1995 Volume 37 Issue 4 Pages 628-640
The purpose of this experiment was to clarify the influence of antibody and complement on the superoxide production [Chemiluminescence (CL) response] and periodontopathic bacteria phagocytosis and killing by polymorphonuclear leukocytes (PMNs). PMNs were obtained from the peritoneal cavity of ICR mice after caseinate injection. Three species of periodontopathic bacteria were used : Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). Mice were immunized with live Aa, Pg or Fn vaccine. Serum was obtained from the blood by cutting the carotid artery. Normal serum was used as complement and inactivated immune serum was used as the antibody. The antibody titers were measured by ELISA using sonicated Aa, Pg and Fn antigen. Serum with a high antibody titer was obtained. IgG levels were high when mice were immunized with either Aa or Pg, whereas IgM levels were high when immunized with Fn. The reaction mixture for the CL response consisted of luminol solution, serum, gelatin Hanks' solution, PMNs and the bacteria. After the CL response was complete, a portion of the reaction mixture was smeared on a glass slide, dried and stained with May-Gruenwald-Giemsa stain. Phagocytic activity was assessed using a microscope. Surviving bacteria were counted on solid medium after treatment with serum, antibody and PMNs alone or in combination.
An increase in the CL response to Aa occurred and was dependent on the addition of complement, and the response to Pg was dependent on both complement and antibody whereas the response to Fn dependent on neither complement nor antibody. The CL response to Fn was inhibited by Dgalactose, N- acetyl-D-galactosamin and mannan. Phagocytic rate of PMN and the number of Aa and Fn bacteria in PMNs was enhanced in the presence of complement. The co-operation of both complement and antibody was needed to increase the phagocytic ratio. The bactericidal effect of complement, antibody and PMN were examined in single or combination mixtures. There was no marked effect on killing the bacteria in any combination.
In conclusion, complement plays the role of enhancing the CL response and phagocytic activity in response to Aa. Co-operation of complement was necesary for phagocytosis of Fn. High titer antibody, complement and PMN had no bactericidal effect under the experimental conditions.
