FIG. 3.

Correlation between anti-PA IgG levels and protection against LeTx-mediated cytotoxicity. The viability of J774 cells was plotted against the IgG antibody titer to PA (μg/ml) in sera from C57BL/6 mice vaccinated two times with PA1-4 (A) or PA1 (B) or in sera from BALB/c mice vaccinated with PA1-4 (C), as described in the legend to Fig. 2. Each point represents the average for five mice per treatment group. Regression lines and correlation coefficients (R² values) are included for each plot.