Different profile of interleukin-10 production in circulating T cells from atopic asthmatics compared with healthy subjects.
BACKGROUND
Interleukin (IL)-10 is a pleiotropic cytokine released from various cells, including T cells. Although IL-10 is suggested to inhibit allergic responses, its role in asthma remains uncertain. The purpose of the present study was to compare the profile of IL-10 in circulating T cells from stable atopic asthmatics, atopic nonasthmatics and healthy controls.


METHODS
Peripheral blood mononuclear cells were isolated, stained with anti-CD3 and CD4/CD8 antibodies, and then processed for intracellular IL-10 detection by flow cytometry.


RESULTS
A kinetic study in healthy controls showed that stimulation with phorbol 12-myristate 13-acetate and ionomycin significantly increased the frequencies of IL-10-producing CD3+, CD4+ and CD8+ cells. Without stimulation, the frequencies of IL-10-producing CD3+, CD4+ and CD8+cells were significantly higher in asthmatics than in healthy controls, while a similar trend was observed in atopic nonasthmatics. Stimulation for 24 h significantly increased IL-10-producing CD3+, CD4+ and CD8+cells in healthy controls and atopic nonasthmatics, but not in asthmatics.


CONCLUSIONS
The frequency of IL-10-producing T cells is increased in the circulation of stable atopic asthmatics compared with normal controls. The lack of enhancement in their frequency by phorbol 12-myristate 13-acetate and ionomycin in asthmatics suggests that the circulating T cells of asthmatic subjects are maximally stimulated with regards to IL-10 production; alternatively, IL-10 production by T cells from asthmatics may be regulated differently than T cells from other subjects.
Matsumoto
K
K
Asthma Research Group, Firestone Institute of Respiratory Health, St Joseph's Healthcare, McMaster University, Hamilton, Ontario.
Narita
S
S
Rerecich
T
T
Snider
D P
DP
O'Byrne
P M
PM
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000328:Adult; D001249:Asthma / Q000276:immunology*; D017252:CD3 Complex / Q000378:metabolism; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000276:immunology*; D016753:Interleukin-10 / Q000096:biosynthesis*; D015759:Ionomycin / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D016210:Methacholine Chloride; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D017252:CD3 Complex; D016210:Methacholine Chloride; D016753:Interleukin-10; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate