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T cells in the lung of patients with hypersensitivity pneumonitis accumulate in a clonal manner
Author(s) -
Facco Monica,
Trentin Livio,
Nicolardi Linda,
Miorin Marta,
Scquizzato Elisa,
Carollo Davide,
Baesso Ilenia,
Bortoli Michela,
Zambello Renato,
Marcer Guido,
Agostini Carlo,
Semenzato Gianpietro
Publication year - 2004
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0503218
Subject(s) - biology , t cell receptor , hypersensitivity pneumonitis , cd8 , t cell , immunology , lung , clone (java method) , t lymphocyte , microbiology and biotechnology , cytotoxic t cell , antigen , immune system , gene , genetics , in vitro , medicine
Hypersensitivity pneumonitis (HP) is characterized by an alveolitis sustained by CD8 + T lymphocytes showing a limited expression of the T cell receptor (TCR). We previously demonstrated that a bias in T cell selection occurs in the lower respiratory tract of patients with HP, with a compartmentalization in the lung of CD8 + T cells bearing (TCR)‐β variable (TCRBV) #2, 3, 5, 6, 8, and 13 gene segments. We herein characterized the clonal T cell populations present in the lung and in the blood of patients with HP. Heteroduplex analyses, cloning, and sequencing T cells bearing TCR indicate oligoclonal expansions of T cells expressing homologous or identical complementary‐determining region 3. Furthermore, T cell clones isolated from the two compartments expressed similar, sometimes identical, junctional regions. Removal from antigenic exposure led to the disappearance of T cell clones. Our findings indicate that expansions of T lymphocytes bearing clonal TCRBV region gene segments take place in the lung of patients with HP during exposure. The evidence that identical T cell clones are present in the lung and the blood of the same patient suggests that the immune reaction occurring at lung level gives rise to a systemic reaction.