FIG 4.

Measurement of C. pneumoniae transcript levels for genes associated with the heat shock response during IFN-γ-mediated persistence. Nucleic acid samples were collected from untreated (solid symbols) and IFN-γ-treated (open symbols) C. pneumoniae-infected HEp2 cells at 24 and 48 h postinfection. Transcript levels for the indicated genes were measured by RT-qPCR and normalized to genomic DNA (nanograms of cDNA/gDNA) for (A) dnaK, (B) hrcA, and (C) dnaJ. All transcript data are the average from at least 3 experiments with standard deviations displayed. *, P ≤ 0.05 for 48-hpi IFN-γ versus 24-hpi IFN-γ.