[The mechanism and implication of costimulatory molecules in dendritic cells in the development of asthma].

Objective: To exploring the role of costimulatory molecules in the development of asthma and its mechanisms.

Methods: Murine asthma model was established with ovalbumin (OVA) sensitization and challenge, and the model was confirmed by histological analysis of lung tissues, cell numbers and differentiations of bronchoalveolar lavage, serum OVA-specific IgE level and interleukin (IL)-4 and IL-5 production by splenic T cells. The purity of spleen-derived dendritic cells was assayed with fluorescein-actived cell sorter (FACS) by analyzing CD(11c) molecule. FACS was also used to measure the expression of CD(80) and CD(86) on spleen-derived dendritic cell (DC) from OVA-sensitized and challenged mice. Finally, the production of IL-4 and IL-5 in naive T cells after stimulation with spleen-derived DC from OVA-sensitized and challenged mice were determined with ELISA.

Results: Histological analysis of lung tissues, components of broncho-alveolar fluid, the level of serum OVA-specific IgE, and the production of IL-4 and IL-5 were all consistent with the characteristic of a murine asthma model. The expression of CD(80) on spleen-derived DC from OVA-sensitized and challenged mice was increased significantly compared with that from PBS-treated mice, while there was no difference in CD(86) expression. On the other hand, DC from OVA-sensitized and challenged mice stimulated the production of IL-4 and IL-5 by naïve T cells.

Conclusion: Our results suggest that DC, via upregulation of CD(80), might play a pivotal role in the maintenance and amplification of allergic immune response, namely the Th2 immune response.