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Ehlers C, Thiele T, Biermann H, Traidl S, Bruns L, Ziegler A, Schefzyk M, Bartsch LM, Kalinke U, Witte T, Graalmann T. Toll-Like Receptor 8 is Expressed in Monocytes in Contrast to Plasmacytoid Dendritic Cells and Mediates Aberrant Interleukin-10 Responses in Patients With Systemic Sclerosis. Arthritis Rheumatol 2024. [PMID: 39112920 DOI: 10.1002/art.42964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/04/2024] [Accepted: 07/24/2024] [Indexed: 08/29/2024]
Abstract
OBJECTIVE Systemic sclerosis (SSc) is a severe rheumatic disease causing fibrotic tissue rearrangement. Aberrant toll-like receptor (TLR) 8 transcripts in plasmacytoid dendritic cells (pDCs) were recently linked to SSc pathogenesis, which is at least partially mediated by increased type I interferon (IFN-I) responses. Here, we addressed the functional role of TLR8 signaling in different immune cell subsets of patients with SSc. METHODS Monocytes, conventional dendritic cells (cDCs), and pDCs from the blood and skin of patients with SSc were analyzed for TLR8 protein expression. To assess TLR function, cytokine responses upon TLR7 and TLR8 stimulation were studied. To identify relevant alterations specific for patients with SSc (n = 16), patients with primary Sjögren disease (pSS; n = 10) and healthy controls (HCs; n = 13) were included into the study. RESULTS In all individuals, TLR8 was expressed in monocytes and cDCs but not in pDCs. The TLR8 expression levels were overall similar in patients with SSc and pSS and HCs. Additionally, in all study participants, TLR8 stimulation of pDCs did not induce IFN-I expression. In contrast, monocytes from patients with SSc revealed increased interleukin (IL)-10 responses upon TLR8 (patients with SSc vs HCs, P = 0.0126) and TLR7/8 stimulation (patients with SSc vs HCs, P = 0.0170). CONCLUSION TLR8 protein is not expressed in pDCs of patients with SSc. Accordingly, they do not respond to TLR8 stimulation. In contrast, monocytes of patients with SSc respond to TLR8 stimulation with increased IL-10 responses. Therefore, TLR8 signaling in monocytes participates in SSc pathogenesis by conferring aberrant IL-10 expression.
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Affiliation(s)
- Christine Ehlers
- Junior Research Group for Translational Immunology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany; Biomedical Research in End-Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Thea Thiele
- Department for Rheumatology and Immunology, Hannover Medical School, Hannover, Germany
| | - Hannah Biermann
- Junior Research Group for Translational Immunology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Stephan Traidl
- Department for Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - Luzia Bruns
- Department for Rheumatology and Immunology, Hannover Medical School, Hannover, Germany
| | - Annett Ziegler
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Matthias Schefzyk
- Department for Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - Lea M Bartsch
- Department for Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Ulrich Kalinke
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Torsten Witte
- Department for Rheumatology and Immunology, Hannover Medical School, Hannover, Germany
| | - Theresa Graalmann
- Junior Research Group for Translational Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany, Biomedical Research in End-Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany, and Department for Rheumatology and Immunology, Hannover Medical School, Hannover, Germany
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Serafino A, Bertinat YA, Bueno J, Pittaluga JR, Birnberg Weiss F, Milillo MA, Barrionuevo P. Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells. PLoS One 2024; 19:e0306429. [PMID: 38980867 PMCID: PMC11232970 DOI: 10.1371/journal.pone.0306429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 06/17/2024] [Indexed: 07/11/2024] Open
Abstract
Brucella abortus (Ba) is a pathogen that survives inside macrophages. Despite being its preferential niche, Ba infects other cells, as shown by the multiple signs and symptoms humans present. This pathogen can evade our immune system. Ba displays a mechanism of down-modulating MHC-I on monocytes/macrophages in the presence of IFN-γ (when Th1 response is triggered) without altering the total expression of MHC-I. The retained MHC-I proteins are located within the Golgi Apparatus (GA). The RNA of Ba is one of the PAMPs that trigger this phenomenon. However, we acknowledged whether this event could be triggered in other cells relevant during Ba infection. Here, we demonstrate that Ba RNA reduced the surface expression of MHC-I induced by IFN-γ in the human bronchial epithelium (Calu-6), the human alveolar epithelium (A-549) and the endothelial microvasculature (HMEC) cell lines. In Calu-6 and HMEC cells, Ba RNA induces the retention of MHC-I in the GA. This phenomenon was not observed in A-549 cells. We then evaluated the effect of Ba RNA on the secretion of IL-8, IL-6 and MCP-1, key cytokines in Ba infection. Contrary to our expectations, HMEC, Calu-6 and A-549 cells treated with Ba RNA had higher IL-8 and IL-6 levels compared to untreated cells. In addition, we showed that Ba RNA down-modulates the MHC-I surface expression induced by IFN-γ on human monocytes/macrophages via the pathway of the Epidermal Growth Factor Receptor (EGFR). So, cells were stimulated with an EGFR ligand-blocking antibody (Cetuximab) and Ba RNA. Neutralization of the EGFR to some extent reversed the down-modulation of MHC-I mediated by Ba RNA in HMEC and A-549 cells. In conclusion, this is the first study exploring a central immune evasion strategy, such as the downregulation of MHC-I surface expression, beyond monocytes and could shed light on how it persists effectively within the host, enduring unseen and escaping CD8+ T cell surveillance.
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Affiliation(s)
- Agustina Serafino
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
| | - Yasmín A. Bertinat
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
| | - Jorgelina Bueno
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
| | - José R. Pittaluga
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
| | - Federico Birnberg Weiss
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
| | - M. Ayelén Milillo
- Universidad Nacional de Río Negro. Instituto de Estudios en Ciencia, Tecnología, Cultura y Desarrollo. Río Negro, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas. Argentina
| | - Paula Barrionuevo
- Instituto de Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Academia Nacional de Medicina; Buenos Aires, Argentina
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Nargan K, Glasgow JN, Nadeem S, Naidoo T, Wells G, Hunter RL, Hutton A, Lumamba K, Msimang M, Benson PV, Steyn AJC. Spatial distribution of Mycobacterium tuberculosis mRNA and secreted antigens in acid-fast negative human antemortem and resected tissue. EBioMedicine 2024; 105:105196. [PMID: 38880068 PMCID: PMC11233921 DOI: 10.1016/j.ebiom.2024.105196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024] Open
Abstract
BACKGROUND The ability to detect evidence of Mycobacterium tuberculosis (Mtb) infection within human tissues is critical to the study of Mtb physiology, tropism, and spatial distribution within TB lesions. The capacity of the widely-used Ziehl-Neelsen (ZN) staining method for identifying Mtb acid-fast bacilli (AFB) in tissue is highly variable, which can limit detection of Mtb bacilli for research and diagnostic purposes. Here, we sought to circumvent these limitations via detection of Mtb mRNA and secreted antigens in human tuberculous tissue. METHODS We adapted RNAscope, an RNA in situ hybridisation (RISH) technique, to detect Mtb mRNA in ante- and postmortem human TB tissues and developed a dual ZN/immunohistochemistry staining approach to identify AFB and bacilli producing antigen 85B (Ag85B). FINDINGS We identified Mtb mRNA within intact and disintegrating bacilli as well as extrabacillary mRNA. Mtb mRNA was distributed zonally within necrotic and non-necrotic granulomas. We also found Mtb mRNA within, and adjacent to, necrotic granulomas in ZN-negative lung tissue and in Ag85B-positive bronchiolar epithelium. Intriguingly, we observed accumulation of Mtb mRNA and Ag85B in the cytoplasm of host cells. Notably, many AFB were negative for Ag85B staining. Mtb mRNA was observed in ZN-negative antemortem lymph node biopsies. INTERPRETATION RNAscope and dual ZN/immunohistochemistry staining are well-suited for identifying subsets of intact Mtb and/or bacillary remnants in human tissue. RNAscope can identify Mtb mRNA in ZN-negative tissues from patients with TB and may have diagnostic potential in complex TB cases. FUNDING Wellcome Leap Delta Tissue Program, Wellcome Strategic Core Award, the National Institutes of Health (NIH, USA), the Mary Heersink Institute for Global Health at UAB, the UAB Heersink School of Medicine.
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Affiliation(s)
- Kievershen Nargan
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Joel N Glasgow
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sajid Nadeem
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Threnesan Naidoo
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa; Department of Forensic and Legal Medicine, Walter Sisulu University, Mthatha, South Africa
| | - Gordon Wells
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Robert L Hunter
- Department of Pathology and Laboratory Medicine, University of Texas Health Sciences Center at Houston, Houston, TX, USA
| | - Anneka Hutton
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kapongo Lumamba
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Mpumelelo Msimang
- Department of Anatomical Pathology, National Health Laboratory Service, IALCH, Durban, South Africa
| | - Paul V Benson
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Adrie J C Steyn
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa; Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA; Centers for AIDS Research and Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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Su MSW, Cheng YL, Lin YS, Wu JJ. Interplay between group A Streptococcus and host innate immune responses. Microbiol Mol Biol Rev 2024; 88:e0005222. [PMID: 38451081 PMCID: PMC10966951 DOI: 10.1128/mmbr.00052-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
SUMMARYGroup A Streptococcus (GAS), also known as Streptococcus pyogenes, is a clinically well-adapted human pathogen that harbors rich virulence determinants contributing to a broad spectrum of diseases. GAS is capable of invading epithelial, endothelial, and professional phagocytic cells while evading host innate immune responses, including phagocytosis, selective autophagy, light chain 3-associated phagocytosis, and inflammation. However, without a more complete understanding of the different ways invasive GAS infections develop, it is difficult to appreciate how GAS survives and multiplies in host cells that have interactive immune networks. This review article attempts to provide an overview of the behaviors and mechanisms that allow pathogenic GAS to invade cells, along with the strategies that host cells practice to constrain GAS infection. We highlight the counteractions taken by GAS to apply virulence factors such as streptolysin O, nicotinamide-adenine dinucleotidase, and streptococcal pyrogenic exotoxin B as a hindrance to host innate immune responses.
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Affiliation(s)
- Marcia Shu-Wei Su
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Lin Cheng
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
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Bullen CK, Singh AK, Krug S, Lun S, Thakur P, Srikrishna G, Bishai WR. MDA5 RNA-sensing pathway activation by Mycobacterium tuberculosis promotes innate immune subversion and pathogen survival. JCI Insight 2023; 8:e166242. [PMID: 37725440 PMCID: PMC10619499 DOI: 10.1172/jci.insight.166242] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 09/13/2023] [Indexed: 09/21/2023] Open
Abstract
Host cytosolic sensing of Mycobacterium tuberculosis (M. tuberculosis) RNA by the RIG-I-like receptor (RLR) family perturbs innate immune control within macrophages; however, a distinct role of MDA5, a member of the RLR family, in M. tuberculosis pathogenesis has yet to be fully elucidated. To further define the role of MDA5 in M. tuberculosis pathogenesis, we evaluated M. tuberculosis intracellular growth and innate immune responses in WT and Mda5-/- macrophages. Transfection of M. tuberculosis RNA strongly induced proinflammatory cytokine production in WT macrophages, which was abrogated in Mda5-/- macrophages. M. tuberculosis infection in macrophages induced MDA5 protein expression, accompanied by an increase in MDA5 activation as assessed by multimer formation. IFN-γ-primed Mda5-/- macrophages effectively contained intracellular M. tuberculosis proliferation to a markedly greater degree than WT macrophages. Further comparisons of WT versus Mda5-/- macrophages revealed that during M. tuberculosis infection MDA5 contributed to IL-1β production and inflammasome activation and that loss of MDA5 led to a substantial increase in autophagy. In the mouse TB model, loss of MDA5 conferred host survival benefits with a concomitant reduction in M. tuberculosis bacillary burden. These data reveal that loss of MDA5 is host protective during M. tuberculosis infection in vitro and in vivo, suggesting that M. tuberculosis exploits MDA5 to subvert immune containment.
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Nargan K, Naidoo T, Msimang M, Nadeem S, Wells G, Hunter RL, Hutton A, Lumamba K, Glasgow JN, Benson PV, Steyn AJ. Detection of Mycobacterium tuberculosis in human tissue via RNA in situ hybridization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.04.560963. [PMID: 37873458 PMCID: PMC10592959 DOI: 10.1101/2023.10.04.560963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Rationale Accurate TB diagnosis is hampered by the variable efficacy of the widely-used Ziehl-Neelsen (ZN) staining method to identify Mycobacterium tuberculosis ( Mtb ) acid-fast bacilli (AFB). Here, we sought to circumvent this current limitation through direct detection of Mtb mRNA. Objectives To employ RNAscope to determine the spatial distribution of Mtb mRNA within tuberculous human tissue, to appraise ZN-negative tissue from confirmed TB patients, and to provide proof-of-concept of RNAscope as a platform to inform TB diagnosis and Mtb biology. Methods We examined ante- and postmortem human TB tissue using RNAscope to detect Mtb mRNA and a dual ZN/immunohistochemistry staining approach to identify AFB and bacilli producing antigen 85B (Ag85B). Measurements and main results We adapted RNAscope for Mtb and identified intact and disintegrated Mtb bacilli and intra- and extracellular Mtb mRNA. Mtb mRNA was distributed zonally within necrotic and non-necrotic granulomas. We also found Mtb mRNA within, and adjacent to, necrotic granulomas in ZN-negative lung tissue and in Ag85B-positive bronchial epithelium. Intriguingly, we observed accumulation of Mtb mRNA and Ag85B in the cytoplasm of host cells. Notably, many AFB were negative for Ag85B staining. Mtb mRNA was observed in ZN-negative antemortem lymph node biopsies. Conclusions RNAscope has diagnostic potential and can guide therapeutic intervention as it detects Mtb mRNA and morphology in ZN-negative tissues from TB patients, and Mtb mRNA in ZN-negative antemortem biopsies, respectively. Lastly, our data provide evidence that at least two phenotypically distinct populations of Mtb bacilli exist in vivo .
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Ha JY, Seok J, Kim SJ, Jung HJ, Ryu KY, Nakamura M, Jang IS, Hong SH, Lee Y, Lee HJ. Periodontitis promotes bacterial extracellular vesicle-induced neuroinflammation in the brain and trigeminal ganglion. PLoS Pathog 2023; 19:e1011743. [PMID: 37871107 PMCID: PMC10621956 DOI: 10.1371/journal.ppat.1011743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 11/02/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023] Open
Abstract
Gram-negative bacteria derived extracellular vesicles (EVs), also known as outer membrane vesicles, have attracted significant attention due to their pathogenic roles in various inflammatory diseases. We recently demonstrated that EVs secreted by the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) can cross the blood-brain barrier (BBB) and that their extracellular RNA cargo can promote the secretion of proinflammatory cytokines, such as IL-6 and TNF-α, in the brain. To gain more insight into the relationship between periodontal disease (PD) and neuroinflammatory diseases, we investigated the effect of Aa EVs in a mouse model of ligature-induced PD. When EVs were administered through intragingival injection or EV-soaked gel, proinflammatory cytokines were strongly induced in the brains of PD mice. The use of TLR (Toll-like receptor)-reporter cell lines and MyD88 knockout mice confirmed that the increased release of cytokines was triggered by Aa EVs via TLR4 and TLR8 signaling pathways and their downstream MyD88 pathway. Furthermore, the injection of EVs through the epidermis and gingiva resulted in the direct retrograde transfer of Aa EVs from axon terminals to the cell bodies of trigeminal ganglion (TG) neurons and the subsequent activation of TG neurons. We also found that the Aa EVs changed the action potential of TG neurons. These findings suggest that EVs derived from periodontopathogens such as Aa might be involved in pathogenic pathways for neuroinflammatory diseases, neuropathic pain, and other systemic inflammatory symptoms as a comorbidity of periodontitis.
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Affiliation(s)
- Jae Yeong Ha
- Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu, Korea
- Craniofacial Nerve-Bone Network Research Center, Kyungpook National University, Daegu, Korea
| | - Jiwon Seok
- Department of Biochemistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Suk-Jeong Kim
- Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu, Korea
- Craniofacial Nerve-Bone Network Research Center, Kyungpook National University, Daegu, Korea
| | - Hye-Jin Jung
- Department of Biochemistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Ka-Young Ryu
- Craniofacial Nerve-Bone Network Research Center, Kyungpook National University, Daegu, Korea
- Department of Biochemistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Michiko Nakamura
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Korea
- Brain Science & Engineering Institute, Kyungpook National University, Daegu, Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Korea
- Brain Science & Engineering Institute, Kyungpook National University, Daegu, Korea
| | - Su-Hyung Hong
- Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Youngkyun Lee
- Craniofacial Nerve-Bone Network Research Center, Kyungpook National University, Daegu, Korea
- Department of Biochemistry, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Heon-Jin Lee
- Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu, Korea
- Craniofacial Nerve-Bone Network Research Center, Kyungpook National University, Daegu, Korea
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Karthikeyan R, Gayathri P, Ramasamy S, Suvekbala V, Jagannadham MV, Rajendhran J. Transcriptome responses of intestinal epithelial cells induced by membrane vesicles of Listeria monocytogenes. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 4:100185. [PMID: 36942003 PMCID: PMC10023947 DOI: 10.1016/j.crmicr.2023.100185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Abstract
Membrane vesicles (MVs) serve as an essential virulence factor in several pathogenic bacteria. The release of MVs by Listeria monocytogenes is only recently recognized; still, the enigmatic role of MVs in pathogenesis is yet to be established. We report the transcriptome response of Caco-2 cells upon exposure to MVs and the L. monocytogenes that leads to observe the up-regulation of autophagy-related genes in the early phase of exposure to MVs. Transcription of inflammatory cytokines is to the peak at the fourth hour of exposure. An array of differentially expressed genes was associated with actin cytoskeleton rearrangement, autophagy, cell cycle arrest, and induction of oxidative stress. At a later time point, transcriptional programs are generated upon interaction with MVs to evade innate immune signals, by modulating the expression of anti-inflammatory genes. KEGG pathway analysis is palpably confirming that MVs appear principally responsible for the induction of immune signaling pathways. Besides, MVs induced the expression of cell cycle regulatory genes, likely responsible for the ability to prolong host cell survival, thus protecting the replicative niche for L. monocytogenes. Notably, we identified several non-coding RNAs (ncRNAs), possibly involved in the regulation of early manipulation of the host gene expression, essential for the persistence of L. monocytogenes.
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Affiliation(s)
- Raman Karthikeyan
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Pratapa Gayathri
- CSIR - Centre for Cellular and Molecular Biology, Tarnaka, Hyderabad 500007, India
| | - Subbiah Ramasamy
- Department of Biochemistry, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Vemparthan Suvekbala
- EDII-Anna Business Incubation Research Foundation, University College of Engineering, BIT Campus, Anna University, Tiruchirappalli 620024, India
| | - Medicharla V. Jagannadham
- CSIR - Centre for Cellular and Molecular Biology, Tarnaka, Hyderabad 500007, India
- Corresponding authors.
| | - Jeyaprakash Rajendhran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
- Corresponding authors.
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Franczyk B, Gluba-Brzózka A, Rysz-Górzyńska M, Rysz J. The Role of Inflammation and Oxidative Stress in Rheumatic Heart Disease. Int J Mol Sci 2022; 23:ijms232415812. [PMID: 36555452 PMCID: PMC9781220 DOI: 10.3390/ijms232415812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022] Open
Abstract
Rheumatic heart disease (RHD), an acquired valvular disease, remains an important cause of morbidity and mortality in developing countries. This chronic illness starts from untreated streptococcal throat infection, resulting in acute rheumatic fever (ARF) in susceptible individuals. Repeated infections lead to a chronic phase characterized by the damage of heart valves. Inflammation has been found to play important role in the development of this disease. All the studies presented in this review clearly show the involvement of the inflammatory state in the progression of this disease. However, the exact role of cytokines in inflammation sites remains to be examined, since most studies have so far focused on peripheral blood. Such analysis would provide information on inflammatory mechanisms in situ.
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Affiliation(s)
- Beata Franczyk
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, 113 Żeromskiego Street, 90-549 Lodz, Poland
| | - Anna Gluba-Brzózka
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, 113 Żeromskiego Street, 90-549 Lodz, Poland
- Correspondence:
| | - Magdalena Rysz-Górzyńska
- Department of Ophthalmology and Visual Rehabilitation, Medical University of Lodz, 113 Żeromskiego Street, 90-549 Lodz, Poland
| | - Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, 113 Żeromskiego Street, 90-549 Lodz, Poland
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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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Nilsen KE, Skjesol A, Frengen Kojen J, Espevik T, Stenvik J, Yurchenko M. TIRAP/Mal Positively Regulates TLR8-Mediated Signaling via IRF5 in Human Cells. Biomedicines 2022; 10:biomedicines10071476. [PMID: 35884781 PMCID: PMC9312982 DOI: 10.3390/biomedicines10071476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/09/2022] [Accepted: 06/17/2022] [Indexed: 11/21/2022] Open
Abstract
Toll-like receptor 8 (TLR8) recognizes single-stranded RNA of viral and bacterial origin as well as mediates the secretion of pro-inflammatory cytokines and type I interferons by human monocytes and macrophages. TLR8, as other endosomal TLRs, utilizes the MyD88 adaptor protein for initiation of signaling from endosomes. Here, we addressed the potential role of the Toll-interleukin 1 receptor domain-containing adaptor protein (TIRAP) in the regulation of TLR8 signaling in human primary monocyte-derived macrophages (MDMs). To accomplish this, we performed TIRAP gene silencing, followed by the stimulation of cells with synthetic ligands or live bacteria. Cytokine-gene expression and secretion were analyzed by quantitative PCR or Bioplex assays, respectively, while nuclear translocation of transcription factors was addressed by immunofluorescence and imaging, as well as by cell fractionation and immunoblotting. Immunoprecipitation and Akt inhibitors were also used to dissect the signaling mechanisms. Overall, we show that TIRAP is recruited to the TLR8 Myddosome signaling complex, where TIRAP contributes to Akt-kinase activation and the nuclear translocation of interferon regulatory factor 5 (IRF5). Recruitment of TIRAP to the TLR8 signaling complex promotes the expression and secretion of the IRF5-dependent cytokines IFNβ and IL-12p70 as well as, to a lesser degree, TNF. These findings reveal a new and unconventional role of TIRAP in innate immune defense.
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Affiliation(s)
- Kaja Elisabeth Nilsen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Astrid Skjesol
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - June Frengen Kojen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Jørgen Stenvik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, NO-7006 Trondheim, Norway
| | - Maria Yurchenko
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (K.E.N.); (A.S.); (J.F.K.); (T.E.); (J.S.)
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
- Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, NO-7006 Trondheim, Norway
- Correspondence:
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12
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Fejtkova M, Sukova M, Hlozkova K, Skvarova Kramarzova K, Rackova M, Jakubec D, Bakardjieva M, Bloomfield M, Klocperk A, Parackova Z, Sediva A, Aluri J, Novakova M, Kalina T, Fronkova E, Hrusak O, Malcova H, Sedlacek P, Liba Z, Kudr M, Stary J, Cooper MA, Svaton M, Kanderova V. TLR8/TLR7 dysregulation due to a novel TLR8 mutation causes severe autoimmune hemolytic anemia and autoinflammation in identical twins. Am J Hematol 2022; 97:338-351. [PMID: 34981838 DOI: 10.1002/ajh.26452] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022]
Abstract
Our study presents a novel germline c.1715G>T (p.G572V) mutation in the gene encoding Toll-like receptor 8 (TLR8) causing an autoimmune and autoinflammatory disorder in a family with monozygotic male twins, who suffer from severe autoimmune hemolytic anemia worsening with infections, and autoinflammation presenting as fevers, enteritis, arthritis, and CNS vasculitis. The pathogenicity of the mutation was confirmed by in vitro assays on transfected cell lines and primary cells. The p.G572V mutation causes impaired stability of the TLR8 protein, cross-reactivity to TLR7 ligands and reduced ability of TLR8 to attenuate TLR7 signaling. This imbalance toward TLR7-dependent signaling leads to increased pro-inflammatory responses, such as nuclear factor-κB (NF-κB) activation and production of pro-inflammatory cytokines IL-1β, IL-6, and TNFα. This unique TLR8 mutation with partial TLR8 protein loss and hyperinflammatory phenotype mediated by TLR7 ligands represents a novel inborn error of immunity with childhood-onset and a good response to TLR7 inhibition.
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Affiliation(s)
- Martina Fejtkova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Martina Sukova
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Katerina Hlozkova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Karolina Skvarova Kramarzova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Marketa Rackova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - David Jakubec
- Bioinformatics Group, Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Prague Czech Republic
- Department of Software Engineering, Faculty of Mathematics and Physics Charles University Prague Czech Republic
| | - Marina Bakardjieva
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Marketa Bloomfield
- Department of Paediatrics, First Faculty of Medicine Charles University and Thomayer University Hospital Prague Czech Republic
- Department of Immunology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Adam Klocperk
- Department of Immunology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Zuzana Parackova
- Department of Immunology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Anna Sediva
- Department of Immunology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Jahnavi Aluri
- Division of Rheumatology/Immunology, Department of Pediatrics Washington University School of Medicine St. Louis Missouri USA
| | - Michaela Novakova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Tomas Kalina
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Eva Fronkova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Ondrej Hrusak
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Hana Malcova
- Department of Paediatric and Adult Rheumatology University Hospital Motol Prague Czech Republic
| | - Petr Sedlacek
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Zuzana Liba
- Department of Paediatric Neurology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Martin Kudr
- Department of Paediatric Neurology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Jan Stary
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Megan A. Cooper
- Division of Rheumatology/Immunology, Department of Pediatrics Washington University School of Medicine St. Louis Missouri USA
| | - Michael Svaton
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
| | - Veronika Kanderova
- CLIP ‐ Childhood Leukaemia Investigation Prague, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine Charles University and University Hospital Motol Prague Czech Republic
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13
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Ayithan N, Ghosh A, Dwivedi A, Wallin JJ, Tan SK, Chen D, Kottilil S, Poonia B. Oral Selective TLR8 Agonist Selgantolimod Induces Multiple Immune Cell Responses in Humans. Viruses 2021; 13:v13122400. [PMID: 34960669 PMCID: PMC8706304 DOI: 10.3390/v13122400] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/18/2022] Open
Abstract
TLR8 agonists have the potential for use as immunomodulatory components in therapeutic modalities for viral infections such as chronic HBV (CHB) and HIV. In this study, using peripheral blood samples from a phase 1a clinical trial, we examined the acute effects of a single oral administration of a selective TLR8 agonist on immune cell phenotypes. Administration of the TLR8 agonist selgantolimod (SLGN) in healthy individuals resulted in alteration in frequencies of peripheral blood monocytes, pDCs, mDCs and MAIT cells. Frequencies of mDCs and lymphoid cells significantly reduced after 8 h of SLGN administration, whereas pDC frequencies significantly increased, with changes possibly reflecting migration of different cell types between peripheral and tissue compartments in response to the agonist. Myeloid cell activation was evident by an upregulated expression of co-stimulatory molecules CD40 and CD86 accompanied by the production of IL-6 and IL-18 from these cells. Concomitantly, there was induction of the early activation marker CD69 on innate and adaptive lymphoid cells, including MAIT and NK cell subsets. Further, these activated lymphoid cells had enhanced expression of the effector molecules granzyme B and perforin. Microarray analysis of isolated lymphocytes and monocytes from baseline and post-SLGN treatment revealed changes in expression of genes involved in cellular response to cytokine stimulus, innate immune response, myeloid cell differentiation and antigen receptor-mediated signaling pathway. In a preliminary analysis of samples from CHB patients treated with selgantolimod, activation of innate and adaptive lymphocytes was evident. In conclusion, this first in-human study shows that selgantolimod administration in humans results in activation of multiple immune cell responses with antiviral potential.
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Affiliation(s)
- Natarajan Ayithan
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.A.); (A.G.); (S.K.)
| | - Alip Ghosh
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.A.); (A.G.); (S.K.)
| | - Ankit Dwivedi
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Jeffrey J. Wallin
- Gilead Sciences Inc., Foster City, CA 94404, USA; (J.J.W.); (S.K.T.); (D.C.)
| | - Susanna K. Tan
- Gilead Sciences Inc., Foster City, CA 94404, USA; (J.J.W.); (S.K.T.); (D.C.)
| | - Diana Chen
- Gilead Sciences Inc., Foster City, CA 94404, USA; (J.J.W.); (S.K.T.); (D.C.)
| | - Shyam Kottilil
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.A.); (A.G.); (S.K.)
| | - Bhawna Poonia
- Division of Clinical Care and Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.A.); (A.G.); (S.K.)
- Correspondence:
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14
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Serrano R, Coch C, Peters C, Hartmann G, Wesch D, Kabelitz D. Monocyte-dependent co-stimulation of cytokine induction in human γδ T cells by TLR8 RNA ligands. Sci Rep 2021; 11:15231. [PMID: 34315922 PMCID: PMC8316369 DOI: 10.1038/s41598-021-94428-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/05/2021] [Indexed: 01/13/2023] Open
Abstract
Human Vγ9Vδ2 T cells recognize pyrophosphates produced by microbes and transformed cells and play a role in anti-infective immunity and tumor surveillance. Toll-like receptors (TLR) are pattern recognition receptors in innate immune cells which sense microbial structures including nucleic acids. Given that γδ T cells are in clinical development for application in cellular cancer immunotherapy and TLR ligands have potent adjuvant activity, we investigated the co-stimulatory role of selected TLR ligands in γδ T-cell activation. Here we have used recently described RNA ligands for TLR7 and TLR8 together with Vγ9Vδ2 T-cell specific pyrophosphate antigens to analyze the rapid cytokine induction in Vδ2 T cells as well as the accessory cell requirements. While TLR8- as well as TLR7/8-specific RNA did not induce IFN-γ in Vδ2 T cells on their own, they provided strong co-stimulation for Vδ2 T cells within peripheral blood mononuclear cells in the presence of additional T-cell receptor activation. In contrast, TLR7 ligands were ineffective. Purified γδ T cells did not directly respond to TLR8 co-stimulation but required the presence of monocytes. Further experiments revealed a critical role of IL-1β and IL-18, and to a slightly lesser extent of IL-12p70, in the co-stimulation of Vδ2 T cells by TLR8 and TLR7/8 RNA ligands. Results of intracellular cytokine expression were validated by ELISA analysis of cytokines in cell culture supernatants. The cell context-dependent adjuvant activity of TLR8 and TLR7/8 RNA ligands described here might be important for the future optimization of γδ T-cell based cancer immunotherapy.
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Affiliation(s)
- Ruben Serrano
- Institute of Immunology, Christian-Albrechts University of Kiel and University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, Building U30, 24105, Kiel, Germany
| | - Christoph Coch
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Christian Peters
- Institute of Immunology, Christian-Albrechts University of Kiel and University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, Building U30, 24105, Kiel, Germany
| | - Gunther Hartmann
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Daniela Wesch
- Institute of Immunology, Christian-Albrechts University of Kiel and University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, Building U30, 24105, Kiel, Germany
| | - Dieter Kabelitz
- Institute of Immunology, Christian-Albrechts University of Kiel and University Hospital Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, Building U30, 24105, Kiel, Germany.
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15
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Richter J, Brouwer S, Schroder K, Walker MJ. Inflammasome activation and IL-1β signalling in group A Streptococcus disease. Cell Microbiol 2021; 23:e13373. [PMID: 34155776 DOI: 10.1111/cmi.13373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/17/2021] [Indexed: 01/02/2023]
Abstract
Group A Streptococcus (GAS) is a Gram-positive bacterial pathogen that causes significant morbidity and mortality worldwide. Recent clinical evidence suggests that the inflammatory marker interleukin-1β (IL-1β) plays an important role in GAS disease progression, and presents a potential target for therapeutic intervention. Interaction with GAS activates the host inflammasome pathway to stimulate production and secretion of IL-1β, but GAS can also stimulate IL-1β production in an inflammasome-independent manner. This review highlights progress that has been made in understanding the importance of host cell inflammasomes and IL-1 signalling in GAS disease, and explores challenges and unsolved problems in this host-pathogen interaction. TAKE AWAY: Inflammasome signalling during GAS infection is an emerging field of research. GAS modulates the NLRP3 inflammasome pathway through multiple mechanisms. SpeB contributes to IL-1β production independently of the inflammasome pathway. IL-1β signalling can be host-protective, but also drive severe GAS disease.
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Affiliation(s)
- Johanna Richter
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Stephan Brouwer
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Kate Schroder
- Australian Infectious Diseases Research Centre, Institute for Molecular Bioscience and IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
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16
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Markelova N, Glazunova O, Alikina O, Panyukov V, Shavkunov K, Ozoline O. Suppression of Escherichia coli Growth Dynamics via RNAs Secreted by Competing Bacteria. Front Mol Biosci 2021; 8:609979. [PMID: 33937321 PMCID: PMC8082180 DOI: 10.3389/fmolb.2021.609979] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/11/2021] [Indexed: 11/13/2022] Open
Abstract
With the discovery of secreted RNAs, it has become apparent that the biological role of regulatory oligonucleotides likely goes beyond the borders of individual cells. However, the mechanisms of their action are still comprehended only in general terms and mainly for eukaryotic microRNAs, which can interfere with mRNAs even in distant recipient cells. It has recently become clear that bacterial cells lacking interference systems can also respond to eukaryotic microRNAs that have targets in their genomes. However, the question of whether bacteria can perceive information transmitted by oligonucleotides secreted by other prokaryotes remained open. Here we evaluated the fraction of short RNAs secreted by Escherichia coli during individual and mixed growth with Rhodospirillum rubrum or Prevotella copri, and found that in the presence of other bacteria E. coli tends to excrete oligonucleotides homologous to alien genomes. Based on this observation, we selected four RNAs secreted by either R. rubrum or P. copri, together with one E. coli-specific oligonucleotide. Both fragments of R. rubrum 23S-RNA suppressed the growth of E. coli. Of the two fragments secreted by P. copri, one abolished the stimulatory effect of E. coli RNA derived from the 3'-UTR of ProA mRNA, while the other inhibited bacterial growth only in the double-stranded state with complementary RNA. The ability of two RNAs secreted by cohabiting bacteria to enter E. coli cells was demonstrated using confocal microscopy. Since selected E. coli-specific RNA also affected the growth of this bacterium, we conclude that bacterial RNAs can participate in inter- and intraspecies signaling.
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Affiliation(s)
- Natalia Markelova
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Glazunova
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Alikina
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Valeriy Panyukov
- Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Laboratory of Bioinformatics, Institute of Mathematical Problems of Biology, Pushchino, Russia
| | - Konstantin Shavkunov
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Ozoline
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
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17
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Dooley LM, Ahmad TB, Pandey M, Good MF, Kotiw M. Rheumatic heart disease: A review of the current status of global research activity. Autoimmun Rev 2020; 20:102740. [PMID: 33333234 DOI: 10.1016/j.autrev.2020.102740] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/04/2020] [Indexed: 01/17/2023]
Abstract
Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.
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Affiliation(s)
- Leanne M Dooley
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Tarek B Ahmad
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Manisha Pandey
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael F Good
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael Kotiw
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
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18
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Guevara MA, Lu J, Moore RE, Chambers SA, Eastman AJ, Francis JD, Noble KN, Doster RS, Osteen KG, Damo SM, Manning SD, Aronoff DM, Halasa NB, Townsend SD, Gaddy JA. Vitamin D and Streptococci: The Interface of Nutrition, Host Immune Response, and Antimicrobial Activity in Response to Infection. ACS Infect Dis 2020; 6:3131-3140. [PMID: 33170652 DOI: 10.1021/acsinfecdis.0c00666] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Streptococcus species are common causes of human infection. These Gram-positive, encapsulated bacterial pathogens infect diverse anatomic spaces, leading to infections including skin and soft tissue infection, endocarditis, pneumonia, meningitis, sinusitis, otitis media, chorioamnionitis, sepsis, and even death. Risk for streptococcal infection is highest in low- and middle-income countries where micronutrient deficiency is common. Epidemiological data reveal that vitamin D deficiency is associated with enhanced risk of streptococcal infection and cognate disease outcomes. Additionally, vitamin D improves antibacterial defenses by stimulating innate immune processes such as phagocytosis and enhancing production of reactive oxygen species (oxidative burst) and antimicrobial peptides (including cathelicidin and lactoferrin), which are important for efficient killing of bacteria. This review presents the most recent published work that studies interactions between the micronutrient vitamin D, the host immune system, and pathogenic streptococci as well as comparisons with other relevant infection models.
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Affiliation(s)
- Miriam A. Guevara
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Jacky Lu
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Rebecca E. Moore
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Schuyler A. Chambers
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Alison J. Eastman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Jamisha D. Francis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Kristen N. Noble
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Kevin G. Osteen
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee 37212, United States
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Steven M. Damo
- Department of Chemistry, Fisk University, Nashville, Tennessee 37208, United States
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, United States
| | - David M. Aronoff
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Natasha B. Halasa
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Steven D. Townsend
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Jennifer A. Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department of Veterans Affairs, Tennessee Valley Healthcare Systems, Nashville, Tennessee 37212, United States
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19
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Ostendorf T, Zillinger T, Andryka K, Schlee-Guimaraes TM, Schmitz S, Marx S, Bayrak K, Linke R, Salgert S, Wegner J, Grasser T, Bauersachs S, Soltesz L, Hübner MP, Nastaly M, Coch C, Kettwig M, Roehl I, Henneke M, Hoerauf A, Barchet W, Gärtner J, Schlee M, Hartmann G, Bartok E. Immune Sensing of Synthetic, Bacterial, and Protozoan RNA by Toll-like Receptor 8 Requires Coordinated Processing by RNase T2 and RNase 2. Immunity 2020; 52:591-605.e6. [PMID: 32294405 DOI: 10.1016/j.immuni.2020.03.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 01/24/2020] [Accepted: 03/18/2020] [Indexed: 01/13/2023]
Abstract
Human toll-like receptor 8 (TLR8) activation induces a potent T helper-1 (Th1) cell response critical for defense against intracellular pathogens, including protozoa. The receptor harbors two distinct binding sites, uridine and di- and/or trinucleotides, but the RNases upstream of TLR8 remain poorly characterized. We identified two endolysosomal endoribonucleases, RNase T2 and RNase 2, that act synergistically to release uridine from oligoribonucleotides. RNase T2 cleaves preferentially before, and RNase 2 after, uridines. Live bacteria, P. falciparum-infected red blood cells, purified pathogen RNA, and synthetic oligoribonucleotides all required RNase 2 and T2 processing to activate TLR8. Uridine supplementation restored RNA recognition in RNASE2-/- or RNASET2-/- but not RNASE2-/-RNASET2-/- cells. Primary immune cells from RNase T2-hypomorphic patients lacked a response to bacterial RNA but responded robustly to small-molecule TLR8 ligands. Our data identify an essential function of RNase T2 and RNase 2 upstream of TLR8 and provide insight into TLR8 activation.
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Affiliation(s)
- Thomas Ostendorf
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Thomas Zillinger
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Katarzyna Andryka
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | | | - Saskia Schmitz
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Samira Marx
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Kübra Bayrak
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Rebecca Linke
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Sarah Salgert
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Julia Wegner
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Tatjana Grasser
- Axolabs GmbH, Fritz-Hornschuch-Strasse 9, 95326 Kulmbach, Germany
| | - Sonja Bauersachs
- Axolabs GmbH, Fritz-Hornschuch-Strasse 9, 95326 Kulmbach, Germany
| | - Leon Soltesz
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Marc P Hübner
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Maximilian Nastaly
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Christoph Coch
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany; Miltenyi Biotech, Biomedicine Division, Bergisch Gladbach, Germany
| | - Matthias Kettwig
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - Ingo Roehl
- Axolabs GmbH, Fritz-Hornschuch-Strasse 9, 95326 Kulmbach, Germany
| | - Marco Henneke
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Cologne, Germany
| | - Winfried Barchet
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Cologne, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - Martin Schlee
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Gunther Hartmann
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Cologne, Germany
| | - Eva Bartok
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.
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20
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Bhagwani A, Thompson AAR, Farkas L. When Innate Immunity Meets Angiogenesis-The Role of Toll-Like Receptors in Endothelial Cells and Pulmonary Hypertension. Front Med (Lausanne) 2020; 7:352. [PMID: 32850883 PMCID: PMC7410919 DOI: 10.3389/fmed.2020.00352] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/12/2020] [Indexed: 01/16/2023] Open
Abstract
Toll-like receptors serve a central role in innate immunity, but they can also modulate cell function in various non-immune cell types including endothelial cells. Endothelial cells are necessary for the organized function of the vascular system, and part of their fundamental role is also the regulation of immune function and inflammation. In this review, we summarize the current knowledge of how Toll-like receptors contribute to the immune and non-immune functions of the endothelial cells.
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Affiliation(s)
- Aneel Bhagwani
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, United States
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, United States
| | - A. A. Roger Thompson
- Department of Infection, Immunity & Cardiovascular Disease, Faculty of Medicine, Dentistry & Health, University of Sheffield, Sheffield, United Kingdom
| | - Laszlo Farkas
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, United States
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21
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Grabowski M, Bermudez M, Rudolf T, Šribar D, Varga P, Murgueitio MS, Wolber G, Rademann J, Weindl G. Identification and validation of a novel dual small-molecule TLR2/8 antagonist. Biochem Pharmacol 2020; 177:113957. [PMID: 32268138 DOI: 10.1016/j.bcp.2020.113957] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/01/2020] [Indexed: 01/01/2023]
Abstract
Toll-like receptor 2 (TLR2) and TLR8 are involved in the recognition of bacterial and viral components and are linked not only to protective antimicrobial immunity but also to inflammatory diseases. Recently, increasing attention has been paid to the receptor crosstalk between TLR2 and TLR8 to fine-tune innate immune responses. In this study, we report a novel dual TLR2/TLR8 antagonist, compound 24 that was developed by a modeling-guided synthesis approach. The modulator was optimized from the previously reported 1,3-benzothiazole derivative, compound 8. Compound 24 was pharmacologically characterized for the ability to inhibit TLR2- and TLR8-mediated responses in TLR-overexpressing reporter cells and THP-1 macrophages. The modulator showed high efficacy with IC50 values in the low micromolar range for both TLRs, selectivity towards other TLRs and low cytotoxicity. At TLR2, a slight predominance for the TLR2/1 heterodimer was found in reporter cells selectively expressing TLR2/1 or TLR2/6 heterodimers. Concentration ratio analysis in the presence of Pam3CSK4 or Pam2CSK4 indicated non-competitive antagonist behavior at hTLR2. In computational docking studies, a plausible alternative binding mode of compound 24 was predicted for both TLR2 and TLR8. Our results provide evidence that it is feasible to simultaneously and selectively target endosomal- and surface-located TLRs. We identified a small-molecule dual TLR2/8 antagonist that may serve as a valuable pharmacological tool to decipher the role of TLR2/8 co-signaling in inflammation.
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Affiliation(s)
- Maria Grabowski
- Pharmacology and Toxicology, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Marcel Bermudez
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Thomas Rudolf
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Dora Šribar
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Péter Varga
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Manuela S Murgueitio
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Gerhard Wolber
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Jörg Rademann
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Günther Weindl
- Pharmacology and Toxicology, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany; Section Pharmacology and Toxicology, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany.
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22
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Nucleic Acid-Sensing Toll-Like Receptors Play a Dominant Role in Innate Immune Recognition of Pneumococci. mBio 2020; 11:mBio.00415-20. [PMID: 32209688 PMCID: PMC7157524 DOI: 10.1128/mbio.00415-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Streptococcus pneumoniae (or pneumococcus) is a highly prevalent human pathogen. Toll-like receptors (TLRs) function as immune sensors that can trigger host defenses against this bacterium. Defects in TLR-activated signaling pathways, including deficiency in the adaptor protein myeloid differentiation factor 88 (MyD88), are associated with markedly increased susceptibility to infection. However, the individual MyD88-dependent TLRs predominantly involved in antipneumococcal defenses have not been identified yet. Here we find that triple knockout mice simultaneously lacking TLR7, TLR9, and TLR13, which sense the presence of bacterial DNA (TLR9) and RNA (TLR7 and TLR13) in the phagolysosomes of phagocytic cells, display a phenotype that largely resembles that of MyD88-deficient mice and rapidly succumb to pneumococcal pneumonitis due to defective neutrophil influx into the lung. Accordingly, TLR7/9/13 triple knockout resident alveolar macrophages were largely unable to respond to pneumococci with the production of neutrophil-attracting chemokines and cytokines. Mice with single deficiencies of TLR7, TLR9, or TLR13 showed unaltered ability to control lung infection but were moderately more susceptible to encephalitis, in association with a decreased ability of microglia to mount cytokine responses in vitro Our data point to a dominant, tissue-specific role of nucleic acid-sensing pathways in innate immune recognition of S. pneumoniae and also show that endosomal TLRs are largely capable of compensating for the absence of each other, which seems crucial to prevent pneumococci from escaping immune recognition. These results may be useful to develop novel strategies to treat infections by antibiotic-resistant pneumococci based on stimulation of the innate immune system.IMPORTANCE The pneumococcus is a bacterium that frequently causes infections in the lungs, ears, sinus cavities, and meninges. During these infections, body defenses are triggered by tissue-resident cells that use specialized receptors, such as Toll-like receptors (TLRs), to sense the presence of bacteria. We show here that pneumococci are predominantly detected by TLRs that are located inside intracellular vacuoles, including endosomes, where these receptors can sense the presence of nucleic acids released from ingested bacteria. Mice that simultaneously lacked three of these receptors (specifically, TLR7, TLR9, and TLR13) were extremely susceptible to lung infection and rapidly died after inhalation of pneumococci. Moreover, tissue-resident macrophages from these mice were impaired in their ability to respond to the presence of pneumococci by producing inflammatory mediators capable of recruiting polymorphonuclear leucocytes to infection sites. This information may be useful to develop drugs to treat pneumococcal infections, particularly those caused by antibiotic-resistant strains.
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23
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Activation of Human γδ T Cells: Modulation by Toll-Like Receptor 8 Ligands and Role of Monocytes. Cells 2020; 9:cells9030713. [PMID: 32183240 PMCID: PMC7140608 DOI: 10.3390/cells9030713] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 12/23/2022] Open
Abstract
Background: Human Vγ9Vδ2 γδ T cells can kill a variety of cancer cells and have attracted substantial interest for cancer immunotherapy. Toll-like receptor (TLR) ligands are promising adjuvants for cancer immunotherapy, but TLR7/8 ligand Resiquimod has been shown to inhibit CD4 T-cell activation in a monocyte-dependent manner. Therefore, we studied the modulation of human γδ T-cell activation by TLR7/8 ligands. Methods: Peripheral blood mononuclear cells (PBMC) or purified γδ T cells together with purified monocytes were stimulated with zoledronic acid or phosphoantigens in the absence or presence of various imidazoquinoline TLR7 or TLR8 agonists. Read-out systems included interferon-γ induction and cellular expansion of γδ T cells, as well as viability, cell surface antigen modulation, and IL-1β and TNF-α production of monocytes. Results: TLR8 ligand TL8-506 and TLR7/8 ligand Resiquimod (but not TLR7 ligands) rapidly induced IFN-γ expression in γδ T cells within PBMC, and co-stimulated phosphoantigen-induced IFN-γ expression in γδ T cells. On the other hand, TLR8 ligands potently suppressed γδ T-cell expansion in response to zoledronic acid and phosphoantigen. Purified monocytes secreted large amounts of IL-1β and TNF-α when stimulated with TLR8 ligands but simultaneously underwent substantial cell death after 24 h. Conclusions: TLR8 ligand-activated monocytes potently co-stimulate early γδ T-cell activation but failed to provide accessory cell function for in vitro expansion of γδ T cells.
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24
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Shao L, You C, Cao J, Jiang Y, Liu Y, Liu Q. High treatment failure rate is better explained by resistance gene detection than by minimum inhibitory concentration in patients with urogenital Chlamydia trachomatis infection. Int J Infect Dis 2020; 96:121-127. [PMID: 32173573 DOI: 10.1016/j.ijid.2020.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 03/01/2020] [Accepted: 03/06/2020] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE The aim of this study was to investigate the relationships between treatment outcomes of patients with urogenital Chlamydia trachomatis infections and minimum inhibitory concentrations (MICs) and drug resistance genes. METHODS The clinical data of 92 patients diagnosed with Chlamydia trachomatis (C. trachomatis) infections were collected. Of these patients, 28 received regular treatment with azithromycin and 64 received minocycline. All patients underwent three monthly follow-ups after the completion of treatment. The microdilution method was used for the in vitro susceptibility tests. The acquisition of 23S rRNA mutations and presence of the tet(M) gene were detected by gene amplification and sequencing. RESULTS The MICs of azithromycin, clarithromycin, erythromycin, tetracycline, doxycycline, and minocycline were comparable for isolates from the treatment failure and treatment success groups. Higher detection rates of 23S rRNA gene mutations and tet(M) were found in the treatment failure group (57.14% and 71.43%, respectively) than in the treatment success group (14.29% and 30.23%, respectively) (p < 0.05). The A2057G, C2452A, and T2611C gene mutations of 23S rRNA were detected in eight clinical isolates from the azithromycin treatment failure group, while the T2611C gene mutation was detected in one clinical strain from the treatment success group. CONCLUSIONS The detection of resistance genes could better explain the high treatment failure rate than the MIC results in patients with urogenital C. trachomatis infections, highlighting the need for genetic antimicrobial resistance testing in infected patients.
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Affiliation(s)
- Lili Shao
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Cong You
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Junya Cao
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Yong Jiang
- Department of Dermatology and Venereology, The Secondary Hospital of Tianjin Medical University, No. 23 Pingjiang Road, Hexi District, Tianjin 300211, China.
| | - Yuanjun Liu
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Quanzhong Liu
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
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25
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Ehrnström B, Kojen JF, Giambelluca M, Ryan L, Moen SH, Hu Z, Yin H, Mollnes TE, Damås JK, Espevik T, Stenvik J. TLR8 and complement C5 induce cytokine release and thrombin activation in human whole blood challenged with Gram-positive bacteria. J Leukoc Biol 2020; 107:673-683. [PMID: 32083344 DOI: 10.1002/jlb.3a0120-114r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 01/08/2023] Open
Abstract
We recently showed that TLR8 is critical for the detection of Gram-positive bacteria by human monocytes. Here, we hypothesized that TLR8 and complement together regulate antibacterial responses in human blood. Anticoagulated blood was treated with selective inhibitors of TLR8 and/or complement C5, and then challenged with live Streptococcus agalactiae (Group B streptococcus, GBS), Staphylococcus aureus, or Escherichia coli. Cytokine production, plasma membrane permeability, bacterial survival, phagocytosis, and activation of coagulation was examined. GBS and S. aureus, but not E. coli, triggered TLR8-dependent production of IL-12p70, IL-1β, TNF, and IL-6 in fresh human whole blood. In purified polymorphonuclear neutrophils (PMN), GBS and S. aureus induced IL-8 release in part via TLR8, whereas PMN plasma membrane leakage and extracellular DNA levels increased independently of TLR8. TLR8 was more important than C5 for bacteria-induced production of IL-12p70, IL-1β, and TNF in blood, whereas IL-8 release was more C5 dependent. Both TLR8 and C5 induced IL-6 release and activation of prothrombin cleavage, and here their combined effects were additive. Blocking of C5 or C5aR1 attenuated phagocytosis and increased the extracellular growth of GBS in blood, whereas TLR8 inhibition neither reduced phagocytosis nor intracellular killing of GBS and S. aureus. In conclusion, TLR8 is more important than C5 for production of IL-12p70, IL-1β, and TNF upon GBS and S. aureus infection in blood, whereas C5 is central for IL-8 release and phagocytosis. Both TLR8 and C5 mediate IL-6 release and activation of coagulation during challenge with Gram-positive bacteria in blood.
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Affiliation(s)
- Birgitta Ehrnström
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - June F Kojen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Miriam Giambelluca
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Liv Ryan
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Siv H Moen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Zhenyi Hu
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Tom E Mollnes
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Research Laboratory, Nordland Hospital, and K. G. Jebsen TREC, University of Tromsø, Norway.,Department of Immunology, Oslo University Hospital and K. G. Jebsen IRC, University of Oslo, Oslo, Norway
| | - Jan K Damås
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jørgen Stenvik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
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26
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Evankovich J, Lear T, Baldwin C, Chen Y, White V, Villandre J, Londino J, Liu Y, McVerry B, Kitsios GD, Mallampalli RK, Chen BB. Toll-like Receptor 8 Stability Is Regulated by Ring Finger 216 in Response to Circulating MicroRNAs. Am J Respir Cell Mol Biol 2020; 62:157-167. [PMID: 31385713 PMCID: PMC6993540 DOI: 10.1165/rcmb.2018-0373oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 08/01/2019] [Indexed: 01/16/2023] Open
Abstract
TLR8 (Toll-like receptor 8) is an intracellular pattern recognition receptor that senses RNA in endosomes to initiate innate immune signaling through NF-κB, and mechanisms regulating TLR8 protein abundance are not completely understood. Protein degradation is a cellular process controlling protein concentrations, accomplished largely through ubiquitin transfer directed by E3 ligase proteins to substrates. In the present study, we show that TLR8 has a short half-life in THP-1 monocytes (∼1 h) and that TLR8 is ubiquitinated and degraded in the proteasome. Treatment with the TLR8 agonist R848 causes rapid depletion of TLR8 concentrations at early time points, an effect blocked by proteasomal inhibition. We show a novel role for RNF216 (ring finger protein 216), an E3 ligase that targets TLR8 for ubiquitination and degradation. RNF216 overexpression reduces TLR8 concentrations, whereas RNF216 knockdown stabilizes TLR8. We describe a potential role for TLR8 activation by circulating RNA ligands in humans with acute respiratory distress syndrome (ARDS): Plasma and extracted RNA fractions from subjects with ARDS activated TLR8 in vitro. MicroRNA (miRNA) expression profiling revealed several circulating miRNAs from subjects with ARDS. miRNA mimics promoted TLR8 proteasomal degradation in THP-1 cells. These data show that TLR8 proteasomal disposal through RNF216 in response to RNA ligands regulates TLR8 cellular concentrations and may have implications for innate immune signaling. In addition, TLR8 activation by circulating RNA ligands may be a previously underrecognized stimulus contributing to excessive innate immune signaling characteristic of ARDS.
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Affiliation(s)
- John Evankovich
- Department of Medicine, Acute Lung Injury Center of Excellence
| | - Travis Lear
- Department of Environmental and Occupational Health, School of Public Health
| | | | | | - Virginia White
- Department of Medicine, Acute Lung Injury Center of Excellence
| | - John Villandre
- Department of Medicine, Acute Lung Injury Center of Excellence
| | - James Londino
- Department of Medicine, The Ohio State University, Columbus, Ohio; and
| | - Yuan Liu
- Department of Medicine, Acute Lung Injury Center of Excellence
- Aging Institute
- McGowan Institute for Regenerative Medicine
| | - Bryan McVerry
- Department of Medicine, Acute Lung Injury Center of Excellence
| | - Georgios D. Kitsios
- Department of Medicine, Acute Lung Injury Center of Excellence
- Center for Medicine and the Microbiome, and
| | - Rama K. Mallampalli
- Department of Medicine, Acute Lung Injury Center of Excellence
- Department of Medicine, The Ohio State University, Columbus, Ohio; and
- Medical Specialty Service Line, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
| | - Bill B. Chen
- Department of Medicine, Acute Lung Injury Center of Excellence
- Aging Institute
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
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27
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Neutrophil extracellular trap-associated RNA and LL37 enable self-amplifying inflammation in psoriasis. Nat Commun 2020; 11:105. [PMID: 31913271 PMCID: PMC6949246 DOI: 10.1038/s41467-019-13756-4] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/13/2019] [Indexed: 12/21/2022] Open
Abstract
Psoriasis is an inflammatory skin disease with strong neutrophil (PMN) infiltration and high levels of the antimicrobial peptide, LL37. LL37 in complex with DNA and RNA is thought to initiate disease exacerbation via plasmacytoid dendritic cells. However, the source of nucleic acids supposed to start this initial inflammatory event remains unknown. We show here that primary murine and human PMNs mount a fulminant and self-propagating neutrophil extracellular trap (NET) and cytokine response, but independently of the canonical NET component, DNA. Unexpectedly, RNA, which is abundant in NETs and psoriatic but not healthy skin, in complex with LL37 triggered TLR8/TLR13-mediated cytokine and NET release by PMNs in vitro and in vivo. Transfer of NETs to naive human PMNs prompts additional NET release, promoting further inflammation. Our study thus uncovers a self-propagating vicious cycle contributing to chronic inflammation in psoriasis, and NET-associated RNA (naRNA) as a physiologically relevant NET component.
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28
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Lentini G, Famà A, Biondo C, Mohammadi N, Galbo R, Mancuso G, Iannello D, Zummo S, Giardina M, De Gaetano GV, Teti G, Beninati C, Midiri A. Neutrophils Enhance Their Own Influx to Sites of Bacterial Infection via Endosomal TLR-Dependent Cxcl2 Production. THE JOURNAL OF IMMUNOLOGY 2019; 204:660-670. [PMID: 31852751 DOI: 10.4049/jimmunol.1901039] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/19/2019] [Indexed: 12/27/2022]
Abstract
The influx of neutrophils to infection sites is a fundamental step in host defenses against the frequent human pathogen group B Streptococcus (GBS) and other extracellular bacteria. Using a mouse model of GBS-induced peritonitis, we show in this study that the chemokines Cxcl1 and Cxcl2 play distinctive roles in enhancing the recruitment and the antibacterial activities of neutrophils in a manner that is linked to differences in the cellular sources of these mediators. Cell depletion experiments demonstrated that neutrophils make a significant contribution to the in vivo production of Cxcl2 but not Cxcl1. In vitro, neutrophils responded weakly to LPS but released high levels of Cxcl2 after stimulation with GBS or other bacteria. Neutrophil-derived Cxcl2 acted in an autocrinous manner to increase its own production and to enhance antibacterial activities, including the release of oxygen radicals. In both neutrophils and macrophages, the production of Cxcl1/2 largely required the presence of functional UNC93B1, a chaperone protein involved in signaling by endosomal TLRs. Moreover, the phenotype of UNC93B1-defective phagocytes could be recapitulated by the simultaneous absence of TLR7, 9, and 13 but not by the absence of individual TLRs. Collectively, our data show that neutrophils recognize Gram-positive and Gram-negative bacteria by means of multiple phagosomal TLRs, resulting in de novo synthesis of Cxcl2, amplification of neutrophil recruitment, and potentiation of their antibacterial activities. These data may be useful to devise alternative therapeutic strategies aimed at enhancing the recruitment and the functional activities of polymorphonuclear leukocytes during infections caused by antibiotic-resistant bacteria.
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Affiliation(s)
- Germana Lentini
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Agata Famà
- Charybdis Vaccines Srl, 98125 Messina, Italy
| | - Carmelo Biondo
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Nastaran Mohammadi
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Roberta Galbo
- Department of Chemical, Biological, Pharmaceutical Sciences and Environmental Sciences, University of Messina, 98166 Messina, Italy; and
| | - Giuseppe Mancuso
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Daniela Iannello
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Sebastiana Zummo
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | - Miriam Giardina
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
| | | | | | - Concetta Beninati
- Department of Human Pathology, University of Messina, 98125 Messina, Italy.,Scylla Biotech SRL, 98125 Messina, Italy
| | - Angelina Midiri
- Department of Human Pathology, University of Messina, 98125 Messina, Italy
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29
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de Marcken M, Dhaliwal K, Danielsen AC, Gautron AS, Dominguez-Villar M. TLR7 and TLR8 activate distinct pathways in monocytes during RNA virus infection. Sci Signal 2019; 12:12/605/eaaw1347. [DOI: 10.1126/scisignal.aaw1347] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human blood CD14+monocytes are bone marrow–derived white blood cells that sense and respond to pathogens. Although innate immune activation by RNA viruses preferentially occurs through intracellular RIG-I–like receptors, other nucleic acid recognition receptors, such as Toll-like receptors (TLRs), play a role in finely programming the final outcome of virus infection. Here, we dissected how human monocytes respond to infection with either Coxsackie (CV), encephalomyocarditis (EMCV), influenza A (IAV), measles (MV), Sendai (SV), or vesicular stomatitis (VSV) virus. We found that in monocytes, type I interferon (IFN) and cytokine responses to infection were RNA virus specific and differentially involved TLR7 and TLR8, which sense single-stranded RNA. These TLRs activated distinct signaling cascades in monocytes, which correlated with differences in the production of cytokines involved in the polarization of CD4+T helper cells. Furthermore, we found that TLR7 signaling specifically increased expression of the transcription factor FOSL1, which reduced IL-27 and TNFα production by monocytes. TLR7, but not TLR8, activation of monocytes also stimulated Ca2+flux that prevented type I IFN responses. Our work demonstrates that in human monocytes, TLR7 and TLR8 triggered different signaling pathways that contribute to distinct phenotypes during RNA virus infection. In addition, we defined individual targets within these pathways that promoted specific T helper and antiviral responses.
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Affiliation(s)
- Marine de Marcken
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Khushwant Dhaliwal
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520, USA
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30
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Kim ML, Martin WJ, Minigo G, Keeble JL, Garnham AL, Pacini G, Smyth GK, Speed TP, Carapetis J, Wicks IP. Dysregulated IL-1β-GM-CSF Axis in Acute Rheumatic Fever That Is Limited by Hydroxychloroquine. Circulation 2019; 138:2648-2661. [PMID: 30571257 DOI: 10.1161/circulationaha.118.033891] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Acute rheumatic fever (ARF) and rheumatic heart disease are autoimmune consequences of group A streptococcus infection and remain major causes of cardiovascular morbidity and mortality around the world. Improved treatment has been stymied by gaps in understanding key steps in the immunopathogenesis of ARF and rheumatic heart disease. This study aimed to identify (1) effector T cell cytokine(s) that might be dysregulated in the autoimmune response of patients with ARF by group A streptococcus, and (2) an immunomodulatory agent that suppresses this response and could be clinically translatable to high-risk patients with ARF. METHODS The immune response to group A streptococcus was analyzed in peripheral blood mononuclear cells from an Australian Aboriginal ARF cohort by a combination of multiplex cytokine array, flow cytometric analysis, and global gene expression analysis by RNA sequencing. The immunomodulatory drug hydroxychloroquine was tested for effects on this response. RESULTS We found a dysregulated interleukin-1β-granulocyte-macrophage colony-stimulating factor (GM-CSF) cytokine axis in ARF peripheral blood mononuclear cells exposed to group A streptococcus in vitro, whereby persistent interleukin-1β production is coupled to overproduction of GM-CSF and selective expansion of CXCR3+CCR4-CCR6- CD4 T cells. CXCR3+CCR4-CCR6- CD4 T cells are the major source of GM-CSF in human CD4 T cells and CXCL10, a CXCR3 ligand and potent T helper 1 chemoattractant, was elevated in sera from patients with ARF. GM-CSF has recently emerged as a key T cell-derived effector cytokine in numerous autoimmune diseases, including myocarditis, and the production of CXCL10 may explain selective trafficking of these cells to the heart. We provide evidence that interleukin-1β amplifies the expansion of GM-CSF-expressing CD4 T cells, which is effectively suppressed by hydroxychloroquine. RNA sequencing showed shifts in gene expression profiles and differentially expressed genes in peripheral blood mononuclear cells derived from patients at different clinical stages of ARF. CONCLUSIONS Given the safety profile of hydroxychloroquine and its clinical pedigree in treating autoimmune diseases such as rheumatoid arthritis, where GM-CSF plays a pivotal role, we propose that hydroxychloroquine could be repurposed to reduce the risk of rheumatic heart disease after ARF.
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Affiliation(s)
- Man Lyang Kim
- Divisions of Inflammation (M.L.K., W.J.M., J.L.K., I.P.W.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Medical Biology (M.L.K., W.J.M., J.L.K., A.L.G., I.P.W.), University of Melbourne, Parkville, Victoria, Australia
| | - William J Martin
- Divisions of Inflammation (M.L.K., W.J.M., J.L.K., I.P.W.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Medical Biology (M.L.K., W.J.M., J.L.K., A.L.G., I.P.W.), University of Melbourne, Parkville, Victoria, Australia
| | - Gabriela Minigo
- Menzies School of Health Research and Charles Darwin University, Casuarina, Northern Territory, Australia (G.M.)
| | - Joanne L Keeble
- Divisions of Inflammation (M.L.K., W.J.M., J.L.K., I.P.W.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Medical Biology (M.L.K., W.J.M., J.L.K., A.L.G., I.P.W.), University of Melbourne, Parkville, Victoria, Australia
| | - Alexandra L Garnham
- Bioinformatics (A.L.G., G.P., G.K.S., T.P.S.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Medical Biology (M.L.K., W.J.M., J.L.K., A.L.G., I.P.W.), University of Melbourne, Parkville, Victoria, Australia
| | - Guido Pacini
- Bioinformatics (A.L.G., G.P., G.K.S., T.P.S.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Gordon K Smyth
- Bioinformatics (A.L.G., G.P., G.K.S., T.P.S.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Departments of Mathematics and Statistics (G.K.S., T.P.S.), University of Melbourne, Parkville, Victoria, Australia
| | - Terence P Speed
- Bioinformatics (A.L.G., G.P., G.K.S., T.P.S.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Departments of Mathematics and Statistics (G.K.S., T.P.S.), University of Melbourne, Parkville, Victoria, Australia
| | - Jonathan Carapetis
- Telethon Kids Institute, University of Western Australia, Princess Margaret Hospital for Children, Perth, Western Australia (J.C.)
| | - Ian P Wicks
- Divisions of Inflammation (M.L.K., W.J.M., J.L.K., I.P.W.), Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Medical Biology (M.L.K., W.J.M., J.L.K., A.L.G., I.P.W.), University of Melbourne, Parkville, Victoria, Australia.,Rheumatology Unit, Royal Melbourne Hospital, Parkville, Victoria, Australia (I.P.W.)
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31
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Vargas-Lagos C, Martínez D, Oyarzún R, Avendaño-Herrera R, Yáñez AJ, Pontigo JP, Vargas-Chacoff L. High doses of Francisella noatunensis induces an immune response in Eleginops maclovinus. FISH & SHELLFISH IMMUNOLOGY 2019; 90:1-11. [PMID: 31015063 DOI: 10.1016/j.fsi.2019.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Francisella noatunensis subsp. noatunensis, the etiological agent of Francisellosis, affects a large number of farmed species such as Salmo salar. This species coexists with several native species in the same ecosystem, including Eleginops maclovinus. Our objective was to evaluate the susceptibility, presence of clinical symptoms, and the ability of Eleginops maclovinus to respond to Francisella infection. For this, healthy individuals were inoculated with 1.5 × 101, 1.5 × 105, and 1.5 × 1010 bact/μL of Francisella by intraperitoneal injection, subsequently the fish were sampled on days 1, 3, 7, 14, 21, and 28 post injection (dpi). At the end of the experiment, no mortality, nor internal and external clinical signs were observed, although in the high dose anaemia was detected. Additionally, bacteria were detected in all three doses, however there was replication at day 28 only in the liver in the high dose. Analysis of gene expression by qPCR showed that the spleen generated an immune response against infection from day 1 dpi, however at day 7 dpi most of the genes suffered repressed expression; observing over expression of the genes C3, NLRC3, NLRC5, MHCI, IgM. In contrast, expression in the anterior kidney did not vary significantly during the challenge. IgM quantification showed the production of antibodies in the medium and high doses. This study provides new knowledge about Francisella infection and the long-lasting and specific immune response generated by Eleginops maclovinus. It also demonstrates its susceptibility to Francisellosis where there is a difference in the immune response according to the tissue.
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Affiliation(s)
- C Vargas-Lagos
- Programa de Magíster en Ciencias, Mención Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; (c)Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
| | - D Martínez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Programa de Doctorado en Ciencias de La Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - R Oyarzún
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Programa de Doctorado en Ciencias de La Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile
| | - R Avendaño-Herrera
- (c)Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile; Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña Del Mar, Chile
| | - A J Yáñez
- (c)Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile; Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - J P Pontigo
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - L Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
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32
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Freund I, Buhl DK, Boutin S, Kotter A, Pichot F, Marchand V, Vierbuchen T, Heine H, Motorin Y, Helm M, Dalpke AH, Eigenbrod T. 2'- O-methylation within prokaryotic and eukaryotic tRNA inhibits innate immune activation by endosomal Toll-like receptors but does not affect recognition of whole organisms. RNA (NEW YORK, N.Y.) 2019; 25:869-880. [PMID: 31019095 PMCID: PMC6573781 DOI: 10.1261/rna.070243.118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/20/2019] [Indexed: 05/10/2023]
Abstract
Bacterial RNA has emerged as an important activator of innate immune responses by stimulating Toll-like receptors TLR7 and TLR8 in humans. Guanosine 2'-O-methylation at position 18 (Gm18) in bacterial tRNA was shown to antagonize tRNA-induced TLR7/8 activation, suggesting a potential role of Gm18 as an immune escape mechanism. This modification also occurs in eukaryotic tRNA, yet a physiological immune function remained to be tested. We therefore set out to investigate the immune modulatory role of Gm18 in both prokaryotic and eukaryotic microorganisms, Escherichia coli and Saccharomyces cerevisiae, and in human cells. Using RiboMethSeq analysis we show that mutation of trmH in E. coli, trm3 in S. cereviase, and CRISPR/Cas9-induced knockout of TARBP1 in H. sapiens results in loss of Gm18 within tRNA. Lack of Gm18 across the kingdoms resulted in increased immunostimulation of peripheral blood mononuclear cells when activated by tRNA preparations. In E. coli, lack of 2'-O-methyltransferase trmH also enhanced immune stimulatory properties by whole cellular RNA. In contrast, lack of Gm18 in yeasts and human cells did not affect immunostimulation by whole RNA preparations. When using live E. coli bacteria, lack of trmH did not affect overall immune stimulation although we detected a defined TLR8/RNA-dependent gene expression signature upon E. coli infection. Together, these results demonstrate that Gm18 is a global immune inhibitory tRNA modification across the kingdoms and contributes to tRNA recognition by innate immune cells, but as an individual modification has insufficient potency to modulate recognition of the investigated microorganisms.
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Affiliation(s)
- Isabel Freund
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Daniel K Buhl
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Sébastien Boutin
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Annika Kotter
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Florian Pichot
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- IMoPA UMR7365 CNRS-Lorraine University, BioPole Lorraine University, 54500 Vandoeuvre-les-Nancy, France
| | - Virginie Marchand
- UMS2008 IBSLor, CNRS-Lorraine University-INSERM, BioPole Lorraine University, 54500 Vandoeuvre-les-Nancy, France
| | - Tim Vierbuchen
- Division of Innate Immunity, Research Center Borstel, 23845 Borstel, Germany
| | - Holger Heine
- Division of Innate Immunity, Research Center Borstel, 23845 Borstel, Germany
| | - Yuri Motorin
- IMoPA UMR7365 CNRS-Lorraine University, BioPole Lorraine University, 54500 Vandoeuvre-les-Nancy, France
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Alexander H Dalpke
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Institute of Medical Microbiology and Hygiene, Technical University Dresden, 01307 Dresden, Germany
| | - Tatjana Eigenbrod
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
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33
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Moen SH, Ehrnström B, Kojen JF, Yurchenko M, Beckwith KS, Afset JE, Damås JK, Hu Z, Yin H, Espevik T, Stenvik J. Human Toll-like Receptor 8 (TLR8) Is an Important Sensor of Pyogenic Bacteria, and Is Attenuated by Cell Surface TLR Signaling. Front Immunol 2019; 10:1209. [PMID: 31214180 PMCID: PMC6554558 DOI: 10.3389/fimmu.2019.01209] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/13/2019] [Indexed: 11/15/2022] Open
Abstract
TLR8 is an endosomal sensor of RNA degradation products in human phagocytes, and is involved in the recognition of viral and bacterial pathogens. We previously showed that in human primary monocytes and monocyte derived macrophages, TLR8 senses entire Staphylococcus aureus and Streptococcus agalactiae (group B streptococcus, GBS), resulting in the activation of IRF5 and production of IFNβ, IL-12p70, and TNF. However, the quantitative and qualitative impact of TLR8 for the sensing of bacteria have remained unclear because selective inhibitors have been unavailable. Moreover, while we have shown that TLR2 activation attenuates TLR8-IRF5 signaling, the molecular mechanism of this crosstalk is unknown. We here used a recently developed chemical antagonist of TLR8 to determine its role in human primary monocytes challenged with S. aureus, GBS, Streptococcus pneumonia, Pseudomonas aeruginosa, and E. coli. The inhibitor completely blocked cytokine production in monocytes stimulated with TLR8-agonists, but not TLR2-, and TLR4-agonists. Upon challenge with S. aureus, GBS, and S. pneumonia, the TLR8 inhibitor almost eliminated the production of IL-1β and IL-12p70, and it strongly reduced the release of IL-6, TNF, and IL-10. With P. aeruginosa infection, the TLR8 inhibitor impaired the production of IL-12p70 and IL-1β, while with E. coli infection the inhibitor had less effect that varied depending on the strain and conditions. Signaling via TLR2, TLR4, or TLR5, but not TLR8, rapidly eliminated IRAK-1 detection by immunoblotting due to IRAK-1 modifications during activation. Silencing of IRAK-1 reduced the induction of IFNβ and TNF by TLR8 activation, suggesting that IRAK-1 is required for TLR8-IRF5 signaling. The TLR-induced modifications of IRAK-1 also correlated closely with attenuation of TLR8-IRF5 activation, suggesting that sequestration and/or modification of Myddosome components by cell surface TLRs limit the function of TLR8. Accordingly, inhibition of CD14- and TLR4-activation during E. coli challenge increased the activation of IRF5 and the production of IL-1β and IL-12p70. We conclude that TLR8 is a dominating sensor of several species of pyogenic bacteria in human monocytes, while some bacteria attenuate TLR8-signaling via cell surface TLR- activation. Taken together, TLR8 appears as a more important sensor in the antibacterial defense system than previously known.
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Affiliation(s)
- Siv H Moen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Birgitta Ehrnström
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - June F Kojen
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Mariia Yurchenko
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kai S Beckwith
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jan E Afset
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Clinic of Laboratory Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - Jan K Damås
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - Zhenyi Hu
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Hang Yin
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, China
| | - Terje Espevik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jørgen Stenvik
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
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Coch C, Hommertgen B, Zillinger T, Daßler-Plenker J, Putschli B, Nastaly M, Kümmerer BM, Scheunemann JF, Schumak B, Specht S, Schlee M, Barchet W, Hoerauf A, Bartok E, Hartmann G. Human TLR8 Senses RNA From Plasmodium falciparum-Infected Red Blood Cells Which Is Uniquely Required for the IFN-γ Response in NK Cells. Front Immunol 2019; 10:371. [PMID: 30972055 PMCID: PMC6445952 DOI: 10.3389/fimmu.2019.00371] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 02/14/2019] [Indexed: 01/03/2023] Open
Abstract
During blood-stage malaria, the innate immune system initiates the production of pro-inflammatory cytokines, including IFN-γ, that are critical to host defense and responsible for severe disease. Nonetheless, the innate immune pathways activated during this process in human malaria remain poorly understood. Here, we identify TLR8 as an essential sensor of Plasmodium falciparum-infected red blood cells (iRBC). In human immune cells, iRBC and RNA purified from iRBC were detected by TLR8 but not TLR7 leading to IFN-γ induction in NK cells. While TLR7 and 9 have been shown to lead to IFN-γ in mice, our data demonstrate that TLR8 was the only TLR capable of inducing IFN-γ release in human immune cells. This unique capacity was mediated by the release of IL-12p70 and bioactive IL-18 from monocytes, the latter via a hitherto undescribed pathway. Altogether, our data are the first reported activation of TLR8 by protozoan RNA and demonstrate both the critical role of TLR8 in human blood-stage malaria and its unique functionality in the human immune system. Moreover, our study offers important evidence that mouse models alone may not be sufficient to describe the human innate immune response to malaria.
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Affiliation(s)
- Christoph Coch
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Benjamin Hommertgen
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Thomas Zillinger
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Juliane Daßler-Plenker
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Bastian Putschli
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Maximilian Nastaly
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | | | - Johanna F Scheunemann
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Beatrix Schumak
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Martin Schlee
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Winfried Barchet
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Achim Hoerauf
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.,Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Eva Bartok
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Gunther Hartmann
- Department of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
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Abstract
In the past decade, the field of the cellular microbiology of group A Streptococcus (S. pyogenes) infection has made tremendous advances and touched upon several important aspects of pathogenesis, including receptor biology, invasive and evasive phenomena, inflammasome activation, strain-specific autophagic bacterial killing, and virulence factor-mediated programmed cell death. The noteworthy aspect of S. pyogenes-mediated cell signaling is the recognition of the role of M protein in a variety of signaling events, starting with the targeting of specific receptors on the cell surface and on through the induction and evasion of NETosis, inflammasome, and autophagy/xenophagy to pyroptosis and apoptosis. Variations in reports on S. pyogenes-mediated signaling events highlight the complex mechanism of pathogenesis and underscore the importance of the host cell and S. pyogenes strain specificity, as well as in vitro/in vivo experimental parameters. The severity of S. pyogenes infection is, therefore, dependent on the virulence gene expression repertoire in the host environment and on host-specific dynamic signaling events in response to infection. Commonly known as an extracellular pathogen, S. pyogenes finds host macrophages as safe havens wherein it survives and even multiplies. The fact that endothelial cells are inherently deficient in autophagic machinery compared to epithelial cells and macrophages underscores the invasive nature of S. pyogenes and its ability to cause severe systemic diseases. S. pyogenes is still one of the top 10 causes of infectious mortality. Understanding the orchestration of dynamic host signaling networks will provide a better understanding of the increasingly complex mechanism of S. pyogenes diseases and novel ways of therapeutically intervening to thwart severe and often fatal infections.
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36
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Hafner A, Kolbe U, Freund I, Castiglia V, Kovarik P, Poth T, Herster F, Weigand MA, Weber ANR, Dalpke AH, Eigenbrod T. Crucial Role of Nucleic Acid Sensing via Endosomal Toll-Like Receptors for the Defense of Streptococcus pyogenes in vitro and in vivo. Front Immunol 2019; 10:198. [PMID: 30846984 PMCID: PMC6394247 DOI: 10.3389/fimmu.2019.00198] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/23/2019] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pyogenes is a major human pathogen causing a variety of diseases ranging from common pharyngitis to life-threatening soft tissue infections and sepsis. Microbial nucleic acids, especially bacterial RNA, have recently been recognized as a major group of pathogen-associated molecular patterns (PAMPs) involved in the detection of Streptococcus pyogenes via endosomal Toll-like receptors (TLRs) in vitro. However, the individual contribution and cooperation between TLRs as well as cell-type and strain specific differences in dependency on nucleic acid detection during S. pyogenes infection in vitro have not been clarified in detail. Moreover, the role of particularly bacterial RNA for the defense of S. pyogenes infection in vivo remains poorly defined. In this study, we report that in all investigated innate immune cells involved in the resolution of bacterial infections, including murine macrophages, dendritic cells and neutrophils, recognition of S. pyogenes strain ATCC12344 is almost completely dependent on nucleic acid sensing via endosomal TLRs at lower MOIs, whereas at higher MOIs, detection via TLR2 plays an additional, yet redundant role. We further demonstrate that different S. pyogenes strains display a considerable inter-strain variability with respect to their nucleic acid dependent recognition. Moreover, TLR13-dependent recognition of S. pyogenes RNA is largely non-redundant in bone marrow-derived macrophages (BMDMs), but less relevant in neutrophils and bone marrow-derived myeloid dendritic cells (BMDCs) for the induction of an innate immune response in vitro. In vivo, we show that a loss of nucleic acid sensing blunts early recognition of S. pyogenes, leading to a reduced local containment of the bacterial infection with subsequent pronounced systemic inflammation at later time points. Thus, our results argue for a crucial role of nucleic acid sensing via endosomal TLRs in defense of S. pyogenes infection both in vitro and in vivo.
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Affiliation(s)
- Anna Hafner
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Ulrike Kolbe
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany
| | - Isabel Freund
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany
| | - Virginia Castiglia
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Pavel Kovarik
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Tanja Poth
- Center for Model System and Comparative Pathology, Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - Franziska Herster
- Department of Immunology, Interfaculty Institute of Cell Biology, Eberhard-Karls-University, Tübingen, Germany
| | - Markus A. Weigand
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander N. R. Weber
- Department of Immunology, Interfaculty Institute of Cell Biology, Eberhard-Karls-University, Tübingen, Germany
| | - Alexander H. Dalpke
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany
- Institute of Medical Microbiology and Hygiene, Technical University Dresden, Dresden, Germany
| | - Tatjana Eigenbrod
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany
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37
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Vierbuchen T, Stein K, Heine H. RNA is taking its Toll: Impact of RNA-specific Toll-like receptors on health and disease. Allergy 2019; 74:223-235. [PMID: 30475385 DOI: 10.1111/all.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 12/13/2022]
Abstract
RNA-sensing Toll-like receptors (TLRs) are often described as antiviral receptors of the innate immune system. However, the past decade has shown that the function and relevance of these receptors are far more complex. They were found to be essential for the detection of various bacterial, archaeal, and eukaryotic microorganisms and facilitate the discrimination between dead and living microbes. The cytokine and interferon response profile that is triggered has the potential to improve the efficacy of next-generation vaccines and may prevent the development of asthma and allergy. Nevertheless, the ability to recognize foreign RNA comes with a cost as also damaged host cells can release nucleic acids that might induce an inappropriate immune response. Thus, it is not surprising that RNA-sensing TLRs play a key role in various autoimmune diseases. However, promising new inhibitors and antagonists are on the horizon to improve their treatment.
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Affiliation(s)
- Tim Vierbuchen
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
| | - Karina Stein
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
| | - Holger Heine
- Division of Innate Immunity Research Center Borstel – Leibniz Lung Center Borstel Germany
- Airway Research Center North (ARCN) German Center for Lung Research (DZL) Borstel Germany
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38
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RNA Modifications Modulate Activation of Innate Toll-Like Receptors. Genes (Basel) 2019; 10:genes10020092. [PMID: 30699960 PMCID: PMC6410116 DOI: 10.3390/genes10020092] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 12/13/2022] Open
Abstract
Self/foreign discrimination by the innate immune system depends on receptors that identify molecular patterns as associated to pathogens. Among others, this group includes endosomal Toll-like receptors, among which Toll-like receptors (TLR) 3, 7, 8, and 13 recognize and discriminate mammalian from microbial, potentially pathogen-associated, RNA. One of the discriminatory principles is the recognition of endogenous RNA modifications. Previous work has identified a couple of RNA modifications that impede activation of TLR signaling when incorporated in synthetic RNA molecules. Of note, work that is more recent has now shown that RNA modifications in their naturally occurring context can have immune-modulatory functions: Gm, a naturally occurring ribose-methylation within tRNA resulted in a lack of TLR7 stimulation and within a defined sequence context acted as antagonist. Additional RNA modifications with immune-modulatory functions have now been identified and recent work also indicates that RNA modifications within the context of whole prokaryotic or eukaryotic cells are indeed used for immune-modulation. This review will discuss new findings and developments in the field of immune-modulatory RNA modifications.
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39
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Alikina OV, Glazunova OA, Bykov AA, Kiselev SS, Tutukina MN, Shavkunov KS, Ozoline ON. A cohabiting bacterium alters the spectrum of short RNAs secreted by Escherichia coli. FEMS Microbiol Lett 2018; 365:5146451. [PMID: 30376063 DOI: 10.1093/femsle/fny262] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/28/2018] [Indexed: 02/07/2023] Open
Abstract
Recently, it has been found that bacteria secrete short RNAs able to affect gene expression in eukaryotic cells, while certain mammalian microRNAs shape the gut microbiome altering bacterial transcriptome. The involvement of bacterial RNAs in communication with other bacteria is also expected, but has not been documented yet. Here, we compared the fractions of extremely short (12-22 nucleotides) RNAs secreted by Escherichia coli grown in a pure culture and jointly with bacteria of the Paenibacillus genus. Besides fragments of rRNAs and tRNAs, abundant in all samples, secreted oligonucleotides (exoRNAs) predominantly contained GC-rich fragments of messenger and antisense RNAs processed from regions with stable secondary structures. They differed in composition from oligonucleotides of intracellular fraction, where fragments of small regulatory RNAs were prevalent. Both fractions contained RNAs capable of forming complementary duplexes, while for exoRNA samples a higher percentage of 3΄-end modified RNAs and different endonuclease cleavage were detected. The presence of a cohabiting bacterium altered the spectrum of E. coli exoRNAs, indicating a population-dependent control over their composition. Possible mechanisms of this effect are discussed.
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MESH Headings
- Biological Transport
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Genome, Bacterial
- Nucleic Acid Conformation
- RNA, Antisense/chemistry
- RNA, Antisense/genetics
- RNA, Antisense/metabolism
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
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Affiliation(s)
- Olga V Alikina
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Olga A Glazunova
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
- Pushchino Research Center of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Alexandr A Bykov
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Sergey S Kiselev
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Maria N Tutukina
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
- Pushchino Research Center of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Konstantin S Shavkunov
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
- Pushchino Research Center of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
| | - Olga N Ozoline
- Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
- Pushchino Research Center of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russian Federation
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40
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Tatematsu M, Funami K, Seya T, Matsumoto M. Extracellular RNA Sensing by Pattern Recognition Receptors. J Innate Immun 2018; 10:398-406. [PMID: 30404092 PMCID: PMC6784046 DOI: 10.1159/000494034] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/25/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
RNA works as a genome and messenger in RNA viruses, and it sends messages in most of the creatures of the Earth, including viruses, bacteria, fungi, plants, and animals. The human innate immune system has evolved to detect single- and double-stranded RNA molecules from microbes by pattern recognition receptors and induce defense reactions against infections such as the production of type I interferons and inflammatory cytokines. To avoid cytokine toxicity causing chronic inflammation or autoimmunity by sensing self-RNA, the activation of RNA sensors is strictly regulated. All of the Toll-like receptors that recognize RNA are localized to endosomes/lysosomes, which require internalization of RNA for sensing through an endocytic pathway. RIG-I-like receptors sense RNA in cytosol. These receptors are expressed in a cell type-specific fashion, enabling sensing of RNA for a wide range of microbial invasions. At the same time, both endosomal and cytoplasmic receptors have strategies to respond only to RNA of pathogenic microorganisms or dying cells. RNA are potential vaccine adjuvants for immune enhancement against cancer and provide a benefit for vaccinations. Understanding the detailed molecular mechanisms of the RNA-sensing system will help us to broaden the clinical utility of RNA adjuvants for patients with incurable diseases.
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Affiliation(s)
- Megumi Tatematsu
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
- Dr. von Hauner Children's Hospital, Department of Pediatrics, University Hospital, LMU Munich, Munich, Germany
| | - Kenji Funami
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Tsukasa Seya
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Misako Matsumoto
- Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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41
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Exploiting vita-PAMPs in vaccines. Curr Opin Pharmacol 2018; 41:128-136. [PMID: 29890457 DOI: 10.1016/j.coph.2018.05.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 05/21/2018] [Indexed: 01/04/2023]
Abstract
Live attenuated vaccines elicit stronger protective immunity than dead vaccines. Distinct PAMPs designated as vita-PAMPs signify microbial viability to innate immune cells. Two vita-PAMPs have been characterized: cyclic-di-adenosine-monophosphate (c-di-AMP) and prokaryotic messenger RNA (mRNA). c-di-AMP produced by live Gram-positive bacteria elicits augmented production of STING-dependent type-I interferon, whereas prokaryotic mRNA from live bacteria is detected by TLR8 enabling discrimination of live from dead bacteria. Bacterial mRNA from live Gram-negative bacteria triggers a heightened type-I interferon and NLRP3 inflammasome response. By mobilizing unique viability-associated innate responses, vita-PAMPs mobilize adaptive immunity that best elicits protection, including follicular T helper cell and antibody responses. Here, we review the molecular mechanisms that confer the unique adjuvanticity of vita-PAMPs and discuss their applications in vaccine design.
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42
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Bösl K, Giambelluca M, Haug M, Bugge M, Espevik T, Kandasamy RK, Bergstrøm B. Coactivation of TLR2 and TLR8 in Primary Human Monocytes Triggers a Distinct Inflammatory Signaling Response. Front Physiol 2018; 9:618. [PMID: 29896111 PMCID: PMC5986927 DOI: 10.3389/fphys.2018.00618] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/07/2018] [Indexed: 01/04/2023] Open
Abstract
Innate immune signaling is essential to mount a fast and specific immune response to pathogens. Monocytes and macrophages are essential cells in the early response in their capacity as ubiquitous phagocytic cells. They phagocytose microorganisms or damaged cells and sense pathogen/damage-associated molecular patterns (PAMPs/DAMPs) through innate receptors such as Toll-like receptors (TLRs). We investigated a phenomenon where co-signaling from TLR2 and TLR8 in human primary monocytes provides a distinct immune activation profile compared to signaling from either TLR alone. We compare gene signatures induced by either stimulus alone or together and show that co-signaling results in downstream differences in regulation of signaling and gene transcription. We demonstrate that these differences result in altered cytokine profiles between single and multi-receptor signaling, and show how it can influence both T-cell and neutrophil responses. The end response is tailored to combat extracellular pathogens, possibly by modifying the regulation of IFNβ and IL12-family cytokines.
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Affiliation(s)
- Korbinian Bösl
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Miriam Giambelluca
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Markus Haug
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infection, St. Olav's University Hospital, Trondheim, Norway
| | - Marit Bugge
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Richard K Kandasamy
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Bjarte Bergstrøm
- Centre of Molecular Inflammation Research, Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infection, St. Olav's University Hospital, Trondheim, Norway
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43
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Abstract
Pattern recognition receptors (PRRs) survey intra- and extracellular spaces for pathogen-associated molecular patterns (PAMPs) within microbial products of infection. Recognition and binding to cognate PAMP ligand by specific PRRs initiates signaling cascades that culminate in a coordinated intracellular innate immune response designed to control infection. In particular, our immune system has evolved specialized PRRs to discriminate viral nucleic acid from host. These are critical sensors of viral RNA to trigger innate immunity in the vertebrate host. Different families of PRRs of virus infection have been defined and reveal a diversity of PAMP specificity for wide viral pathogen coverage to recognize and extinguish virus infection. In this review, we discuss recent insights in pathogen recognition by the RIG-I-like receptors, related RNA helicases, Toll-like receptors, and other RNA sensor PRRs, to present emerging themes in innate immune signaling during virus infection.
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Affiliation(s)
- Kwan T Chow
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
| | - Michael Gale
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
| | - Yueh-Ming Loo
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
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44
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Ugolini M, Gerhard J, Burkert S, Jensen KJ, Georg P, Ebner F, Volkers SM, Thada S, Dietert K, Bauer L, Schäfer A, Helbig ET, Opitz B, Kurth F, Sur S, Dittrich N, Gaddam S, Conrad ML, Benn CS, Blohm U, Gruber AD, Hutloff A, Hartmann S, Boekschoten MV, Müller M, Jungersen G, Schumann RR, Suttorp N, Sander LE. Recognition of microbial viability via TLR8 drives TFH cell differentiation and vaccine responses. Nat Immunol 2018; 19:386-396. [DOI: 10.1038/s41590-018-0068-4] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 02/15/2018] [Indexed: 11/09/2022]
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45
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Abstract
Group A Streptococcus (GAS) is a leading human bacterial pathogen with diverse clinical manifestations. Macrophages constitute a critical first line of host defense against GAS infection, using numerous surface and intracellular receptors such as Toll-like receptors and inflammasomes for pathogen recognition and activation of inflammatory signaling pathways. Depending on the intensity of the GAS infection, activation of these signaling cascades may provide a beneficial early alarm for effective immune clearance, or conversely, may cause hyperinflammation and tissue injury during severe invasive infection. Although traditionally considered an extracellular pathogen, GAS can invade and replicate within macrophages using specific molecular mechanisms to resist phagolysosomal and xenophagic killing. Unraveling GAS-macrophage encounters may reveal new treatment options for this leading agent of infection-associated mortality. [Formula: see text].
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Affiliation(s)
- J Andrés Valderrama
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA.,Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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46
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Ehrnström B, Beckwith KS, Yurchenko M, Moen SH, Kojen JF, Lentini G, Teti G, Damås JK, Espevik T, Stenvik J. Toll-Like Receptor 8 Is a Major Sensor of Group B Streptococcus But Not Escherichia coli in Human Primary Monocytes and Macrophages. Front Immunol 2017; 8:1243. [PMID: 29042860 PMCID: PMC5632357 DOI: 10.3389/fimmu.2017.01243] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/19/2017] [Indexed: 02/05/2023] Open
Abstract
TLR8 is the major endosomal sensor of degraded RNA in human monocytes and macrophages. It has been implicated in the sensing of viruses and more recently also bacteria. We previously identified a TLR8-IFN regulatory factor 5 (IRF5) signaling pathway that mediates IFNβ and interleukin-12 (IL-12) induction by Staphylococcus aureus and is antagonized by TLR2. The relative importance of TLR8 for the sensing of various bacterial species is however still unclear. We here compared the role of TLR8 and IRF5 for the sensing of Group B Streptococcus (GBS), S. aureus, and Escherichia coli in human primary monocytes and monocyte-derived macrophages (MDM). GBS induced stronger IFNβ and TNF production as well as IRF5 nuclear translocation compared to S. aureus grown to the stationary phase, while S. aureus in exponential growth appeared similarly potent to GBS. Cytokine induction in primary human monocytes by GBS was not dependent on hemolysins, and induction of IFNβ and IL-12 as well as IRF5 activation were reduced with TLR2 ligand costimulation. Heat inactivation of GBS reduced IRF5 and NF-kB translocation, while only the viable E. coli activated IRF5. The attenuated stimulation correlated with loss of bacterial RNA integrity. The E. coli-induced IRF5 translocation was not inhibited by TLR2 costimulation, suggesting that IRF5 was activated via a TLR8-independent mechanism. Gene silencing of MDM using siRNA revealed that GBS-induced IFNβ, IL-12-p35, and TNF production was dependent on TLR8 and IRF5. In contrast, cytokine induction by E. coli was TLR8 independent but still partly dependent on IRF5. We conclude that TLR8-IRF5 signaling is more important for the sensing of GBS than for stationary grown S. aureus in human primary monocytes and MDM, likely due to reduced resistance of GBS to phagosomal degradation and to a lower production of TLR2 activating lipoproteins. TLR8 does not sense viable E. coli, while IRF5 still contributes to E. coli-induced cytokine production, possibly via a cytosolic nucleic acid sensing mechanism.
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Affiliation(s)
- Birgitta Ehrnström
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - Kai Sandvold Beckwith
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Mariia Yurchenko
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Siv Helen Moen
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - June Frengen Kojen
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Germana Lentini
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Giuseppe Teti
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Jan Kristian Damås
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jørgen Stenvik
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Infectious Diseases, Clinic of Medicine, St. Olavs Hospital HF, Trondheim University Hospital, Trondheim, Norway
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47
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Speer EM, Lin X, Murthy A, Hou W, Islam S, Hanna N. Pentoxifylline inhibits lipopolysaccharide-induced inflammatory mediators in human second trimester placenta explants. Placenta 2017; 58:60-66. [DOI: 10.1016/j.placenta.2017.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 11/25/2022]
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48
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Schmitt FCF, Freund I, Weigand MA, Helm M, Dalpke AH, Eigenbrod T. Identification of an optimized 2'- O-methylated trinucleotide RNA motif inhibiting Toll-like receptors 7 and 8. RNA (NEW YORK, N.Y.) 2017; 23:1344-1351. [PMID: 28576825 PMCID: PMC5558904 DOI: 10.1261/rna.061952.117] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/26/2017] [Indexed: 05/20/2023]
Abstract
Bacterial RNA serves an important function as activator of the innate immune system. In humans bacterial RNA is sensed by the endosomal receptors TLR7 and TLR8. Differences in the posttranscriptional modification profile of prokaryotic when compared with eukaryotic RNA allow innate immune cells to discriminate between "host" and "foreign" RNA. Ribose 2'-O-methylation is of particular importance and has been reported to antagonize TLR7/8 activation. Yet, the exact sequence context in which 2'-O-methylation has to occur to mediate its inhibitory activity remains largely undefined. On the basis of a naturally occurring 2'-O-methylated RNA sequence, we performed a systematic permutation of the methylated nucleotide as well as adjacent bases and hereby identify two minimal trinucleotide motifs within a 9-mer oligoribonucleotide that are necessary and sufficient to antagonize TLR7 and TLR8 activation, respectively. Given the growing interest in the development of inhibitors of nucleic acid-sensing TLRs for therapeutic purposes, these results will facilitate the rational design of such antagonists in the future.
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Affiliation(s)
- Felix C F Schmitt
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
- German Center for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany
| | - Isabel Freund
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Markus A Weigand
- Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Alexander H Dalpke
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
- German Center for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany
| | - Tatjana Eigenbrod
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120 Heidelberg, Germany
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49
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Gidon A, Åsberg SE, Louet C, Ryan L, Haug M, Flo TH. Persistent mycobacteria evade an antibacterial program mediated by phagolysosomal TLR7/8/MyD88 in human primary macrophages. PLoS Pathog 2017; 13:e1006551. [PMID: 28806745 PMCID: PMC5570494 DOI: 10.1371/journal.ppat.1006551] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/24/2017] [Accepted: 07/25/2017] [Indexed: 12/20/2022] Open
Abstract
Pathogenic mycobacteria reside in macrophages where they avoid lysosomal targeting and degradation through poorly understood mechanisms proposed to involve arrest of phagosomal maturation at an early endosomal stage. A clear understanding of how this relates to host defenses elicited from various intracellular compartments is also missing and can only be studied using techniques allowing single cell and subcellular analyses. Using confocal imaging of human primary macrophages infected with Mycobacterium avium (Mav) we show evidence that Mav phagosomes are not arrested at an early endosomal stage, but mature to a (LAMP1+/LAMP2+/CD63+) late endosomal/phagolysosomal stage where inflammatory signaling and Mav growth restriction is initiated through a mechanism involving Toll-like receptors (TLR) 7 and 8, the adaptor MyD88 and transcription factors NF-κB and IRF-1. Furthermore, a fraction of the mycobacteria re-establish in a less hostile compartment (LAMP1-/LAMP2-/CD63-) where they not only evade destruction, but also recognition by TLRs, growth restriction and inflammatory host responses that could be detrimental for intracellular survival and establishment of chronic infections. Mycobacterium avium is increasingly reported as a causative agent of non-tuberculous disease in immunocompromised patients and in individuals with underlying disease or using immunosuppressant drugs, with prevalence often higher than the more pathogenic M. tuberculosis in developed countries. Both M. avium and M. tuberculosis cause persistent infections by surviving inside host macrophages. Here, we identify from which compartment M. avium evoke inflammatory signaling in human primary macrophages, and the pattern-recognition receptors involved. In essence, we present three key findings: 1) M. avium phagosomes are not arrested at an early endosomal stage, but rather mature normally into phagolysosomes from where a fraction of the bacteria escape and re-establish in a new compartment. 2) In addition to avoiding degradation in phagolysosomes, by escaping M. avium also evade inflammatory signaling. 3) M. avium unable to escape is degraded in phagolysosomes and recognized by Toll-like receptors 7 and 8. Our results can contribute to new understanding of intracellular infections, and thus have vital clinical implications for development of novel anti-microbial strategies and host-targeted therapy to mycobacterial and other infectious diseases.
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Affiliation(s)
- Alexandre Gidon
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Signe Elisabeth Åsberg
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Claire Louet
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Liv Ryan
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Markus Haug
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
- The Central Norway Regional Health Authority, Trondheim, Norway
| | - Trude Helen Flo
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
- * E-mail:
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Awuh JA, Flo TH. Molecular basis of mycobacterial survival in macrophages. Cell Mol Life Sci 2017; 74:1625-1648. [PMID: 27866220 PMCID: PMC11107535 DOI: 10.1007/s00018-016-2422-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 12/31/2022]
Abstract
Macrophages play an essential role in the immune system by ingesting and degrading invading pathogens, initiating an inflammatory response and instructing adaptive immune cells, and resolving inflammation to restore homeostasis. More interesting is the fact that some bacteria have evolved to use macrophages as a natural habitat and tools of spread in the host, e.g., Mycobacterium tuberculosis (Mtb) and some non-tuberculous mycobacteria (NTM). Mtb is considered one of humanity's most successful pathogens and is the causal agent of tuberculosis, while NTMs cause opportunistic infections all of which are of significant public health concern. Here, we describe mechanisms by which intracellular pathogens, with an emphasis on mycobacteria, manipulate macrophage functions to circumvent killing and live inside these cells even under considerable immunological pressure. Such macrophage functions include the selective evasion or engagement of pattern recognition receptors, production of cytokines, reactive oxygen and nitrogen species, phagosome maturation, as well as other killing mechanisms like autophagy and cell death. A clear understanding of host responses elicited by a specific pathogen and strategies employed by the microbe to evade or exploit these is of significant importance for the development of effective vaccines and targeted immunotherapy against persistent intracellular infections like tuberculosis.
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Affiliation(s)
- Jane Atesoh Awuh
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, PB 8905, 7491, Trondheim, Norway
| | - Trude Helen Flo
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, PB 8905, 7491, Trondheim, Norway.
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