title: Flow cytometrical determination of regulatory cytokines (IL-10, IL-12) and circulating dendritic cell cytokines in allergic asthmatic children.
abstract: Interleukin (IL)-10 and IL-12 have been suggested to be key regulators in the pathogenesis of allergic asthma. Several of the secretion products of dendritic cells (DC), such as IL-12, IL-10, IL-1beta and TNF-alpha, are considered to play a role in allergic asthma. This study compares the production of IL-10 and IL-12 in allergic asthmatic children (n = 17) and controls (n = 14) by measuring their extracellular secretion in whole blood samples after stimulation, using a microsphere-based immunoassay. Additionally, we assessed intracellular production of IL-1beta, TNF-alpha, IL-12 and IL-10 by circulating DC in stimulated whole blood samples of asthmatic and healthy children. The concentration of IL-10 in the supernatants of LPS-stimulated whole blood was significantly lower in allergic asthmatic children as compared to healthy children (463 (207-768) vs 881 (364-2626) pg/mL; p = 0.005). When a combined LPS and IFN-gamma stimulation was used, IL-10 production decreased significantly as compared to LPS alone, especially in healthy children. Consequently, no difference in IL-10 production after LPS/IFN-gamma stimulation was found between healthy and allergic children. In contrast to isolated LPS stimulation, stimulation with LPS/IFN-gamma induced higher IL-12 production; allergic asthmatic children showed a significantly lower IL-12 secretion after LPS/IFN-gamma stimulation as compared to healthy children (20 (5-247) vs 208 (7-775) pg/mL; p=0.03). Moreover, the number of IL-12 producing CD11c-positive DC (DC1) tended to be lower in asthmatic children compared to healthy children (0.05 (0.00-0.45) vs 0.27 (0.00-0.83) 10(6)/L) and correlated with the extracellular release of IL-12 in asthmatic children (r = 0.65; p = 0.016). The number of IL-1beta and TNF-alpha producing CD11c-positive DC (DC1) was comparable between healthy and asthmatic children. We hypothesize that the decreased production of IL-10 and IL-12 is responsible for Th2 polarized responses in allergic asthmatic children.
authors.affiliation: Department of Immunology, University of Antwerp, Universiteitsplein 1, 2610 Antwerpen, Belgium.
authors.forename: Margo M
authors.initials: MM
authors.lastname: Hagendorens
authors.forename: Didier G
authors.initials: DG
authors.lastname: Ebo
authors.forename: Chris H
authors.initials: CH
authors.lastname: Bridts
authors.forename: Luc S
authors.initials: LS
authors.lastname: De Clerck
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Stevens
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000494:pharmacology; D001249:Asthma / Q000188:drug therapy / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003713:Dendritic Cells / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism*; D018664:Interleukin-12 / Q000378:metabolism*; D008297:Male; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12