Decrease of Interleukin-10-Producing T Cells in the Peripheral Blood of Severe Unstable Atopic Asthmatics

Abstract

Background: Although IL-10 is known as an immunoregulatory cytokine produced by various cells including T cells, its basic profile in atopic asthma remains uncertain. Objective: The profiles of IL-10 production in circulating CD4+ T cells of atopic asthmatics were investigated with respect to clinical severity. Methods: Forty atopic asthmatics were divided into three groups: mild, and severe but stable and severe unstable asthmatics. Eosinophils were counted in the peripheral blood and sputum, and exhaled nitric oxide was assessed. PBMCs were stimulated with or without anti-CD3 and anti-CD28 antibodies and then processed for detecting IL-10-producing CD4+ cells using flow cytometry. Results: There was no difference in the eosinophil count in blood or sputum and in nitric oxide level among the three groups. IL-10-producing CD4+ cells were mainly detected in a CD45RO+ memory population. The frequency of IL-10-producing cells after stimulation was significantly lower in the severe unstable group compared to the mild group. In addition, the frequency of IL-10-producing cells in the severe unstable group was significantly lower than that in the severe stable group despite the fact that both groups received similar treatments with high-dose inhaled corticosteroids. The IL-10 production of CD4+CD45RO+ cells in response to dexamethasone did not differ among the three groups. Conclusions: IL-10-producing CD4+CD45RO+ cells in the peripheral blood are decreased in severe unstable asthmatics, which is not explained by the effect of high-dose inhaled corticosteroid medication.

Regulatory T-lymphocytes in asthma

“…The role of IL-10 producing T-cells in the severity of allergic asthma in adults has been studied by MATSUMOTO et al [100] by comparing mild, severe-stable and severe-unstable asthmatics.…”

Role of Interferon-Γ and Interlukin-10 on the Pathogenesis of Asthma Phenotypes in Saudi Patients.

“…This suggests that IL-10 production from T-cells is unregulated in asthmatic cases. Since IL-10 promoters polymorphisms have been reported (17), it is possible that IL-10 effector functions are reduced in atopic asthmatic subjects, in which a decrease in IL-10 expression in asthma has been reported (18). It has also been proved that remission of allergy symptoms is related to an increase in IL-10 expression in allergen-specific T-lymphocytes (19).…”

Different Profiles of IL-10+IFN-γ–IL-4–CD4+ T Cells in the Peripheral Blood in Atopic and Non-Atopic Asthmatics

“…Our previous study showed that IL-10+CD4+ T cells in the peripheral blood of atopic asthmatics was decreased in severe unstable asthmatics compared with mild and severe stable asthmatics [21]. Another study reported that the production of IL-10 in monocytes was also impaired in cases of severe asthma [25].…”

“…The frequencies of IL-10-producing CD3+, CD4+ and CD8+ cells in the peripheral blood were significantly higher in atopic asthmatics than in healthy subjects [20]. In addition, we reported that IL-10+CD4+ T cells in the peripheral blood were decreased in severe unstable asthmatics compared with mild and severe stable asthmatics [21]. Although these results suggest a possible association of peripheral blood IL-10+CD4+ T cells with atopic asthma, several questions remain unanswered.…”