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-gamma. 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-gamma 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.
Hamzaoui
Agnes
A
Department of Pediatric and Respiratory Diseases, Abderahmane Mami Hospital, Tunisia.
Chaouch
Nawel
N
Graïri
Hedia
H
Ammar
Jamel
J
Hamzaoui
Kamel
K
D000328:Adult; D001249:Asthma / Q000276:immunology* / Q000503:physiopathology; D018106:CD28 Antigens / Q000276:immunology*; D019002:CD56 Antigen / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013183:Sputum / Q000166:cytology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology
D018106:CD28 Antigens; D019002:CD56 Antigen; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D007371:Interferon-gamma