FIG. 5.

Humoral-immunity analyses of TDAG8 KO mice. Preimmune sera were collected from male WT and KO mice on the C57BL/6 background at 8 to 12 weeks of age. (A) Baseline immunoglobulin titers were determined by ELISA as previously described (18). Numbers of mice: 18 per genotype for IgA, IgG1, and IgG2a determinations; 4 WT mice and 3 KO mice for IgG2b, IgG3, and IgM determinations. The error bars indicate SEM. (B) Mice were immunized i.p. with a mixture of 25 μg ABA-CGG and 5 × 10⁸ heat-killed Bordetella pertussis (BP) cells, as described in Materials and Methods. Seven days later, the mice were also immunized with TNP-Ficoll. Two weeks after the first immunization, primary antibody responses against TNP-bovine serum albumin (IgM; n = 4 mice/genotype), CGG (IgG1; n = 20 WT mice and n = 22 KO mice), and B. pertussis (IgG2a; n = 20 WT mice and n = 22 KO mice) were determined by ELISA. Four weeks postimmunization, the mice were rechallenged with ABA-CGG to measure secondary immune responses. Seven days later, titers of IgG1 antibodies against CGG were determined by ELISA (n = 8 mice/genotype).