C. burnetii infection induces phosphorylation of host proteins involved in cell survival. Lysates of mock- or C. burnetii phase II-infected THP-1 cells were harvested at the indicated times and processed for the Bio-Plex assay as described in Materials and Methods. Protein phosphorylation levels of infected cell lysates (gray bars) were compared to those of uninfected cell lysates (black bars). Phosphorylation of c-Jun, Hsp27, JNK, and p38 was transient, while phosphorylation of Akt and Erk1/2 increased through 72 hpi. Samples were analyzed in triplicate, and results are representative of those found in two independent experiments. Error bars represent the standard deviation from the mean. An asterisk indicates a P value of <0.05 in comparison to uninfected control cells as determined by a Student's t test. p, phosphorylated.