Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.

BACKGROUND: Animal African trypanosomosis, a disease mainly caused by the protozoan parasite Trypanosoma congolense, is a major constraint to livestock productivity and has a significant impact in the developing countries of Africa. RNA interference (RNAi) has been used to study gene function and id...

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Main Authors: Virginie Coustou, Fabien Guegan, Nicolas Plazolles, Théo Baltz
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-01-01
Series:PLoS Neglected Tropical Diseases
Online Access:http://europepmc.org/articles/PMC2830455?pdf=render
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author Virginie Coustou
Fabien Guegan
Nicolas Plazolles
Théo Baltz
author_facet Virginie Coustou
Fabien Guegan
Nicolas Plazolles
Théo Baltz
author_sort Virginie Coustou
collection DOAJ
description BACKGROUND: Animal African trypanosomosis, a disease mainly caused by the protozoan parasite Trypanosoma congolense, is a major constraint to livestock productivity and has a significant impact in the developing countries of Africa. RNA interference (RNAi) has been used to study gene function and identify drug and vaccine targets in a variety of organisms including trypanosomes. However, trypanosome RNAi studies have mainly been conducted in T. brucei, as a model for human infection, largely ignoring livestock parasites of economical importance such as T. congolense, which displays different pathogenesis profiles. The whole T. congolense life cycle can be completed in vitro, but this attractive model displayed important limitations: (i) genetic tools were currently limited to insect forms and production of modified infectious BSF through differentiation was never achieved, (ii) in vitro differentiation techniques lasted several months, (iii) absence of long-term bloodstream forms (BSF) in vitro culture prevented genomic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We optimized culture conditions for each developmental stage and secured the differentiation steps. Specifically, we devised a medium adapted for the strenuous development of stable long-term BSF culture. Using Amaxa nucleofection technology, we greatly improved the transfection rate of the insect form and designed an inducible transgene expression system using the IL3000 reference strain. We tested it by expression of reporter genes and through RNAi. Subsequently, we achieved the complete in vitro life cycle with dramatically shortened time requirements for various wild type and transgenic strains. Finally, we established the use of modified strains for experimental infections and underlined a host adaptation phase requirement. CONCLUSIONS/SIGNIFICANCE: We devised an improved T. congolense model, which offers the opportunity to perform functional genomics analyses throughout the whole life cycle. It represents a very useful tool to understand pathogenesis mechanisms and to study potential therapeutic targets either in vitro or in vivo using a mouse model.
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spelling doaj.art-7d1fb77590574b69acd93715ea81f2762022-12-21T23:54:35ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352010-01-0143e61810.1371/journal.pntd.0000618Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.Virginie CoustouFabien GueganNicolas PlazollesThéo BaltzBACKGROUND: Animal African trypanosomosis, a disease mainly caused by the protozoan parasite Trypanosoma congolense, is a major constraint to livestock productivity and has a significant impact in the developing countries of Africa. RNA interference (RNAi) has been used to study gene function and identify drug and vaccine targets in a variety of organisms including trypanosomes. However, trypanosome RNAi studies have mainly been conducted in T. brucei, as a model for human infection, largely ignoring livestock parasites of economical importance such as T. congolense, which displays different pathogenesis profiles. The whole T. congolense life cycle can be completed in vitro, but this attractive model displayed important limitations: (i) genetic tools were currently limited to insect forms and production of modified infectious BSF through differentiation was never achieved, (ii) in vitro differentiation techniques lasted several months, (iii) absence of long-term bloodstream forms (BSF) in vitro culture prevented genomic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We optimized culture conditions for each developmental stage and secured the differentiation steps. Specifically, we devised a medium adapted for the strenuous development of stable long-term BSF culture. Using Amaxa nucleofection technology, we greatly improved the transfection rate of the insect form and designed an inducible transgene expression system using the IL3000 reference strain. We tested it by expression of reporter genes and through RNAi. Subsequently, we achieved the complete in vitro life cycle with dramatically shortened time requirements for various wild type and transgenic strains. Finally, we established the use of modified strains for experimental infections and underlined a host adaptation phase requirement. CONCLUSIONS/SIGNIFICANCE: We devised an improved T. congolense model, which offers the opportunity to perform functional genomics analyses throughout the whole life cycle. It represents a very useful tool to understand pathogenesis mechanisms and to study potential therapeutic targets either in vitro or in vivo using a mouse model.http://europepmc.org/articles/PMC2830455?pdf=render
spellingShingle Virginie Coustou
Fabien Guegan
Nicolas Plazolles
Théo Baltz
Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
PLoS Neglected Tropical Diseases
title Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
title_full Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
title_fullStr Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
title_full_unstemmed Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
title_short Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.
title_sort complete in vitro life cycle of trypanosoma congolense development of genetic tools
url http://europepmc.org/articles/PMC2830455?pdf=render
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AT fabienguegan completeinvitrolifecycleoftrypanosomacongolensedevelopmentofgenetictools
AT nicolasplazolles completeinvitrolifecycleoftrypanosomacongolensedevelopmentofgenetictools
AT theobaltz completeinvitrolifecycleoftrypanosomacongolensedevelopmentofgenetictools