Inflammatory Process of CD8(+)CD28(−) T Cells in Induced Sputum From Asthmatic Patients

Previously unreported CD8(+)CD28(−) and CD8(+)CD28(+) T-cell subsets occur in healthy individuals and expand in patients suffering from autoimmune disease. Here we studied, for the first time, the expression of CD8(+)CD28(+), CD8(+)CD28(−), and CD8(+)CD56(+) subpopulations in induced sputum from asthmatics. Using sputum samples, purified CD8(+) T cells were stained for surface antigen CD28, CD56, FITC-conjugated anti-perforin, and anti-IFN-γ. Cytotoxic activity was evaluated in a chromium releasing test. Induced sputum CD8(+)CD28(−) T cells were found to be more expanded and expressed low levels of IFN-γ in severe asthmatics than mild asthma and age-matched healthy controls. The predominance of CD8(+)CD28(−) T cells can be in part explained by the expansion of CD8(+)CD56(+). CD8(+)CD28(−) T cells from severe asthmatics produced high intracytoplasmic perforin and exerted a potent cytotoxic activity. Considering their phenotyping and functional properties, the CD8(+)CD28(−) T-cell subset may constitute an intermediate phenotype in the process of CD8(+) T-cell differentiation of effector-type cells in severe asthmatics. Functional studies showed that CD8(+)CD28(−) T cells had cytotoxic function

NKT Cells in the Induced Sputum of Severe Asthmatics

To determine whether there was a specific inflammatory process in severe asthmatics, the phenotypic characteristics of induced sputum immune cells were analysed among patients with severe asthma. Twenty-two induced sputa (10 severe asthmatics) were studied. Flow cytometric analysis was performed using immune cells of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ. The number of NKT (CD3(+)CD56(+)) cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups (P < .05). CD8(+)CD56(+) cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3(+)CD56(+)Vα24(+), TCRγδ(+) CD56(+), and CD4(+)CD25(+) T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8(+)CD56(+) NKT cells may play an important role in the immunopathogenesis of severe asthma

Mediators of Inflammation Inflammatory Process of CD8 + CD28 − T Cells in Induced Sputum From Asthmatic Patients

Previously unreported CD8 + CD28 − and CD8 + CD28 + T-cell subsets occur in healthy individuals and expand in patients suffering from autoimmune disease. Here we studied, for the first time, the expression of CD8 + CD28 + , CD8 + CD28 − , and CD8 + CD56 + subpopulations in induced sputum from asthmatics. Using sputum samples, purified CD8 + T cells were stained for surface antigen CD28, CD56, FITC-conjugated anti-perforin, and anti-IFN-γ. Cytotoxic activity was evaluated in a chromium releasing test. Induced sputum CD8 + CD28 − T cells were found to be more expanded and expressed low levels of IFN-γ in severe asthmatics than mild asthma and age-matched healthy controls. The predominance of CD8 + CD28 − T cells can be in part explained by the expansion of CD8 + CD56 + . CD8 + CD28 − T cells from severe asthmatics produced high intracytoplasmic perforin and exerted a potent cytotoxic activity. Considering their phenotyping and functional properties, the CD8 + CD28 − T-cell subset may constitute an intermediate phenotype in the process of CD8 + T-cell differentiation of effector-type cells in severe asthmatics. Functional studies showed that CD8 + CD28 − T cells had cytotoxic function