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Escape mechanisms of African trypanosomes: why trypanosomosis is keeping us awake

Published online by Cambridge University Press:  05 December 2014

JENNIFER CNOPS ,
STEFAN MAGEZ  and
CARL De TREZ
JENNIFER CNOPS*
Affiliation:
Laboratory for Cellular and Molecular Immunology, Vrije Universiteit Brussel, Building E8.01, Pleinlaan 2, 1050 Brussels, Belgium Department of Structural Biology, VIB, Brussels, Belgium
STEFAN MAGEZ
Affiliation:
Laboratory for Cellular and Molecular Immunology, Vrije Universiteit Brussel, Building E8.01, Pleinlaan 2, 1050 Brussels, Belgium Department of Structural Biology, VIB, Brussels, Belgium
CARL De TREZ
Affiliation:
Laboratory for Cellular and Molecular Immunology, Vrije Universiteit Brussel, Building E8.01, Pleinlaan 2, 1050 Brussels, Belgium Department of Structural Biology, VIB, Brussels, Belgium
*
* Corresponding author. Vrije Universiteit Brussel (VUB), Building E8.01, Pleinlaan 2, 1050 Brussels, Belgium. E-mail: [email protected]
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Summary

African trypanosomes have been around for more than 100 million years, and have adapted to survival in a very wide host range. While various indigenous African mammalian host species display a tolerant phenotype towards this parasitic infection, and hence serve as perpetual reservoirs, many commercially important livestock species are highly disease susceptible. When considering humans, they too display a highly sensitive disease progression phenotype for infections with Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense, while being intrinsically resistant to infections with other trypanosome species. As extracellular trypanosomes proliferate and live freely in the bloodstream and lymphatics, they are constantly exposed to the immune system. Due to co-evolution, this environment however no longer poses a hostile threat, but has become the niche environment where trypanosomes thrive and obligatory await transmission through the bites of tsetse flies or other haematophagic vectors, ideally without causing severe side infection-associated pathology to their host. Hence, African trypanosomes have acquired various mechanisms to manipulate and control the host immune response, evading effective elimination. Despite the extensive research into trypanosomosis over the past 40 years, many aspects of the anti-parasite immune response remain to be solved and no vaccine is currently available. Here we review the recent work on the different escape mechanisms employed by African Trypanosomes to ensure infection chronicity and transmission potential.

Keywords

African trypanosomesescape mechanismsimmune modulationinflammationantigenic variation
Type
Review Article
Information
Parasitology , Volume 142 , Issue 3 , March 2015 , pp. 417 - 427
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Copyright © Cambridge University Press 2014 

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