FIG. 7.

Characterization of sLLO strain infection in C.B-17 mice. (A and B) C.B-17 mice were treated with 1 mg of either the LLO-neutralizing antibody A4-8 or the GIR.208 control antibody, and 24 h later, they were infected with 10⁸ CFU of the sLLO strain. (A) Mice were sacrificed at day 2 postinfection, and colony counts were determined. (B) Histology from the mice was scored for extent of apoptosis. Lesions were classified by size from negative (neg; negative/no apoptosis) through low (small apoptotic lesions; <25% white pulp profile apoptotic), medium (med; medium apoptotic lesions, 25 to50% white pulp profile apoptotic), and high (hi; large apoptotic lesions; >75% white pulp profile apoptotic). The data show the percentage of white pulp profiles from each mouse that fit each of the four categories. Bars are the mean ± standard error of the mean from four mice per group. (C and D) C.B-17 mice were treated with 250 μg of RB6-8C5 or rat immunoglobulin G (IgG) at days −3 and −1. At day 0, mice were infected with either 10⁴ CFU of EGD or 10⁷ CFU of the sLLO strain. At day 3, mice were sacrificed and colony counts were determined. Points represent individual titers per mouse organ. Bars are the mean ± standard error for two independent experiments with three or four mice per group.