Publications
2012
Ramakrishnan Chandra, Rademacher Annika, Soichot Julien, Costa Giulia, Waters Andy P, Janse Chris J, Ramesar J, Franke-Fayard Blandine M, Levashina Elena A
Salivary gland-specific P. berghei reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes Article de journal
Dans: PLoS One, vol. 7, no. 5, p. e36376, 2012.
Résumé | Liens | BibTeX | Étiquettes: luciferase, M3i, Plasmodium berghei, salivary gland
@article{C2012,
title = {Salivary gland-specific P. berghei reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes},
author = {Chandra Ramakrishnan and Annika Rademacher and Julien Soichot and Giulia Costa and Andy P Waters and Chris J Janse and J Ramesar and Blandine M Franke-Fayard and Elena A Levashina},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22574152},
year = {2012},
date = {2012-05-04},
journal = {PLoS One},
volume = {7},
number = {5},
pages = {e36376},
abstract = {Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of Plasmodium development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic P. berghei reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on P. berghei ookinete/oocyst development. It offers a new powerful tool to study infectivity of P. berghei to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines.},
keywords = {luciferase, M3i, Plasmodium berghei, salivary gland},
pubstate = {published},
tppubtype = {article}
}
2006
Shiao Shin-Hong, Whitten Miranda M A, Zachary Daniel, Hoffmann Jules A, Levashina Elena A
Fz2 and cdc42 mediate melanization and actin polymerization but are dispensable for Plasmodium killing in the mosquito midgut Article de journal
Dans: PLoS Pathog., vol. 2, no. 12, p. e133, 2006, ISSN: 1553-7374.
Résumé | Liens | BibTeX | Étiquettes: Actins, Animals, Anopheles, Carrier Proteins, cdc42 GTP-Binding Protein, Double-Stranded, Electron, Frizzled Receptors, Gastrointestinal Tract, hoffmann, Host-Parasite Interactions, Immunity, Innate, Insect Vectors, Intestinal Mucosa, M3i, Melanins, Microarray Analysis, Microscopy, Plasmodium berghei, Polymers, Protozoan, RNA, scanning, telomerase
@article{shiao_fz2_2006,
title = {Fz2 and cdc42 mediate melanization and actin polymerization but are dispensable for Plasmodium killing in the mosquito midgut},
author = {Shin-Hong Shiao and Miranda M A Whitten and Daniel Zachary and Jules A Hoffmann and Elena A Levashina},
doi = {10.1371/journal.ppat.0020133},
issn = {1553-7374},
year = {2006},
date = {2006-12-01},
journal = {PLoS Pathog.},
volume = {2},
number = {12},
pages = {e133},
abstract = {The midgut epithelium of the mosquito malaria vector Anopheles is a hostile environment for Plasmodium, with most parasites succumbing to host defenses. This study addresses morphological and ultrastructural features associated with Plasmodium berghei ookinete invasion in Anopheles gambiae midguts to define the sites and possible mechanisms of parasite killing. We show by transmission electron microscopy and immunofluorescence that the majority of ookinetes are killed in the extracellular space. Dead or dying ookinetes are surrounded by a polymerized actin zone formed within the basal cytoplasm of adjacent host epithelial cells. In refractory strain mosquitoes, we found that formation of this zone is strongly linked to prophenoloxidase activation leading to melanization. Furthermore, we identify two factors controlling both phenomena: the transmembrane receptor frizzled-2 and the guanosine triphosphate-binding protein cell division cycle 42. However, the disruption of actin polymerization and melanization by double-stranded RNA inhibition did not affect ookinete survival. Our results separate the mechanisms of parasite killing from subsequent reactions manifested by actin polymerization and prophenoloxidase activation in the A. gambiae-P. berghei model. These latter processes are reminiscent of wound healing in other organisms, and we propose that they represent a form of wound-healing response directed towards a moribund ookinete, which is perceived as damaged tissue.},
keywords = {Actins, Animals, Anopheles, Carrier Proteins, cdc42 GTP-Binding Protein, Double-Stranded, Electron, Frizzled Receptors, Gastrointestinal Tract, hoffmann, Host-Parasite Interactions, Immunity, Innate, Insect Vectors, Intestinal Mucosa, M3i, Melanins, Microarray Analysis, Microscopy, Plasmodium berghei, Polymers, Protozoan, RNA, scanning, telomerase},
pubstate = {published},
tppubtype = {article}
}
Frolet Cécile, Thoma Martine, Blandin Stéphanie A, Hoffmann Jules A, Levashina Elena A
Boosting NF-kappaB-dependent basal immunity of Anopheles gambiae aborts development of Plasmodium berghei Article de journal
Dans: Immunity, vol. 25, no. 4, p. 677–685, 2006, ISSN: 1074-7613.
Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles gambiae, blandin, Gene Expression, Gene Expression Regulation, Genes, hoffmann, Immunity, Insect, M3i, NF-kappa B, Plasmodium berghei, telomerase
@article{frolet_boosting_2006,
title = {Boosting NF-kappaB-dependent basal immunity of Anopheles gambiae aborts development of Plasmodium berghei},
author = {Cécile Frolet and Martine Thoma and Stéphanie A Blandin and Jules A Hoffmann and Elena A Levashina},
url = {http://www.ncbi.nlm.nih.gov/pubmed/17045818},
doi = {10.1016/j.immuni.2006.08.019},
issn = {1074-7613},
year = {2006},
date = {2006-10-01},
journal = {Immunity},
volume = {25},
number = {4},
pages = {677--685},
abstract = {Anopheles gambiae, the major vector for the protozoan malaria parasite Plasmodium falciparum, mounts powerful antiparasitic responses that cause marked parasite loss during midgut invasion. Here, we showed that these antiparasitic defenses were composed of pre- and postinvasion phases and that the preinvasion phase was predominantly regulated by Rel1 and Rel2 members of the NF-kappaB transcription factors. Concurrent silencing of Rel1 and Rel2 decreased the basal expression of the major antiparasitic genes TEP1 and LRIM1 and abolished resistance of Anopheles to the rodent malaria parasite P. berghei. Conversely, depletion of a negative regulator of Rel1, Cactus, prior to infection, enhanced the basal expression of TEP1 and of other immune factors and completely prevented parasite development. Our findings uncover the crucial role of the preinvasion defense in the elimination of parasites, which is at least in part based on circulating blood molecules.},
keywords = {Animals, Anopheles gambiae, blandin, Gene Expression, Gene Expression Regulation, Genes, hoffmann, Immunity, Insect, M3i, NF-kappa B, Plasmodium berghei, telomerase},
pubstate = {published},
tppubtype = {article}
}
2004
Blandin Stephanie A, Shiao Shin-Hong, Moita Luis F, Janse Chris J, Waters Andrew P, Kafatos Fotis C, Levashina Elena A
Complement-like protein TEP1 is a determinant of vectorial capacity in the malaria vector Anopheles gambiae Article de journal
Dans: Cell, vol. 116, no. 5, p. 661–670, 2004, ISSN: 0092-8674.
Résumé | BibTeX | Étiquettes: Animals, Anopheles, blandin, Female, Genetic, Humans, Insect Proteins, Insect Vectors, M3i, Malaria, Models, Molecular, Plasmodium berghei, Polymorphism, Protein Structure, RNA, Sequence Alignment, Tertiary
@article{blandin_complement-like_2004,
title = {Complement-like protein TEP1 is a determinant of vectorial capacity in the malaria vector Anopheles gambiae},
author = {Stephanie A Blandin and Shin-Hong Shiao and Luis F Moita and Chris J Janse and Andrew P Waters and Fotis C Kafatos and Elena A Levashina},
issn = {0092-8674},
year = {2004},
date = {2004-01-01},
journal = {Cell},
volume = {116},
number = {5},
pages = {661--670},
abstract = {Anopheles mosquitoes are major vectors of human malaria in Africa. Large variation exists in the ability of mosquitoes to serve as vectors and to transmit malaria parasites, but the molecular mechanisms that determine vectorial capacity remain poorly understood. We report that the hemocyte-specific complement-like protein TEP1 from the mosquito Anopheles gambiae binds to and mediates killing of midgut stages of the rodent malaria parasite Plasmodium berghei. The dsRNA knockdown of TEP1 in adults completely abolishes melanotic refractoriness in a genetically selected refractory strain. Moreover, in susceptible mosquitoes this knockdown increases the number of developing parasites. Our results suggest that the TEP1-dependent parasite killing is followed by a TEP1-independent clearance of dead parasites by lysis and/or melanization. Further elucidation of the molecular mechanisms of TEP1-mediated parasite killing will be of great importance for our understanding of the principles of vectorial capacity in insects.},
keywords = {Animals, Anopheles, blandin, Female, Genetic, Humans, Insect Proteins, Insect Vectors, M3i, Malaria, Models, Molecular, Plasmodium berghei, Polymorphism, Protein Structure, RNA, Sequence Alignment, Tertiary},
pubstate = {published},
tppubtype = {article}
}
1999
Lowenberger C A, Kamal S, Chiles J, Paskewitz S, Bulet Philippe, Hoffmann Jules A, Christensen B M
Mosquito-Plasmodium interactions in response to immune activation of the vector Article de journal
Dans: Exp. Parasitol., vol. 91, no. 1, p. 59–69, 1999, ISSN: 0014-4894.
Résumé | Liens | BibTeX | Étiquettes: Aedes, Animals, Anopheles, Culicidae, Defensins, Digestive System, Escherichia coli, Female, Genetic, Hemolymph, hoffmann, Insect Vectors, M3i, messenger, Micrococcus luteus, Plasmodium, Plasmodium berghei, Plasmodium gallinaceum, Proteins, Reverse Transcriptase Polymerase Chain Reaction, RNA, Transcription
@article{lowenberger_mosquito-plasmodium_1999,
title = {Mosquito-Plasmodium interactions in response to immune activation of the vector},
author = {C A Lowenberger and S Kamal and J Chiles and S Paskewitz and Philippe Bulet and Jules A Hoffmann and B M Christensen},
doi = {10.1006/expr.1999.4350},
issn = {0014-4894},
year = {1999},
date = {1999-01-01},
journal = {Exp. Parasitol.},
volume = {91},
number = {1},
pages = {59--69},
abstract = {During the development of Plasmodium sp. within the mosquito midgut, the parasite undergoes a series of developmental changes. The elongated ookinete migrates through the layers of the midgut where it forms the oocyst under the basal lamina. We demonstrate here that if Aedes aegypti or Anopheles gambiae, normally susceptible to Plasmodium gallinaceum and P. berghei, respectively, are immune activated by the injection of bacteria into the hemocoel, and subsequently are fed on an infectious bloodmeal, there is a significant reduction in the prevalence and mean intensity of infection of oocysts on the midgut. Only those mosquitoes immune activated prior to, or immediately after, parasite ingestion exhibit this reduction in parasite development. Mosquitoes immune activated 2-5 days after bloodfeeding show no differences in parasite burdens compared with naive controls. Northern analyses reveal that transcriptional activity for mosquito defensins is not detected in the whole bodies of Ae. aegypti from 4 h to 10 days after ingesting P. gallinaceum, suggesting that parasite ingestion, passage from the food bolus through the midgut, oocyst formation, and subsequent release of sporozoites into the hemolymph do not induce the production of defensin. However, reverse transcriptase-PCR of RNA isolated solely from the midguts of Ae. aegypti indicates that transcription of mosquito defensins occurs in the midguts of naive mosquitoes and those ingesting an infectious or noninfectious bloodmeal. Bacteria-challenged Ae. aegypti showed high levels of mature defensin in the hemolymph that correlate with a lower prevalence and mean intensity of infection with oocysts. Because few oocysts were found on the midgut of immune-activated mosquitoes, the data suggest that some factor, induced by bacterial challenge, kills the parasite at a preoocyst stage.},
keywords = {Aedes, Animals, Anopheles, Culicidae, Defensins, Digestive System, Escherichia coli, Female, Genetic, Hemolymph, hoffmann, Insect Vectors, M3i, messenger, Micrococcus luteus, Plasmodium, Plasmodium berghei, Plasmodium gallinaceum, Proteins, Reverse Transcriptase Polymerase Chain Reaction, RNA, Transcription},
pubstate = {published},
tppubtype = {article}
}