Aminophylline On Mechanism Of Dendritic Cells In Asthma And Its Clinical Significance Of Research

[Objectives] 1. To investigate the effect of Aminophylline-treatment with three different concentration on the distribution and density of airway intraepithelial dendritic Cells in murine asthma models. 2. To investigate the effect of low dose of Aminophylline on airway inflammation induced by dermatophagoides farinae and the distribution and density of airway intraepithelial dendritic cell(DC) in murine asthma models. 3. To investigate the effect of Aminophylline on the expressions of HLA-DR, CD83 ,CD80 and the production of IL-10 in human dendritic cells.[Methods] 1. Fifty BALB/c mouse were randomly divided into five groups:control group, asthmatic group. aminophylline-treatment group(low s middle, high dose), the animal model of asthma was established by OVA sensitizing-challenging, Immunohistochemistry was used to detect DC, furthermore, transmission electron microscope and Computer image analysis were applied to analyse the morphology of DC. 2. Thirty BALB/c mouse were randomly divided into three groups: control group, asthmatic group and aminophylline-treatment group(20mg/kg). The animal model of asthma was parepared by sensitivity and exposition of dermatophagoides farinae, the pulmonary and tracheal samples and bronchoalveolar lavage(BAL) were examined at 24h after last challenge. The method of immunohistochemistry was used to detect the alteration of distribution and density of DC, and Transmission electron microscope and Computer image analysis were applied to analyse the morphology of DC. The cell count, and the count of eosinophil(EOS) in bronchoalveolar lavage fluid(BALF) were examined. IL-5 in BALF was detected by ELISA. 3. DC weregenerated by culturing peripheral blood mononuclear cell of asthmatic patients with GM-CSF, IL-4 and TNF-a in vitro. The expressions of HLA-DR, CD83 and CD80 were examined by flow cytometry after being stained with immunofluorescence antibodies. ELISA was used to detect the level of IL-10.[Results] 1. After OVA challenge ,There were higher numbers of NLDC-145+DC in the bronchial mucosa of asthmatic mouse compared with healthy controls(P <0.02).After seven days of treament, we found a significant lower numbers of NLDC-145+DC in low concentration group than in the asthmatic group(P <0.01),while in middle, high dose group , there were no obvious change(P>0.05). 2. The EOS count and the level of IL-5 in BALF of the asthmatic models , were more increased than that of the controls[(3.29 ± 1.38)×l06/L vs (0.05 ± 0.01)×l06/L and (25 ± 5)pg/ml vs (6 ± 3)pg/ml, P<0.05, P<0.01]. There was significant difference on the density of airway DC between the asthmatic group and the controls[(1542 ±28)cells/mm2 vs (600±20)cells/mm2, P<0.01]. And there was also significant difference on the density of airway DC and EOS count and IL-5 in BALF between aminophylline-treatment group and asthmatic group(P<0.05). In three groups, there was no obviously alteration of the distribution of airway DC. 3. Chronic stimulation(48h) of DCs with low, noncytotoxic aminophylline dose increased TNF-a-induced-DC membrane expression of CD83 and CD80, enhanced the production of IL-10,and decreased the expression of FILA-DR.[Conclusion] 1. It is suggested that dendritic cells are involved in inflammation of airway of asthmatic murine and that low concentration aminophylline may down-regulate the numbers of dendritic cells and inhibit airway inflammation in murine lung. 2. Aminophylline may be asan important regulatory agent to decrease the expression of HLA-DR and increase the production of IL-10 by DCs in human.