ABSTRACT
OBJECTIVE: Interleukin-16 (IL-16) is a chemoattractant of CD4+ lymphocytes, and it has been implicated in the pathogenesis of various inflammatory diseases. The aim of the present study was to measure IL-16 in pleural effusions caused by tuberculosis and malignancy and its relationship with cell and differential counts as well as lymphocyte subsets. METHODS: Pleural effusion and venous blood samples were collected from 32 patients with tuberculous pleuritis and 30 lung cancer patients with malignant effusion. Analysis of pleural effusion for total leukocytes and cell differentials of leukocytes was performed. Three-color flow cytometry was performed to determine T lymphocyte subsets in cell pellets of pleural effusion. The concentration of IL-16 in cell-free supernatants of pleural effusion and sera was measured by a sandwich enzyme-linked immunosorbent assay. RESULTS: In all the studied patients, the level of IL-16 was significantly higher in pleural effusion than in serum. The levels of IL-16 were significantly higher in tuberculous than in malignant effusions. In pleural effusion, positive correlations were found between the IL-16 levels and total cell counts, lymphocytes, CD3+ T cells, as well as CD4+ T cells. CONCLUSIONS: Compared to malignant pleural effusion, IL-16 appeared to be increased in tuberculous pleural effusion. The pleural effusion IL-16 levels were positively related to the numbers of CD4+ T cells, suggesting that IL-16 might be capable of inducing CD4+ T cell infiltration into pleural space.
Subject(s)
Interleukin-16/metabolism , Pleural Effusion, Malignant/immunology , Pleural Effusion/immunology , Tuberculosis, Pleural/immunology , Adult , Aged , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/immunology , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Male , Middle Aged , Pleural Effusion/metabolism , Pleural Effusion, Malignant/metabolism , T-Lymphocyte Subsets/immunology , Tuberculosis, Pleural/metabolismABSTRACT
BACKGROUND: Antigen-loaded eosinophils (EOSs) instilled intratracheally into mice were capable of inducing Th2-type cytokine production in the draining lymph nodes. The aim of the present study was to evaluate whether EOSs within the tracheobronchial lumen can stimulate Th2 cell expansion in the lung tissues. METHODS: Airway EOSs were recovered from ovalbumin-sensitized and -challenged BALB/c mice, these EOSs were then cocultured with CD4+ cells isolated from sensitized mice in the absence or presence of anti-CD80 or/and -CD86 monoclonal antibodies. Airway EOSs were instilled into the trachea of sensitized mice. At the day 3 thereafter, the lung tissues were removed and prepared into cell suspensions for culture. Cell-free culture supernatants were collected for detection of cytokines. RESULTS: Airway EOSs functioned as CD80- and CD86-dependent antigen-presenting cells to stimulate lung CD4+ lymphocytes to produce interleukin-4, interleukin-5 and interleukin-13, but not interferon-gamma in in vitro assay. When instilled intratracheally in sensitized recipient mice, airway EOSs primed lung Th2 cells in vivo for interleukin-4, interleukin-5 and interleukin-13, but not interferon-gamma, production during the in vitro culture that was also CD80- and CD86-dependent. CONCLUSION: EOSs within the lumina of airways could process inhaled antigen and function in vitro and in vivo as antigen-presenting cells to promote expansion of Th2 cells in the lungs.
