Cytotoxic activity and probable apoptotic effect of Sph2, a sphigomyelinase hemolysin from Leptospira interrogans strain Lai

BMB Rep. 2008 Feb 29;41(2):119-25. doi: 10.5483/bmbrep.2008.41.2.119.

Abstract

Our previous work confirmed that Sph2/LA1029 was a sphigomyelinase-like hemolyisn of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai. Characteristics of both hemolytic and cytotoxic activities of Sph2 were reported in this paper. Sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase C of Staphylococcus aureus upon sheep erythrocytes. The cytotoxic activity of Sph2 was shown in mammalian cells such as BALB/C mouse lymphocytes and macrophages, as well as human L-02 liver cells. Transmission electron microscopic observation showed that the Sph2 treated BALB/C mouse lymphocytes were swollen and ruptured with membrane breakage. They also demonstrated condensed chromatin as a high-density area. Cytoskeleton changes were observed via fluorescence confocal microscope in Sph2 treated BALB/C mouse lymphocytes and macrophages, where both cytokine IL-1beta and IL-6 were induced. In addition, typical apoptotic morphological features were observed in Sph2 treated L-02 cells via transmission electron microscope and the percentage of apoptotic cells did increase after the Sph2 treatment detected by flow cytometry. Therefore, Sph2 was likely an apoptosis-inducing factor of human L-02 liver cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Bacterial Proteins / toxicity*
  • Cytoskeleton / metabolism
  • Erythrocytes / pathology*
  • Flow Cytometry
  • Hemolysin Proteins / toxicity*
  • Humans
  • Interleukin-1beta / metabolism
  • Interleukin-6 / metabolism
  • Leptospira interrogans / enzymology*
  • Liver / metabolism
  • Liver / pathology*
  • Liver / ultrastructure
  • Lymphocytes / metabolism
  • Lymphocytes / pathology*
  • Lymphocytes / ultrastructure
  • Macrophages / metabolism
  • Macrophages / pathology*
  • Macrophages / ultrastructure
  • Mice
  • Mice, Inbred BALB C
  • Sheep

Substances

  • Bacterial Proteins
  • Hemolysin Proteins
  • Interleukin-1beta
  • Interleukin-6
  • SphH protein, Leptospira interrogans