FIG. 4.

Relative levels of IL-8 mRNAs obtained from GEC treated with P. gingivalis or F. nucleatum. P. gingivalis 33277 (P. ging) (10⁶ cells), F. nucleatum (F. nuc) (10⁸ cells), or a combination of P. gingivalis (10⁶ cells) and F. nucleatum (10⁸ cells) (P. ging/F. nuc) was used. After 18 h of exposure to the bacteria, mRNA was extracted from GEC and the relative amounts of IL-8 and actin mRNAs were determined by RT-PCR with appropriate probes. Scanning densitometry and quantitation of the gel using NIH Image 1.6 revealed a 75% decrease in the amount of IL-8 mRNA compared to that of actin mRNA in P. gingivalis-infected GEC.