Project description:The emergence of fully antimicrobial resistant Neisseria gonorrhoeae has led global public health agencies to identify a critical need for next generation anti-gonococcal pharmaceuticals. The development and success of these compounds will rely upon valid pre-clinical models of gonorrhoeae infection. We recently developed and reported the first model of upper genital tract gonococcal infection. During initial characterization, we observed significant reproductive cycle-based variation in infection outcome. When uterine infection occurred in the diestrus phase, there was significantly greater pathology than during estrus phase. The aim of this study was to evaluate transcriptional profiles of infected uterine tissue from mice in either estrus or diestrus phase in order to elucidate possible mechanisms for these differences. Genes and biological pathways with phase-independent induction during infection showed a chemokine dominant cytokine response to Neisseria gonorrhoeae. Despite general induction being phase-independent, this common anti-gonococcal response demonstrated greater induction during diestrus phase infection. Greater activity of granulocyte adhesion and diapedesis regulators during diestrus infection, particularly in chemokines and diapedesis regulators, was also shown. In addition to a greater induction of the common anti-gonococcal response, Gene Set Enrichment Analysis (GSEA) identified a diestrus-specific induction of type-1 interferon signaling pathways. This transcriptional analysis of murine uterine gonococcal infection during distinct points in the natural reproductive cycle provided evidence for a common anti-gonococcal response characterized by significant induction of granulocyte chemokine expression and high proinflammatory mediators. The basic biology of this host response to N. gonorrhoeae in estrus and diestrus is similar at the pathway level, but varies drastically in magnitude. Overlaying this, we observed type-1 interferon induction specifically in diestrus infection where greater pathology is observed. This supports recent work suggesting this pathway has a significant, possibly host-detrimental, function in gonococcal infection. Together these findings lay the groundwork for further examination of the role of interferons in gonococcal infection. Additionally, this work enables the implementation of the diestrus uterine infection model using the newly characterized host response as a marker of pathology and its prevention as a correlate of candidate vaccine efficacy and ability to protect against the devastating consequences of N. gonorrhoeae-associated sequelae. Murine microarrays were used to examine transcriptional differences underlying significantly different phenotypes associated with uterine N. gonorrhoeae infection in the estrus versus diestrus phases of the natural reproductive cycle.
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.
Project description:The human-restricted pathogenNeisseria gonorrhoeaeascends into the upper female reproductive tract to cause damaging inflammation within the Fallopian tubes (salpingitis) and pelvic inflammatory disease (PID), increasing the risk of infertility and life-threatening ectopic pregnancy. The loss of ciliated cells from the epithelium is thought to be both a consequence of inflammation and a cause of the associated adverse sequelae. However, the links between infection, inflammation, and ciliated cell extrusion remain unresolved. With the use ofex vivocultures of human Fallopian tube paired with RNA sequencing we defined the tissue response to gonococcal challenge, identifying cytokine, chemokine, cell adhesion, and apoptosis related transcripts not previously recognized as potentiators of gonococcal PID. Unexpectedly, the cytokine IL-17C was one of the most highly induced genes. Yet, this cytokine has no previous association with gonococcal disease nor any sexually transmitted infection and thus it was selected for further characterization in our model. We show that human Fallopian tubes express the IL-17C receptor (IL-17RE) on the epithelial surface and that treatment with purified IL-17C induces pro-inflammatory cytokine secretion in addition to sloughing of the epithelium and generalized tissue damage. These results demonstrate a previously unrecognized but critical role of IL-17C in the damaging inflammation induced by gonococci in a human explant model of PID.
Project description:The immune response to Neisseria gonorrhoeae is poorly understood, but its extensive antigenic variability and resistance to complement are thought to allow it to evade destruction by the host’s immune defenses. We propose that N. gonorrhoeae also avoids inducing protective immune responses in the first place. We previously found that N. gonorrhoeae induces IL-17-dependent innate responses in mice and suppresses Th1/Th2-dependent adaptive responses in murine cells in vitro through the induction of TGF-β. In this study using a murine model of vaginal gonococcal infection, mice treated with anti-TGF-β antibody during primary infection showed accelerated clearance of N. gonorrhoeae with incipient development of Th1 and Th2 responses and diminished Th17 responses in genital tract tissue. Upon secondary reinfection, mice that had been treated with anti-TGF-β during primary infection showed anamnestic recall of both Th1 and Th2 responses, with the development of anti-gonococcal antibodies in serum and secretions, and enhanced resistance to reinfection. In knockout mouse strains defective in Th1 or Th2 responses, accelerated clearance of primary infection due to anti-TGF-β treatment was dependent on Th1 but not Th2 activity, whereas resistance to secondary infection resulting from anti-TGF-β treatment during primary infection was due to both Th1- and Th2-dependent memory responses. We propose that N. gonorrhoeae proactively elicits Th-17-driven innate responses that it can resist, and suppresses Th1/Th2-driven specific adaptive immunity that would protect the host. Blockade of TGF-β reverses this pattern of host immune responsiveness and facilitates the emergence of protective anti-gonococcal immunity.
2011-03-22 | GSE28055 | GEO
Project description:Complete Genome Sequences of Seven Neisseria gonorrhoeae Clinical Isolates from Mucosal and Disseminated Gonococcal Infections
Project description:Maintenance of an anaerobic respiratory system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobic and anaerobically grown cells. We found that the anaerobic stimulon in gonococci was large, and that 198 chromosomal genes were found to be differentially expressed. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Secondary analysis of genes found to be differentially expressed by RNA-seq using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. Several novel factors were identified to be anaerobically regulated, as well as a large number of hypothetical proteins were induced. Two biological replicates of cells grown aerobically or anaerobically with nitrite were analyzed, for a total of four samples subject to SOLiD RNA sequencing.
Project description:The immune response to Neisseria gonorrhoeae is poorly understood, but its extensive antigenic variability and resistance to complement are thought to allow it to evade destruction by the host’s immune defenses. We propose that N. gonorrhoeae also avoids inducing protective immune responses in the first place. We previously found that N. gonorrhoeae induces IL-17-dependent innate responses in mice and suppresses Th1/Th2-dependent adaptive responses in murine cells in vitro through the induction of TGF-β. In this study using a murine model of vaginal gonococcal infection, mice treated with anti-TGF-β antibody during primary infection showed accelerated clearance of N. gonorrhoeae with incipient development of Th1 and Th2 responses and diminished Th17 responses in genital tract tissue. Upon secondary reinfection, mice that had been treated with anti-TGF-β during primary infection showed anamnestic recall of both Th1 and Th2 responses, with the development of anti-gonococcal antibodies in serum and secretions, and enhanced resistance to reinfection. In knockout mouse strains defective in Th1 or Th2 responses, accelerated clearance of primary infection due to anti-TGF-β treatment was dependent on Th1 but not Th2 activity, whereas resistance to secondary infection resulting from anti-TGF-β treatment during primary infection was due to both Th1- and Th2-dependent memory responses. We propose that N. gonorrhoeae proactively elicits Th-17-driven innate responses that it can resist, and suppresses Th1/Th2-driven specific adaptive immunity that would protect the host. Blockade of TGF-β reverses this pattern of host immune responsiveness and facilitates the emergence of protective anti-gonococcal immunity. We only did microarray assay for wild-type mice with or without anti-TGF-b treatment. Experiment A: Totally there are three groups: Sham-infected mice without treatment; N.gonorrhoeae-infected with control IgG treatment; N.gonorrhoeae-infected with anti-TGF-β treatment. For each group, two mice were studied. Total RNA from mouse vagina were analysed. Experiment B: Totally there are three groups: Sham-reinfected mice without treatment; N.gonorrhoeae-reinfected with control IgG treatment; N.gonorrhoeae-reinfected with anti-TGF-β treatment. For each group, two mice were studied. Total RNA from mouse vagina were analysed.
Project description:We collected infected wheat leaf material at up to nine time points per Z. tritici isolate and conducted confocal microscopy analyses to select samples for RNA extraction and transcriptome sequencing based on the morphological infection stage. Thereby, we generated stage-specific RNA-seq datasets corresponding to the four core infection stages allowing us to compare the isolate-specific expression profiles at the same developmental stage of infection. Our final dataset comprises four stage-specific transcriptomes per isolate with two biological replicates per sample. Comparative transcriptome analyses reveal that the expression phenotypes of the three isolates differ significantly.
Project description:Candida albicans is exposed to a different host environment during different site of infection. Thus, different virulence factors may be active during differenttypes of infection. However,little is known about the C. albicans genes that are required for the initiation and maintenance of candidiasis. To identify potential virulence factors relevant to hematogenously disseminated candidiasis, we determined the transcriptional response of C. albicans to human umbilical vein endothelial cells (HUVECs) in vitro. Keywords: cell interaction Two different Candida albicans strains, CAI4-URA and a clinical isolate 36082, were used to identify the transcriptional response of C. albicans to HUVECs. The strains were incubated with either the HUVECs or bare plastic for 45, 90, and 180 min. C. albicans RNA was extracted and the transcriptional profile of these organisms was analyzed using the C. albicans oligonucleotide microarray. The transcriptional response to HUVECs was compared to that to bare plastic as a control condition. Each time point contains six biological replicates, three of which are from each C. albicans strain.