Lytic activity from schistosomes: interactions with blood cells

Area of Science:

• Parasitology
• Biochemistry
• Immunology

Background:

• Schistosome lytic agent exhibits hemolytic activity.
• Phosphatidyl choline and albumin influence agent activity.
• Human mononuclear cells are affected by the agent.

Purpose of the Study:

• To investigate the mechanism of schistosome lytic agent's action on red blood cells.
• To determine the role of phosphatidyl choline and albumin in modulating the agent's activity.
• To assess the impact of the agent on human mononuclear cells.

Main Methods:

• Hemolysis assays using red blood cells from different species with varying phosphatidyl choline levels.
• Incubation of the lytic agent with phosphatidyl choline and albumin.
• Exposure of human mononuclear cells to the lytic agent.
• Protease pretreatment of red blood cells.

Main Results:

• The agent lysed red blood cells with high phosphatidyl choline (dog, mouse, rat) more efficiently than those without (goat, sheep).
• Human mononuclear cells showed reduced viability upon exposure to the agent.
• Preincubation with phosphatidyl choline or bovine serum albumin decreased the agent's lytic activity.
• Albumin in the extracellular environment protected red blood cells from lysis.
• Protease pretreatment enhanced red blood cell lysis by 10-30%.

Conclusions:

• Phosphatidyl choline is crucial for the efficient lysis of red blood cells by the schistosome lytic agent.
• Albumin acts as a protective factor against schistosome-induced hemolysis.
• The agent exhibits cytotoxic effects on human mononuclear cells.
• Protease activity may enhance the agent's hemolytic function.