Objective To investigate the effects of house dust mites(HDM)with diverse concentrations on the expressions of co-stimulatory molecules of HDM major antigen gene Der p2 modified dendritic cell(DC).Methods Der p2 gene modified DC(Der p2-DC)and control DC(non-transfected DC)were treated 72 h by HDM with diverse concentrations respectively.The expressions of CD80,CD86 and MHCⅡ,the surface co-stimulatory molecules on Der p2-DC and control DC,were detected by FACS.Results FACS analysis showed that positive expression percentages of CD80,CD86 and MHCⅡ on Der p2-DC treated with HDM had no significant change,compared with Der p2-DC treated without HDM.After treated with HDM,positive expression percentages of CD80,CD86 and MHCⅡ on control DC increased significantly.Conclusions Specific allergen pulsing could not increase the expressions of costimulatory molecules of allergen gene modified DC.