Figure 3. E. faecalis MN1 secretes a factor responsible for inhibition of IL-8 production by HVECs in response to TSST-1.

Transwell permeable supports (0.4 µm pore size) were used to determine the ability of E. faecalis MN1 secreted factors to inhibit TSST-1-induced IL-8 production by HVECs. HVECs were grown to confluency in the bottom wells and transwell permeable supports were added on the day of experimentation. E. faecalis MN1 (2×10⁷ CFU) was added to either the transwell (to assess secreted factors) or the bottom well (as a positive control) in the presence or absence of TSST-1 (100 µg/ml) and incubated for 6 h. In one condition, catalase enzyme (100 µg/ml) was added to break down hydrogen peroxide produced by the lactobacilli. Cell culture supernates were collected and analyzed by ELISA for IL-8 production. These results contain data averaged from three separate experiments, with 6 total replicates in each experimental condition. *All conditions with E. faecalis MN1 present demonstrated significantly lower IL-8 levels compared to the TSST-1 only control by individual Student's t tests (p<0.01).