Transcription profiling of human S. aureus-exposed macrophages
ABSTRACT: It 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. In order to examine the effect of S. aureus on the macrophage transcriptome, we performed microarray expression analysis on human monocyte-derived macrophages treated with S. aureus. Experiment Overall Design: Human monocyte-derived macrophages (hMDMs) were separated from fractions of peripheral blood mononuclear cells (PBMCs) obtained from the blood of healthy donors. Control and S. aureus-exposed macrophages were incubated at 37C for 8, 24, or 48 hours
Project description:It 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. In order to examine the effect of S. aureus on the macrophage transcriptome, we performed microarray expression analysis on human monocyte-derived macrophages treated with S. aureus. Keywords: time course Overall design: Human monocyte-derived macrophages (hMDMs) were separated from fractions of peripheral blood mononuclear cells (PBMCs) obtained from the blood of healthy donors. Control and S. aureus-exposed macrophages were incubated at 37C for 8, 24, or 48 hours
Project description:miR-182 over-expression enhances macrophage resistance to intracellular pathogens. This transcriptional profiling experiment was conducted to identify the basis for protection. Primary human alveolar macrophage-like monocyte derived macrophages were transfected with miR-182 mimic or control RNA, then infected overnight with F. tularensis Live Vaccine Strain at MOI-10 or mock infected.
Project description:Toll-like receptors (TLRs) are essential sensors in innate immunity and among the first to detect invading pathogens. Many studies of TLR responses have focused on the intracellular signaling events that occur upon receptor stimulation. However, proteins released from the cell play a key role in cell-cell communication during an immune response. We have used mass spectrometry-based proteomic methods to investigate both the intracellular and extracellular responses of macrophages stimulated with individual TLR2, TLR4, and TLR7 ligands and whole pathogens. We performed global quantitative analyses of the mouse macrophage proteome and secretome using stable isotope labeling with amino acids and high-resolution mass spectrometry.
Project description:microRNAs are small non-coding RNAs that regulate gene expression at a post-translational level, and play a crucial role in the development of cells of the immune system. Macrophages are essential for generating inflammatory reactions upon tissue damage and encountering of invading pathogens, yet modulation of their immune responses is critical for maintaining tissue homeostasis. Macrophages can present different phenotypes, depending on the cytokine environment they encounter in the affected tissues. In this study, we have identified expression signatures of miRNAs that are differentially regulated during maturation of monocytes and polarization of macrophages by cytokines. We present a comprehensive characterization of miRNA expression in human monocytes and M1, M2a and M2c polarized macrophages, using next-generation Sequencing by Oligonucleotide Ligation and Detection (SOLiD). We have analyzed freshly isolated human monocytes and 5 day monocyte-derived macrophages unstimulated, or stimulated with IFNgamma+TNFalpha (M1), IL-4 (M2a) or IL-10 (M2c).
Project description:Understanding the molecular defense mechanism of macrophages and identifying their effector molecules against malarial parasites may provide important clues for the discovery of new therapies. To analyze the immunological responses of malarial parasite-induced macrophages, we used DNA microarray technology to examine the gene profile of differentiated macrophages phagocytizing Plasmodium falciparum-parasitized erythrocytes (iRBCs). The transcriptional gene profile of macrophages in response to iRBCs represented 168 down-regulated genes, which were mainly involved in the cellular immune response, and 216 upregulated genes, which were involved in cellular proteolysis, growth, and adhesion. Importantly, the specific upregulation of β-defensin 130 (DEFB130) in these macrophages suggested a possible role for DEFB130 in malarial parasite elimination. Strikingly, differentiated macrophages phagocytizing iRBCs exhibited an increase in intracellular DEFB130 levels and DEFB130 appeared to accumulate at the site of iRBC engulfment. Furthermore, DEFB130 synthetic peptide exhibited a modest toxic effect on P. falciparum in vitro and P. yoelii in vivo, unlike scrambled DEFB130 peptide, which showed no antiplasmodial activity. Our data broaden our knowledge of the immunological response of macrophages to iRBCs and shed light on a new target for therapeutic intervention. Overall design: Human monocyte-derived macrophages were co-cultured with plasmodium falciparum-infected erythrocytes (iRBCs), saponin-treated iRBCs, or non-infected erythrocytes (RBCs).
Project description:The S. aureus transcriptome was assessed for strains Newman (wild type) and Newman (sarZ) during both exponential (2hr) and early stationary (5hr) cell growth. The S. aureus transcriptome was assessed for strains Newman (wild type) and Newman (sarZ) during both exponential (2hr) and early stationary (5hr) cell growth. The experiment was performed in duplicate or triplicate, and RNA samples labeled/hybridized to independent commercially available Affymetrix GeneChips
Project description:Transcriptional profile of human monocyte-derived macrophages infected with L.(V.)panamensis was compared to the profile of uninfected cells to delineate transcriptional activation triggered by the infection. two condition experiment: human monocyte-derived macrophages infected with L.(V.)panamensis. 6-5 donors per time point. 3 times point. 1-3 replicates per donor-time point.
Project description:Nitric oxide (NO) produced by macrophages (MØs) is toxic to both host tissues and invading pathogens and its regulation is therefore essential to suppress host cytotoxicity. MØ arginase 1 (Arg1) inhibits NO production by competing with NO synthases for arginine, the common substrate of NO synthases and arginases. Two signal transduction pathways control Arg1 expression in MØs. First, a MyD88-dependent pathway induces Arg1 in intracellular infections, while a second Stat6-dependent pathway is required for Arg1 expression in alternativelyactivated MØs. We found that mycobacteria-infected MØs produce soluble factors that induce Arg1 in an autocrine-paracrine manner via Stat3. We identify these factors as IL-6, IL-10 and GCSF. We further establish that Arg1 expression is controlled by the MyD88-dependent production of IL-6, IL-10 and G-CSF rather than cell intrinsic MyD88 signaling to Arg1. Our data reveal the MyD88-dependent pathway of Arg1induction following BCG infection requires Stat3 activation and may result in the development of an immunosuppressive niche in granulomas due to the induced Arg1 production in surrounding uninfected MØs We used microarrays to perform genome wide expression analysis in mycobacteria-infected macrophages from C57Bl/6 WT and MyD88-knockout mice.
Project description:Staphylococcus aureus is a Gram-positive human pathogen causing a variety of human diseases in both hospital and community settings. This bacterium is so closely associated with prophages that it is rare to find S. aureus isolates without prophages. Two phages are known to be important for staphylococcal virulence: the beta-hemolysin (hlb) converting phage and the Panton-Valentine Leukocidin (PVL) converting phage. The hlb-converting phage is found in more than 90% of clinical isolates of S. aureus. This phage produces exotoxins and immune modulatory molecules, which inhibit human innate immune responses. The PVL-converting phage produces the two-component exotoxin PVL, which can kill human leucocytes. This phage is wide-spread among community-associated methicillin resistant S. aureus (CA-MRSA). It also shows strong association with soft tissue infections and necrotizing pneumonia. Several lines of evidence suggest that staphylococcal prophages increase bacterial virulence not only by providing virulence factors but also by altering bacterial gene expression: 1) Transposon insertion into prophage regulatory genes, but not into the genes of virulence factors, reduced S. aureus killing of Caenorhabditis elegans.; 2) Although the toxins and immune modulatory molecules encoded by the hlb- converting phages do not function in the murine system, deletion of ϕNM3, the hlb-converting phage in S. aureus Newman, reduced staphylococcal virulence in the murine abscess formation model. 3) In a preliminary microarray experiment, prophages in S. aureus Newman altered the expression of more than 300 genes. In this research proposal, using microarray and high-throughput quantitative RT-PCR (qRT-PCR) technologies, we will identify the effects of the two important staphylococcal phages on the gene expression of S. aureus in both in vitro and in vivo conditions. This project is intended to be completed within one year. All the data – microarray, qRT-PCR and all the primer sequences- will be made available to public 6 month after completion. Data from this project will help us to understand the role of prophages in the S. aureus pathogenesis and can lead to development of a strategy to interfere with the pathogenesis process. Overall design: Following strains were grown in TSA broth: Staphylococcus aureus USA300 (reference) Staphylococcus aureus USA300 with deletion of ϕSa2usa (Query) Staphylococcus aureus USA300 with deletion of ϕSa3usa (Query) Staphylococcus aureus USA300 Prophage-free mutant (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa2mw (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa3usa (Query) strain: Staphylococcus aureus USA300 Prophage-free mutant lysogenized with both ϕSa2mw and ϕSa3usa (Query) RNA samples were harvested at early log, midlog and stationary phase.Samples were hybridized on aminosilane coated slides with 70-mer oligos.