FIG. 5.

Inhibition of SEB transcytosis by SEB 152-161 and SEB 130-160. Peptides were incubated with 1 μg of SEB/ml at the indicated ratios for 24 h, and toxin transcytosis was assessed. Results are presented as the mean ± standard error of SEB that was able to cross a monolayer of T-84 cells in the presence of the synthetic SEB peptides. In the absence of peptide, 46.1 ng of SEB/ml was transcytosed with a standard error of 9.6 ng/ml. Data were normalized based on transcytosis of toxin alone from three replicate experiments. SEB 130-160 at 1:10 and 1:100 toxin-to-peptide ratios and SEB 152-161 at all ratios were significantly different from toxin alone, as determined by analysis of variance followed by Scheffe's F-test (P < 0.05).