Escaping Deleterious Immune Response in Their Hosts: Lessons from Trypanosomatids.
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.
UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G , Montpellier , France.
Anne
A
Geiger
UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G , Montpellier , France.
Géraldine
G
Bossard
UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G , Montpellier , France.
Denis
D
Sereno
UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G , Montpellier , France.
Joana
J
Pissarra
UMR INTERTRYP, IRD-CIRAD, CIRAD TA A-17/G , Montpellier , France.
Jean-Loup
JL
Lemesre
UMR 177, IRD-CIRAD Université de Bordeaux Laboratoire de Parasitologie , Bordeaux , France.
Philippe
P
Vincendeau
UMRCMAEE CIRAD-INRA TA-A15/G "Contrôle des maladies animales exotiques et émergentes" , Montpellier , France.
Philippe
P
Holzmuller
Leishmania sp.; Trypanosoma brucei sp.; Trypanosoma cruzi; Trypanosomatidae family; immunosuppression; parasite–host interactions