射到通过气管内给予TNP-KLH产生BALT增生的大鼠体内，然后通过免疫组织化学方法检查BALT中标记细胞的数量。注射后12小时，我们研究了以下三组：A组，肠道内免疫供体和气管内免疫受体；B组，未免疫供体和气管内免疫受体；C组（对照组），未免疫供体和未免疫受体。对A组和C组在注射后0.5、4、12和24小时进行了时间进程研究。在细胞动力学研究中，发现A组在12小时和24小时时CFSE标记的淋巴细胞数量比C组多。注射后12小时，A组每个BALT中CFSE标记的淋巴细胞绝对数量显著高于B组（p < 0.05），且在C组中最低。组织学上，A组高内皮静脉（HEV）有明显增生，HEV内有淋巴细胞黏附和流入现象。这些观察结果表明，免疫的BALT通过HEV中淋巴细胞 - 内皮识别的特定机制积极招募免疫的TDL，这部分解释了BALT作为局部免疫效应组织的发育过程。
