FIG 6.

(A) Blastocystis isolate ST7-B (but not ST4-WR1) excreted-secreted products (ESPs) degrade LL-37, as shown by ELISA results. ELISA plates were coated with the LL-37 peptide, and the plates were incubated with Blastocystis ESPs for 2 h. Degradation was prevented when ST7-B ESPs were incubated with a protease inhibitor cocktail prior to incubation with the peptide. OD₄₀₅, optical density at 405 nm. (B) Viability experiments were also done by using LL-37 previously incubated with ST7-B ESPs. The graph shows that ST7-B ESPs attenuated LL-37 activity. This was reversed when the ESP was first heated to denature proteins. *, P < 0.05.