<p>Mice were immunized with <i>N. meningitidis</i> P1.5-1,2-2 OMVs and antigen-specific titers of IgG, IgG1, IgG2a/c, IgG2b, and IgG3 in sera were determined with ELISA. Also total IgE in sera of mice immunized with PBS or <i>N. meningitidis</i> P1.5-1,2-2 OMVs was measured with ELISA. Results for C57BL/6, TLR2−/−, and TRIF-deficient (TRIFdef) mice are shown in panel A, results for C3H/HeOuJ and C3H/HeJ mice are shown in panel B. Levels of serum bactericidal antibodies after immunization with <i>N. meningitidis</i> P1.5-1,2-2 OMVs are shown in panel C. Data are expressed as means of log<sub>10</sub> titers for 6 mice per group, except levels of serum bactericidal antibodies in C57BL/6 and TLR2−/− mice (n = 12). Error bars represent S.E.M. An asterisk indicates a significant difference compared to the wild type group, * indicates p<0.05, ** indicates p<0.01.</p
