Expression of Surface Markers on Mature Monocyte-Derived Dendritic Cells from Allergic Asthmatics

Dendritic cells (DCs) are one type of important inflammatory cells in the pathogenesis of asthma for early response to allergen exposure. Monocyte-derived DCs (MoDCs) are characterized by a high antigen uptake capacity and poor T-cell stimulatory activity, both features of immature DCs. By stimulation with tumor necrosis factor-alpha (TNF-alpha) or antigen capture, these cells differentiate into mature DCs with the disappearance of antigen-capturing regions, and increase in stimulatory activity. We measured the expression of some molecules on MoDCs before and after stimulation with TNF-alpha or house dust mite (HDM) antigen, from 9 house dust mite (HDM)-allergic asthmatic patients and 8 normal control subjects by flow cytometry. Primary MoDCs from HDM-allergic asthmatics showed a greater expression of histocompatibility leukocyte antigen (HLA)-DR and mannose receptor (MR), but not of CD80, CD86 or intercellular adhesion molecule-1 (ICAM-1), than those from normal subjects (P < 0.05). After stimulation with TNF-alpha or HDM, DCs from asthmatic patients showed a greater expression of HLA-DR, CD86 and ICAM-1, than those from normal subjects. In HDM-allergic asthmatic patients, MR expression on DCs significantly declined after stimulation by HDM compared with stimulation by TNF-alpha (P < 0.05). Results suggest that the reduction of MR expression may be characteristic on mature DCs after HDM exposure in allergic asthma.