The Inhibition of Cysteine Proteases Rhodesain and TbCatB: A Valuable Approach to Treat Human African Trypanosomiasis

Mini Rev Med Chem. 2016;16(17):1374-1391. doi: 10.2174/1389557515666160509125243.

Abstract

Human African Trypanosomiasis (HAT) is an endemic parasitic disease of sub-Saharan Africa, caused by two subspecies of protozoa belonging to Trypanosoma genus: T. brucei gambiense and T. brucei rhodesiense. In this context the inhibition of the papain-family cysteine proteases rhodesain and TbCatB has to be considered a promising strategy for HAT treatment. Rhodesain, the major cathepsin L-like cysteine protease of T. brucei rhodesiense, is a lysosomal protease essential for parasite survival. It is involved in parasite invasivity, allowing it to cross the blood-brain barrier (BBB) of the human host, causing the second lethal stage of the disease. Moreover, it plays an important role in immunoevasion, being involved in the turnover of variant surface glycoproteins of the T. brucei coat and in the degradation of immunoglobulins, avoiding a specific immune response by the host cells. On the other hand TbCatB, a cathepsin B-like cysteine protease, present in minor abundance in T. brucei, showed a key role in the degradation of host transferrin, which is necessary for iron acquisition by the parasite. In this review article we now discuss the most active peptide, peptidomimetic and non-peptide rhodesain and TbCatB inhibitors as valuable strategy to treat HAT, due also to the complementary role of the two T. brucei proteases.

Publication types

  • Review

MeSH terms

  • Aziridines / chemistry
  • Aziridines / metabolism
  • Aziridines / pharmacology
  • Aziridines / therapeutic use
  • Blood-Brain Barrier / metabolism
  • Cysteine Endopeptidases / chemistry
  • Cysteine Endopeptidases / metabolism*
  • Cysteine Proteinase Inhibitors / chemistry
  • Cysteine Proteinase Inhibitors / metabolism*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Cysteine Proteinase Inhibitors / therapeutic use
  • Humans
  • Protozoan Proteins / antagonists & inhibitors
  • Protozoan Proteins / metabolism*
  • Sulfones / chemistry
  • Sulfones / metabolism
  • Sulfones / pharmacology
  • Sulfones / therapeutic use
  • Trypanocidal Agents / chemistry
  • Trypanocidal Agents / metabolism*
  • Trypanocidal Agents / pharmacology
  • Trypanocidal Agents / therapeutic use
  • Trypanosoma brucei brucei / drug effects
  • Trypanosoma brucei brucei / enzymology
  • Trypanosomiasis, African / drug therapy

Substances

  • Aziridines
  • Cysteine Proteinase Inhibitors
  • Protozoan Proteins
  • Sulfones
  • Trypanocidal Agents
  • aziridine-2,3-dicarboxylate
  • divinyl sulfone
  • Cysteine Endopeptidases
  • rhodesain