Comparison of cytokine induction by lipopolysaccharide of Bacteroides fragilis with Salmonella typhimurium in mice.
Comparison of cytokine stimulation by lipopolysaccharide (LPS) of Bacteroides fragilis and Salmonella typhimurium was done to study the early events occurring in vivo. Mice injected intraperitoneally with either LPS demonstrated endogenous production of all the cytokines studied (tumor necrosis factor-alpha, interferon-gamma and interleukin-6) within 6 hr in the bloodstream. However induction of all the cytokines by B. fragilis LPS (50 micrograms/mouse) was much weaker compared with S. typhimurium LPS (50 micrograms/mouse). Even a dose of S. typhimurium LPS 40 times smaller (1.2 micrograms/mouse) induced cytokines more strongly compared with B. fragilis LPS. Thus, a weak biological response to B. fragilis LPS as evidenced by chick embryo lethality, limulus lysate gelation, LD50 for mice and rabbit pyrogenicity could be due to weak induction of bioactive mediators by LPS.
Institute of Anaerobic Bacteriology, Gifu University School of Medicine, Japan.
R
R
Jotwani
Y
Y
Tanaka
K
K
Watanabe
K
K
Tanaka-Bandoh
N
N
Kato
K
K
Ueno
D000818:Animals; D001441:Bacteroides fragilis / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D007274:Injections, Intraperitoneal; D007371:Interferon-gamma / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012486:Salmonella typhimurium / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma