[Roles of interleukin-10 differentiated dendritic cell of allergic asthma patients in T-lymphocyte proliferation in vitro].

Objective: To explore the roles of interleukin (IL)-10 differentiated peripheral blood monocyte-derived dendritic cell (DC-10) of allergic asthma patients in T-lymphocytes proliferation in vitro.

Methods: From January to June 2011, 10 subjects with dust mite allergic asthma treated at Third Affiliated Hospital of Soochow University were enrolled. Their peripheral blood monocytes were isolated by Ficoll-Hypaque solution density gradient centrifugation and adherent method. And the adherent monocytes were routinely cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF)+interleukin-4 (IL-4)+tumor necrosis factor-alpha (TNF-α), stimulated with/without interleukin-10 (IL-10), pulsed with dust mite allergen and finally harvested. The cell surface molecules including CD80, CD83, CD86, human leukocyte antigen (HLA)-DR and immunoglobulin-like transcript 2 (ILT2) were detected by immunofluorescent labeling and flow cytometry. And cellular functions were estimated by detecting the capacities of DC uptake antigens with fluorescein isothiocyanate (FITC)-dextran capturing assay. The IL-10 differentiation DC (DC-10) were cultured with autologous peripheral T cells (DC-10 group), either alone (DC-TNF group) or together (combined group) with autologous immunostimulatory DC (DC-TNF). And the impact of this treatment on T-cell responses was assessed for each donor by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay. The production of interferon-γ (IFN-γ), IL-4, interleukin-5 (IL-5) and interleukin-13 (IL-13) were measured with the quantification of enzyme linked immunosorbent assay (ELISA) kits.

Results: In DC-10, the levels of some mature DC's markers (CD80, CD83, CD86 & HLA-DR) decreased, ILT2 increased and there were the higher capacities of up-taking FITC-dextran particle (72.32%±2.93% vs 54.41%±2.95%, P<0.01). Compared with the DC-TNF group (1.74±0.15), the T cell proliferation of the DC-10 group (1.06±0.18) and that of the combined group (1.34±0.16) were significantly inhibited (P<0.01). The secretion levels of IFN-γ, IL-4, IL-5 and IL-10 were (2998±141), (157±17), (2608±254) and (55±11) ng/L in the DC-10 group versus (3223±203), (149±19), (2465±183) and (88±10) ng/L respectively in the combined group. They were all significantly reduced versus (3639±209), (173±16), (2771±183) and (127±11) ng/L in the DC-TNF group (all P<0.01).

Conclusions: The IL-10-treated human DC may express a tolerogenic phenotype and induce the allergen tolerance of T cells. And the induction of DC-10 represents a promising target for therapeutic intervention of effectively managing the clinical outcomes of allergic asthma.