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Puriified lipopolysaccharides (LPS) from strains of Bacteroides, Fusobacterium and Veillonella incubated with guinea pig serum, were tested for chemotatic activity against rabbit polymorphonuclear leukocytes (PMNs) in modified Boyden chambers. Comparisons were made to a Salmonella LPS (S. enteriditis S-795). Submicrogram amounts of LPS induced positive chemotaxis, and a typical dose-response relationship up to certain dose levels was observed. The difference in chemotactic activity between the Veillonella LPS and LPS-S-795 was not statistically significant. The Fusobacterium LPS showed either a non-significant or a highly significantly lower chemotatic capacity than LPS-S-795. The Bacteroides LPS were also clearly chemotactic, but considerable less when compared to the Salmonella LPS. When serum was not added, the LPS preparation showed no chemotactic activity.

Phenol-water extracted lipopolysaccharides (LPS) from Veillonella, Fusobacterium nucleatum, Bacteroides fragilis and Bacteroides melaninogenicus were lethal for mice and 11-days-old chick embryos, pyrogenic in rabbits, and gelated Limulus amoebocyte lysate. Mouse lethality was considerably enhanced by actinomycin-D. In all test systems the endotoxin activity of Veillonella and Fusocbacterium LPS was comparable to that of LPS from Salmonella enteritidis, which was included as a reference endotoxin. The endotoxicity of the Bacteroides LPS was very low. While nanograms of the Veillonella and Fusobacterium LPS killed the chick embryos and gelated the Limulus lysates, microgram amounts of the Bacteroides LPS were needed to give positive reaction in the same test systems. As much as 74 microgram of the most active B. fragilis LPS were required to give a typical biphasic fever response in rabbits. A significant correlation was found between all test results (r = 0.90-0.98, p less than 0.001).

Optimal stimulatory doses of purified phenol-water extracted lipopolysaccharides (LPS) from 5 selected strains of 3 putative periodontopathogens (Fusobacterium nucleatum, Prevotella intermedia, and Veillonella), 3 strains of 2 nonoral bacterial species (Bacteroides fragilis and Salmonella enteritidis), and pokeweed mitogen (PWM ) iduced significantly higher maximum mitogenic responses and polyclonal Ig production in cultures of unfractionated spleen cells from nu/nu-BALB/c (nude) than from BALB/c (normal) mice. Compared with PWM, the LPS were stronger mitogens showing relative mitogenic capacities B. fragilis LPS> F. nucleatum LPS> S. enteritidis LPS, Veillonella LPS, and P. intermedia LPS B. fragilis LPS was the most and S. enteritidis LPS the least effective polyclonal B cell activator of total Ig, IgG2a, lgG2b, IgG3, IgA, and IgM secretion IgGI was not detected, P. intermedia LPS was the strongest IgA inducer Kinetic observations indicated mitogenic responses and polyclonal B cell activation in a close sequential order in nude and normal cells. The LPS were potent Ag- and T-cell Independent polyclonal B cell activators and LPS of subgingival plaque bacteria may therefore play a nonspecific role in the pathogenesis of periodontal diseases. [ABSTRACT FROM AUTHOR]