We are interested in exploring the interactions between the mosquito (A. gambiae and A. stephensi) immune system and the malaria parasite and to understand how they determine vector competence. Some major areas of interest include: Cell biology of ookinete invasion. Detailed studies of the cellular responses of mosquito midgut epithelial cells to parasite invasion in the An. stephensi-P.berghei system revealed that parasites inflict extensive damage as they migrate through midgut epithelial cells, which ultimately leads to genome fragmentation, nuclear picnosis and cell death. This studies led us to propose the Time-Bomb Model of Invasion, which states that ookinetes have a limited time window to escape unharmed from the invaded cell, as the cascade of responses mediating epithelial cell death are also potentially lethal to the parasite. Recent studies indicate that protein nitration is a two-step process involving NOS and inducible peroxidases. A publications describing this work has been submitted. We are currently raising antibodies against these enzymes using DNA vaccines and recombinant proteins to establish their subcellular localization and silencing their expression to determine how this would affect parasite survival. Comparative studies using the A. aegypti-P.gallinaceum model system revealed that the parasite-induced damage to epithelial cells during invasion is repaired by a different repair mechanism and does not involve NOS or peroxidase induction. The role of Reactive Oxygen Species (ROS) in An. gambiae refractoriness to malaria infection. A genetically selected refractory strain of A. gambiae blocks Plasmodium development, melanizing and encapsulating the parasite. Morphological, microarray mRNA and physiological studies indicate that the refractory strain is in a chronic state of oxidative stress, which is exacerbated by blood feeding, resulting in increased steady state levels of ROS, which favor melanization of parasites as well as Sephadex beads. Dietary supplementation with antioxidants reduced parasite and bead encapsulation. We are currently silencing catalase expression to determine if decrease clearance of ROS decreases parasite survival. The role of the STAT pathway in epithelial responses to malaria infection. Band shift experiments from midgut nuclear extracts indicate that parasite invasion activates the STAT (Signal Transducers and Activators of Transcription) pathway. We have characterized two members of this family of transcription factors in A. gambaie as well as to repressors, SOCS and PIAS, which are induced by malaria infection at the transcriptional and translational level, respectively We are currently performing a series of dsRNA silencing experiments in vivo and in tissue culture to establish the relevance of the STAT pathway in the outcome of parasite midgut infection. Trypsin activity and dengue-2 (DEN-2) midgut infection in Aedes aegypti. The role of midgut trypsin activity on viral invasion and replication was investigating by administering soybean trypsin activity in vivo. Trypsin was found to play a critical role regulating viral replication at the level of transcription and translation. Direct contact of trypsin with the virus also transiently enhanced the association of DEN-2 with the midgut epithelium, suggesting that proteolytic processing of the viral surface increases infectivity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Intramural Research (Z01)
Project #
1Z01AI000947-01
Application #
6987137
Study Section
(LMVR)
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
2004
Total Cost
Indirect Cost
Name
Niaid Extramural Activities
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Canepa, Gaspar E; Molina-Cruz, Alvaro; Yenkoidiok-Douti, Lampouguin et al. (2018) Antibody targeting of a specific region of Pfs47 blocks Plasmodium falciparum malaria transmission. NPJ Vaccines 3:26
Castillo, Julio César; Ferreira, Ana Beatriz Barletta; Trisnadi, Nathanie et al. (2017) Activation of mosquito complement antiplasmodial response requires cellular immunity. Sci Immunol 2:
Molina-Cruz, Alvaro; Canepa, Gaspar E; Barillas-Mury, Carolina (2017) Plasmodium P47: a key gene for malaria transmission by mosquito vectors. Curr Opin Microbiol 40:168-174
Ramirez, Jose Luis; de Almeida Oliveira, Giselle; Calvo, Eric et al. (2015) A mosquito lipoxin/lipocalin complex mediates innate immune priming in Anopheles gambiae. Nat Commun 6:7403
Molina-Cruz, Alvaro; Canepa, Gaspar E; Kamath, Nitin et al. (2015) Plasmodium evasion of mosquito immunity and global malaria transmission: The lock-and-key theory. Proc Natl Acad Sci U S A 112:15178-83
Jaramillo-Gutierrez, Giovanna; Rodrigues, Janneth; Ndikuyeze, Georges et al. (2009) Mosquito immune responses and compatibility between Plasmodium parasites and anopheline mosquitoes. BMC Microbiol 9:154
Barillas-Mury, Carolina (2007) CLIP proteases and Plasmodium melanization in Anopheles gambiae. Trends Parasitol 23:297-9
Waterhouse, Robert M; Kriventseva, Evgenia V; Meister, Stephan et al. (2007) Evolutionary dynamics of immune-related genes and pathways in disease-vector mosquitoes. Science 316:1738-43
Gomez-Anduro, Gracia A; Barillas-Mury, Carolina-V; Peregrino-Uriarte, Alma B et al. (2006) The cytosolic manganese superoxide dismutase from the shrimp Litopenaeus vannamei: Molecular cloning and expression. Dev Comp Immunol 30:893-900
Gupta, Lalita; Kumar, Sanjeev; Han, Yeon Soo et al. (2005) Midgut epithelial responses of different mosquito-Plasmodium combinations: the actin cone zipper repair mechanism in Aedes aegypti. Proc Natl Acad Sci U S A 102:4010-5

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