FIG. 4.

An increase in intracellular iron would be expected to result from an upregulation of TfRs. The graph shows the intracellular iron content determined by inductively coupled plasma emission of J774A.1 cell cultures inoculated with viable (open circles) and inactivated C. burnetii (filled circles) as well as an uninoculated control (triangles). The results shown are the means for an experiment done in triplicate, and error bars indicate standard deviation. There are no error bars for two points at 36 h, as one data point was available for cells inoculated with inactivated C. burnetii and two were available for uninoculated cells.