IL-10 production in circulating T cells differs between allergen-induced isolated early and dual asthmatic responders.
BACKGROUND
IL-10 is an anti-inflammatory cytokine released from various cells, including T cells. The role of IL-10 in asthma pathogenesis remains uncertain. Allergen inhalation by atopic asthmatic subjects results in 2 bronchoconstrictor phenotypes: isolated early response and dual response. Persistence of allergen-induced airway inflammation is a feature of dual responders.


OBJECTIVE
The kinetics of IL-10 production in circulating T cells were investigated to examine a potential role of IL-10 in allergen-induced responses and airway inflammation.


METHODS
Fourteen subjects with mild asthma (7 isolated early and 7 dual responders) were challenged with allergen. PBMCs taken before and 24 hours after allergen challenge were processed for intracellular IL-10 staining with fluorescent-conjugated anti-IL-10 antibody. The frequency of IL-10-producing cells was assessed for CD4(+) and CD8(+) T-cell subsets by using flow cytometry.


RESULTS
Before allergen administration, the frequency of IL-10-producing CD4(+) cells was significantly higher in dual than in isolated early responders. IL-10-producing CD4(+) cells significantly increased after allergen in early responders, whereas IL-10-producing CD4(+) cells significantly decreased in dual responders. Simultaneous assessments of IL-5-producing T cells did not show any differences between each group before or after allergen administration.


CONCLUSIONS
These results suggest that the contrasting profiles of IL-10 production may be associated with the different time course of allergen-induced airway inflammation between allergen-induced early and dual responders.
Matsumoto
Koichiro
K
Asthma Research Group, St Joseph's Healthcare and McMaster University, Hamilton, Ontario, Canada.
Gauvreau
Gail M
GM
Rerecich
Tracy
T
Watson
Richard M
RM
Wood
Lorna J
LJ
O'Byrne
Paul M
PM
D000280:Administration, Inhalation; D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000276:immunology*; D001249:Asthma / Q000209:etiology / Q000276:immunology*; D001985:Bronchial Provocation Tests; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis*; D008297:Male; D013183:Sputum / Q000166:cytology / Q000276:immunology
D000485:Allergens; D016753:Interleukin-10