FIG. 4.
(A) Inhibition of SEB toxin blastogenesis of PBMCs by the 6343 peptide PBMCs (2 × 105) were stimulated with either 2 μg of SEB or a combination of 2 μg of SEB with various doses of the peptide. These were incubated for 6 days, and the results were measured via tritiated thymidine incorporation. cpm, counts per minute. Note the dose-related inhibition of SEB tested by the 6343 peptide. Data are the averages of four experiments, and error bars are the standard errors of the mean. ∗P < 0.05 equals the difference between SEB and all doses of the peptide. The molar concentrations of toxins and peptide are also given. (B) Noninhibition of SEB toxin blastogenesis of PBMCs by the 6345 peptide under the conditions described above. (C) Noninhibition of SEB toxin blastogenesis of PBMCs by the 6343X peptide (lysine substituted for cysteine) under the conditions described above.