Pathogenicity ofSerpulina hyodysenteriae:in vivoinduction of tumor necrosis factor and interleukin-6 by a serpulinal butanol/water extract (endotoxin)

Abstract

Lipopolysaccharide (LPS) of Gram-negative bacteria is a classic inducer of inflammatory cytokines. In the present experiments, LPS-like (phenol/water extract) or endotoxin-like (butanol/water extract) preparations fromSerpulina hyodysenteriaewere examined for their ability to induce serum tumor necrosis factor (TNF) or interleukin (IL)-6 bioactivity in mice and swine.Serpulina hyodysenteriaeendotoxin (butanol/water extract) elicited increased serum TNF activity in mice, although serpulinal endotoxin was at least 10 times less potent than the LPS preparations ofE. coliorS. typhimuriumon a weight basis for induction of TNF bioactivity.S. hyodysenteriaeLPS induced lower levels of serum TNF in mice thanS. hyodysenteriaeendotoxin. In contrast, pigs injected withS. hyodysenteriaeendotoxin demonstrated no increase in serum TNF activity. However, an induction of IL-6 bioactivity was observed in serum samples from pigs injected with serpulinal endotoxin. In pigs, the serpulinal preparations were five times less potent (on a weight basis) thanE. coliorS. typhimuriumLPS for induction of IL-6 bioactivity. These data indicate that serpulinal endotoxin, although less bioactive thanE. coliorS. typhimuriumLPS, is nonetheless capable of inducing thein vivoproduction of specific pro-inflammatory cytokines.