Isolation of a cytotoxin from L-form Salmonella typhimurium.
A cytotoxic protein was isolated from the sodium dodecyl sulphate (SDS)-solubilized extract of the stable L forms of Salmonella typhimurium by ion-retardation chromatography, ion-exchange chromatography, isoelectric focusing and gel filtration. The purified toxin, with a molecular mass of 32 kDa and with isoelectric point of 6.4, was thermolabile and trypsin-sensitive. Against mouse macrophages, its cytolytic effect was detectable in vitro at concentrations higher than 0.7 micrograms/ml, with a complete lysis obtained at 5 micrograms/ml. In contrast, it stimulated C3H/HeJ macrophages in the dose range of 0.1-0.5 micrograms/ml to allow the cell to respond to endotoxin, resulting in the significant production of tumor necrosis factor alpha. By Northern blot analysis, this effect was detectable at a dose as low as 0.01 micrograms/ml. These findings suggest that the transformation of bacillary S. typhimurium into L forms in vivo may induce alterations in host resistance against murine typhoid.
Kita
E
E
Department of Bacteriology, Nara Medical University, Japan.
Kamikaidou
N
N
Nakano
A
A
Kashiba
S
S
D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification* / Q000633:toxicity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003603:Cytotoxins / Q000302:isolation & purification* / Q000633:toxicity; D004731:Endotoxins / Q000302:isolation & purification* / Q000633:toxicity; D007525:Isoelectric Focusing; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D012486:Salmonella typhimurium / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D001427:Bacterial Toxins; D003603:Cytotoxins; D004731:Endotoxins; D014409:Tumor Necrosis Factor-alpha; C027952:salmonella toxin