Project description:In this study, we performed deep sequencing and bioinformatics analyses of short RNAs from Plasmodium falciparum parasites to identify and characterize novel type of small RNAs. A total of 14,828,877 raw reads were produced from small RNA libraries. We detected a new type of small RNA from tranfer RNA known as tRFs.
Project description:The human malaria parasite Plasmodium falciparum has a complex and multi-stage life cycle that requires extensive immune escape, invasion of human liver and blood cells, and transmission through the female Anopholes mosquito. To date, the regulatory elements orchestrating these critical parasite processes remain largely unknown. However, there is mounting evidence across a broad range of species that intergenic long non-coding RNA (lncRNA) and antisense RNA can regulate chromatin state and gene expression. To pursue such functional roles for lncRNAs in P. falciparum, we performed deep, strand-specific RNA sequencing of fifteen non-polyA-selected blood stage samples, and assembled and characterized the properties of 660 intergenic lncRNAs, 474 antisense RNAs, and 1381 circular RNAs (circRNAs). We further validated the non-canonical splice junctions of seven P. falciparum circRNAs, an emerging class of non-coding RNA with regulatory potential and unexplored functional significance in P. falciparum. Our comprehensive analysis of P. falciparum lncRNAs indicates a functional role for these transcripts; P. falciparum intergenic lncRNAs and antisense RNAs are developmentally regulated in a similar periodic fashion to annotated transcripts, and sense-antisense pair expression is significantly anti-correlated. Notable outliers include intergenic lncRNAs that strongly peak in expression during parasite invasion, such as the telomere-associated lncRNA-TARE family, antisense transcripts that drop in expression during parasite invasion, and a highly correlated, multi-exonic, antisense counterpart to P. falciparum Gametocyte Developmental Protein 1 (PfGDV1). Taken together, our results present over two thousand P. falciparum intergenic lncRNA, antisense, and circRNA candidates and highlight promising P. falciparum lncRNAs for future investigation.
Project description:ChIP-seq experiments were performed for the putative telomere repeat-binding factor (PfTRF) in the malaria parasite Plasmodium falciparum strain 3D7. The gene encoding this factor (PF3D7_1209300) was endogenously tagged with either a GFP- or a 3xHA-tag and these transgenic parasite lines were used in ChIP-sequencing experiments. Sequencing of the ChIP and input libraries showed enrichment of PfTRF at all telomere-repeat containing chromosome ends (reference genome Plasmodium falciparum 3D7 from PlasmoDB version 6.1) as well as in all upsB var promoters.In addition,PfTRF was enriched at seven additional, intra-chromosomal sites and called in the PfTRF-HA ChIP-seq only. Plasmodium falciparum 3D7 parasites were generated with -GFP or -3xHA C-terminal tagged TRF (PF3D7_1209300). Nuclei were isolated from formaldehyde cross-linked schizont-stage transgenic parasites and used to prepare chromatin. Chromatin immunoprecipitations were performed using mouse anti-GFP (Roche Diagnostics, #11814460001) or rat anti-HA 3F10 (Roche Diagnostics, #12158167001). Sequencing libraries were prepared according to a Plasmodium-optimized library preparation procedure including KAPA polymerase-mediated PCR amplification.
Project description:We took a systems immunology approach to analyse the evolution of the human immune response to the first three infections of life in a re-challenge model of falciparum malaria. Ten volunteers were infected up to three times with Plasmodium falciparum in 4- to 8-month intervals. Remarkably, parasite densities and the dynamics of blood-stage infection were not altered over the course of three homologous infections. To track the development of immunity in real-time we used whole blood RNA-sequencing to analyse each volunteer’s transcriptional response throughout infection and convalescence (up to 9 time points per volunteer per infection).
Project description:This resource comprises a single-cell multi-lineage map of first trimester infected placental cells. We have included data from both uninfected cells and cells infected with three pathogens known to cause maternal and fetal disorders: Plasmodium falciparum, Listeria monocytogenes, and Toxoplasma gondii. We also generated single-nuclei map of infected trophoblasts and their corresponding controls. Furthermore, we created a single-nuclei reference dataset containing information from uninfected primary placental organoids as well as organoids infected with P. falciparum. Additionally, we conducted sequencing at a single-cell level for P. falciparum parasites that were bound to the placenta (pf_b), parasites unbound to the placenta (pf_nb), and parasites that were cultured in vitro (pf_iv).