DksA controls the response of the Lyme disease spirochete Borrelia burgdorferi to starvation
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PROVIDER: PRJNA487786 | ENA |
REPOSITORIES: ENA
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Project description:The pathogenic spirochete Borrelia burgdorferi senses and responds to diverse environmental challenges, including changes in nutrient availability, throughout its natural infectious cycle in Ixodes spp. ticks and mammalian hosts. This study examined the role of the putative DnaK suppressor protein (DksA) in the transcriptional response of B. burgdorferi to starvation. Wild-type and dksA-deficient B. burgdorferi strains were subjected to starvation by shifting mid-logarithmic cultures grown in BSK-II medium to serum-free RPMI medium for six hours under microaerobic conditions (5% CO2, 3% O2). Microarray analyses of wild-type B. burgdorferi revealed that genes encoding flagellar components, ribosomal proteins, and DNA replication machinery were downregulated in response to starvation. DksA mediated transcriptomic responses to starvation in B. burgdorferi as the dksA-deficient B. burgdorferi strain differentially expressed only 47 genes in response to starvation compared to the 500 genes differentially expressed by wild-type strains. Consistent with a role for DksA in the starvation response of B. burgdorferi, fewer CFUs were observed for dksA-deficient spirochetes after prolonged starvation in RPMI medium compared to wild-type B. burgdorferi. Transcriptomic analyses revealed a partial overlap between the DksA regulon and the regulon of the guanosine tetraphosphate and guanosine pentaphosphate [(p)ppGpp] synthase RelBbu, while the DksA regulon also included many plasmid-borne genes. Corresponding to a DksA-(p)ppGpp regulatory relationship, (p)ppGpp levels were constitutively elevated in the dksA-deficient strain compared to the wild-type strain. Together, these data indicate that DksA directs the stringent response with a regulatory interplay with (p)ppGpp that is fundamental to B. burgdorferi responses to the environment.
2018-12-18 | GSE119023 | GEO
Project description:Adiponectin-mediated pathways contribute to mammalian homeostasis; however, little is known about adiponectin and adiponectin receptor signaling in arthropods. In this study, we demonstrate that Ixodes scapularis ticks have an adiponectin receptor-like protein (ISARL) but lack adiponectin, suggesting activation by alternative pathways. ISARL expression is significantly upregulated in the tick gut after Borrelia burgdorferi infection, suggesting that ISARL signaling may be co-opted by the Lyme disease agent. Consistent with this, RNA interference (RNAi)-mediated silencing of ISARL significantly reduced the B. burgdorferi burden in the tick. RNA-seq-based transcriptomics and RNAi assays demonstrate that ISARL-mediated phospholipid metabolism by phosphatidylserine synthase I is associated with B. burgdorferi survival. Furthermore, the tick complement C1q-like protein 3 interacts with ISARL, and B. burgdorferi facilitates this process. This study identifies a new tick metabolic pathway that is connected to the life cycle of the Lyme disease spirochete.
2021-12-08 | GSE169293 | GEO
Project description:Borrelia burgdorferi, the agent of Lyme disease, promotes pro-inflammatory changes in endothelium that lead to the recruitment of leukocytes. The host immune response to infection results in increased levels of IFN-gamma in the serum and lesions of Lyme disease patients that correlate with greater severity of disease. Therefore, the effect of IFN-gamma on the gene expression profile of primary human endothelial cells exposed to B. burgdorferi was determined. B. burgdorferi and IFN-gamma synergistically augmented the expression of 34 genes, seven of which encode chemokines. Six of these (CCL7, CCL8, CX3CL1, CXCL9, CXCL10, and CXCL11) attract T lymphocytes, and one (CXCL2) is specific for neutrophils. Synergistic production of the attractants for T cells was confirmed at the protein level. IL-1beta, TNF-alpha, and LPS also cooperated with IFN-gamma to induce synergistic production of CXCL10 by endothelium, indicating that IFN-gamma potentiates inflammation in concert with a variety of mediators. An in vitro model of the blood vessel wall revealed that an increased number of human T lymphocytes traversed endothelium exposed to B. burgdorferi and IFN-gamma, as compared to unstimulated endothelial monolayers. In contrast, addition of IFN-gamma diminished the migration of neutrophils across B. burgdorferi-activated endothelium. IFN-gamma thus alters gene expression by endothelium exposed to B. burgdorferi in a manner that promotes recruitment of T cells and suppresses that of neutrophils. This modulation may facilitate the development of chronic inflammatory lesions in Lyme disease. Experiment Overall Design: Human umbilical vein endothelial cells (HUVEC) were stimulated with Interferon-gamma (IFN-g), Borrelia burgdorferi or both IFN-g and Borrelia or were left unstimulated. Affymetrix HGU133 plus 2.0 slides were used in duplicate for each condition.
2008-06-14 | E-GEOD-6092 | biostudies-arrayexpress
Project description:We report the results of gene expression profiling via RNA-sequencing of primary human choroid plexus epithelial cells in vitro that were infected with Borrelia burgdorferi, the causative agent of Lyme disease. Epithelial cells were cultured with B. burgdorferi for 48 hours prior to RNA isolation. Following high-throughput sequencing via Illumina HiSeq 4000, a total of 258 differentially expressed genes were identified. Subsequent data analysis indicates an inflammatory and immune response generated by the epithelial cells following infection, marked by chemotactic cytokines and interferon stimulated genes. Several genes associated with tight and adherens junctions were found to be downregulated. These data represent the first study to investigate the impact of B. burgdorferi on choroid plexus epithelial cells, implicating the choroid plexus in the pathogenesis of neurological manifestations of Lyme disease.
2020-07-10 | GSE153261 | GEO
Project description:Macrophages mediate the elimination of pathogens by phagocytosis resulting in the activation of specific signaling pathways that lead to the production of cytokines, chemokines and other factors. Borrelia burgdorferi, the causative agent of Lyme disease, causes a wide variety of pro-inflammatory symptoms. The proinflammatory capacity of macrophages is intimately related to the internalization of the spirochete. However, most receptors mediating this process are largely unknown. We have applyedapplied a multiomic approach, including the proteomic analysis of B. burgdorferi-containing phagosome-enriched fractions, to identify surface receptors that are involved in the phagocytic capacity of macrophages as well as their inflammatory output. Sucrose gradient protein fractions of human monocyte-derived macrophages exposed to B. burgdorferi contained the phagocytic receptor, CR3/CD14 highlighting the major role played by these proteins in spirochetal phagocytosis. Among others, Other proteins identified proteins include C-type lectins, scavenger receptors or siglecs, and contain uPAR and MARCO. We also identified the Fc gamma receptor pathway as involved both in the phagocytosis of , and TNF induction by B. burgdorferi in the absence of antibodies. The common gamma chain, FcR, mediates the phagocytosis of the spirochete, likely through Fc receptors and C-type lectins, in a process that involves Syk activation. Overall, these findings highlight the complex array of receptors involved in the phagocytic response of macrophages to B. burgdorferi.
2019-12-06 | PXD012854 | Pride
Project description:Purpose: To determine whether Borrelia burgdorferi, the spirochetal agent of Lyme disease, responds to sub-lethal doses of antibiotics. Methods: mRNA profiles of Borrelia burgdorferi were compared after subculturing in 0.2μg/mL amoxicillin, 0.2μg/mL doxycycline, or media control for 3h or 24h (n=3 per group) by paired-end sequencing using the Illumina NextSeq 500. The sequence reads were aligned using Salmon aligner followed by DESeq2 for differential expression analysis. Results: After culturing for 24 h in a sub-lethal concentration of doxycycline, there were significant increases in a substantial number of transcripts for proteins that are involved with translation. Bacteria continued to elongate, but appeared to be defective in septation and formed filaments. In contrast, incubation with sublethal concentration of amoxicillin led to membrane blebbing and swelling, indicative of cell wall disruption, but no significant changes in levels of any bacterial transcript. Conclusion: We conclude that B. burgdorferi has a mechanism(s) that detects translational inhibition by doxycycline, and increases production of translational machinery in compensation. In contrast, The absence of response to the inhibition of cell wall synthesis by amoxicillin implies that B. burgdorferi lacks a mechanism to assess cell wall integrity.
2022-03-08 | GSE197338 | GEO
Project description:Background: Lyme borrelia genotypes differ in their capacity to cause disseminated disease. Gene array analysis was employed to profile the host transcriptome induced by Borrelia burgdorferi strains with different capacities for causing disseminated disease in the blood of C3H/HeJ mice during early infection. Results: Borrelia burgdorferi B515, a clinical isolate that causes disseminated infection in mice, differentially regulated 236 transcripts (P<0.05 by ANOVA, with fold change of at least 2). The 216 significantly induced transcripts included IFN-responsive genes and genes involved in immunity and inflammation. In contrast, B. burgdorferi B331, a clinical isolate that causes transient skin infection but does not disseminate in C3H/HeJ mice, stimulated changes in only a few genes (1 induced, 4 repressed). Transcriptional regulation of type I IFN and IFN-related genes was measured by quantitative RT-PCR in mouse skin biopsies collected from the site of infection 24 hours after inoculation with B. burgdorferi. The mean values for transcript of Ifnb, Cxcl10, Gbp1, Ifit1, Ifit3, Irf7, Mx1, and Stat2, were found to be significantly increased in B. burgdorferi strain B515-infected mice relative to the control group. In contrast, transcription of these genes was not significantly changed in response to B. burgdorferi strain B331 or B31-4, a mutant that is unable to disseminate. Conclusions: These results establish a positive association between the disseminating capacity of B. burgdorferi and early type I IFN induction in a murine model of Lyme disease.
2016-03-25 | E-MTAB-3325 | biostudies-arrayexpress
Project description:The similarity of Lyme borreliosis to other diseases and the complex pathogenesis cause diagnostic and therapeutic difficulties. Changes at the cellular and molecular level after Borrelia sp. infection remain still poorly understood. Therefore, the present study focused on the gene expression in human dermal fibroblasts in differentiation of infection with Borrelia garinii, Borrelia afzelii and Borrelia burgdorferi sensu stricto spirochetes. For microarray analysis 10 samples were used: 3 control samples - K, 2 samples of NHDF cells infected with Borrelia garinii - G, 2 samples of NHDF cells infected with Borrelia afzelii - A and 3 samples of NHDF cells infected with Borrelia burgdorferi sensu stricto - SS.
2015-05-12 | E-GEOD-68741 | biostudies-arrayexpress
Project description:The Lyme disease spirochete Borrelia burgdorferi drives a range of acute and chronic maladies in humans and other incidental hosts infected with the pathogen. However, the primary vertebrate reservoir, Peromyscus leucopus appears spared from any symptomology following infection. This has led to a common hypothesis that P. leucopus and B. burgdorferi exist symbiotically: P. leucopus restrain their immune response against the microbe and enable the enzootic cycle while B. burgdorferi avoids causing damage to the host. While aspects of this hypothesis have been tested, the exact interactions that occur between P. leucopus and B. burgdorferi during infection remain largely unknown. Here we utilized an inbred colony of P. leucopus in order to compare B. burgdorferi (B31) fitness in these rodents to the traditional B. burgdorferi murine models—C57BL/6J and C3H/HeN Mus musculus, which develop signs of inflammation akin to human disease. We find that in contrast to our expectations, B. burgdorferi were able to reach much higher burdens in M. musculus, and that the overall kinetics of infection differed between the two rodent species. Surprisingly, we also found that P. leucopus remained infectious to larval Ixodes scapularis for a far shorter period than either M. musculus strain. In line with these observations, we found that P. leucopus does launch a modest but sustained inflammatory response against B. burgdorferi in the skin, which we hypothesize leads to reduced bacterial viability and infectivity in these hosts. These observations provide new insight into the nature of reservoir species and the B. burgdorferi enzootic cycle.
2024-01-03 | GSE244071 | GEO
Project description:The similarity of Lyme borreliosis to other diseases and the complex pathogenesis cause diagnostic and therapeutic difficulties. Changes at the cellular and molecular level after Borrelia sp. infection remain still poorly understood. Therefore, the present study focused on the gene expression in human dermal fibroblasts in differentiation of infection with Borrelia garinii, Borrelia afzelii and Borrelia burgdorferi sensu stricto spirochetes.
2015-05-12 | GSE68741 | GEO