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Utpal Tatu - One of the best experts on this subject based on the ideXlab platform.
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recurrent fever promotes plasmodium falciparum Development in human erythrocytes
Journal of Biological Chemistry, 2004Co-Authors: Soundara Raghavan Pavithra, Gowrishankar Banumathy, Omana Joy, Varsha Singh, Utpal TatuAbstract:The human malarial Parasite Plasmodium falciparum (Pf) is exposed to wide temperature fluctuations during its life cycle, ranging from 25 °C in the mosquito vector and 37 °C in humans to 41 °C during febrile episodes in the patient. The repeated occurrence of fever at regular intervals is a characteristic of human malaria. We have examined the influence of repeated exposure to elevated temperatures encountered during fever on the intraerythrocytic Development of the Parasite. Using flow cytometry, we show that repeated exposure to temperatures mimicking febrile episodes promotes Parasite Development in human erythrocytes. Heat shock-mediated cytoprotection and growth promotion is dependent on the heat shock protein 90 (PfHsp90) multi-chaperone complex. Inhibition of PfHsp90 function using geldanamycin attenuates temperature-dependent progression from the ring to the trophozoite stage. Geldanamycin inhibits Parasite Development by disrupting the Pf- Hsp90 complex consisting of PfHsp70, PfPP5, and tubulin,among other proteins. While explaining the contribution of febrile episodes to the pathogenesis of malaria, our results implicate temperature as an important environmental cue used by the Parasite to coordinate its Development in humans.
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recurrent fever promotes plasmodium falciparum Development in human erythrocytes
Journal of Biological Chemistry, 2004Co-Authors: Soundara Raghavan Pavithra, Gowrishankar Banumathy, Omana Joy, Varsha Singh, Utpal TatuAbstract:The human malarial Parasite Plasmodium falciparum (Pf) is exposed to wide temperature fluctuations during its life cycle, ranging from 25 degrees C in the mosquito vector and 37 degrees C in humans to 41 degrees C during febrile episodes in the patient. The repeated occurrence of fever at regular intervals is a characteristic of human malaria. We have examined the influence of repeated exposure to elevated temperatures encountered during fever on the intraerythrocytic Development of the Parasite. Using flow cytometry, we show that repeated exposure to temperatures mimicking febrile episodes promotes Parasite Development in human erythrocytes. Heat shock-mediated cytoprotection and growth promotion is dependent on the heat shock protein 90 (PfHsp90) multi-chaperone complex. Inhibition of PfHsp90 function using geldanamycin attenuates temperature-dependent progression from the ring to the trophozoite stage. Geldanamycin inhibits Parasite Development by disrupting the PfHsp90 complex consisting of PfHsp70, PfPP5, and tubulin, among other proteins. While explaining the contribution of febrile episodes to the pathogenesis of malaria, our results implicate temperature as an important environmental cue used by the Parasite to coordinate its Development in humans.
Christiane Eichner - One of the best experts on this subject based on the ideXlab platform.
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host gill attachment causes blood feeding by the salmon louse lepeophtheirus salmonis chalimus larvae and alters Parasite Development and transcriptome
Parasites & Vectors, 2020Co-Authors: Erna Irene Heggland, Frank Nilsen, Michael Dondrup, Christiane EichnerAbstract:Blood-feeding is a common strategy among parasitizing arthropods, including the ectoparasitic salmon louse (Lepeophtheirus salmonis), feeding off its salmon host’s skin and blood. Blood is rich in nutrients, among these iron and heme. These are essential molecules for the louse, yet their oxidative properties render them toxic to cells if not handled appropriately. Blood-feeding might therefore alter Parasite gene expression. We infected Atlantic salmon with salmon louse copepodids and sampled the lice in two different experiments at day 10 and 18 post-infestation. Parasite Development and presence of host blood in their intestines were determined. Lice of similar instar age sampled from body parts with differential access to blood, namely from gills versus lice from skin epidermis, were analysed for gene expression by RNA-sequencing in samples taken at day 10 for both experiments and at day 18 for one of the experiments. We found that lice started feeding on blood when becoming mobile preadults if sitting on the fish body; however, they may initiate blood-feeding at the chalimus I stage if attached to gills. Lice attached to gills develop at a slower rate. By differential expression analysis, we found 355 transcripts elevated in lice sampled from gills and 202 transcripts elevated in lice sampled from skin consistent in all samplings. Genes annotated with “peptidase activity” were among the ones elevated in lice sampled from gills, while in the other group genes annotated with “phosphorylation” and “phosphatase” were pervasive. Transcripts elevated in lice sampled from gills were often genes relatively highly expressed in the louse intestine compared with other tissues, while this was not the case for transcripts elevated in lice sampled from skin. In both groups, more than half of the transcripts were from genes more highly expressed after attachment. Gill settlement results in an alteration in gene expression and a premature onset of blood-feeding likely causes the Parasite to develop at a slower pace.
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host gill attachment enables blood feeding by the salmon louse lepeophtheirus salmonis chalimus larvae and alters Parasite Development and transcriptome
bioRxiv, 2019Co-Authors: Erna Irene Heggland, Frank Nilsen, Michael Dondrup, Christiane EichnerAbstract:Blood-feeding is a common strategy among parasitizing arthropods, including the ectoparasitic salmon louse (Lepeophtheirus salmonis), feeding off its salmon host′s skin and blood. Blood is rich in nutrients, among these iron and heme. These are essential molecules for the louse, yet their oxidative properties render them toxic to cells if not handled properly. Blood-feeding might therefore alter Parasite gene expression. We infected Atlantic salmon with salmon louse copepodids and sampled the lice in two different experiments at day 10 and 18 post infestation. Parasite Development and presence of host blood in their intestines were determined. We find that lice start feeding on blood when becoming mobile preadults if sitting on the fish body, however they may initiate in blood-feeding at the chalimus I stage if attached to gills. Lice attached to gills develop at a slower rate. Lice of similar instar age from gills versus lice from skin epidermis were analyzed for gene expression by RNA-sequencing in samples taken at day 10 for both experiments and at day 18 for one of the experiments. By differential expression analysis, we found 355 transcripts elevated in lice sampled from gills and 202 transcripts elevated in lice sampled from skin consistent in all experiments. Genes annotated with ″peptidase activity″ are among the ones elevated in lice sampled from gills, while in the other group genes annotated with ″phosphorylation″ and ″phosphatase″ is pervasive. Transcripts elevated in lice sampled from gills are often genes relatively highly expressed in the louse intestine compared with other tissues, while this was not the case for transcripts found elevated in lice sampled from skin. In both groups, more than half the transcripts are from genes higher expressed after attachment. In conclusion, blood-feeding results in an alteration in gene expression, and a premature onset of blood-feeding likely causes the Parasite to develop at a slower pace.
Marcelo Jacobslorena - One of the best experts on this subject based on the ideXlab platform.
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distinct roles of plasmodium rhomboid 1 in Parasite Development and malaria pathogenesis
PLOS Pathogens, 2009Co-Authors: Prakash Srinivasan, Isabelle Coppens, Marcelo JacobslorenaAbstract:Invasion of host cells by the malaria Parasite involves recognition and interaction with cell-surface receptors. A wide variety of Parasite surface proteins participate in this process, most of which are specific to the Parasite's particular invasive form. Upon entry, the Parasite has to dissociate itself from the host-cell receptors. One mechanism by which it does so is by shedding its surface ligands using specific enzymes. Rhomboid belongs to a family of serine proteases that cleave cell-surface proteins within their transmembrane domains. Here we identify and partially characterize a Plasmodium berghei rhomboid protease (PbROM1) that plays distinct roles during Parasite Development. PbROM1 localizes to the surface of sporozoites after salivary gland invasion. In blood stage merozoites, PbROM1 localizes to the apical end where proteins involved in invasion are also present. Our genetic analysis suggests that PbROM1 functions in the invasive stages of Parasite Development. Whereas wild-type P. berghei is lethal to mice, animals infected with PbROM1 null mutants clear the Parasites efficiently and develop long-lasting protective immunity. The results indicate that P. berghei Rhomboid 1 plays a nonessential but important role during Parasite Development and identify rhomboid proteases as potential targets for disease control.
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hemolytic c type lectin cel iii from sea cucumber expressed in transgenic mosquitoes impairs malaria Parasite Development
PLOS Pathogens, 2007Co-Authors: Shigeto Yoshida, Anil K Ghosh, Marcelo Jacobslorena, Yohei Shimada, Daisuke Kondoh, Yoshiaki Kouzuma, Robert E SindenAbstract:The midgut environment of anopheline mosquitoes plays an important role in the Development of the malaria Parasite. Using genetic manipulation of anopheline mosquitoes to change the environment in the mosquito midgut may inhibit Development of the malaria Parasite, thus blocking malaria transmission. Here we generate transgenic Anopheles stephensi mosquitoes that express the C-type lectin CEL-III from the sea cucumber, Cucumaria echinata, in a midgut-specific manner. CEL-III has strong and rapid hemolytic activity toward human and rat erythrocytes in the presence of serum. Importantly, CEL-III binds to ookinetes, leading to strong inhibition of ookinete formation in vitro with an IC50 of 15 nM. Thus, CEL-III exhibits not only hemolytic activity but also cytotoxicity toward ookinetes. In these transgenic mosquitoes, sporogonic Development of Plasmodium berghei is severely impaired. Moderate, but significant inhibition was found against Plasmodium falciparum. To our knowledge, this is the first demonstration of stably engineered anophelines that affect the Plasmodium transmission dynamics of human malaria. Although our laboratory-based research does not have immediate applications to block natural malaria transmission, these findings have significant implications for the generation of refractory mosquitoes to all species of human Plasmodium and elucidation of mosquito–Parasite interactions.
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mosquito midgut barriers to malaria Parasite Development
Insect Biochemistry and Molecular Biology, 2004Co-Authors: Eappen G Abraham, Marcelo JacobslorenaAbstract:Malaria is one of the deadliest infectious diseases and kills more than one million people every year. For transmission to occur, the malaria Parasite has to complete an elaborate Developmental program in hostile mosquito environment. Thus, understanding the molecular mechanisms by which mosquitoes limit the Parasite Development may lead to new methods for controlling malaria. There has been considerable progress during the last decade in this research area. This review focuses on the mosquito response to midgut invasion of the malaria Parasite and examines the role of mosquito digestive enzymes, peritrophic matrix and microvillar proteins as barriers to Parasite Development.
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bee venom phospholipase inhibits malaria Parasite Development in transgenic mosquitoes
Journal of Biological Chemistry, 2002Co-Authors: Luciano Andrade Moreira, Junitsu Ito, Anil K Ghosh, Martin Devenport, Helge Zieler, Eappen G Abraham, Andrea Crisanti, Tony Nolan, Flaminia Catteruccia, Marcelo JacobslorenaAbstract:Malaria kills millions of people every year, and new control measures are urgently needed. The recent demonstration that (effector) genes can be introduced into the mosquito germ line to diminish their ability to transmit the malaria Parasite offers new hope toward the fight of the disease (Ito, J., Ghosh, A., Moreira, L. A., Wimmer, E. A. & Jacobs-Lorena, M. (2002) Nature, 417, 452-455). Because of the high selection pressure that an effector gene imposes on the Parasite population, Development of resistant strains is likely to occur. In search of additional antiparasitic effector genes, we have generated transgenic Anopheles stephensi mosquitoes that express the bee venom phospholipase A2 (PLA2) gene from the gut-specific and blood-inducible Anopheles gambiae carboxypeptidase (AgCP) promoter. Northern blot analysis indicated that the PLA2 mRNA is specifically expressed in the guts of transgenic mosquitoes with peak expression at approximately 4 h after blood ingestion. Western blot and immunofluorescence analyses detected PLA2 protein in the midgut epithelia of transgenic mosquitoes from 8 to 24 h after a blood meal. Importantly, transgene expression reduced Plasmodium berghei oocyst formation by 87% on average and greatly impaired transmission of the Parasite to naive mice. The results indicate that PLA2 may be used as an additional effector gene to block the Development of the malaria Parasite in mosquitoes.
Matthew B Thomas - One of the best experts on this subject based on the ideXlab platform.
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exploring the lower thermal limits for Development of the human malaria Parasite plasmodium falciparum
Biology Letters, 2019Co-Authors: Jessica L Waite, Eunho Suh, Penelope A Lynch, Matthew B ThomasAbstract:The rate of malaria transmission is strongly determined by Parasite Development time in the mosquito, known as the extrinsic incubation period (EIP), since the quicker Parasites develop, the greater the chance that the vector will survive long enough for the Parasite to complete Development and be transmitted. EIP is known to be temperature-dependent but this relationship is surprisingly poorly characterized. There is a single degree-day model for EIP of Plasmodium falciparum that derives from a limited number of poorly controlled studies conducted almost a century ago. Here, we show that the established degree-day model greatly underestimates the rate of Development of P. falciparum in both Anopheles stephensi and An. gambiae mosquitoes at temperatures in the range of 17-20°C. We also show that realistic daily temperature fluctuation further speeds Parasite Development. These novel results challenge one of the longest standing models in malaria biology and have potentially important implications for understanding the impacts of future climate change.
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implications of temperature variation for malaria Parasite Development across africa
Scientific Reports, 2013Co-Authors: Justine I Blanford, Simon Blanford, Robert G Crane, Michael E Mann, Krijn P Paaijmans, Kathleen V Schreiber, Matthew B ThomasAbstract:Temperature is an important determinant of malaria transmission. Recent work has shown that mosquito and Parasite biology are influenced not only by average temperature, but also by the extent of the daily temperature variation. Here we examine how Parasite Development within the mosquito (Extrinsic Incubation Period) is expected to vary over time and space depending on the diurnal temperature range and baseline mean temperature in Kenya and across Africa. Our results show that under cool conditions, the typical approach of using mean monthly temperatures alone to characterize the transmission environment will underestimate Parasite Development. In contrast, under warmer conditions, the use of mean temperatures will overestimate Development. Qualitatively similar patterns hold using both outdoor and indoor temperatures. These findings have important implications for defining malaria risk. Furthermore, understanding the influence of daily temperature dynamics could provide new insights into ectotherm ecology both now and in response to future climate change.
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temperature dependent pre bloodmeal period and temperature driven asynchrony between Parasite Development and mosquito biting rate reduce malaria transmission intensity
PLOS ONE, 2013Co-Authors: Krijn P Paaijmans, Lauren J Cator, Matthew B ThomasAbstract:A mosquito needs to bite at least twice for malaria transmission to occur: once to acquire Parasites and, after these Parasites complete their Development in their mosquito host, once to transmit the Parasites to the next vertebrate host. Here we investigate the relationship between temperature, Parasite Development, and biting frequency in a mosquito-rodent malaria model system. We show that the pre-bloodmeal period (the time lag between mosquito emergence and first bloodmeal) increases at lower temperatures. In addition, Parasite Development time and feeding exhibit different thermal sensitivities such that mosquitoes might not be ready to feed at the point at which the Parasite is ready to be transmitted. Exploring these effects using a simple theoretical model of human malaria shows that delays in infection and transmission can reduce the vectorial capacity of malaria mosquitoes by 20 to over 60%, depending on temperature. These delays have important implications for disease epidemiology and control, and should be considered in future transmission models.
Soundara Raghavan Pavithra - One of the best experts on this subject based on the ideXlab platform.
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recurrent fever promotes plasmodium falciparum Development in human erythrocytes
Journal of Biological Chemistry, 2004Co-Authors: Soundara Raghavan Pavithra, Gowrishankar Banumathy, Omana Joy, Varsha Singh, Utpal TatuAbstract:The human malarial Parasite Plasmodium falciparum (Pf) is exposed to wide temperature fluctuations during its life cycle, ranging from 25 °C in the mosquito vector and 37 °C in humans to 41 °C during febrile episodes in the patient. The repeated occurrence of fever at regular intervals is a characteristic of human malaria. We have examined the influence of repeated exposure to elevated temperatures encountered during fever on the intraerythrocytic Development of the Parasite. Using flow cytometry, we show that repeated exposure to temperatures mimicking febrile episodes promotes Parasite Development in human erythrocytes. Heat shock-mediated cytoprotection and growth promotion is dependent on the heat shock protein 90 (PfHsp90) multi-chaperone complex. Inhibition of PfHsp90 function using geldanamycin attenuates temperature-dependent progression from the ring to the trophozoite stage. Geldanamycin inhibits Parasite Development by disrupting the Pf- Hsp90 complex consisting of PfHsp70, PfPP5, and tubulin,among other proteins. While explaining the contribution of febrile episodes to the pathogenesis of malaria, our results implicate temperature as an important environmental cue used by the Parasite to coordinate its Development in humans.
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recurrent fever promotes plasmodium falciparum Development in human erythrocytes
Journal of Biological Chemistry, 2004Co-Authors: Soundara Raghavan Pavithra, Gowrishankar Banumathy, Omana Joy, Varsha Singh, Utpal TatuAbstract:The human malarial Parasite Plasmodium falciparum (Pf) is exposed to wide temperature fluctuations during its life cycle, ranging from 25 degrees C in the mosquito vector and 37 degrees C in humans to 41 degrees C during febrile episodes in the patient. The repeated occurrence of fever at regular intervals is a characteristic of human malaria. We have examined the influence of repeated exposure to elevated temperatures encountered during fever on the intraerythrocytic Development of the Parasite. Using flow cytometry, we show that repeated exposure to temperatures mimicking febrile episodes promotes Parasite Development in human erythrocytes. Heat shock-mediated cytoprotection and growth promotion is dependent on the heat shock protein 90 (PfHsp90) multi-chaperone complex. Inhibition of PfHsp90 function using geldanamycin attenuates temperature-dependent progression from the ring to the trophozoite stage. Geldanamycin inhibits Parasite Development by disrupting the PfHsp90 complex consisting of PfHsp70, PfPP5, and tubulin, among other proteins. While explaining the contribution of febrile episodes to the pathogenesis of malaria, our results implicate temperature as an important environmental cue used by the Parasite to coordinate its Development in humans.
