Intracellular IL-5 and T-lymphocyte subsets in atopic and nonatopic bronchial asthma.
BACKGROUND
Allergen-stimulated IL-5 production by CD4+ T cells is the key issue in atopic asthma. On the other hand, virus-specific CD8+ T cells produce IL-5 and might play an important role in the pathogenesis of nonatopic asthma.


OBJECTIVE
We sought to compare the IL-5-producing T-lymphocyte subsets in the peripheral blood of atopic and nonatopic asthmatic subjects, especially the contribution of IL-5-producing CD8(+) T cells in nonatopic asthma.


METHODS
Heparinized blood samples were obtained from subjects with atopic asthma (n = 10), subjects with nonatopic asthma (n = 10), and healthy subjects (n = 10) and stimulated with ionomycin and phorbol myristate acetate in the presence of brefeldin A. Two-color flow cytometric analysis with mAbs to cell-surface antigens and intracellular IL-5 was used to detect the IL-5-producing T-cell subsets.


RESULTS
A higher percentage of IL-5-producing CD3(+) T cells was detected in subjects with atopic and nonatopic asthma than that seen in the healthy subjects. The percentage of IL-5-producing CD4(+) T cells was significantly higher in subjects with atopic asthma than in the healthy subjects. The percentage of IL-5-producing CD8(+) T cells was significantly higher in subjects with nonatopic asthma than in the healthy subjects. The percentage of IL-5-producing CD8(+) T cells was higher in subjects with nonatopic asthma than in those with atopic asthma, but the difference was not statistically significant.


CONCLUSIONS
CD4(+) T cells are the major source of IL-5 among CD3(+) lymphocytes in subjects with atopic asthma. On the other hand, increased IL-5 production by CD8(+) T cells, as well as by CD4(+) T cells, is a characteristic feature of nonatopic asthma.
Shiota
Yutaro
Y
Department of Clinical Research, Kure Kyosai Hospital, Kure, Japan.
Arikita
Hitomi
H
Horita
Naokatsu
N
Hiyama
Junichiro
J
Ono
Tetsuya
T
Yamakido
Michio
M
D000328:Adult; D000368:Aged; D001249:Asthma / Q000276:immunology*; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D015848:Interleukin-5 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism
D017252:CD3 Complex; D015848:Interleukin-5