Project description:The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquitoes to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the host or compromising host survival is poorly understood. Here we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of subjects with febrile malaria in the transmission season, reflecting longer circulation within each replicative cycle, of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication, but rather increased efficiency of splenic clearance of longer-circulating infected erythrocytes. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence.
2020-08-20 | GSE148125 | GEO
Project description:Microbial characteristics of rhizosphere soil of teak intercropping Alpinia katsumadai Hayata in dry and rainy seasons
Project description:Inflammaging is the name given to this chronic and asymptomatic inflammatory state generated by the aging process and by chronic and infectious diseases. Chronic diseases can alter the epigenetic profile of tissues leading to an increased epigenetic aging and some of the differentially methylated genes can be used to characterize the disease and as disease biomarkers. Leprosy is an infection caused by Mycobacterium leprae and can be lifelong, exposing the individual to a low-grade inflammation environment. In this study, we evaluated the inflammatory profile in 35 individuals from a leprosy endemic area from Brazil by cytokine analysis with a luminex assay. In adition, we investigated the leucocytes genome-wide DNA methylation profile using the Infinium MethylationEPIC BeadChip array. A total number of 31 CpGs were significantly methylated, between cases and controls, which belonged to 8 genes potentially peripherally perturbed in the pathogenesis of the disease. Affected individuals from endemic area were epigenetically aged in relation to control samples and interesting control samples from endemic area were aged in relation to unaffected control samples from non-endemic area. In conclusion, leprosy showed a deregulated methylation profile in comparison with control samples. The epigenetic analysis provided valuable clues for further investigations in understanding peripherical blood leprosy alterations and the use of these genes as biomarkers.
Project description:Igh/Myc translocations underlie both sporadic Burkitt lymphoma (BL) and the endemic clinical form affecting African children infected with malaria. However, while sporadic translocations decapitate Myc from 5' proximal regulatory elements, most endemic events occur hundreds of kilobases away from Myc. The origin of these rearrangements and how they deregulate oncogenes at such distances remain unclear. Here we recapitulate endemic BL-like translocations in plasmacytomas from uracil N-glycosylase (UNG) deficient mice. We demonstrate that in these animals, rare endemic-like translocations arise from non-targeted DNA breaks at Myc loci. Deep-sequencing analyses revealed that the deregulated 3' Igh enhancer alpha physically interacts with and remodels 0.45Mb of translocated chromatin. The results thus explain the long-range deregulation of oncogenes in human and mouse B cell tumors. ChIP-Seq, 4C, and 1 RNASeq samples used to characterize mouse plasmacytoma cell lines and in vitro activated mouse B cells. Biological replicates are present for many of the samples.
Project description:Epstein-Barr virus (EBV) related nasopharyngeal carcinoma (NPC) is an epithelial malignancy with higher incidence in Asian endemic area (EA) than in non-endemic area (NEA), where frequency is below 1/105/year. The causes of such difference are unclear and might be related to viral, environmental (e.g. diet) and genomic factors. We aimed at dissecting the gene expression (GE) and microenvironment landscape in NPC leading to the identification of molecular subtypes explaining the differences between EA and NEA.
Project description:Climate change forecasts increase the susceptibility of forest due to longer drier seasons. The adaptive management protocols have highlighted the reduction of the forest densification to improve their vulnerability to extreme climate events (i.g. drought). One of this sensitive woody species to climate change is the Abies pinsapo, a relic conifer tree endemic from the southern Spain. Previous works have shown changes in their trends because of the climate change action, being carried out experimental thinning management in their lowest distribution limit, in Sierra de las Nieves Natural Park (Malaga). Our objective is to evaluate the water improvements of thinned trees in terms of light availability by means of a shading treatment in those thinned trees. To do that we have evaluated the synergic effect of ecophysiology, metabolomics and transcriptomics in control, thinning and thinning+shading plots in wet and dry seasons for two years. The results showed strong differences between summer and spring seasons at the three studied levels. The water deficit shows a greater influence than light exposure in the ecophysiology and metabolomics tree response. And the transcriptomics suggested an improvement of thinned trees when light exposure was reduced. Our results support the necessity of adaptive forest management in order to improve the conservation status of A. pinsapo forest. The combination of different levels of tree response is paramount to understand and predict the tree physiology under water and light stress conditions.
Project description:Igh/Myc translocations underlie both sporadic Burkitt lymphoma (BL) and the endemic clinical form affecting African children infected with malaria. However, while sporadic translocations decapitate Myc from 5' proximal regulatory elements, most endemic events occur hundreds of kilobases away from Myc. The origin of these rearrangements and how they deregulate oncogenes at such distances remain unclear. Here we recapitulate endemic BL-like translocations in plasmacytomas from uracil N-glycosylase (UNG) deficient mice. We demonstrate that in these animals, rare endemic-like translocations arise from non-targeted DNA breaks at Myc loci. Deep-sequencing analyses revealed that the deregulated 3' Igh enhancer alpha physically interacts with and remodels 0.45Mb of translocated chromatin. The results thus explain the long-range deregulation of oncogenes in human and mouse B cell tumors.
Project description:We studied bacterioplankton community structure in a tropical estuary during dry and rainy season, using Illumina sequensing of the 16S RNA gene.
Project description:The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquitoes to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the host or compromising host survival is poorly understood. Here we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of subjects with febrile malaria in the transmission season, reflecting longer circulation within each replicative cycle, of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication, but rather increased splenic clearance of longer-circulating infected erythrocytes. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence.