FIG. 7.

Effect of a serine protease inhibitor on Acanthamoeba-derived cytolytic factors. Trophozoites were incubated with 100 mM mannose for 48 h at 35°C. Supernatants were collected, centrifuged, filter sterilized, concentrated fourfold, and dialyzed against a 10-kDa-cutoff membrane. Supernatants were mixed with 10 μg of PMSF per ml 30 min prior to addition to CHCE cell monolayers. CPE was assessed spectrophotometrically after 48 h. Negative controls consisted of monolayers incubated in medium alone (0% CPE). Results are expressed as mean ± standard deviation. ∗, the difference between the two groups was significant (P = 0.04). □, mannose supernatant; ▨, mannose supernatant + PMSF.