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Milillo MA, Velásquez LN, Barrionuevo P. Microbial RNA, the New PAMP of Many Faces. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.924719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Traditionally, pathogen-associated molecular patterns (PAMPs) were described as structural molecular motifs shared by different classes of microorganisms. However, it was later discovered that the innate immune system is also capable of distinguishing metabolically active microbes through the detection of a special class of viability-associated PAMPs (vita-PAMPs). Indeed, recognition of vita-PAMPs triggers an extra warning sign not provoked by dead bacteria. Bacterial RNA is classified as a vita-PAMP since it stops being synthesized once the microbes are eliminated. Most of the studies in the literature have focused on the pro-inflammatory capacity of bacterial RNA on macrophages, neutrophils, endothelial cells, among others. However, we, and other authors, have shown that microbial RNA also has down-modulatory properties. More specifically, bacterial RNA can reduce the surface expression of MHC class I and MHC class II on monocytes/macrophages and help evade CD8+ and CD4+ T cell-mediated immune surveillance. This phenomenon has been described for several different bacteria and parasites, suggesting that microbial RNA plays a significant immunoregulatory role in the context of many infectious processes. Thus, beyond the pro-inflammatory capacity of microbial RNA, it seems to be a crucial component in the intricate collection of immune evasion strategies. This review focuses on the different facets of the immune modulating capacity of microbial RNA.
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Landoni VI, Pittaluga JR, Carestia A, Castillo LA, Nebel MDC, Martire-Greco D, Birnberg-Weiss F, Schattner M, Schierloh P, Fernández GC. Neutrophil Extracellular Traps Induced by Shiga Toxin and Lipopolysaccharide-Treated Platelets Exacerbate Endothelial Cell Damage. Front Cell Infect Microbiol 2022; 12:897019. [PMID: 35811684 PMCID: PMC9262415 DOI: 10.3389/fcimb.2022.897019] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure in the pediatric population. The etiology of HUS is linked to Gram-negative, Shiga toxin (Stx)-producing enterohemorrhagic bacterial infections. While the effect of Stx is focused on endothelial damage of renal glomerulus, cytokines induced by Stx or bacterial lipopolysaccharide (LPS) and polymorphonuclear cells (PMNs) are involved in the development of the disease. PMN release neutrophil extracellular traps (NETs) to eliminate pathogens, although NETs favor platelets (Plts) adhesion/thrombus formation and can cause tissue damage within blood vessels. Since thrombus formation and occlusion of vessels are characteristic of HUS, PMN–Plts interaction in the context of Stx may promote netosis and contribute to the endothelial damage observed in HUS. The aim of this study was to determine the relevance of netosis induced by Stx in the context of LPS-sensitized Plts on endothelial damage. We observed that Stx2 induced a marked enhancement of netosis promoted by Plts after LPS stimulation. Several factors seemed to promote this phenomenon. Stx2 itself increased the expression of its receptor on Plts, increasing toxin binding. Stx2 also increased LPS binding to Plts. Moreover, Stx2 amplified LPS induced P-selectin expression on Plts and mixed PMN–Plts aggregates formation, which led to activation of PMN enhancing dramatically NETs formation. Finally, experiments revealed that endothelial cell damage mediated by PMN in the context of Plts treated with LPS and Stx2 was decreased when NETs were disrupted or when mixed aggregate formation was impeded using an anti-P-selectin antibody. Using a murine model of HUS, systemic endothelial damage/dysfunction was decreased when NETs were disrupted, or when Plts were depleted, indicating that the promotion of netosis by Plts in the context of LPS and Stx2 plays a fundamental role in endothelial toxicity. These results provide insights for the first time into the pivotal role of Plts as enhancers of endothelial damage through NETs promotion in the context of Stx and LPS. Consequently, therapies designed to reduce either the formation of PMN–Plts aggregates or NETs formation could lessen the consequences of endothelial damage in HUS.
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Affiliation(s)
- Verónica Inés Landoni
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Jose R. Pittaluga
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Agostina Carestia
- Laboratorio de Trombosis Experimental e Inmunobiología de la Inflamación, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Luis Alejandro Castillo
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Marcelo de Campos Nebel
- Laboratorio de Mutagénesis, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Daiana Martire-Greco
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Federico Birnberg-Weiss
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Mirta Schattner
- Laboratorio de Trombosis Experimental e Inmunobiología de la Inflamación, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
| | - Pablo Schierloh
- Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática, Centro Científico Tecnológico Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Gabriela C. Fernández
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Ciudad Autónoma de Buenos Aires (CABA), Argentina
- *Correspondence: Gabriela C. Fernández, ;
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Lentini G, De Gaetano GV, Famà A, Galbo R, Coppolino F, Mancuso G, Teti G, Beninati C. Neutrophils discriminate live from dead bacteria by integrating signals initiated by Fprs and TLRs. EMBO J 2022; 41:e109386. [PMID: 35112724 PMCID: PMC8886525 DOI: 10.15252/embj.2021109386] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/15/2021] [Accepted: 01/12/2022] [Indexed: 11/09/2022] Open
Abstract
The mechanisms whereby neutrophils respond differentially to live and dead organisms are unknown. We show here that neutrophils produce 5- to 30-fold higher levels of the Cxcl2 chemokine in response to live bacteria, compared with killed bacteria or isolated bacterial components, despite producing similar levels of Cxcl1 or pro-inflammatory cytokines. Secretion of high levels of Cxcl2, which potently activates neutrophils by an autocrine mechanism, requires three signals. The first two signals are provided by two different sets of signal peptides released by live bacteria, which selectively activate formylated peptide receptor 1 (Fpr1) and Fpr2, respectively. Signal 3 originates from Toll-like receptor activation by microbial components present in both live and killed bacteria. Mechanistically, these signaling pathways converge at the level of the p38 MAP kinase, leading to activation of the AP-1 transcription factor and to Cxcl2 induction. Collectively, our data demonstrate that the simultaneous presence of agonists for Fpr1, Fpr2, and Toll-like receptors represents a unique signature associated with viable bacteria, which is sensed by neutrophils and induces Cxcl2-dependent autocrine cell activation.
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Affiliation(s)
- Germana Lentini
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | | | - Agata Famà
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | - Roberta Galbo
- Department of Chemical, Biological and Pharmaceutical SciencesUniversity of MessinaMessinaItaly
| | - Francesco Coppolino
- Department of BiomedicalDental, Morphological and Functional Imaging SciencesUniversity of MessinaMessinaItaly
| | | | | | - Concetta Beninati
- Department of Human PathologyUniversity of MessinaMessinaItaly,Scylla Biotech SrlMessinaItaly
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Smolarz M, Zawrotniak M, Satala D, Rapala-Kozik M. Extracellular Nucleic Acids Present in the Candida albicans Biofilm Trigger the Release of Neutrophil Extracellular Traps. Front Cell Infect Microbiol 2021; 11:681030. [PMID: 34123878 PMCID: PMC8187917 DOI: 10.3389/fcimb.2021.681030] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Neutrophils, the first line of the host's defense, use a variety of antimicrobial mechanisms to fight invading pathogens. One of the most crucial is the production of neutrophil extracellular traps (NETs) in the process called NETosis. The unique structure of NETs effectively inhibits the spread of pathogens and ensures their exposure to a high concentration of NET-embedded antimicrobial compounds. NETosis strategy is often used by the host to defend against fungal infection caused by Candida albicans. In immunocompromised patients, this microorganism is responsible for developing systemic fungal infections (candidiasis). This is correlated with the use of a vast array of virulence factors, leading to the acquisition of specific resistance to host defense factors and available drug therapies. One of the most important features favoring the development of drug resistance is a C. albicans ability to form biofilms that protect fungal cells mainly through the production of an extracellular matrix (ECM). Among the main ECM-building macromolecules extracellular nucleic acids have been identified and their role is probably associated with the stbilization of the biofilm structure. The complex interactions of immune cells with the thick ECM layer, comprising the first line of contact between these cells and the biofilm structure, are still poorly understood. Therefore, the current studies aimed to assess the release of extracellular nucleic acids by C. albicans strains at different stages of biofilm formation, and to determine the role of these molecules in triggering the NETosis. We showed for the first time that fungal nucleic acids, purified directly from mature C. albicans biofilm structure or obtained from the whole fungal cells, have the potential to induce NET release in vitro. In this study, we considered the involvement of TLR8 and TLR9 in NETosis activation. We showed that DNA and RNA molecules initiated the production of reactive oxygen species (ROS) by activation of the NADPH oxidase complex, essential for ROS-dependent NETosis. Furthermore, analysis of the cell migration showed that the nucleic acids located in the extracellular space surrounding the biofilm may be also effective chemotactic factors, driving the dynamic migration of human neutrophils to the site of ongoing fungal infection.
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Affiliation(s)
- Magdalena Smolarz
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Marcin Zawrotniak
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Dorota Satala
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Maria Rapala-Kozik
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
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Tosar JP, Cayota A. Extracellular tRNAs and tRNA-derived fragments. RNA Biol 2020; 17:1149-1167. [PMID: 32070197 PMCID: PMC7549618 DOI: 10.1080/15476286.2020.1729584] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 01/08/2023] Open
Abstract
Fragmentation of tRNAs generates a family of small RNAs collectively known as tRNA-derived fragments. These fragments vary in sequence and size but have been shown to regulate many processes involved in cell homoeostasis and adaptations to stress. Additionally, the field of extracellular RNAs (exRNAs) is rapidly growing because exRNAs are a promising source of biomarkers in liquid biopsies, and because exRNAs seem to play key roles in intercellular and interspecies communication. Herein, we review recent descriptions of tRNA-derived fragments in the extracellular space in all domains of life, both in biofluids and in cell culture. The purpose of this review is to find consensus on which tRNA-derived fragments are more prominent in each extracellular fraction (including extracellular vesicles, lipoproteins and ribonucleoprotein complexes). We highlight what is becoming clear and what is still controversial in this field, in order to stimulate future hypothesis-driven studies which could clarify the role of full-length tRNAs and tRNA-derived fragments in the extracellular space.
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Affiliation(s)
- Juan Pablo Tosar
- Analytical Biochemistry Unit, Nuclear Research Center, Faculty of Science, Universidad de la República, Montevideo, Uruguay
- Functional Genomics Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Alfonso Cayota
- Functional Genomics Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Department of Medicine, University Hospital, Universidad de la República, Montevideo, Uruguay
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Birnberg-Weiss F, Castillo LA, Pittaluga JR, Martire-Greco D, Gómez SA, Landoni VI, Fernández GC. Modulation of neutrophil extracellular traps release by Klebsiella pneumoniae. J Leukoc Biol 2020; 109:245-256. [PMID: 32640486 DOI: 10.1002/jlb.4ma0620-099r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 12/21/2022] Open
Abstract
One of the main bactericidal mechanisms of polymorphonuclear neutrophils (PMN) is the release of neutrophil extracellular traps (NETs), which capture and destroy pathogens. Klebsiella pneumoniae (Kpn) producer of carbapenemase (KPC) and belonging to the sequence type 258 (ST258), is a hyper epidemic clone that causes a large number of infections worldwide associated with high persistence and mortality. It is necessary to investigate the interaction of Kpn KPC with the immune system to improve prevention and treatment of infections mediated by this bacterium. Based on the hypothesis that Kpn is able to subvert PMN-mediated death, the aim was to assess whether Kpn KPC ST258 could modulate the bactericidal response of PMN, focusing on NETs formation, compared to another opportunistic pathogen, as Escherichia coli (Eco). The results showed that the release of NETs was absent when PMN were challenged with Kpn KPC, while Eco was a strong inducer of NETosis. Moreover, Kpn KPC was able to inhibit NETosis induced by Eco. The inhibition of Kpn KPC-mediated NETs formation still occurred in spite of exogenous addition of hydrogen peroxide (H2 O2 ), did not involve bacterial-released soluble factors or cell wall components, and was dependent on bacterial viability. Moreover, when degranulation was investigated, we found that Kpn KPC affected only the mobilization of primary granules, which harbor the proteins with more potent bactericidal properties and those related to NETosis. In conclusion, Kpn KPC ST258 effectively managed to evade the PMN response by inhibiting the release of NETs, and primary granule mobilization.
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Affiliation(s)
- Federico Birnberg-Weiss
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
| | - Luis A Castillo
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
| | - Jose R Pittaluga
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
| | - Daiana Martire-Greco
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
| | - Sonia A Gómez
- Servicio de Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas, ANLIS 'Dr Carlos G. Malbrán', CABA, Argentina
| | - Verónica I Landoni
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
| | - Gabriela C Fernández
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, CABA, Argentina
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Castillo LA, Birnberg Weiss F, Rodriguez-Rodrigues N, Pittaluga JR, Martire-Greco D, Milillo MA, Grinstein SF, Camelli MR, Mena Aybar AJ, Landoni VI, Fernández GC. Prokaryotic RNA activates endothelial cells promoting neutrophil transmigration. Immunol Cell Biol 2019; 97:815-825. [PMID: 31264260 DOI: 10.1111/imcb.12282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/27/2019] [Accepted: 06/29/2019] [Indexed: 01/18/2023]
Abstract
Endothelial cell (EC)-neutrophil (PMN) interactions are crucial in the resolution of bacterial infections. Prokaryotic RNA (pRNA) has been reported as a pathogen-associated molecular pattern that is released from bacteria upon death and is able to activate PMN. In this work, we studied the effects of pRNA on EC and investigated whether these effects could modulate EC-PMN interaction. For this purpose, we purified total pRNA from Escherichia coli and used it as a stimulus for Human Umbilical Vein Endothelial Cells (HUVEC). We found that the incubation of pRNA with HUVEC caused the increase of surface intercellular adhesion molecule 1 (ICAM-1 or CD54) expression on HUVEC, and the secretion of IL-8 and von Willebrand factor, characteristics consistent with HUVEC activation, without causing toxic effects. Moreover, pRNA-treated HUVEC also induced PMN adhesion and the conditioned medium obtained from treated-HUVEC was chemotactic for PMN and caused their activation, as determined by CD11b upregulation. As reported previously, the degradation products of pRNA induced similar biological effects. The treatment of HUVEC with endocytosis inhibitors revealed that the entry of pRNA partially relied on a clathrin-dependent mechanism, whereas the effects of degradation products could not be inhibited by any of the inhibitors tested. Using a transwell system, we found that pRNA or degraded pRNA were also able to stimulate HUVEC when recognized from the basolateral side. Our results indicate that pRNA activates EC, resulting in the modulation of EC-PMN interaction by inducing PMN chemotaxis, adhesion and activation. In the context of infection, pRNA sensed by EC and PMN could favor bacterial clearance.
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Affiliation(s)
- Luis A Castillo
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Federico Birnberg Weiss
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Nahuel Rodriguez-Rodrigues
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - José R Pittaluga
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Daiana Martire-Greco
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Maria A Milillo
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Sebastian F Grinstein
- Servicio de Obstetricia, Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich, Luis María Campos 726, C1426BOR, Ciudad Autónoma de Buenos Aires, Argentina
| | - María R Camelli
- Servicio de Obstetricia, Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich, Luis María Campos 726, C1426BOR, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ana J Mena Aybar
- Servicio de Obstetricia, Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich, Luis María Campos 726, C1426BOR, Ciudad Autónoma de Buenos Aires, Argentina
| | - Verónica I Landoni
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gabriela C Fernández
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET, Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM, Ciudad Autónoma de Buenos Aires, Argentina
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Castillo LA, Birnberg-Weiss F, Rodriguez-Rodrigues N, Martire-Greco D, Bigi F, Landoni VI, Gomez SA, Fernandez GC. Klebsiella pneumoniae ST258 Negatively Regulates the Oxidative Burst in Human Neutrophils. Front Immunol 2019; 10:929. [PMID: 31105712 PMCID: PMC6497972 DOI: 10.3389/fimmu.2019.00929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/11/2019] [Indexed: 11/13/2022] Open
Abstract
The epidemic clone of Klebsiella pneumoniae (Kpn), sequence type 258 (ST258), carbapenamase producer (KPC), commonly infects hospitalized patients that are left with scarce therapeutic option since carbapenems are last resort antibiotics for life-threatening bacterial infections. To improve prevention and treatment, we should better understand the biology of Kpn KPC ST258 infections. Our hypothesis was that Kpn KPC ST258 evade the first line of defense of innate immunity, the polymorphonuclear neutrophil (PMN), by decreasing its functional response. Therefore, our aim was to evaluate how the ST258 Kpn clone affects PMN responses, focusing on the respiratory burst, compared to another opportunistic pathogen, Escherichia coli (Eco). We found that Kpn KPC ST258 was unable to trigger bactericidal responses as reactive oxygen species (ROS) generation and NETosis, compared to the high induction observed with Eco, but both bacterial strains were similarly phagocytized and cause increases in cell size and CD11b expression. The absence of ROS induction was also observed with other Kpn ST258 strains negative for KPC. These results reflect certain selectivity in terms of the functions that are triggered in PMN by Kpn, which seems to evade specifically those responses critical for bacterial survival. In this sense, bactericidal mechanisms evasion was associated with a higher survival of Kpn KPC ST258 compared to Eco. To investigate the mechanisms and molecules involved in ROS inhibition, we used bacterial extracts (BE) and found that BE were able to inhibit ROS generation triggered by the well-known ROS inducer, fMLP. A sequence of experiments led us to elucidate that the polysaccharide part of LPS was responsible for this inhibition, whereas lipid A mediated the other responses that were not affected by bacteria, such as cell size increase and CD11b up-regulation. In conclusion, we unraveled a mechanism of immune evasion of Kpn KPC ST258, which may contribute to design more effective strategies for the treatment of these multi-resistant bacterial infections.
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Affiliation(s)
- Luis A Castillo
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
| | - Federico Birnberg-Weiss
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
| | - Nahuel Rodriguez-Rodrigues
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
| | - Daiana Martire-Greco
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
| | - Fabiana Bigi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Veronica I Landoni
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
| | - Sonia A Gomez
- Servicio de Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas Dr. Carlos G. Malbrán (INEI), Administración Nacional de Laboratorios e Institutos de Salud (ANLIS), Buenos Aires, Argentina
| | - Gabriela C Fernandez
- Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)- Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET)/Academia Nacional de Medicina de Buenos Aires, Buenos Aires, Argentina
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Ugolini M, Sander LE. Dead or alive: how the immune system detects microbial viability. Curr Opin Immunol 2018; 56:60-66. [PMID: 30366275 DOI: 10.1016/j.coi.2018.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 12/14/2022]
Abstract
Immune detection of microbial viability is increasingly recognized as a potent driver of innate and adaptive immune responses. Here we describe recent mechanistic insights into the process of how the immune system discriminates between viable and non-viable microbial matter. Accumulating evidence suggests a key role for microbial RNA as a widely conserved viability associated PAMP (vita-PAMP) and a molecular signal of increased infectious threat. Toll-like receptor 8 (TLR8) has recently emerged as a critical sensor for viable bacteria, ssRNA viruses, and archaea in human antigen presenting cells (APC). We discuss the role of microbial RNA, and other potential vita-PAMPs in antimicrobial immunity and vaccine responses.
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Affiliation(s)
- Matteo Ugolini
- Max Planck Unit for the Science of Pathogens, Berlin, Germany; Max Planck Institute for Infection Biology, Berlin, Germany
| | - Leif E Sander
- Department of Infectious Diseases and Pulmonary Medicine, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; German Center for Lung Research (DZL), Berlin, Germany.
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Tsatsaronis JA, Franch-Arroyo S, Resch U, Charpentier E. Extracellular Vesicle RNA: A Universal Mediator of Microbial Communication? Trends Microbiol 2018; 26:401-410. [PMID: 29548832 DOI: 10.1016/j.tim.2018.02.009] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/08/2018] [Accepted: 02/14/2018] [Indexed: 01/18/2023]
Abstract
Both extracellular RNAs and extracellular vesicles (EVs) have recently garnered attention as novel mediators of intercellular communication in eukaryotes and prokaryotes alike. EVs not only permit export of RNA, but also facilitate delivery and trans-kingdom exchange of these and other biomolecules, for instance between microbes and their hosts. In this Opinion article, we propose that EV-mediated export of RNA represents a universal mechanism for interkingdom and intrakingdom communication that is conserved among bacterial, archaeal, and eukaryotic microbes. We speculate how microbes might use EV RNA to influence target cell gene expression or manipulate host immune responses.
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Affiliation(s)
- James A Tsatsaronis
- Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany; Current address: School of Biological Sciences, University of Wollongong, 2522 Wollongong, Australia; Both authors contributed equally to this work
| | - Sandra Franch-Arroyo
- Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany; Both authors contributed equally to this work
| | - Ulrike Resch
- Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany
| | - Emmanuelle Charpentier
- Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, 10117 Berlin, Germany; The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden; Institute for Biology, Humboldt University, 10115 Berlin, Germany.
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