Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Immunomodulatory activities of RNA species derived from commensal and pathogenic bacteria
Download
index.pdf
Date
2017
Author
Kayaoğlu, Başak
Metadata
Show full item record
Item Usage Stats
229
views
77
downloads
Cite This
Bacterial RNAs are recognized by various types of immune sensors. Here, we aimed to investigate the differential immune activation mediated by RNAs purified from commensal or pathogenic bacteria. For this, total RNAs and/or individual ribosomal RNAs (5S, 16S and 23S) were isolated from two commensal bacteria, Lactobacillus salivarious and Lactobacillus fermentum and two pathogens, Listeria monocytogenes, and Streptococcus pyogenes. Bacterial RNA species isolated from pathogens induced stronger pro-inflammatory cytokine production in human peripheral blood mononuclear cells (hPBMCs) and triggered activation of NF-κB/AP-1 in HEK-Blue cells expressing TLR3 or TLR7 receptors. Conversely, significant amount of type I IFN production was induced following delivery of commensal RNAs (total RNAs and 23S rRNAs), but not pathogenic RNAs, to cytosol. Moreover dsRNA content of commensal derived RNAs was shown to be higher than pathogen derived RNAs. These findings suggest the involvement of cytosolic dsRNA sensors like RIG-I and MDA-5 in commensal but not pathogen derived RNA recognition. Data further showed that the major type I IFN producing cells responding to commensal RNAs were monocytes but not plasmacytoid dendritic cells (pDCs). Interferogenic activity of commensal origin RNAs was also tested in human monocyte cell line THP-1, confirming the results obtained using primary monocytes. In conclusion, our data implicate that RNAs from commensals and pathogens are recognized differentially by the immune system to initiate either a type I interferon or a pro-inflammatory cytokine dominated immune response.
Subject Keywords
RNA.
,
Immunology.
,
Commensalism.
,
Pathogenic bacteria.
URI
http://etd.lib.metu.edu.tr/upload/12620704/index.pdf
https://hdl.handle.net/11511/26237
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Differential activation of immune cells by commensal versus pathogen-derived bacterial RNA
Özcan, Mine; Gürsel, Mayda; Department of Biology (2014)
Immunological mechanisms contributing to distinguishing signals derived from commensal versus pathogenic bacteria is an active area of research and recent evidence suggests that commensal and pathogens may express different variants of pathogen associated molecular patterns (PAMP). In this thesis, we propose that as a major member of PAMP, bacterial RNAs derived from commensal and pathogens may have distinct immunostimulatory activities due to differentially recognition by the host immune system. In order t...
Differential activation of immune cells by commensal versus pathogen-derived bacterial DNA
Günalp, Sinem; Gürsel, Mayda; Department of Biology (2015)
Immunological mechanisms making contribution to discriminating signals obtained from commensal versus pathogenic bacteria is an active area of research and recent evidence proposes that commensals and pathogens might express discrete variants of pathogen associated molecular patterns (PAMP). We hypothesized that as a major member of PAMP, bacterial DNA (bacDNA) originating from commensals versus pathogens might possess distinct immunostimulatory activities, enabling their dis- crimination by the immune syst...
Immunomodulatory effects of commensal bacteria-derived membrane vesicles
Alpdündar, Esin; Gürsel, Mayda; Department of Biology (2013)
Constitutive secretion of extracellular membrane vesicles is a common feature of cells from all domains of life including Archaea, Bacteria, and Eukarya. Although the contribution of gram negative bacterial outer membrane vesicles in disease pathogenesis has been extensively studied, whether commensal bacteria constitutively secrete such vesicles is still unknown. Given the importance of microbiota as regulators of immune homeostasis, we aimed to assess the immunomodulatory properties of extracellular vesic...
Investigation of the Ligand Binding Characteristics of Staphylococcus aureus NorA Efflux Pump
Işık , Esra Büşra; Serçinoğlu, Onur (Orta Doğu Teknik Üniversitesi Enformatik Enstitüsü; 2022-10)
Staphylococcus aureus is a gram-positive bacterial pathogen which is highly adaptive to environmental conditions and causes various disorders. Excessive usage of antibiotics may result in development of antibiotic resistance in S. aureus. One of the resistance mechanisms is increase in the activity of transmembrane multi-drug efflux pumps. NorA is the most studied efflux pump in S. aureus, which belongs to Major Facilitator Superfamily (MFS). NorA has been shown to contribute to resistance against a variety...
Differential immune activation following encapsulation of immunostimulatory CpG oligodeoxynucleotide in nanoliposomes.
Erikçi, E; Gürsel, Mayda; Gürsel, I (2011-02-01)
The immunogenicity of a vaccine formulation is closely related to the effective internalization by the innate immune cells that provide prolonged and simultaneous delivery of antigen and adjuvant to relevant antigen presenting cells. Endosome associated TLR9 recognizes microbial unmethylated CpG DNA. Clinical applications of TLR9 ligands are significantly hampered due to their pre-mature in vivo digestion and rapid clearance. Liposome encapsulation is a powerful tool to increase in vivo stability as well as...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
B. Kayaoğlu, “Immunomodulatory activities of RNA species derived from commensal and pathogenic bacteria,” M.S. - Master of Science, Middle East Technical University, 2017.