Borrelia burgdorferi induces a type I interferon response during early stages of disseminated infection in mice
ABSTRACT: 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.
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.
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.
Project description:Lyme disease is challenging to diagnose, as clinical manifestations are variable and current tools to detect nucleic acid or antibody responses from Borrelia burgdorferi infection have low sensitivity. Here we conducted the first study of the global transcriptome of patients with Lyme disease to identify potential diagnostic biomarkers. Twenty-nine patients were enrolled and compared to 13 healthy controls at three time points after infection. Fifteen publicly available transcriptome datasets from patients in vivo or infection models in vitro were used to assess specificity of differentially expressed genes (DEGs). We found that Lyme disease results in profound and sustained changes in the patient transcriptomes, with a specific signature that shares 44% DEGs with other infections. Gene expression profile from peripheral mononuclear blood cells (PBMC) of Lyme disease patients against healthy controls was undertaken. A total of 29 Lyme disease patients were sampled at 3 time points: acute Lyme pre-treatment (V1), 3 weeks later, immediately following completion of a standard course of antibiotics (V2), and 6 months following treatment completion (V5). 13 healthy controls were also sampled at one time point. Total RNA was extracted from 10e7 PBMC, followed by mRNA purification, paired-end barcode library preparation and sequencing on an Illumina Hiseq 2000.
Project description:Transcriptional profiling of gene expression between parental strain B31 and rrp1 mutant. Cyclic-di-GMP is a bacterial second messenger that modulates many biological processes. Although its role in bacterial pathogenesis during mammalian infection has been widely recognized, the role of c-di-GMP in pathogen's life cycle in vector hosts is less understood. The enzootic cycle of the Lyme disease pathogen Borrelia burgdorferi involves both a mammalian host and an Ixodes tick vector. The B. burgdorferi genome encodes a single copy of the diguanylate cyclase gene (rrp1), which is responsible for the production of c-di-GMP. To determine the role of c-di-GMP in the life cycle of B. burgdorferi, an Rrp1-deficient B. burgdorferi strain was generated. The rrp1 mutant remains infectious in the mammalian host, but could not survive in the tick vector. To identify the mechanisms of Rrp1 contributing to B. burgdorferi pathogenesis and gene regulation, microarray was employed to compare gene expression profiles between the parental strain B31 and the rrp1 mutant. Overall design: Two-condition experiment, B31 vs. rrp1 mutant. Biological replicates: 3 B31, 3 rrp1 mutant, independently grown and harvested. One replicate (dye-swap) per array.
Project description:The aim of the study was to compare the global transcriptional responses elicited in NHDF cells by three different strains of Borrelia burgdorferi ss (the agent of Lyme borreliosis), representative of different stages in the life cycle of Borrelia: one reference strain isolated from a tick (strain N40), and two invasive strains isolated from skin biopsy of erythema migrans (strain Pbre c4) and acrodermatitis chronica atrophians skin lesions (strain 1408 c1). Three different experimental conditions have been tested: (1) unstimulated NHDF vs NHDF stimulated by Borrelia strain N40 / (2) unstimulated NHDF vs NHDF stimulated by Borrelia strain Pbre c4 / (3) unstimulated NHDF vs NHDF stimulated by Borrelia strain 1408 c1. There is 2 biological replicates for each condition. All NHDF stimulation have been performed in independent experiments.
Project description:The overall goal of these experiments was to determine how human cells respond to ontegrin binding by Borrelia burgdorferi. Lyme disease is the most common vector-borne infection in the Northern hemisphere, yet little is understood about the pathogenic mechanisms of the causative agent, Borrelia burgdorferi. Cells in culture were infected with the bacteria that do and do not express the beta3 integrin ligand P66, which are otherwise isogenic. As additional controls, uninfected cells were also included in the analyses. Overall design: The cell line used for primary data analyses provided here was Ea.hy926, a macrovascular line (Edgell, C. J.,et al. 1990. Endothelium specific Weibel-Palade bodies in a continuous human cell line, EA.hy926. In vitro Cell. & Dev. Biol. 26:1167-1172, and Edgell, C. J., et al. 1983. Permanent cell line expressing human factor VIII-related antigen established by hybridization. Proc. Natl. Acad. Sci. 80:3734-3737). Epithelial cells HEK-293 (which does not express b3 integrins) and HEK-293 transfected to express integrin αvβ3 were also analyzed. Infection times were 1 hour or 3 hours for cells lifted with EDTA and washed prior to bacterial infection. RNA was harvested and reverse transcribed. Labeled cDNAs were used to probe 2 color arrays. In each of at least three biological replicate experiments, for each time point, three comparisons were made. First, cells infected with B. burgdorferi with a marker inserted adjacent to the p66 gene (p66+) were compared to the cells infected with B. burgdorferi with the p66 gene interrupted by the marker (Coburn, J. and Cugini, C. (2003) Targeted mutation of P66 of Borrelia burgdorferi disrupts attachment to integrin αvβ3. Proc. Natl. Acad. Sci. 100:7301-7306). Second, the p66+-infected cells were compared to the uninfected cells. Third, the p66- mutant-infected cells were compared to the uninfected cells. Arrays used were generated at the Tufts University core faculity using Operon's human v2.1.2 plus v2.1.4 cDNA library (Operon Technologies, Inc., Alameda, CA). Only data generated from spots that in all three experiments were of sufficient quality to allow interpretation are included. IEa.hy926 endothelial cell lines, or HEK-293 epithelial cells, or transfected HEK-293 derivative expressing integrin avb3
Project description:Previously, using a forward genetic approach we identified B. burgdorferi arthritis-associated locus 1 (Bbaa1), a quantitative trait locus on Chr4, which physically encompasses the type I IFN gene cluster and regulates Lyme arthritis through heightened type I IFN production. Reciprocal radiation chimeras between B6.C3-Bbaa1 and B6 mice revealed that arthritis is initiated by radiation-sensitive cells, but orchestrated by radiation-resistant components of joint tissue. Advanced congenic lines were developed to reduce the physical size of the Bbaa1 interval, and RNA-seq of resident CD45- joint cells from advanced interval specific recombinant congenic lines (ISRCL4 and ISRCL3) identified myostatin as uniquely upregulated in association with Bbaa1 arthritis development. Our manuscript further demonstrates that myostatin expression is linked to IFN-β production, and in vivo inhibition of myostatin suppresses Lyme arthritis in the reduced interval Bbaa1 congenic mice, formally implicating myostatin as a novel downstream mediator of joint-specific inflammatory response to B. burgdorferi. Overall design: 22 days following infection with B. burgdorferi, mouse rear ankle joints were gently digested into single-cell suspensions and CD45 negative cells were isolated by magnetic bead separation. CD45 negative cells from both rear ankle joints of two mice were pooled for each n sample in order to increase RNA concentration for gene expression analysis (n=5 per genotype). Gene expression comparisons were made between B6 (control group) and ISRCL4/ISRCL3 congenic lines.
Project description:Transcriptional profiling of gene expression between parental strain B31 and rrp1 mutant. Cyclic-di-GMP is a bacterial second messenger that modulates many biological processes. Although its role in bacterial pathogenesis during mammalian infection has been widely recognized, the role of c-di-GMP in pathogen's life cycle in vector hosts is less understood. The enzootic cycle of the Lyme disease pathogen Borrelia burgdorferi involves both a mammalian host and an Ixodes tick vector. The B. burgdorferi genome encodes a single copy of the diguanylate cyclase gene (rrp1), which is responsible for the production of c-di-GMP. To determine the role of c-di-GMP in the life cycle of B. burgdorferi, an Rrp1-deficient B. burgdorferi strain was generated. The rrp1 mutant remains infectious in the mammalian host, but could not survive in the tick vector. To identify the mechanisms of Rrp1 contributing to B. burgdorferi pathogenesis and gene regulation, microarray was employed to compare gene expression profiles between the parental strain B31 and the rrp1 mutant. Two-condition experiment, B31 vs. rrp1 mutant. Biological replicates: 3 B31, 3 rrp1 mutant, independently grown and harvested. One replicate (dye-swap) per array.
Project description:Lyme borreliosis is first characterized by a cutaneous inflammation, the erythema migrans, and if dissemination occurs after an infected tick bite cutaneous, nervous and articular manifestations appear. Although antibiotic treatments are efficient in the early stage of the infection, a significant number of patients develop disseminated manifestations due to unnoticed or absence of erythema migrans, or to inappropriate treatment. Vaccine could be an efficient approach to decrease Lyme disease incidence. We have developed a proteomic approach based on a Ge-LC-MS/MS strategy to identify new vaccine candidates. We analyzed a disseminating clone and the associated wild type strain for each major pathogenic Borrelia species: B. burgdorferi sensu stricto, B. garinii and B. afzelii. We managed to identify proteins specific and common to the disseminating clones of the 3 main species. In parallel, we used a spectral counting strategy in order to identify up-regulated proteins common to the clones. Thus, we identified 40 proteins that are potentially involved in bacterial virulence and could be of interest in the development of a new vaccine.
Project description:The murine model of Lyme disease provides a unique opportunity to study the localized host response to similar stimulus, B. burgdorferi, in the joints of mice destined to develop severe arthritis (C3H) or mild disease (C57BL/6). Pathways associated with the response to infection and the development of Lyme arthritis were identified by global gene expression patterns using oligonucleotide microarrays. A robust induction of IFN responsive genes was observed in severely arthritic C3H mice at one week of infection, which was absent from mildly arthritic C57BL/6 mice. In contrast, infected C57BL/6 mice displayed a novel expression profile characterized by genes involved in epidermal differentiation and wound repair, which were decreased in the joints of C3H mice. These expression patterns were associated with disease state rather than inherent differences between C3H and C57BL/6 mice, as C57BL/6-IL10-/- mice infected with B. burgdorferi develop more severe arthritis that C57BL/6 mice and displayed an early gene expression profile similar to C3H mice. Gene expression profiles at two and four weeks post infection revealed a common response of all strains that was likely to be important for the host defense to B. burgdorferi and mediated by NF-kB-dependent signaling. The gene expression profiles identified in this study add to the current understanding of the host response to B. burgdorferi and identify two novel pathways that may be involved in regulating the severity of Lyme arthritis. Experiment Overall Design: Expression profiling of ankle tissues of C3H, C57BL/6, and C57BL/6-IL10-/- mice infected with B. burgdorfer (0, 1, 2, and 4 weeks post-infection)