FIG. 4.

Activation of BBEC with TNF-α increases the number of adherent H. somnus. BBEC were activated with 100 ng/nl TNF-α at 37°C for 1 h. Cells were washed, and approximately 30 H. somnus CFU were added per endothelial cell. The cells were incubated for 1 or 4 h at 37°C and then washed five times with PBS. The endothelial cells were lysed, and the adherent bacteria were enumerated by plating BBEC lysates on sheep blood agar plates. Results are displayed as the percentage of CFU adherent to untreated control BBEC. Data represent the mean ± SEM of three independent experiments. **, P < 0.01.