Polyclonal B cell activation, endotoxin tolerance, and limulus tests of endotoxin preparations of some periodontopathogens.

Potencies of polyclonal B-cell activation in C3H/HeN mice of Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis endotoxins were 0.36, 0.13 and 0.04, taking Salmonella abortusequi as 1.0. F. nucleatum and P. gingivalis endotoxins showed positive reactions in C3H/HeJ mice. Most activities in C3H/HeN other than that of F. nucleatum were suppressed by polymyxin B. In C3H/HeJ mice, similar inhibitions were only 60% for P. gingivalis and hardly observed with F. nucleatum. The resistances to polymyxin B could be due to protein in the endotoxins. A promoting effect of T cells added to B cells was observed only in the activity of F. nucleatum endotoxin in C3H/HeJ mice; there was no influence in other groups. Test endotoxins had nearly the same ability to produce colony stimulating factor as did references and could not produce the factor in tolerant mice. The clinical significance of tolerance is discussed. Regression lines of endotoxin doses and limulus activities of test endotoxins and Salmonella were parallel, either in specific or non-specific tests. The lines of two test groups were also parallel; values obtained by two tests were very close. These data indicate that the test endotoxins did not contain (1-3)-beta-D-glucan and elicited qualitatively similar limulus reactions to that of the reference, despite their different chemical natures. In conclusion, these test preparations had an endotoxicity similar to that of the reference and contribute to produce periodontitis through polyclonal B cell activation.