Dilution curves of mouse plasma IgM binding to antigens.

<p>A, B) C57BL/6 mice were immunized with heat-killed <i>P. gingivalis</i> ATCC33277 (Pg) and controls (Co) received saline. The plasma was diluted 1∶100–1∶6400 and IgM binding to MDA-LDL, CuOx-LDL, native LDL, PC-BSA (A), <i>P. gingivalis</i> and recombinant gingipain domains Rgp44, Rgp15–27 and RgpCAT (B) were determined before (pre) and after (post) immunization with chemiluminescence immunoassay. Mean ± SD for two samples is shown. C, D) LDLR^−/− mice were immunized with killed <i>P. gingivalis</i> (3 strains mixed) (Pg) and controls (Co) received PBS. Pooled plasma from two mice was used for each dilution curve, and mean ± SD for two dilution curves is shown. IgM binding to MDA-LDL, CuOx-LDL, native LDL, PC-BSA (C), <i>P. gingivalis</i> and recombinant gingipain domain Rgp44, Rgp15–27 and RgpCAT (D) were determined before (pre) and after the second booster immunization (imm) as described.