Analysis of the human endothelial cell response to Borrelia burgdorferi wild-type and deleted in the gene encoding the integrin ligand P66
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE27996 | GEO | 2011/03/18
SECONDARY ACCESSION(S): PRJNA137805
REPOSITORIES: GEO
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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.
2011-03-18 | GSE27995 | GEO
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.
2011-03-18 | GSE27252 | GEO
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. 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). In addition, the human microvascular endothelial cell line HMEC (Ades et al, 1992. HMEC-1: establishment of an immortalized human microvascular endothelial cell line. J Invest Dermatol. 99:683-690) was used. Epithelial cells HEK-293 (which does not express b3 integrins) and HEK-293 transfected to express integrin ?v?3 were also analyzed. Infection times were 1 hour or 3 hours for cells lifted with EDTA and washed prior to bacterial infection, or 3, 6, and 24 hours for samples in which the bacteria were added to adherent cells. 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, the following comparisons were made. First, cells infected with B. burgdorferi with a marker inserted adjacent to the p66 gene (p66+) were compared to uninfected cells. Second, cells infected 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 ?v?3. Proc. Natl. Acad. Sci. 100:7301-7306) the mutant-infected cells were compared to the uninfected cells. In some experiments, cells infected with p66+ were compared to cells infected with the p66- mutant. Arrays used were HEEBO arrays purchased from Microarrays Inc. (Nashville, TN). Ea.hy926 or HMEC endothelial cell lines, or HEK-293 epithelial cells, or transfected HEK-293 derivative expressing integrin avb3
2011-03-18 | E-GEOD-27252 | biostudies-arrayexpress
Project description:Borrelia burgdorferi, an agent of Lyme disease, establishes persistent infection in immunocompetent animals and humans. Although the infection in humans can be cleared by antibiotic therapy, persistence in reservoir animals is necessary for the maintenance of the bacterium in the natural reservoir host?tick vector infectious cycle. B. burgdorferi binds to ?(1)- and ?(3)-chain integrins, and the P66 outer membrane protein is responsible for at least some of the integrin binding activity of the spirochete. Because integrins are transmembrane, bidirectional signaling molecules, integrin binding may alter the nature of the host response to the bacteria. We used isogenic B. burgdorferi p66(+) and ?p66 strains to analyze the responses of cultured human cells to P66-integrin interaction during infection. Microarray results suggest that the response differs according to the cell type, infection time, and experimental conditions. Clusters of genes in functionally related categories that showed significant changes included proteins involved in cell-extracellular matrix interactions, actin dynamics, stress response, and immune responses. Integrin binding by P66 may therefore help B. burgdorferi establish infection by facilitating tissue invasion and modulating the activation of the immune system to other components of the bacteria, e.g., lipoproteins. These results provide insight into how B. burgdorferi is able to establish infection in immunocompetent hosts.
| S-EPMC3147572 | biostudies-literature
Project description:P66 is a Borrelia burgdorferi surface protein with ?? integrin binding and channel forming activities. In this study, the role of P66 in mammalian and tick infection was examined. B.?burgdorferi?p66 strains were not infectious in wild-type, TLR2?/?- or MyD88?/?-deficient mice. Strains with p66 restored to the chromosome restored near wild-type infectivity, while complementation with p66 on a shuttle vector did not restore infectivity. ?p66 mutants are cleared quickly from the site of inoculation, but analyses of cytokine expression and cellular infiltrates at the site of inoculation did not reveal a specific mechanism of clearance. The defect in these mutants cannot be attributed to nutrient limitation or an inability to adapt to the host environment in vivo as ?p66 bacteria were able to survive as well as wild type in dialysis membrane chambers in the rat peritoneum. ?p66 bacteria were able to survive in ticks through the larva to nymph moult, but were non-infectious in mice when delivered by tick bite. Independent lines of evidence do not support any increased susceptibility of the ?p66 strains to factors in mammalian blood. This study is the first to define a B.?burgdorferi adhesin as essential for mammalian, but not tick infection.
| S-EPMC3438374 | biostudies-literature
Project description:Borrelia burgdorferi is a causative agent of Lyme disease, the most common arthropod-borne disease in the United States. B. burgdorferi evades host immune defenses to establish a persistent, disseminated infection. Previous work showed that P66-deficient B. burgdorferi (Δp66) is cleared quickly after inoculation in mice. We demonstrate that the Δp66 strain is rapidly cleared from the skin inoculation site prior to dissemination. The rapid clearance of Δp66 bacteria is not due to inherent defects in multiple properties that might affect infectivity: bacterial outer membrane integrity, motility, chemotactic response, or nutrient acquisition. This led us to the hypothesis that P66 has a role in mouse cathelicidin-related antimicrobial peptide (mCRAMP; a major skin antimicrobial peptide) and/or neutrophil evasion. Neither wild-type (WT) nor Δp66 B. burgdorferi was susceptible to mCRAMP. To examine the role of neutrophil evasion, we administered neutrophil-depleting antibody anti-Ly6G (1A8) to C3H/HeN mice and subsequently monitored the course of B. burgdorferi infection. Δp66 mutants were unable to establish infection in neutrophil-depleted mice, suggesting that the important role of P66 during early infection is through another mechanism. Neutrophil depletion did not affect WT B. burgdorferi bacterial burdens in the skin (inoculation site), ear, heart, or tibiotarsal joint at early time points postinoculation. This was unexpected given that prior in vitro studies demonstrated neutrophils phagocytose and kill B. burgdorferi These data, together with our previous work, suggest that despite the in vitro ability of host innate defenses to kill B. burgdorferi, individual innate immune mechanisms have limited contributions to controlling early B. burgdorferi infection in the laboratory model used.
| S-EPMC5778354 | biostudies-literature
Project description:The host immune response to infection is a well-coordinated system of innate and adaptive immune cells working in concert to prevent the colonization and dissemination of a pathogen. While this typically leads to a beneficial outcome and the suppression of disease pathogenesis, the Lyme borreliosis bacterium, Borrelia burgdorferi sensu lato, can elicit an immune profile that leads to a deleterious state. As B. burgdorferi s.l. produces no known toxins, it is suggested that the immune and inflammatory response of the host are responsible for the manifestation of symptoms, including flu-like symptoms, musculoskeletal pain, and cognitive disorders. The past several years has seen a substantial increase in the use of microarray and sequencing technologies to investigate the transcriptome response induced by B. burgdorferi s.l., thus enabling researchers to identify key factors and pathways underlying the pathophysiology of Lyme borreliosis. In this review we present the major host transcriptional outcomes induced by the bacterium across several studies and discuss the overarching theme of the host inflammatory and immune response, and how it influences the pathology of Lyme borreliosis.
| S-EPMC8127729 | biostudies-literature
Project description:We examined global changes in protein expression in the B31 strain of Borrelia burgdorferi, in response to two environmental cues (pH and temperature) chosen for their reported similarity to those encountered at different stages of the organism's life cycle. Multidimensional nano-liquid chromatographic separations coupled with tandem mass spectrometry were used to examine the array of proteins (i.e., the proteome) of B. burgdorferi for different pH and temperature culture conditions. Changes in pH and temperature elicited in vitro adaptations of this spirochete known to cause Lyme disease and led to alterations in protein expression that are associated with increased microbial pathogenesis. We identified 1,031 proteins that represent 59% of the annotated genome of B. burgdorferi and elucidated a core proteome of 414 proteins that were present in all environmental conditions investigated. Observed changes in protein abundances indicated varied replicon usage, as well as proteome functional distributions between the in vitro cell culture conditions. Surprisingly, the pH and temperature conditions that mimicked B. burgdorferi residing in the gut of a fed tick showed a marked reduction in protein diversity. Additionally, the results provide us with leading candidates for exploring how B. burgdorferi adapts to and is able to survive in a wide variety of environmental conditions and lay a foundation for planned in situ studies of B. burgdorferi isolated from the tick midgut and infected animals.
| S-EPMC2970547 | biostudies-literature
Project description:The Lyme disease spirochete Borrelia (Borreliella) burgdorferi must tolerate nutrient stress to persist in the tick phase of its enzootic life cycle. We previously found that the stringent response mediated by RelBbu globally regulates gene expression to facilitate persistence in the tick vector. Here, we show that RelBbu regulates the expression of a swath of small RNAs (sRNA), affecting 36% of previously identified sRNAs in B. burgdorferi. This is the first sRNA regulatory mechanism identified in any spirochete. Threefold more sRNAs were RelBbu-upregulated than downregulated during nutrient stress and included antisense, intergenic and 5' untranslated region sRNAs. RelBbu-regulated sRNAs associated with genes known to be important for host infection (bosR and dhhp) as well as persistence in the tick (glpF and hk1) were identified, suggesting potential mechanisms for post-transcriptional regulation of gene expression.
| S-EPMC6041397 | biostudies-literature
Project description:The cellular attachment and entry of pathogenic microorganisms can be facilitated by the expression of microbial adhesins that bind fibronectin. We have previously described a Borrelia burgdorferi gene, bbk32, that encodes a 47-kDa fibronectin-binding protein. In this study, the ligand-binding region of BBK32 from B. burgdorferi isolate B31 was localized to 32 amino acids. The bbk32 gene was cloned and sequenced from three additional B. burgdorferi isolates representing different genospecies of B. burgdorferi sensu lato. All four bbk32 genes encoded proteins having fibronectin-binding activity when expressed in Escherichia coli, and the deduced proteins shared 81 to 91% amino acid sequence identity within the ligand-binding domain. In addition, the ligand-binding region of BBK32 was found to share sequence homology with a fibronectin-binding peptide defined for protein F1 of Streptococcus pyogenes. The structural and functional similarity between the ligand-binding region of BBK32 and the UR region of protein F1 suggests a common mechanism of cellular adhesion and entry for B. burgdorferi and S. pyogenes.
| S-EPMC98480 | biostudies-literature