Unknown

Dataset Information

0

Role of sphingomyelinase in infectious diseases caused by Bacillus cereus.


ABSTRACT: Bacillus cereus (B. cereus) is a pathogen in opportunistic infections. Here we show that Bacillus cereus sphingomyelinase (Bc-SMase) is a virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew in vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant of the ATCC strain carrying a recombinant plasmid containing the Bc-SMase gene grew in vivo, but that with the gene for E53A, which has little enzymatic activity, did not. Administration of an anti-Bc-SMase antibody and immunization against Bc-SMase prevented death caused by the clinical isolates, showing that Bc-SMase plays an important role in the diseases caused by B. cereus. Treatment of mouse macrophages with Bc-SMase resulted in a reduction in the generation of H(2)O(2) and phagocytosis of macrophages induced by peptidoglycan (PGN), but no effect on the release of TNF-α and little release of LDH under our experimental conditions. Confocal laser microscopy showed that the treatment of mouse macrophages with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that the cells treated with Bc-SMase exhibited a reduction in membrane fluidity. The results suggest that Bc-SMase is essential for the hydrolysis of SM in membranes, leading to a reduction in phagocytosis.

SUBMITTER: Oda M 

PROVIDER: S-EPMC3368938 | biostudies-literature |

REPOSITORIES: biostudies-literature

Similar Datasets

| S-EPMC3628865 | biostudies-literature
| S-EPMC219565 | biostudies-literature
| S-EPMC1135697 | biostudies-other
| S-EPMC6211302 | biostudies-other
2004-10-28 | GSE568 | GEO
2009-11-25 | GSE19068 | GEO
| S-EPMC7262785 | biostudies-literature
| S-EPMC2293152 | biostudies-literature
| S-EPMC3213081 | biostudies-literature
| S-EPMC3668673 | biostudies-literature