Activity of trypanosome lytic factor: A novel component of innate immunity

Abstract

Trypanosome lytic factors (TLFs) are high-density lipoproteins and components of primate innate immunity. TLFs are characterized by their ability to kill extracellular protozoon parasites of the genus Trypanosoma. Two subspecies of Trypanosoma brucei have evolved resistance to TLFs and can consequently infect humans, resulting in the disease African sleeping sickness. The unique protein components of TLFs are a hemoglobin-binding protein, haptoglobin-related protein and a pore-forming protein, apoL-I. The recent advances in our understanding of the roles that these proteins play in the mechanism of TLF-mediated lysis are highlighted in this article. In light of recent data, which demonstrate that TLFs can ameliorate infection by the intracellular pathogen Leishmania, we also discuss the broader function of TLFs as components of innate immunity.

Keywords:

• African sleeping sickness
• apolipoprotein L-I
• apoL-I
• haptoglobin-related protein
• Hpr
• innate immunity
• Leishmania
• pore-forming protein
• serum resistance-associated protein
• SRA protein
• Trypanosoma brucei
• trypanosome lytic factor
• TLF

Financial & competing interests disclosure

This work was supported by funding from the NIH/NIAID (R01 AI041233) and the American Heart Foundation to Jayne Raper. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Additional information

Funding

This work was supported by funding from the NIH/NIAID (R01 AI041233) and the American Heart Foundation to Jayne Raper. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.