FIG. 6.

Inhibition of amebic galactose-specific adherence to CHO cells by sera (A) or fecal supernates (B) from peptide (1,600-μg-dose)-immunized or control baboons. Axenic E. histolytica trophozoites were incubated at 4°C with or without increasing concentrations of galactose, sera, or fecal supernates. As expected, increasing concentrations of galactose demonstrated a dose-dependent inhibition of ameba-CHO cell rosette formation (P, <0.01 for each concentration compared to control media). Sera from peptide-immunized baboons (P, <0.01 at each dilution) and sera from baboons receiving adjuvant only (P, <0.001 at each comparable dilution) demonstrated significant inhibition of amebic galactose-specific adherence compared to control media. The adherence-inhibitory effects of immune baboon sera were no different from those of galactose. Fecal supernates from peptide-immunized baboons inhibited amebic adherence to CHO cells compared to fecal supernates from baboons receiving CT adjuvant only (P, <0.01 at each dilution). The adherence-inhibitory effects of fecal supernates from immunized baboons were also concentration dependent (P, <0.01 for each dilution compared to the proceeding one) and comparable to the adherence-inhibitory effects of galactose.