Project description:We report our microarray analysis of Brugia malayi microfilariae-derived miRNA comparing parasite-derived EVs and supernatants Microarray analysis was performed using isolated RNA from three biological replicates of Brugia malayi microfilariae with a focus on the parasite-derived EVs and supernatant
Project description:As is the case in vertebrates, successful mosquito immune responses depend on a complex and carefully orchestrated network of processes in order to defend the host from a foreign invader and to simultaneously maintain a homeostatic environment. Although commonalities exist between immune response mechanisms across phyla, invertebrates (e.g., mosquitoes) lack anticipatory, adaptive immune responses. However, a number of immune response elements, both cellular and humoral, exist to combat infection. Organisms that successfully invade the mosquito body cavity (hemocoel) potentially are subjected to a variety of mosquito defenses including: melanotic encapsulation, the production of antimicrobial peptides (AMPs) or reactive oxygen and nitrogen intermediates, or to engulfment by phagocytic cells. These arrays are used to temporally compare and contrast transcriptome profiles associated with these responses, as manifest in the cells (hemocytes) that circulate in the mosquito body cavity. Hemocytes have documented association with phagocytosis and melanization reactions in mosquitoes, and these responses, to a variety of Gram positive and Gram negative bacteria, have been characterized. Inoculated Escherichia coli elicit a strong phagocytic response, and Micrococcus luteus are rapidly melanized. For transcriptome profiling, inoculated moquitoes are compared to naïve (uninoculated) mosquitoes. Data obtained will begin to clarify the interactive role of hemocyte genes and gene products in orchestrating phagocytic, melanization, and AMP responses against invading bacteria. Keywords: time course
Project description:Filarial nematodes are arthropod-borne nematodes that cause a variety of economically important diseases such as onchocerciasis (river blindness), lymphatic filariasis, and heartworm disease. The most widespread filarial disease of humans is lymphatic filariasis, caused by worms in the genera Wuchereria and Brugia. Lymphatic filariasis is an economic and social burden in endemic countries and affects approximately 119 million people worldwide (Michael, 1997). In humans, the worms live in and block the lymph vessels, causing improper flow of lymph, and inflammation of the lymphatic system. The symptoms are fever, swollen limbs and genitals, generalized malaise, and can progress to a debilitating condition known as elephantiasis This research focuses on the transmission of these worms to the disseminating mosquito host, and it is based on the interesting observation that mf must be at least 7 days old to successfully infect the mosquito (de Hollanda, 1982). Newborn mf that have not â??maturedâ?? cannot successfully penetrate the midgut of the mosquito, and subsequently cannot develop to the L3 stage (Fuhrman, 1987). Previous work done by another group 20 years ago suggests that the molecular makeup of the worm surface changes during this maturation process (Furman, 1983 a and b). We used microarray analysis to characterize changes in gene expression that take place during the mf maturation process. Understanding the gene expression changes that occur as the mf mature will allow us to understand the nature of the philological transition that allows mf to move from the human to the mosquito host. With this information in hand, we can eventually identify parasite molecules that could be targeted to either stop parasite reproduction or prevent transmission of the mf to the mosquito. This would stop parasite transmission in endemic areas. This SuperSeries is composed of the following subset Series: GSE14939: Brugia pahangi mature vs immature microfilariae GSE14940: Brugia malayi mature vs immature microfilariae Refer to individual Series
Project description:Armigeres subalbatus is a natural vector of the filarial worm Brugia pahangi, but it kills Brugia malayi microfilariae (mf) by melanotic encapsulation. Because B. malayi and B. pahangi are morphologically and biologically similar, this mosquito-parasite system serves as a valuable model for studying resistance mechanisms in mosquito vectors. Comparing Ar. subalbatus-B. pahangi susceptibility and Ar. subalbatus-B. malayi refractoriness could provide significant insight into recognition mechanisms required to mount an effective anti-filarial worm immune response in the mosquito, as well as provide considerable detail into the molecular components involved in vector competence. Accordingly, we initiated transcriptome profiling studies of Ar. subalbatus in relation to filarial worm infection to provide information on the molecular components involved in B. pahangi susceptibility for comparison with our earlier studies on B. malayi refractoriness (Aliota et al., 2007). In addition, these studies also provide information on the infection response of a natural vector, i.e., the overall transcriptional and physiological change that occurs in the mosquito as a result of parasite infection, for comparison with our previous studies that employed a highly susceptible laboratory model, Aedes aegypti (Erickson et al., 2009). The time course chosen facilitated an examination of key events in the development of the parasite, beginning with the very start of filarial worm infection and spanning to well after infective-stage parasites had completed development in the mosquito. Herein, we demonstrate that filarial worm susceptibility in Ar. subalbatus is a highly complex process during the first 24 hours of infection. It is a process that involves many factors of both known and unknown function which are most likely associated with filarial worm penetration through the midgut lumen, invasion into thoracic muscle cells, and maintenance of homeostasis in the hemolymph environment. The data show that there are distinct and separate transcriptional patterns associated with filarial worm susceptibility as compared to refractoriness, and that an infection response in Ar. subalbatus, a natural vector, can differ significantly from that observed in Ae. aegypti, a common laboratory model. Finally, the data presented herein provide us with a cadre of information to design wet lab experiments and select candidates for further study to more fully dissect the nature of the anti-filarial worm immune response in this mosquito-parasite system.
Project description:Melanization is an integral part of the insect defense system and is often induced by pathogen invasion. Phenoloxidases (POs) are critical enzymes that catalyze melanin formation. PO3 is associated with the antifungal response of the mosquito, Aedes aegypti, but the molecular mechanism of the prophenoloxidase-3 (PPO3) activation is unclear. Here we report that PPO3 cleavage activation is mediated by a clip-domain serine protease, CLIPB9. We purified recombinant CLIPB9 and found that it cleaved PPO3 and increased PO activity in the hemolymph. We then identified CLIPA14 (a serine protease homolog) by co-immunoprecipitation using anti-CLIPB9 antibody. After being cleaved by CLIPB9, Ae. aegypti CLIPA14 acted as a cofactor for PPO3 activation. In addition, dsRNA co-silencing of CLIPB9 and CLIPA14 genes reduced melanization after infection with the entomopathogen, Beauveria bassiana, making the adult mosquitoes more sensitive to fungal infection. These results illustrate the roles of CLIPB9 and CLIPA14 in the PPO activation pathway and revealed the complexity of the upstream serine protease network controlling melanization.