E. Coli Infection Adjust The Expression Of Cd40,b7-1 And B7-2 On The Surface Of Mouse Dcs

Objective: the aim of this study was to determine the expression of CD40,B7-1 and B7-2 on the surface of mouse DCs when E.coli infecting.Methods: 1,utilization different concentrations (2×107,2×106) of E. coli to stimulate mouse DCs (DC2.4, 2×105 cells / well), LPS treatment group as a positive control, PBS treated as a negative control. After 4h and 24h stimulating, cells were collected, extract RNA, using RT-PCR detected the expression of CD40 mRNA of DC cells. 2,Expand the cell culture (DC:1×106 cells / well, E. coli :1×108 and 1×107), 4h and 24h after infection,cells were collected,use the flow cytometry to detect the expression of CD40,B7-1 and B7-2 molecules of DC cells.Results: 1,Compare with the negative control group,the mouse DC cells after E. coli stimulation,the expression of CD40 molecules significantly increased,there was significant difference between the two groups(P < 0. 05). In which,the increasing level of stimulate for 4h is significantly lower than thar for 24h[(6714.5±1367.74)copies/μl vs (13105.0±801.06)copies/μl;(10101.0±797.69)copies/μl vs (15785.0± 676.23)copies/μl], there was significant difference between the two groups(P < 0. 01),and the increasing level of lower concentration stimulate (1×107)is significantly higher than that of higher concentrations stimulate(1×108) [(10101.0±797.69)copies/μl vs (6714.5±1367.74)copies/μl;(15785.0±676.23)copies/μl vs (13105.0±801.06)copies/μl],there was significant difference between the two groups (P < 0. 01). 2,cultrue the mouse DCs with E,coli, the increasing level of the B7-1 and B7-1 molecules on the surface is no significant difference compare with that culture with LPS or PBS.Conclusions: 1,The culture mouse DC cells have CD40 molecules expression on the surface,after E. coli stimulation ,the level of expression increasing。The degree of the level has positive correlation with stimulus time and negative correlation with stimulus concentration, Initial proof that the Th cell polarization effected by different antigen loading. 2,The culture mouse DC cells have high expression of B7-1 and B7-2 molecules on the surface,after E. coli stimulation,the expression of B7-1 and B7-2 molecules have no significant change.