Article

Effects of Fusobacterium necrophorum subspecies necrophorum on extracellular matrix of tissue-cultured bovine kidney cells.

Laboratory of Animal Health, Tokyo University of Agriculture, Japan.
Microbios 02/2000; 101(400):147-56.
Source: PubMed

ABSTRACT The effects of Fusobacterium necrophorum subsp. necrophorum on the extracellular matrix were investigated. The toxic preparation from the culture induced reduction in the number of tissue-cultured bovine kidney cells. The exposed cells often manifested partial loss of cytoplasm and were morphologically irregular. Scanning electron microscopy demonstrated partial loss of the microvilli on the exposed cells and roughness of the cell surfaces. Finally, sodium dodecyl sulphate polyacrylamide gel electrophoresis profiles revealed complete degradation of bovine collagen type 1 after treatment with the toxic preparation. This degradation was inhibited by the addition of homologous antiserum. These findings indicate that the degradation may contribute to the establishment of the infection caused by F.n. subsp. necrophorum.

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  • Article: Fusobacterium necrophorum leukotoxin induces activation and apoptosis of bovine leukocytes.
    Sanjeevkumar Narayanan, George C Stewart, M M Chengappa, Lloyd Willard, Wilma Shuman, Melinda Wilkerson, T G Nagaraja
    [show abstract] [hide abstract]
    ABSTRACT: Fusobacterium necrophorum, a gram-negative, rod-shaped, anaerobic bacterium, is a primary or secondary etiological agent in a variety of necrotic, purulent infections in humans and animals. Its major virulence factor is leukotoxin, a high-molecular-weight secreted protein, primarily toxic to ruminant leukocytes. In this study, bovine peripheral blood leukocytes were exposed to various concentrations of immunoaffinity-purified leukotoxin and the cytotoxicity was analyzed by flow cytometry and scanning and transmission electron microscopy. At very low toxin concentrations, polymorphonuclear leukocytes (PMNs) showed activation, as indicated by translocation of primary and secondary granules to the periphery of the cytoplasm. Furthermore, these cells showed changes characteristic of apoptosis, including decreased cell size, organelle condensation, cytoplasmic membrane blebbing (zeiosis), and chromatin condensation and margination, and decrease in cellular DNA content. At moderately high concentrations of leukotoxin, bovine mononuclear cells were also induced to undergo programmed cell death. At very high concentrations, leukotoxin caused necrotic cell death of bovine peripheral leukocytes. The ability of F. necrophorum leukotoxin to modulate the host immune system by its toxicity, including cellular activation of PMNs and apoptosis-mediated killing of phagocytes and immune effector cells, represents a potentially important mechanism of its pathogenesis.
    Infection and Immunity 09/2002; 70(8):4609-20. · 4.16 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

bovine collagen type 1
 
cell surfaces
 
culture induced reduction
 
exposed cells
 
extracellular matrix
 
Fusobacterium necrophorum subsp
 
homologous antiserum
 
microvilli
 
morphologically irregular
 
partial loss
 
roughness
 
sodium dodecyl sulphate polyacrylamide gel electrophoresis profiles
 
tissue-cultured bovine kidney cells
 

Y Okada