Different cytokine response of primary colonic epithelial cells to commensal bacteria

Figure 2 Bacterial growth (A) and kinetics of CEC cytokine gene expression (B) in CEC:bacteria co-cultures. A: Determination of bacterial (L. rhamnosus and E. coli) CFU by harvesting cells from CEC:bacteria co-cultures at hourly intervals up to 4 h by extensive washing of adherent CEC and plating serial dilutions onto agar plates and counting bacterial colonies 24 h later (left-hand panel). B. ovatus were cultured either alone under anaerobic conditions in RGM media or with CEC in 50 mL/L CO₂ and complete MEM (right-hand panel). CEC numbers (solid circle on both graphs) were determined by counting the number of cells recovered from co-cultures at the indicated times using a counting chamber; B: CEC cultured in the presence of E. coli for up to 5 h. CECs were processed for RNA isolation and RT-PCR analysis using primers specific for the housekeeping gene β-actin, and MIP-1α and TNFα as described in Materials and Methods. Quantitative densitometry was carried out on EtBr-stained gels and the results from three independent experiments were compiled to produce the data shown. Error bars indicate 95% confidence limits.