Chlamydia trachomatis serovariants are responsible for either Trachoma, the leading cause of infectious blindness or sexually transmitted disease, wherein the endocervix is the most frequently infected site in women. Disease caused by Chlamydia typically involves chronic inflammation and scarring. Recent work with a live-attenuated A2497 plasmid deficient vaccine strain (A2497-) demonstrated protection in nonhuman primates against trachoma and a lack of measurable ocular pathology in A2497- infected monkeys. We therefore performed host cell transcriptome analysis of Hela cells infected with A2497 plasmid-containing (A2497) and A2497- Chlamydia over time. Our results indicate that relative to wild type A2497, the A2497- variant illicits a transcriptome response indicative of lowered inflammation response a delayed apoptosis response, a reduction in immune cell recruitement cytokine expression and a reduction in genes involved in cell proliferation and or fibrosis-like activities. The data provided here suggests a model that may explain how plasmid deficient chlamydia may provide an immuno-protective response without the pathology normally seen with plasmid-containing bacteria.
Transcriptional profiling of human epithelial cells infected with plasmid-bearing and plasmid-deficient Chlamydia trachomatis.
Disease, Cell line
View SamplesInterleukin-17 (IL-17) is essential in host defense against extracellular bacteria and fungi, especially at mucosal sites, but it also contributes significantly to inflammatory and autoimmune disease pathologies. Binding of IL-17 to its receptor leads to recruitment of the adaptor protein CIKS/Act1 via heterotypic association of their respective SEFIR domains and to activation of the transcription factor NF-kB; it is not known whether CIKS and/or NF-kB are required for all gene induction events. Here we report that CIKS is essential for all IL-17 induced immediate-early genes in primary mouse embryo fibroblasts, while NF-kB is profoundly involved. We also identify a novel sub-domain in the N-terminus of CIKS that is essential for IL-17-mediated NF-kB activation. This domain is both necessary and sufficient for the interaction between CIKS and TRAF6, an adaptor required for NF-kB activation. The ability of decoy peptides to block this interaction may provide a new therapeutic strategy for intervention in IL-17-driven autoimmune and inflammatory diseases.
IL-17-induced NF-kappaB activation via CIKS/Act1: physiologic significance and signaling mechanisms.
Specimen part, Treatment
View SamplesResistance to amebiasis is associated with a polymorphism in the leptin receptor. Previous studies demonstrated that humans with the ancestral Q223 leptin receptor allele were nearly four times less likely to be infected with Entamoeba histolytica than those carrying the mutant R223 allele. We hypothesized that the Q223 allele protected against E. histolytica via STAT3-mediated transcription of genes required for mucosal immunity. To test this, mice containing the humanized LEPR Q or R allele at codon 223 were intracecally infected with E. histolytica. Susceptibility to amebiasis was assessed, and cecal tissues analyzed for changes in gene expression. By 72 h post-challenge all Q223 mice had cleared E. histolytica, whereas 39% of 223R mice were infected. 37 genes were differentially expressed in response to infection at 72 h, including pro-inflammatory genes (CXCL2, calprotectin (S100A8/9), Pla2g7, Itbg2, and MMP9) and functions pertaining to the movement and activity of immune cells. A comparison at 12 h post-challenge of infected Q223 vs. R223 mice identified a subset of differentially-expressed genes, many of which were closely linked to leptin signaling. Further analyses indicated that the Q223 gene expression pattern was consistent with a suppressed apoptotic response to infection, while 223R showed increased cellular proliferation and recruitment. These studies are the first to illuminate the downstream effects of leptin receptor polymorphisms on intestinal infection by E. histolytica. As such, they are important for the insight that they provide to this previously uncharacterized mechanism of mucosal immunity. Resistance to amebiasis is associated with a polymorphism in the leptin receptor. Previous studies demonstrated that humans with the ancestral Q223 leptin receptor allele were nearly four times less likely to be infected with Entamoeba histolytica than those carrying the mutant R223 allele. We hypothesized that the Q223 allele protected against E. histolytica via STAT3-mediated transcription of genes required for mucosal immunity. To test this, mice containing the humanized LEPR Q or R allele at codon 223 were intracecally infected with E. histolytica. Susceptibility to amebiasis was assessed, and cecal tissues analyzed for changes in gene expression. By 72 h post-challenge all Q223 mice had cleared E. histolytica, whereas 39% of 223R mice were infected. 37 genes were differentially expressed in response to infection at 72 h, including pro-inflammatory genes (CXCL2, calprotectin (S100A8/9), Pla2g7, Itbg2, and MMP9) and functions pertaining to the movement and activity of immune cells. A comparison at 12 h post-challenge of infected Q223 vs. R223 mice identified a subset of differentially-expressed genes, many of which were closely linked to leptin signaling. Further analyses indicated that the Q223 gene expression pattern was consistent with a suppressed apoptotic response to infection, while 223R showed increased cellular proliferation and recruitment. These studies are the first to illuminate the downstream effects of leptin receptor polymorphisms on intestinal infection by E. histolytica. As such, they are important for the insight that they provide to this previously uncharacterized mechanism of mucosal immunity.
Effect of the leptin receptor Q223R polymorphism on the host transcriptome following infection with Entamoeba histolytica.
Specimen part, Time
View SamplesA delay in the mammalian inflammatory response is a prominent feature of infection with Yersinia pestis, the agent of bubonic and pneumonic plague. Y. pestis factors have been identified that either do not stimulate a normal inflammatory response, or actively suppress it. Prominent among these are components of the Type III secretion system that is encoded on the Yersinia virulence plasmid (pYV). We used a rat model of bubonic plague to characterize the kinetics and extent of the mammalian transcriptomic response to infection with wild-type or pYV-negative Y. pestis in the draining lymph node. Remarkably, dissemination and multiplication of wild-type Y. pestis during the bubonic stage of disease did not induce any detectable gene expression response by host lymph node cells. This was followed, however, by an extensive transcriptomic response, including upregulation of several cytokine, chemokine, and other immune response genes, after systemic spread during septicemic plague. Matched lymph node samples used for histopathology and extracellular cytokine measurements, combined with the microarray data set, broadly outlined the mammalian immune response to Y. pestis and how it is influenced by pYV-encoded factors. The results indicate that both WT and pYV Y. pestis induce primarily a Th17 response, and not a Th1 or Th2 response. In the absence of pYV, a sustained recruitment of polymorphonuclear leukocytes, the major Th17 effector cell, to the lymph node resulted in clearance of infection. Thus, the ability to counteract a Th17- driven PMN response in the lymph node appears to be a major function of the Y. pestis virulence plasmid. In contrast, classic markers of the proinflammatory response and macrophage activation, such as TNF- and IFN-, were not induced at all by pYV Y. pestis, and appeared only late in infection with WT Y. pestis.
Transcriptomic and innate immune responses to Yersinia pestis in the lymph node during bubonic plague.
Sex, Specimen part, Treatment, Time
View SamplesCommunity-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are often caused by strains encoding Panton-Valentine leukocidin (PVL). PVL can cause lysis of polymorphonuclear leukocytes (PMNs) and other myeloid cells in vitro, a function considered widely as the primary means by which PVL might contribute to disease. However, at sublytic concentrations PVL can function as a PMN agonist. To better understand this phenomenon, we investigated the ability of PVL to alter human PMN function. PMNs exposed to PVL had enhanced capacity to produce superoxide in response to N-formyl-methionyl-leucyl-phenylalanine (fMLF), but unlike priming by lipopolysaccharide, this response did not require Toll-like receptor signal transduction. On the other hand, there was subcellular redistribution of NADPH oxidase components in PMNs following exposure of these cells to PVL - a finding consistent with priming. Priming of PMNs with other agonists such as IL-8 or GM-CSF altered the ability PVL to cause formation of pores in the plasma membranes of these cells. Microarray analysis revealed significant changes in the human PMN transcriptome following exposure to PVL, including up-regulation of molecules that regulate the inflammatory response. Consistent with the microarray data, mediators of the inflammatory response were released from PMNs after stimulation with PVL. We conclude that exposure of human PMNs to sublytic concentrations of PVL elicits a proinflammatory response that is regulated in part at the level of gene expression. We propose that PVL-mediated priming of PMNs enhances the host innate immune response.
Sublytic concentrations of Staphylococcus aureus Panton-Valentine leukocidin alter human PMN gene expression and enhance bactericidal capacity.
Specimen part
View SamplesIt is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis.
Phagocytosis of Staphylococcus aureus by macrophages exerts cytoprotective effects manifested by the upregulation of antiapoptotic factors.
No sample metadata fields
View SamplesChronic hepatitis C virus (HCV) infection is now routinely treated with interferon (IFN)-free regimens composed of directly acting antiviral (DAA) agents. Changes in hepatic and peripheral innate and adaptive immune function during DAA therapy associate with achieving a sustained virologic response (SVR). The present study explored the impact of cirrhosis on host endogenous interferon pathways during DAA therapy. mRNA and micro-RNA (miRNA) expression profiling was performed on paired pre- and end-of-treatment (EOT) liver biopsies from subjects treated with a 2 DAA regimen (sofosbuvir/ledipasvir [SOF/LDV]) for 12 weeks (n=4, 3 with cirrhosis) or a 3 DAA regimen (SOF/LDV with GS-9669 or GS-9451) for 6 weeks (n=6, 0 with cirrhosis). Nine of ten subjects achieved SVR, with one relapse in the GS-9669 treatment arm (ISHAK fibrosis 4). Hepatic interferon-stimulated gene expression was down-regulated in the liver of all subjects, with no observable impact of cirrhosis or duration of treatment. Hepatic down-regulation of all type-III IFNs was observed (IFNL1, IFNL2, IFNL3, IFNL4-G), while IFNA2 expression, undetectable in all subjects pre-treatment, was detected in 3 of 9 subjects at EOT (all 3 achieved SVR). Only the subject who relapsed had detectable IFNL4-G expression in EOT liver. No change in IFNB1, IFNG, or IFNA5 expression was observed, and expression of other type-I IFNs (IFNA1, IFNA4, IFNA5, IFNA6, IFNA8, IFNA16, IFNA17) was not detected pre- or post-treatment. While expression of multiple miRNAs changed in liver tissue over the course of treatment, most miRNAs previously associated with HCV replication, innate interferon signaling, and hepatic fibrosis did not change significantly. Conclusions: Changes in the host IFN-response during DAA therapy associate with favorable treatment outcome regardless of composition and duration of therapy or extent of hepatic fibrosis.
Achieving sustained virologic response after interferon-free hepatitis C virus treatment correlates with hepatic interferon gene expression changes independent of cirrhosis.
No sample metadata fields
View SamplesIn this manuscript, we present a more extensive analysis of inflammatory suppression mediated by L. plantarum at the respiratory tract. Via full genome microarray of whole lung tissue, we have generated an extensive list of soluble proinflammatory mediators that are expressed in response to PVM infection and we identify those mediators that are suppressed and also those that are not suppressed in response to L. plantarum priming. We focused further study on three specific virus-induced soluble mediators that are differentially expressed and that serve as specific biomarkers for Lactobacillus-mediated survival in response to acute respiratory virus infection. Among several novel directions, we use these biomarker cytokines to explore Lactobacillus-mediated actions at the respiratory tract that are unique and distinct from those taking place at gastrointestinal mucosa.
Immunobiotic Lactobacillus administered post-exposure averts the lethal sequelae of respiratory virus infection.
Specimen part
View SamplesPolymorphonuclear leukocytes (PMN) from patients with chronic granulomatous disease (CGD) fail to produce microbicidal concentrations of reactive oxygen species due to mutations in NOX2. Patients with CGD suffer from severe, life-threatening infections and inflammatory complications. Granulibacter bethesdensis is an emerging Gram-negative pathogen in CGD that resists killing by CGD PMN and inhibits PMN apoptosis through unknown mechanisms. Microarray analysis was used to study mRNA expression in normal and CGD PMN during incubation with G. bethesdensis and, simultaneously, in G. bethesdensis with normal and CGD PMN. We detected upregulation of anti-apoptotic genes (e.g., XIAP, GADD45B) and downregulation of pro-apoptotic genes (e.g., CASP8, APAF1) in infected PMN. Transcript and protein levels of inflammation and immunity-related genes were also altered. Upon interaction with PMN, G. bethesdensis altered expression of ROS-resistance genes in the presence of normal but not CGD PMN. Bacterial stress response genes, including ClpB, increased during phagocytosis by both normal and CGD PMN demonstrating responses to oxygen-independent PMN antimicrobial systems. Antisense knock down demonstrated that ClpB is dispensable for extracellular growth but is essential for bacterial resistance to both normal and CGD PMN. Metabolic adaptation of Granulibacter growth in PMN included upregulation of pyruvate dehydrogenase. Pharmacologic inhibition of pyruvate dehydrogenase by triphenylbismuthdichloride was lethal to Granulibacter. This study expands knowledge of microbial pathogenesis by Granulibacter in cells from permissive (CGD) and non-permissive (normal) hosts and identifies potentially druggable microbial factors, such as pyruvate dehydrogenase and ClpB, to help combat this antibiotic-resistant pathogen.
Simultaneous Host-Pathogen Transcriptome Analysis during Granulibacter bethesdensis Infection of Neutrophils from Healthy Subjects and Patients with Chronic Granulomatous Disease.
Specimen part, Disease, Disease stage, Time
View SamplesThymic stromal lymphopoietin (TSLP) is a type I cytokine that plays a central role in induction of allergic inflammatory responses. Its principal targets have been reported to be dendritic cells and / or CD4 T cells; epithelial cells are a principal source. We report here the development of a reporter mouse (TSLP-ZsG) in which a ZsGreen (ZsG)-encoding construct has been inserted by recombineering into a bacterial artificial chromosome (BAC) immediately at the translation initiating ATG of TSLP. The expression of ZsG by mice transgenic for the recombinant BAC appears to be a faithful surrogate for TSLP expression, particularly in keratinocytes and medullary thymic epithelials cells (mTECs). A comparison of gene expression in ZsG expressing and ZsG negative mTECs and cortical thymic epithelial cells, which are all ZsG negative, revealed that all three populations can be distinguished from one another. In particular ZsG (and TSLP) expressing mTECs and ZsG- mTECs are separable populations based on gene expression profiling. Little or no expression of ZsG is observed in bone marrow-derived mast cells or basophils or in CD45+ cells infiltrating TSLP/ZsG-expressing skin. Using the TSLP-ZsG reporter mouse, we show that TNFa and IL-4/IL-13 are potent inducers of TSLP expression by keratinocytes and that local activation of Th2 and Th1 cells induces keratinocyte TSLP expression. We suggest that the capacity of TSLP to both induce Th2 differentiation and to be induced by activated Th2 cells raises the possibility that TSLP may be involved in a positive feedback loop to enhance allergic inflammatory conditions.
TSLP expression: analysis with a ZsGreen TSLP reporter mouse.
Specimen part, Treatment
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