FIG 7.

IL-8 induction by OMVs of V. cholerae O1 strains in the T84 cell line. (A) Comparative analysis of IL-8 secretion from T84 cells coincubated with OMVs from V. cholerae O1 El Tor strain C6709, its isogenic protease mutant strains CHA6.8, CHA6.8 ΔprtV, and CHA6.8 ΔprtV ΔVC1649, and CHA6.8 ΔprtV ΔVC1649::VC1649 (Comp VC1649) determined by ELISA. Data represent mean ± SD from three independent experiments performed under similar conditions. Variables were compared for significance using two-way analysis of variance and the Bonferroni test (*, P value between 0.01 and0.05; **, P value between 0.01 and 0.001). (B) IL-8 production from T84 cells was analyzed at the mRNA and protein levels by RT-PCR and resolved in a 2% agarose gel. IL-8 expression in T84 cells treated with OMVs from O1 El Tor strain C6709 and its protease knockout mutant strains CHA6.8, CHA6.8 ΔprtV, CHA6.8 ΔprtV ΔVC1649, and Comp VC1649 is displayed in lanes 2 to 5, respectively, and the untreated control is in lane 1. Densitometric quantification in densitometric units (DU) for IL-8 after normalization to GAPDH is shown below the agarose gel.