Escaping Deleterious Immune Response in Their Hosts: Lessons from Trypanosomatids - Project 2.1 journal article

Authors: Geiger Anne, Bossard Géraldine, Sereno Denis, Pissarra Joana, Lemesre Jean-Loup, Vincendeau Philippe, Holzmuller Philippe

Journal: Frontiers in Immunology, 7

Abstract

The Trypanosomatidae family includes the genera Trypanosoma and Leishmania, protozoan
parasites displaying complex digenetic life cycles requiring a vertebrate host and an
insect vector. Trypanosoma brucei gambiense, Trypanosoma cruzi, and Leishmania spp.
are important human pathogens causing human African trypanosomiasis (HAT or sleeping
sickness), Chagas’ disease, and various clinical forms of Leishmaniasis, respectively.
They are transmitted to humans by tsetse flies, triatomine bugs, or sandflies, and affect
millions of people worldwide. In humans, extracellular African trypanosomes (T. brucei)
evade the hosts’ immune defenses, allowing their transmission to the next host, via the
tsetse vector. By contrast, T. cruzi and Leishmania sp. have developed a complex intracellular
lifestyle, also preventing several mechanisms to circumvent the host’s immune
response. This review seeks to set out the immune evasion strategies developed by the
different trypanosomatids resulting from parasite–host interactions and will focus on:
clinical and epidemiological importance of diseases; life cycles: parasites–hosts–vectors;
innate immunity: key steps for trypanosomatids in invading hosts; deregulation
of antigen-presenting cells; disruption of efficient specific immunity; and the immune
responses used for parasite proliferation.