Project description:There has been an emergence and expansion of tick-borne diseases in Europe, Asia and North America in recent years, including Lyme disease, tick-borne encephalitis, and human anaplasmosis. The primary tick vectors implicated are hard ticks of the Ixodes genera. Although much is known about the host response to these bacterial and viral pathogens, there is limited knowledge of the cellular responses to infection within the tick vector. The bacterium Anaplasma phagocytophilum (A. phagocytophilum), is able to bypass apoptotic processes in ticks, enabling infection to proceed. However, the tick cellular responses to infection with the flaviviruses tick-borne encephalitis virus (TBEV) and louping ill virus (LIV), which cause tick-borne encephalitis and louping ill respectively, are less clear. Infection of an Ixodes ricinus (I. ricinus) tick cell line with the viruses LIV and TBEV, and the bacterium A. phagocytophilum, identified activation of common and distinct cellular pathways. In particular, commonly-upregulated genes included those that modulate apoptotic pathways (HSP70), putative anti-pathogen genes (FKBP and XBL1), and genes that influence the tick innate immune response, including selective activation of toll genes. These data provide an insight into potentially key genes involved in the tick cellular response to viral or bacterial infection.
2017-01-01 | GSE85300 | GEO
Project description:Microbiome analysis of Ixodes Ricinus ticks from Chernobyl Ukraine
Project description:In Europe, ticks are the most important vectors of diseases threatening humans, livestock, wildlife and companion animals. Nevertheless, genomic sequence information and functional annotation of proteins of the most important European tick, Ixodes ricinus, is limited. Here we present the first analysis of the I. ricinus genome and of the transcriptome of the unfed I. ricinus midgut. We combined and integrated data from genome, transcriptome and proteome. The de novo assembly of 1 billion paired-end sequences identified 6,415 putative genes providing an unprecedented insight into the I. ricinus genome. Mapping of our midgut mRNA reads to the assembled contigs let us estimate to cover around two third of the unique genomic sequences. In addition, more than 10,000 transcripts from naïve midgut were annotated functionally and/or locally. By combining the alignment-based with a motif-search based annotation approach, we could double the number of annotations throughout all groups without shifting the dataset. Moreover, 1,175 proteins expressed in the naïve midgut were identified by mass spectrometry confirming the high completeness of our transcriptome database, and 608 were significantly annotated for function and/or localization. This multiple-omics study vastly extends the publicly available DNA, RNA and protein databases for I. ricinus and ticks in general.
Project description:Here, we challenged rabbits with repeated feeding of Ixodes ricinus adults and observed the formation of specific antibodies against several tick salivary proteins. To identify the salivary antigens, isolated immunoglobulins from repeatedly infested rabbits were utilised for a pull-down from the saliva of pilocarpine-treated ticks. Eluted antigens were separated on 1D SDS-PAGE and analysed by peptide mass fingerprinting. To increase the authenticity of immunogens identified, we also performed, for the first time, de novo assembly of the sialome from I. ricinus females fed for six days, a timepoint used for pilocarpine-salivation.
Project description:Ticks are obligate hematophagous arthropods that transmit a wide range of pathogens to humans as well as wild and domestic animals. They also harbor a non-pathogenic microbiota, although our previous study has shown that the diverse bacterial microbiome in the midgut of Ixodes ricinus is quantitatively poor and lacks a core microbe. In artificial infections by capillary feeding of ticks with two model bacteria (Gram-positive Micrococcus luteus and Gram-negative Pantoea sp.), rapid clearance of these microbes from the midgut was observed, indicating the presence of active immune mechanisms in this organ. In the current study, RNA-seq analysis was performed on the midgut of I. ricinus females inoculated with either M. luteus or Pantoea sp. or with sterile water as a control. While no immune-related transcripts were upregulated by microbial inoculation compared to the sterile control, capillary feeding itself triggered dramatic transcriptional changes in the tick midgut. Manual curation of the transcriptome from the midgut of unfed I. ricinus females, complemented by proteomic analysis, revealed the presence of several constitutively expressed putative antimicrobial peptides (AMPs) that are independent of microbial stimulation and are referred to here as ‘guard’ AMPs. These included two types of midgut-specific defensins, two different domesticated amidase effector 2 (Dae2), microplusin/ricinusin-related molecules, two lysozymes and two gamma interferon-inducible lysosomal thiol reductases (GILTs). The in vitro antimicrobial activity assays of two synthetic mature defensins, defensin 1 and defensin 8, confirmed their specificity against Gram-positive bacteria showing exceptional potency to inhibit the growth of M. luteus at nanomolar concentrations. The antimicrobial activity of midgut defensins is likely part of a multicomponent system responsible for the rapid clearance of bacteria in the tick midgut. Further studies are needed to evaluate the role of other identified ‘guard‘ AMPs in controlling microorganisms entering the tick midgut.
2024-10-17 | PXD053128 | Pride
Project description:Microbiome analysis for Dermacentor reticulatus and Ixodes ricinus ticks from Kyiv, Ukraine
Project description:Tick bites often predispose to meat allergy. The mechanisms involved in this process is not fully understood. Here we investigated the changes in the gut induced by Ixodes ricinus bites.
Project description:In order to select genes that are differentially expressed in salivary glands during Ixodes ricinus infection by Bartonella henselae we compare the transcriptome of infected and non-infected salivary glands