Antihemostatic factors secreted by parasitic fluke Schistosoma mansoni

Abstract text

Introduction: Hemostasis is a defense mechanism that prevents blood loss by sticking platelets together and forming a fibrin clot at the site of injury. Proteolytic enzymes involved in the hemostatic cascades belong to the group of serine peptidases and their activity must be strictly controlled by endogenous inhibitors. The blood flukes Schistosoma mansoni, same as other blood-feeding parasites, have to overcome the hemostasis of host blood and mimic the host regulation mechanism. Thus, they have developed molecular equipment containing a range of anti-hemostatic, anti-inflammatory, and immunomodulatory molecules that contribute to the suppression of the host protective mechanisms and enable parasite survival. In our project, we focus on the life stages of adults and eggs, which both occur in the mesenteric veins and closely interact with host blood elements.

Objectives: The main goal of the project is to identify and characterize bioactive molecules secreted by parasitic flukes and their eggs for the modulation of host hemostasis and to evaluate their potential applications in biomedicine.

Materials & methods: Based on an analysis of transcriptomic and proteomic data of S. mansoni adults and mature/ immature eggs, we selected suitable candidate molecules such as annexins, Kunitz-type inhibitors, and serpins for our experiments. Production of their recombinant forms in E. coli bacterial system is now in process.

Results: Our preliminary results indicate a significantly different composition of the excretory-secretory products from adults and mature/ immature eggs of S. mansoni. Based on the results combined with the transcriptome analysis, we selected several potential antihemostatic candidates.

Conclusion: This project will reveal the functions of selected molecules and identify their role within the complex interaction mechanisms.