Expression of endothelia and lymphocyte adhesion molecules in bronchus-associated lymphoid tissue (BALT) in adult human lung.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Departments of Immunology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan. kawamata@po5.synapse.ne.jp
Nakaaki
N
Kawamata
Baohui
B
Xu
Hiroo
H
Nishijima
Kohji
K
Aoyama
Mayumi
M
Kusumoto
Toru
T
Takeuchi
Chuwa
C
Tei
Sara A
SA
Michie
Takami
T
Matsuyama
D000328:Adult; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D001980:Bronchi / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000032:analysis*; D006801:Humans; D007113:Immunity, Innate; D018928:Immunity, Mucosal; D007136:Immunoglobulins / Q000032:analysis; D007150:Immunohistochemistry; D007156:Immunologic Memory; D016130:Immunophenotyping; D039441:Integrin alpha4 / Q000032:analysis; D019041:L-Selectin / Q000032:analysis; D008175:Lung Neoplasms / Q000276:immunology* / Q000601:surgery; D042601:Lymphatic Vessels / Q000276:immunology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D008214:Lymphocytes / Q000276:immunology*; D008221:Lymphoid Tissue / Q000276:immunology*; D008565:Membrane Proteins / Q000032:analysis; D009088:Mucoproteins / Q000032:analysis; D011013:Pneumonectomy; D019010:Vascular Cell Adhesion Molecule-1 / Q000032:analysis
D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; C069886:L-selectin counter-receptors; D016169:Lymphocyte Function-Associated Antigen-1; C504265:MADCAM1 protein, human; D008565:Membrane Proteins; D009088:Mucoproteins; D019010:Vascular Cell Adhesion Molecule-1; D019041:L-Selectin; D039441:Integrin alpha4