FIG 2.

Increase of proinflammatory cytokine mRNA expression requires stimulation with either Chlamydia pneumoniae or C. pneumoniae plus CNTs, but not CNTs alone. Transcription of IL-1β, IL-8, or TNF-α mRNA was determined by qRT-PCR, and the data (means ± standard deviations) are shown as a ratio (fold change) of each of the target cytokine genes to the GAPDH gene. *, statistically significant difference (P < 0.05 versus control, Student's t test; n = 3). NS, not significant; Cpn, C. pneumoniae; CNT, carbon nanotube; IL-1β, interleukin-1β; TNF-α, tumor necrosis factor alpha.