FIG. 1.

Experimental procedure. Eight-week-old female Apoe^shl mice were randomly divided into four groups: group 1 was inoculated with 100 μl of PBS (▿), group 2 was inoculated with 100 μl (10⁸ CFU) of P. gingivalis (▾), group 3 was immunized with 40-kDa OMP plus CT () and inoculated with 100 μl (10⁸ CFU) of P. gingivalis (▾), and group 4 was immunized with CT only () and inoculated with 100 μl (10⁸ CFU) of P. gingivalis (▾). The immunized animals were nasally vaccinated with 40-kDa OMP plus CT or CT alone once a week for 3 weeks prior to the bacterial challenge. The animals were challenged i.v. with P. gingivalis strain 381 three times a week for 3 weeks. The animals were sacrificed either 24 h or 3 weeks after the final challenge.