Departments of Immunology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Respir Res. 2009 Oct 22;10(1):97. doi: 10.1186/1465-9921-10-97.
Bronchus-associated lymphoid tissue (BALT) is the secondary lymphoid tissue in bronchial mucosa and is involved in the development of bronchopulmonary immune responses. Although migration of lymphocytes from blood vessels into secondary lymphoid tissues is critical for the development of appropriate adaptive immunity, the endothelia and lymphocyte adhesion molecules that recruit specific subsets of lymphocytes into human BALT are not known. The aim of this study was to determine which adhesion molecules are expressed on lymphocytes and high endothelial venules (HEVs) in human BALT.
We immunostained frozen sections of BALT from lobectomy specimens from 17 patients with lung carcinoma with a panel of monoclonal antibodies to endothelia and lymphocyte adhesion molecules.
Sections of BALT showed B cell follicles surrounded by T cells. Most BALT CD4+ T cells had a CD45RO+ memory phenotype. Almost all BALT B cells expressed alpha4 integrin and L-selectin. In contrast, 43% of BALT T cells expressed alpha4 integrin and 20% of BALT T cells expressed L-selectin. Almost all BALT lymphocytes expressed LFA-1. HEVs, which support the migration of lymphocytes from the bloodstream into secondary lymphoid tissues, were prominent in BALT. All HEVs expressed peripheral node addressin, most HEVs expressed vascular cell adhesion molecule-1, and no HEVs expressed mucosal addressin cell adhesion molecule-1.
Human BALT expresses endothelia and lymphocyte adhesion molecules that may be important in recruiting naive and memory/effector lymphocytes to BALT during protective and pathologic bronchopulmonary immune responses.
支气管相关淋巴组织（BALT）是支气管黏膜中的次级淋巴组织，参与支气管肺免疫反应的发生。尽管淋巴细胞从血管向次级淋巴组织的迁移对适当适应性免疫的发展至关重要，但将特定淋巴细胞亚群募集到人类 BALT 的内皮细胞和淋巴细胞黏附分子尚不清楚。本研究旨在确定哪些黏附分子在人类 BALT 的淋巴细胞和高内皮小静脉（HEV）上表达。
我们用一组针对内皮细胞和淋巴细胞黏附分子的单克隆抗体对 17 例肺癌肺叶切除术标本的 BALT 冷冻切片进行免疫染色。
BALT 切片显示 B 细胞滤泡被 T 细胞包围。大多数 BALT CD4+T 细胞具有 CD45RO+记忆表型。几乎所有 BALT B 细胞均表达 α4 整合素和 L-选择素。相比之下，43%的 BALT T 细胞表达 α4 整合素，20%的 BALT T 细胞表达 L-选择素。几乎所有 BALT 淋巴细胞均表达 LFA-1。HEV 支持淋巴细胞从血流向次级淋巴组织的迁移，在 BALT 中很明显。所有 HEV 均表达外周淋巴结地址素，大多数 HEV 表达血管细胞黏附分子-1，而没有 HEV 表达黏膜地址素细胞黏附分子-1。
人类 BALT 表达内皮细胞和淋巴细胞黏附分子，这些分子可能在保护性和病理性支气管肺免疫反应中将幼稚和记忆/效应淋巴细胞募集到 BALT 中发挥重要作用。
