Escaping deleterious immune response in their hosts: lessons from Trypanosomatids

Anne Geiger (1) , Géraldine Bossard (1) , Denis Sereno (1) , Joana Pissarra (1) , Jean-Loup Lemesre (1) , Philippe Vincendeau (2) , Philippe Holzmuller (3)

1 UMR INTERTRYP - Interactions hôtes-vecteurs-parasites-environnement dans les maladies tropicales négligées dues aux trypanosomatides
2 UMR 177 Laboratoire de Parasitologie
3 UMR CMAEE - Contrôle des maladies animales exotiques et émergentes

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, Trypanosorna 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.

Mots clés: trypanosomatidae family; parasite-host interactions; immunosuppression; Leishmania sp.; Trypanosoma brucei sp.; Trypanosome cruzi; pathogen; tsetse fly; trypanosomiasis; immunologic reactions

Mots clés: trypanosoma; agent pathogène; mouche tsé tsé; glossina; maladie du sommeil; réponse immunitaire; interaction hôte parasite

Domaines: Biodiversité et Ecologie

Anne Geiger, Géraldine Bossard, Denis Sereno, Joana Pissarra, Jean-Loup Lemesre, et al.. Escaping deleterious immune response in their hosts: lessons from Trypanosomatids. Frontiers in Immunology, 2016, 7, 21 p. ⟨10.3389/fimmu.2016.00212⟩. ⟨hal-01512013⟩