1
|
Xu J, Xie L. Advances in immune response to pulmonary infection: Nonspecificity, specificity and memory. Chronic Dis Transl Med 2023; 9:71-81. [PMID: 37305110 PMCID: PMC10249196 DOI: 10.1002/cdt3.71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 04/02/2023] [Accepted: 04/14/2023] [Indexed: 06/13/2023] Open
Abstract
The lung immune response consists of various cells involved in both innate and adaptive immune processes. Innate immunity participates in immune resistance in a nonspecific manner, whereas adaptive immunity effectively eliminates pathogens through specific recognition. It was previously believed that adaptive immune memory plays a leading role during secondary infections; however, innate immunity is also involved in immune memory. Trained immunity refers to the long-term functional reprogramming of innate immune cells caused by the first infection, which alters the immune response during the second challenge. Tissue resilience limits the tissue damage caused by infection by controlling excessive inflammation and promoting tissue repair. In this review, we summarize the impact of host immunity on the pathophysiological processes of pulmonary infections and discuss the latest progress in this regard. In addition to the factors influencing pathogenic microorganisms, we emphasize the importance of the host response.
Collapse
Affiliation(s)
- Jianqiao Xu
- College of Pulmonary & Critical Care Medicine, 8th Medical CenterChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Lixin Xie
- College of Pulmonary & Critical Care Medicine, 8th Medical CenterChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| |
Collapse
|
2
|
Fraga-Silva TFDC, Boko MMM, Martins NS, Cetlin AA, Russo M, Vianna EO, Bonato VLD. Asthma-associated bacterial infections: Are they protective or deleterious? THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. GLOBAL 2023; 2:14-22. [PMID: 37780109 PMCID: PMC10510013 DOI: 10.1016/j.jacig.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/04/2022] [Accepted: 08/09/2022] [Indexed: 10/03/2023]
Abstract
Eosinophilic, noneosinophilic, or mixed granulocytic inflammations are the hallmarks of asthma heterogeneity. Depending on the priming of lung immune and structural cells, subjects with asthma might generate immune responses that are TH2-prone or TH17-prone immune response. Bacterial infections caused by Haemophilus, Moraxella, or Streptococcus spp. induce the secretion of IL-17, which in turn recruit neutrophils into the airways. Clinical studies and experimental models of asthma indicated that neutrophil infiltration induces a specific phenotype of asthma, characterized by an impaired response to corticosteroid treatment. The understanding of pathways that regulate the TH17-neutrophils axis is critical to delineate and develop host-directed therapies that might control asthma and its exacerbation episodes that course with infectious comorbidities. In this review, we outline clinical and experimental studies on the role of airway epithelial cells, S100A9, and high mobility group box 1, which act in concert with the IL-17-neutrophil axis activated by bacterial infections, and are related with asthma that is difficult to treat. Furthermore, we report critically our view in the light of these findings in an attempt to stimulate further investigations and development of immunotherapies for the control of severe asthma.
Collapse
Affiliation(s)
| | - Mèdéton Mahoussi Michaël Boko
- Basic and Applied Immunology Program, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Núbia Sabrina Martins
- Basic and Applied Immunology Program, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Andrea Antunes Cetlin
- Pulmonary Division, Department of Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Momtchilo Russo
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Elcio Oliveira Vianna
- Pulmonary Division, Department of Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Vania Luiza Deperon Bonato
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
- Basic and Applied Immunology Program, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| |
Collapse
|
3
|
Kennedy II DE, Mody P, Gout JF, Tan W, Seo KS, Olivier AK, Rosch JW, Thornton JA. Contribution of Puma to Inflammatory Resolution During Early Pneumococcal Pneumonia. Front Cell Infect Microbiol 2022; 12:886901. [PMID: 35694536 PMCID: PMC9177954 DOI: 10.3389/fcimb.2022.886901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/25/2022] [Indexed: 11/17/2022] Open
Abstract
Apoptosis of cells at the site of infection is a requirement for shutdown of inflammatory signaling, avoiding tissue damage, and preventing progression of sepsis. Puma+/+ and Puma-/- mice were challenged with TIGR4 strain pneumococcus and cytokines were quantitated from lungs and blood using a magnetic bead panel analysis. Puma-/- mice exhibited higher lung and blood cytokine levels of several major inflammatory cytokines, including IL-6, G-CSF, RANTES, IL-12, IFN-ϒ, and IP-10. Puma-/- mice were more susceptible to bacterial dissemination and exhibited more weight loss than their wild-type counterparts. RNA sequencing analysis of whole pulmonary tissue revealed Puma-dependent regulation of Nrxn2, Adam19, and Eln. Enrichment of gene ontology groups differentially expressed in Puma-/- tissues were strongly correlated to IFN-β and -ϒ signaling. Here, we demonstrate for the first time the role of Puma in prohibition of the cytokine storm during bacterial pneumonia. These findings further suggest a role for targeting immunomodulation of IFN signaling during pulmonary inflammation. Additionally, our findings suggest previously undemonstrated roles for genes encoding regulatory and binding proteins during the early phase of the innate immune response of pneumococcal pneumonia.
Collapse
Affiliation(s)
- Daniel E. Kennedy II
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Perceus Mody
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Jean-Francois Gout
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Wei Tan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Keun Seok Seo
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Alicia K. Olivier
- Department of Population and Pathobiology, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Jason W. Rosch
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Justin A. Thornton
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
- *Correspondence: Justin A. Thornton,
| |
Collapse
|
4
|
Tissue-resident immunity in the lung: a first-line defense at the environmental interface. Semin Immunopathol 2022; 44:827-854. [PMID: 36305904 PMCID: PMC9614767 DOI: 10.1007/s00281-022-00964-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/08/2022] [Indexed: 12/15/2022]
Abstract
The lung is a vital organ that incessantly faces external environmental challenges. Its homeostasis and unimpeded vital function are ensured by the respiratory epithelium working hand in hand with an intricate fine-tuned tissue-resident immune cell network. Lung tissue-resident immune cells span across the innate and adaptive immunity and protect from infectious agents but can also prove to be pathogenic if dysregulated. Here, we review the innate and adaptive immune cell subtypes comprising lung-resident immunity and discuss their ontogeny and role in distinct respiratory diseases. An improved understanding of the role of lung-resident immunity and how its function is dysregulated under pathological conditions can shed light on the pathogenesis of respiratory diseases.
Collapse
|
5
|
Advances on the Role and Applications of Interleukin-1 in Tuberculosis. mBio 2021; 12:e0313421. [PMID: 34809460 PMCID: PMC8609357 DOI: 10.1128/mbio.03134-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interleukin-1 (IL-1) is a key player in the immune response to pathogens due to its role in promoting inflammation and recruiting immune cells to the site of infection. In tuberculosis (TB), tight regulation of IL-1 responses is critical to ensure host resistance to infection while preventing immune pathology. In the mouse model of Mycobacterium tuberculosis infection, both IL-1 absence and overproduction result in exacerbated disease and mortality. In humans, several polymorphisms in the IL1B gene have been associated with increased susceptibility to TB. Importantly, M. tuberculosis itself has evolved several strategies to manipulate and regulate host IL-1 responses for its own benefit. Given all this, IL-1 appears as a promising target for host-directed therapies in TB. However, for that to succeed, more detailed knowledge on the biology and mechanisms of action of IL-1 in vivo, together with a deep understanding of how host-M. tuberculosis interactions modulate IL-1, is required. Here, we discuss the most recent advances in the biology and therapeutic potential of IL-1 in TB as well as the outstanding questions that remain to be answered.
Collapse
|
6
|
Lindenberg M, Almeida L, Dhillon-LaBrooy A, Siegel E, Henriques-Normark B, Sparwasser T. Clarithromycin impairs tissue-resident memory and Th17 responses to macrolide-resistant Streptococcus pneumoniae infections. J Mol Med (Berl) 2021; 99:817-829. [PMID: 33595670 PMCID: PMC8164591 DOI: 10.1007/s00109-021-02039-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/17/2020] [Accepted: 01/12/2021] [Indexed: 01/01/2023]
Abstract
Abstract The increasing prevalence of antimicrobial resistance in pathogens is a growing public health concern, with the potential to compromise the success of infectious disease treatments in the future. Particularly, the number of infections by macrolide antibiotics-resistant Streptococcus pneumoniae is increasing. We show here that Clarithromycin impairs both the frequencies and number of interleukin (IL)-17 producing T helper (Th) 17 cells within the lungs of mice infected with a macrolide-resistant S. pneumoniae serotype 15A strain. Subsequently, the tissue-resident memory CD4+ T cell (Trm) response to a consecutive S. pneumoniae infection was impaired. The number of lung resident IL-17+ CD69+ Trm was diminished upon Clarithromycin treatment during reinfection. Mechanistically, Clarithromycin attenuated phosphorylation of the p90-S6-kinase as part of the ERK pathway in Th17 cells. Moreover, a strong increase in the mitochondrial-mediated maximal respiratory capacity was observed, while mitochondrial protein translation and mTOR sisgnaling were unimpaired. Therefore, treatment with macrolide antibiotics may favor the spread of antimicrobial-resistant pathogens not only by applying a selection pressure but also by decreasing the natural T cell immune response. Clinical administration of macrolide antibiotics as standard therapy procedure during initial hospitalization should be reconsidered accordingly and possibly be withheld until microbial resistance is determined. Key messages • Macrolide-resistant S. pneumoniae infection undergoes immunomodulation by Clarithromycin • Clarithromycin treatment hinders Th17 and tissue-resident memory responses • Macrolide antibiotics impair Th17 differentiation in vitro by ERK-pathway inhibition Supplementary Information The online version contains supplementary material available at 10.1007/s00109-021-02039-5.
Collapse
Affiliation(s)
- Marc Lindenberg
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hanover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hanover, Germany
- German Centre for Infection Research, partner site Hanover-Brunswick, Hanover, Germany
| | - Luis Almeida
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hanover, Germany
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Ayesha Dhillon-LaBrooy
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hanover, Germany
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Ekkehard Siegel
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, MTC, Karolinska Institutet, Stockholm, Sweden
- Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hanover, Germany.
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
| |
Collapse
|
7
|
Berry SB, Haack AJ, Theberge AB, Brighenti S, Svensson M. Host and Pathogen Communication in the Respiratory Tract: Mechanisms and Models of a Complex Signaling Microenvironment. Front Med (Lausanne) 2020; 7:537. [PMID: 33015094 PMCID: PMC7511576 DOI: 10.3389/fmed.2020.00537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/29/2020] [Indexed: 01/15/2023] Open
Abstract
Chronic lung diseases are a leading cause of morbidity and mortality across the globe, encompassing a diverse range of conditions from infections with pathogenic microorganisms to underlying genetic disorders. The respiratory tract represents an active interface with the external environment having the primary immune function of resisting pathogen intrusion and maintaining homeostasis in response to the myriad of stimuli encountered within its microenvironment. To perform these vital functions and prevent lung disorders, a chemical and biological cross-talk occurs in the complex milieu of the lung that mediates and regulates the numerous cellular processes contributing to lung health. In this review, we will focus on the role of cross-talk in chronic lung infections, and discuss how different cell types and signaling pathways contribute to the chronicity of infection(s) and prevent effective immune clearance of pathogens. In the lung microenvironment, pathogens have developed the capacity to evade mucosal immunity using different mechanisms or virulence factors, leading to colonization and infection of the host; such mechanisms include the release of soluble and volatile factors, as well as contact dependent (juxtracrine) interactions. We explore the diverse modes of communication between the host and pathogen in the lung tissue milieu in the context of chronic lung infections. Lastly, we review current methods and approaches used to model and study these host-pathogen interactions in vitro, and the role of these technological platforms in advancing our knowledge about chronic lung diseases.
Collapse
Affiliation(s)
- Samuel B Berry
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.,Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Amanda J Haack
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Ashleigh B Theberge
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Susanna Brighenti
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Mattias Svensson
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
8
|
Dunlap MD, Prince OA, Rangel-Moreno J, Thomas KA, Scordo JM, Torrelles JB, Cox J, Steyn AJC, Zúñiga J, Kaushal D, Khader SA. Formation of Lung Inducible Bronchus Associated Lymphoid Tissue Is Regulated by Mycobacterium tuberculosis Expressed Determinants. Front Immunol 2020; 11:1325. [PMID: 32695111 PMCID: PMC7338767 DOI: 10.3389/fimmu.2020.01325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the causative agent of the infectious disease tuberculosis (TB), which is a leading cause of death worldwide. Approximately one fourth of the world's population is infected with Mtb. A major unresolved question is delineating the inducers of protective long-lasting immune response without inducing overt, lung inflammation. Previous studies have shown that the presence of inducible Bronchus-Associated Lymphoid Tissue (iBALT) correlate with protection from Mtb infection. In this study, we hypothesized that specific Mtb factors could influence the formation of iBALT, thus skewing the outcome of TB disease. We infected non-human primates (NHPs) with a transposon mutant library of Mtb, and identified specific Mtb mutants that were over-represented within iBALT-containing granulomas. A major pathway reflected in these mutants was Mtb cell wall lipid transport and metabolism. We mechanistically addressed the function of one such Mtb mutant lacking mycobacteria membrane protein large 7 (MmpL7), which transports phthiocerol dimycocerosate (PDIM) to the mycobacterial outer membrane (MOM). Accordingly, murine aerosol infection with the Mtb mutant Δmmpl7 correlated with increased iBALT-containing granulomas. Our studies showed that the Δmmpl7 mutant lacking PDIMs on the surface overexpressed diacyl trehaloses (DATs) in the cell wall, which altered the cytokine/chemokine production of epithelial and myeloid cells, thus leading to a dampened inflammatory response. Thus, this study describes an Mtb specific factor that participates in the induction of iBALT formation during TB by directly modulating cytokine and chemokine production in host cells.
Collapse
Affiliation(s)
- Micah D Dunlap
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Oliver A Prince
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | | | - Kimberly A Thomas
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Julia M Scordo
- Texas Biomedical Research Institute, San Antonio, TX, United States
| | | | - Jeffery Cox
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Adrie J C Steyn
- Department of Microbiology, Centers for AIDS Research and Free Radical Biology, University of Alabama at Alabama, Birmingham, AL, United States.,African Health Research Institute (AHRI), Durban, South Africa
| | - Joaquín Zúñiga
- Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Deepak Kaushal
- Texas Biomedical Research Institute, San Antonio, TX, United States.,Division of Bacteriology, Tulane National Primate Research Center, Covington, LA, United States.,Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Shabaana A Khader
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
9
|
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: 7] [Impact Index Per Article: 1.8] [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.
Collapse
|
10
|
Wang R, Wang W, Li A, Wang Y, Jin J, Huang Z, Huang G. Lipopolysaccharide enhances DNA-induced IFN-β expression and autophagy by upregulating cGAS expression in A549 cells. Exp Ther Med 2019; 18:4157-4164. [PMID: 31602251 DOI: 10.3892/etm.2019.8001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 07/05/2019] [Indexed: 12/12/2022] Open
Abstract
Cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) is a newly identified cytosolic DNA sensor, but its function in lung epithelial cells is relatively unknown. In the present study, the effects of lipopolysaccharide (LPS) on the expression and function of cGAS in the A549 lung epithelial cell line was investigated. The cells were treated with LPS at different concentrations (e.g., 100, 200, 400 and 800 ng/ml), and the cGAS expression levels were examined via western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The cells were pretreated with LPS, followed by E. coli DNA transfection using Lipofectamine® 3000. After 24 h, interferon (IFN)-β production was measured using ELISA and the expression of the autophagic markers, microtubule-associated proteins 1A/1B light chain 3 and sequestosome-1, were determined using western blot analysis. The cells were also pretreated with either a toll-like receptor (TLR) 4 inhibitor, a serine/threonine-protein kinase TBK1 (TBK1) inhibitor or an nuclear factor (NF)-κB inhibitor, followed by LPS treatment, and the cGAS expression levels were examined via western blot analysis and RT-qPCR. The result showed that LPS treatment upregulated cGAS expression in a dose-dependent manner. E. coli DNA treatment could induce IFN-β production and autophagy via cGAS, which was enhanced by LPS pretreatment. The effect of LPS on cGAS expression was suppressed by treatment with a TLR4 inhibitor, a TBK1 inhibitor and an NF-κB inhibitor. In conclusion, LPS enhances DNA-induced IFN-β production and autophagy by upregulating cGAS expression through the myeloid differentiation primary response protein MyD88-independent TLR4 signaling pathway in A549 cells.
Collapse
Affiliation(s)
- Rong Wang
- Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Wei Wang
- Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Aili Li
- Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Yongqin Wang
- China-USA Lipids in Health and Disease Research Center, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,Guangxi Key Laboratory of Molecular Medicine in Liver Injury and Repair, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Junfei Jin
- China-USA Lipids in Health and Disease Research Center, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,Guangxi Key Laboratory of Molecular Medicine in Liver Injury and Repair, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Zhaoquan Huang
- Department of Pathology, Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Guojin Huang
- Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,China-USA Lipids in Health and Disease Research Center, Guilin Medical University, Guilin, Guangxi 541001, P.R. China.,Guangxi Key Laboratory of Molecular Medicine in Liver Injury and Repair, Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| |
Collapse
|
11
|
Hughes BM, Burton CS, Reese A, Jabeen MF, Wright C, Willis J, Khoshaein N, Marsh EK, Peachell P, Sun SC, Dockrell DH, Marriott HM, Sabroe I, Condliffe AM, Prince LR. Pellino-1 Regulates Immune Responses to Haemophilus influenzae in Models of Inflammatory Lung Disease. Front Immunol 2019; 10:1721. [PMID: 31417543 PMCID: PMC6685348 DOI: 10.3389/fimmu.2019.01721] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/09/2019] [Indexed: 11/24/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) is a frequent cause of lower respiratory tract infection in people with chronic obstructive pulmonary disease (COPD). Pellino proteins are a family of E3 ubiquitin ligases that are critical regulators of TLR signaling and inflammation. The aim of this study was to identify a role for Pellino-1 in airway defense against NTHi in the context of COPD. Pellino-1 is rapidly upregulated by LPS and NTHi in monocyte-derived macrophages (MDMs) isolated from individuals with COPD and healthy control subjects, in a TLR4 dependent manner. C57BL/6 Peli1−/− and wild-type (WT) mice were subjected to acute (single LPS challenge) or chronic (repeated LPS and elastase challenge) airway inflammation followed by NTHi infection. Both WT and Peli1−/− mice develop airway inflammation in acute and chronic airway inflammation models. Peli1−/− animals recruit significantly more neutrophils to the airway following NTHi infection which is associated with an increase in the neutrophil chemokine, KC, in bronchoalveolar lavage fluid as well as enhanced clearance of NTHi from the lung. These data suggest that therapeutic inhibition of Pellino-1 may augment immune responses in the airway and enhance bacterial clearance in individuals with COPD.
Collapse
Affiliation(s)
- Bethany M Hughes
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Charlotte S Burton
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Abigail Reese
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Maisha F Jabeen
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Carl Wright
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Jessica Willis
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Nika Khoshaein
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Elizabeth K Marsh
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Peter Peachell
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Shao C Sun
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - David H Dockrell
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom.,MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Helen M Marriott
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Ian Sabroe
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Alison M Condliffe
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Lynne R Prince
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| |
Collapse
|
12
|
Liu G, Betts C, Cunoosamy DM, Åberg PM, Hornberg JJ, Sivars KB, Cohen TS. Use of precision cut lung slices as a translational model for the study of lung biology. Respir Res 2019; 20:162. [PMID: 31324219 PMCID: PMC6642541 DOI: 10.1186/s12931-019-1131-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 07/09/2019] [Indexed: 12/28/2022] Open
Abstract
Animal models remain invaluable for study of respiratory diseases, however, translation of data generated in genetically homogeneous animals housed in a clean and well-controlled environment does not necessarily provide insight to the human disease situation. In vitro human systems such as air liquid interface (ALI) cultures and organ-on-a-chip models have attempted to bridge the divide between animal models and human patients. However, although 3D in nature, these models struggle to recreate the architecture and complex cellularity of the airways and parenchyma, and therefore cannot mimic the complex cell-cell interactions in the lung. To address this issue, lung slices have emerged as a useful ex vivo tool for studying the respiratory responses to inflammatory stimuli, infection, and novel drug compounds. This review covers the practicality of precision cut lung slice (PCLS) generation and benefits of this ex vivo culture system in modeling human lung biology and disease pathogenesis.
Collapse
Affiliation(s)
- Guanghui Liu
- RIA Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Catherine Betts
- Pathology, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Danen M Cunoosamy
- Bioscience, Respiratory Inflammation and Autoimmunity, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.,Present Address: Sanofi, Cambridge, MA, USA
| | - Per M Åberg
- RIA Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jorrit J Hornberg
- RIA Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Kinga Balogh Sivars
- RIA Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Taylor S Cohen
- Microbial Sciences, BioPharmaceuticals R&D, AstraZeneca, One Medimmune Way, Gaithersburg, MD, 20877, USA.
| |
Collapse
|
13
|
Mamareli P, Kruse F, Friedrich C, Smit N, Strowig T, Sparwasser T, Lochner M. Epithelium-specific MyD88 signaling, but not DCs or macrophages, control acute intestinal infection with Clostridium difficile. Eur J Immunol 2019; 49:747-757. [PMID: 30802297 DOI: 10.1002/eji.201848022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/21/2019] [Accepted: 02/20/2019] [Indexed: 12/11/2022]
Abstract
Infection with Clostridium difficile is one of the major causes of health care acquired diarrhea and colitis. Signaling though MyD88 downstream of TLRs is critical for initiating the early protective host response in mouse models of C. difficile infection (CDI). In the intestine, MyD88 is expressed in various tissues and cell types, such as the intestinal epithelium and mononuclear phagocytes (MNP), including DC or macrophages. Using a genetic gain-of-function system, we demonstrate here that restricting functional MyD88 signaling to the intestinal epithelium, but also to MNPs is sufficient to protect mice during acute CDI by upregulation of the intestinal barrier function and recruitment of neutrophils. Nevertheless, we also show that mice depleted for CD11c-expressing MNPs in the intestine display no major defects in mounting an effective inflammatory response, indicating that the absence of these cells is irrelevant for inducing host protection during acute infection. Together, our results highlight the importance of epithelial-specific MyD88 signaling and demonstrate that although functional MyD88 signaling in DC and macrophages alone is sufficient to correct the phenotype of MyD88-deficiency, these cells do not seem to be essential for host protection in MyD88-sufficient animals during acute infection with C. difficile.
Collapse
Affiliation(s)
- Panagiota Mamareli
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany.,Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Germany
| | - Friederike Kruse
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Christin Friedrich
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany.,Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany.,Institute of Systems Immunology, University of Würzburg, Würzburg, Germany
| | - Nathiana Smit
- Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Till Strowig
- Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany.,Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Germany
| | - Matthias Lochner
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| |
Collapse
|
14
|
de Porto AP, Liu Z, de Beer R, Florquin S, de Boer OJ, Hendriks RW, van der Poll T, de Vos AF. Btk inhibitor ibrutinib reduces inflammatory myeloid cell responses in the lung during murine pneumococcal pneumonia. Mol Med 2019; 25:3. [PMID: 30646846 PMCID: PMC6332549 DOI: 10.1186/s10020-018-0069-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/21/2018] [Indexed: 12/18/2022] Open
Abstract
Background Streptococcus pneumoniae is a major causative agent in community-acquired pneumonia and sepsis. Overwhelming lung inflammation during pneumococcal pneumonia may hamper lung function. Ibrutinib is an irreversible inhibitor of Bruton’s tyrosine kinase (Btk), a key signaling protein controlling the activation of various immune cells, including macrophages and neutrophils. The aim of this study was to determine whether ibrutinib treatment ameliorates acute lung inflammation during pneumococcal pneumonia. Methods Mice were treated orally with ibrutinib and the effect on acute pulmonary inflammation elicited by the gram-positive bacterial cell wall component lipoteichoic acid (LTA) and during ceftriaxone-treated pneumococcal pneumonia was assessed. Results Treatment with ibrutinib prior to and after intranasal LTA instillation reduced alveolar macrophage activation, neutrophil influx, cytokine release and plasma leakage into the lung. Postponed treatment with ibrutinib supplementing antibiotic therapy during ongoing pneumococcal pneumonia did not impair bacterial killing in lung, blood and spleen. In this setting, ibrutinib reduced alveolar macrophage and systemic neutrophil activation and substantially diminished further monocyte and neutrophil influx in the lung. In vitro, ibrutinib inhibited macrophage TNF secretion and neutrophil activation upon LTA and pneumococcal stimulation. Conclusions Taken together, these data indicate that the Btk inhibitor ibrutinib reduces inflammatory myeloid cell responses during acute pulmonary inflammation evoked by LTA and antibiotic-treated pneumococcal pneumonia and suggest that ibrutinib has the potential to inhibit ongoing lung inflammation in an acute infectious setting. Electronic supplementary material The online version of this article (10.1186/s10020-018-0069-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Alexander P de Porto
- Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-132, 1105, AZ, Amsterdam, the Netherlands. .,Amsterdam Infection and Immunity Institute (AI&II), Amsterdam UMC, Amsterdam, the Netherlands.
| | - Zhe Liu
- Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-132, 1105, AZ, Amsterdam, the Netherlands.,Amsterdam Infection and Immunity Institute (AI&II), Amsterdam UMC, Amsterdam, the Netherlands
| | - Regina de Beer
- Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-132, 1105, AZ, Amsterdam, the Netherlands.,Amsterdam Infection and Immunity Institute (AI&II), Amsterdam UMC, Amsterdam, the Netherlands
| | - Sandrine Florquin
- Department of Pathology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Onno J de Boer
- Department of Pathology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Rudi W Hendriks
- Department of Pulmonary Medicine, Erasmus MC Rotterdam, Rotterdam, The Netherlands
| | - Tom van der Poll
- Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-132, 1105, AZ, Amsterdam, the Netherlands.,Amsterdam Infection and Immunity Institute (AI&II), Amsterdam UMC, Amsterdam, the Netherlands.,Division of Infectious Diseases, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Alex F de Vos
- Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-132, 1105, AZ, Amsterdam, the Netherlands.,Amsterdam Infection and Immunity Institute (AI&II), Amsterdam UMC, Amsterdam, the Netherlands
| |
Collapse
|
15
|
Kirsebom FCM, Kausar F, Nuriev R, Makris S, Johansson C. Neutrophil recruitment and activation are differentially dependent on MyD88/TRIF and MAVS signaling during RSV infection. Mucosal Immunol 2019; 12:1244-1255. [PMID: 31358860 PMCID: PMC6778055 DOI: 10.1038/s41385-019-0190-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 06/14/2019] [Accepted: 06/29/2019] [Indexed: 02/04/2023]
Abstract
Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract infections, especially in infants. Lung neutrophilia is a hallmark of RSV disease but the mechanism by which neutrophils are recruited and activated is unclear. Here, we investigate the innate immune signaling pathways underlying neutrophil recruitment and activation in RSV-infected mice. We show that MyD88/TRIF signaling is essential for lung neutrophil recruitment while MAVS signaling, leading to type I IFN production, is necessary for neutrophil activation. Consistent with that notion, administration of type I IFNs to the lungs of RSV-infected Mavs-/- mice partially activates lung neutrophils recruited via the MyD88/TRIF pathway. Conversely, lack of neutrophil recruitment to the lungs of RSV-infected Myd88/Trif-/- mice can be corrected by administration of chemoattractants and those neutrophils become fully activated. Interestingly, Myd88/Trif-/- mice did not have increased lung viral loads during RSV infection, suggesting that neutrophils are dispensable for viral control. Thus, two distinct pathogen sensing pathways collaborate for neutrophil recruitment and full activation during RSV infection.
Collapse
Affiliation(s)
- Freja C. M. Kirsebom
- 0000 0001 2113 8111grid.7445.2National Heart and Lung Institute, Imperial College London, St Mary’s Hospital, Norfolk Place, London, W2 1PG UK
| | - Fahima Kausar
- 0000 0001 2113 8111grid.7445.2National Heart and Lung Institute, Imperial College London, St Mary’s Hospital, Norfolk Place, London, W2 1PG UK
| | - Rinat Nuriev
- 0000 0001 2113 8111grid.7445.2National Heart and Lung Institute, Imperial College London, St Mary’s Hospital, Norfolk Place, London, W2 1PG UK
| | - Spyridon Makris
- 0000 0001 2113 8111grid.7445.2National Heart and Lung Institute, Imperial College London, St Mary’s Hospital, Norfolk Place, London, W2 1PG UK ,0000000122478951grid.14105.31Present Address: MRC/UCL Lab for Molecular Cell Biology, London, UK
| | - Cecilia Johansson
- 0000 0001 2113 8111grid.7445.2National Heart and Lung Institute, Imperial College London, St Mary’s Hospital, Norfolk Place, London, W2 1PG UK
| |
Collapse
|
16
|
Abstract
Pneumonia is a type of acute lower respiratory infection that is common and severe. The outcome of lower respiratory infection is determined by the degrees to which immunity is protective and inflammation is damaging. Intercellular and interorgan signaling networks coordinate these actions to fight infection and protect the tissue. Cells residing in the lung initiate and steer these responses, with additional immunity effectors recruited from the bloodstream. Responses of extrapulmonary tissues, including the liver, bone marrow, and others, are essential to resistance and resilience. Responses in the lung and extrapulmonary organs can also be counterproductive and drive acute and chronic comorbidities after respiratory infection. This review discusses cell-specific and organ-specific roles in the integrated physiological response to acute lung infection, and the mechanisms by which intercellular and interorgan signaling contribute to host defense and healthy respiratory physiology or to acute lung injury, chronic pulmonary disease, and adverse extrapulmonary sequelae. Pneumonia should no longer be perceived as simply an acute infection of the lung. Pneumonia susceptibility reflects ongoing and poorly understood chronic conditions, and pneumonia results in diverse and often persistent deleterious consequences for multiple physiological systems.
Collapse
Affiliation(s)
- Lee J Quinton
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
| | - Allan J Walkey
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
| | - Joseph P Mizgerd
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
| |
Collapse
|
17
|
Stüve P, Minarrieta L, Erdmann H, Arnold-Schrauf C, Swallow M, Guderian M, Krull F, Hölscher A, Ghorbani P, Behrends J, Abraham WR, Hölscher C, Sparwasser TD, Berod L. De Novo Fatty Acid Synthesis During Mycobacterial Infection Is a Prerequisite for the Function of Highly Proliferative T Cells, But Not for Dendritic Cells or Macrophages. Front Immunol 2018; 9:495. [PMID: 29675017 PMCID: PMC5895737 DOI: 10.3389/fimmu.2018.00495] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/26/2018] [Indexed: 12/21/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis, is able to efficiently manipulate the host immune system establishing chronic infection, yet the underlying mechanisms of immune evasion are not fully understood. Evidence suggests that this pathogen interferes with host cell lipid metabolism to ensure its persistence. Fatty acid metabolism is regulated by acetyl-CoA carboxylase (ACC) 1 and 2; both isoforms catalyze the conversion of acetyl-CoA into malonyl-CoA, but have distinct roles. ACC1 is located in the cytosol, where it regulates de novo fatty acid synthesis (FAS), while ACC2 is associated with the outer mitochondrial membrane, regulating fatty acid oxidation (FAO). In macrophages, mycobacteria induce metabolic changes that lead to the cytosolic accumulation of lipids. This reprogramming impairs macrophage activation and contributes to chronic infection. In dendritic cells (DCs), FAS has been suggested to underlie optimal cytokine production and antigen presentation, but little is known about the metabolic changes occurring in DCs upon mycobacterial infection and how they affect the outcome of the immune response. We therefore determined the role of fatty acid metabolism in myeloid cells and T cells during Mycobacterium bovis BCG or Mtb infection, using novel genetic mouse models that allow cell-specific deletion of ACC1 and ACC2 in DCs, macrophages, or T cells. Our results demonstrate that de novo FAS is induced in DCs and macrophages upon M. bovis BCG infection. However, ACC1 expression in DCs and macrophages is not required to control mycobacteria. Similarly, absence of ACC2 did not influence the ability of DCs and macrophages to cope with infection. Furthermore, deletion of ACC1 in DCs or macrophages had no effect on systemic pro-inflammatory cytokine production or T cell priming, suggesting that FAS is dispensable for an intact innate response against mycobacteria. In contrast, mice with a deletion of ACC1 specifically in T cells fail to generate efficient T helper 1 responses and succumb early to Mtb infection. In summary, our results reveal ACC1-dependent FAS as a crucial mechanism in T cells, but not DCs or macrophages, to fight against mycobacterial infection.
Collapse
Affiliation(s)
- Philipp Stüve
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Lucía Minarrieta
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Hanna Erdmann
- Infection Immunology, Research Center Borstel, Borstel, Germany
| | - Catharina Arnold-Schrauf
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Maxine Swallow
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Melanie Guderian
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Freyja Krull
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | | | - Peyman Ghorbani
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Jochen Behrends
- Core Facility Fluorescence Cytometry, Research Center Borstel, Borstel, Germany
| | - Wolf-Rainer Abraham
- Department of Chemical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Tim D Sparwasser
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Luciana Berod
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| |
Collapse
|
18
|
Expression of Toll-Like Receptor 2 by Dendritic Cells Is Essential for the DnaJ-ΔA146Ply-Mediated Th1 Immune Response against Streptococcus pneumoniae. Infect Immun 2018; 86:IAI.00651-17. [PMID: 29229733 DOI: 10.1128/iai.00651-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/05/2017] [Indexed: 02/07/2023] Open
Abstract
The fusion protein DnaJ-ΔA146Ply could induce cross-protective immunity against pneumococcal infection via mucosal and subcutaneous immunization in mice in the absence of additional adjuvants. DnaJ and Ply are both Toll-like receptor 4 (TLR4) but not TLR2 ligands. However, we found that TLR2-/- mice immunized subcutaneously with DnaJ-ΔA146Ply showed significantly lower survival rates and higher bacterial loads in nasal washes than did wild-type (WT) mice after being challenged with pneumococcal strain D39 or 19F. The gamma interferon (IFN-γ) level in splenocytes decreased in TLR2-/- mice, indicating that Th1 immunity elicited by DnaJ-ΔA146Ply was impaired in these mice. We explored the mechanism of protective immunity conferred by DnaJ-ΔA146Ply and the role of TLR2 in this process. DnaJ-ΔA146Ply effectively promoted dendritic cell (DC) maturation via TLR4 but not the TLR2 signaling pathway. In a DnaJ-ΔA146Ply-treated DC and naive CD4+ T cell coculture system, the deficiency of TLR2 in DCs resulted in a significant decline of IFN-γ production and Th1 subset differentiation. The same effect was observed in adoptive-transfer experiments. In addition, TLR2-/- DCs showed remarkably lower levels of the Th1-polarizing cytokine IL-12p70 than did WT DCs, suggesting that TLR2 was indispensable for DnaJ-ΔA146Ply-induced IL-12 production and Th1 proliferation. Thus, our findings illustrate that dendritic cell expression of TLR2 is essential for optimal Th1 immune response against pneumococci in mice immunized subcutaneously with DnaJ-ΔA146Ply.
Collapse
|
19
|
Puttur F, Francozo M, Solmaz G, Bueno C, Lindenberg M, Gohmert M, Swallow M, Tufa D, Jacobs R, Lienenklaus S, Kühl AA, Borkner L, Cicin-Sain L, Holzmann B, Wagner H, Berod L, Sparwasser T. Conventional Dendritic Cells Confer Protection against Mouse Cytomegalovirus Infection via TLR9 and MyD88 Signaling. Cell Rep 2017; 17:1113-1127. [PMID: 27760315 DOI: 10.1016/j.celrep.2016.09.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 08/09/2016] [Accepted: 09/16/2016] [Indexed: 12/17/2022] Open
Abstract
Cytomegalovirus (CMV) is an opportunistic virus severely infecting immunocompromised individuals. In mice, endosomal Toll-like receptor 9 (TLR9) and downstream myeloid differentiation factor 88 (MyD88) are central to activating innate immune responses against mouse CMV (MCMV). In this respect, the cell-specific contribution of these pathways in initiating anti-MCMV immunity remains unclear. Using transgenic mice, we demonstrate that TLR9/MyD88 signaling selectively in CD11c+ dendritic cells (DCs) strongly enhances MCMV clearance by boosting natural killer (NK) cell CD69 expression and IFN-γ production. In addition, we show that in the absence of plasmacytoid DCs (pDCs), conventional DCs (cDCs) promote robust NK cell effector function and MCMV clearance in a TLR9/MyD88-dependent manner. Simultaneously, cDC-derived IL-15 regulates NK cell degranulation by TLR9/MyD88-independent mechanisms. Overall, we compartmentalize the cellular contribution of TLR9 and MyD88 signaling in individual DC subsets and evaluate the mechanism by which cDCs control MCMV immunity.
Collapse
Affiliation(s)
- Franz Puttur
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Marcela Francozo
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany; Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Gülhas Solmaz
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Carlos Bueno
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany; Laboratorio de Virología, Departamento de Química Biológica, IQUIBICEN, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
| | - Marc Lindenberg
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Melanie Gohmert
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Maxine Swallow
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Dejene Tufa
- Department of Clinical Immunology and Rheumatology, MHH, 30625 Hannover, Germany
| | - Roland Jacobs
- Department of Clinical Immunology and Rheumatology, MHH, 30625 Hannover, Germany
| | - Stefan Lienenklaus
- Institute for Laboratory Animal Science, MHH, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany; Institute for Experimental Infection Research, Twincore, MHH and HZI, Feodor-Lynen-Strasse 7, 30625 Hannover, Germany
| | - Anja A Kühl
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology)/Research Center ImmunoScience, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12200 Berlin, Germany
| | - Lisa Borkner
- Department for Vaccinology/Immune Aging and Chronic Infection, HZI, 38124 Braunschweig, Germany
| | - Luka Cicin-Sain
- Department for Vaccinology/Immune Aging and Chronic Infection, HZI, 38124 Braunschweig, Germany
| | - Bernard Holzmann
- Department of Surgery, Technische Universität München, 81675 Munich, Germany
| | - Hermann Wagner
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, 81675 Munich, Germany
| | - Luciana Berod
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany
| | - Tim Sparwasser
- Institute of Infection Immunology, Centre for Experimental and Clinical Infection Research (Twincore), Hannover Medical School (MHH) and Helmholtz Centre for Infection Research (HZI), 30625 Hannover, Germany.
| |
Collapse
|
20
|
Anas AA, Claushuis TAM, Mohan RA, Christoffels VM, Aidinis V, Florquin S, Van't Veer C, Hou B, de Vos AF, van der Poll T. Epithelial Myeloid-Differentiation Factor 88 Is Dispensable during Klebsiella Pneumonia. Am J Respir Cell Mol Biol 2017; 56:648-656. [PMID: 28187270 DOI: 10.1165/rcmb.2016-0190oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Klebsiella pneumoniae is a common cause of pneumonia. Previous studies have documented an important role for Toll-like receptors (TLRs) expressed by myeloid cells in the recognition of K. pneumoniae and the initiation of a protective immune response. Lung epithelial cells also express TLRs and can participate in innate immune defense. The aim of this study was to examine the role of the common TLR adaptor protein myeloid-differentiation factor (MyD) 88 in lung epithelium during host defense against K. pneumoniae-induced pneumonia. To this end, we first crossed mice expressing cre recombinase under the control of the surfactant protein C (SftpCcre) or the club cell 10 kD (CC10cre) promoter with reporter mice to show that SftpCcre mice mainly express cre in type II alveolar cells, whereas CC10cre mice express cre almost exclusively in bronchiolar epithelial cells. We then generated mice with cell-targeted deletion of MyD88 in type II alveolar (SftpCcre-MyD88-lox) and bronchiolar epithelial (CC10cre-MyD88-lox) cells, and infected them with K. pneumoniae via the airways. Bacterial growth and dissemination were not affected by the loss of MyD88 in SftpCcre-MyD88-lox or CC10cre-MyD88-lox mice compared with control littermates. Furthermore, inflammatory responses induced by K. pneumoniae in the lung were not dependent on MyD88 expression in type II alveolar or bronchiolar epithelial cells. These results indicate that MyD88 expression in two distinct lung epithelial cell types does not contribute to host defense during pneumonia caused by a common human gram-negative pathogen.
Collapse
Affiliation(s)
- Adam A Anas
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,2 Center of Experimental and Molecular Medicine
| | - Theodora A M Claushuis
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,2 Center of Experimental and Molecular Medicine
| | - Rajiv A Mohan
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,3 Department of Anatomy, Embryology, and Physiology, and
| | - Vincent M Christoffels
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,3 Department of Anatomy, Embryology, and Physiology, and
| | - Vassilis Aidinis
- 4 Division of Immunology, Biomedical Sciences Research Center Alexander Flemming, Athens, Greece
| | - Sandrine Florquin
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,5 Department of Pathology
| | - Cornelis Van't Veer
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,2 Center of Experimental and Molecular Medicine
| | - Baidong Hou
- 6 Institute of Biophysics, Chaoyang District, Beijing, China; and
| | - Alex F de Vos
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,2 Center of Experimental and Molecular Medicine
| | - Tom van der Poll
- 1 Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,2 Center of Experimental and Molecular Medicine.,7 Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
21
|
MyD88 signaling in dendritic cells and the intestinal epithelium controls immunity against intestinal infection with C. rodentium. PLoS Pathog 2017; 13:e1006357. [PMID: 28520792 PMCID: PMC5433783 DOI: 10.1371/journal.ppat.1006357] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 04/18/2017] [Indexed: 12/29/2022] Open
Abstract
MyD88-mediated signaling downstream of Toll-like receptors and the IL-1 receptor family is critically involved in the induction of protective host responses upon infections. Although it is known that MyD88-deficient mice are highly susceptible to a wide range of bacterial infections, the cell type-specific contribution of MyD88 in protecting the host against intestinal bacterial infection is only poorly understood. In order to investigate the importance of MyD88 in specific immune and nonimmune cell types during intestinal infection, we employed a novel murine knock-in model for MyD88 that enables the cell type-specific reactivation of functional MyD88 expression in otherwise MyD88-deficient mice. We report here that functional MyD88 signaling in CD11c+ cells was sufficient to activate intestinal dendritic cells (DC) and to induce the early group 3 innate lymphoid cell (ILC3) response as well as the development of colonic Th17/Th1 cells in response to infection with the intestinal pathogen C. rodentium. In contrast, restricting MyD88 signaling to several other cell types, including macrophages (MO), T cells or ILC3 did not induce efficient intestinal immune responses upon infection. However, we observed that the functional expression of MyD88 in intestinal epithelial cells (IEC) also partially protected the mice during intestinal infection, which was associated with enhanced epithelial barrier integrity and increased expression of the antimicrobial peptide RegIIIγ and the acute phase protein SAA1 by epithelial cells. Together, our data suggest that MyD88 signaling in DC and IEC is both essential and sufficient to induce a full spectrum of host responses upon intestinal infection with C. rodentium. MyD88-dependent signaling pathways play a critical role in the protective immune response during intestinal infections. However, the significance of MyD88-mediated signaling in specific intestinal immune and nonimmune cell types for the activation of the early innate, adaptive and epithelial host responses upon infection remains poorly understood. Using a novel knock-in mouse model for MyD88, we report here that MyD88 signaling in CD11c+ dendritic cells (DC) is sufficient to activate RORγt+ group 3 innate lymphoid cells (ILC3) as well as Th17/Th1 cells in response to infection with C. rodentium. In contrast, restricting functional MyD88 signaling to several other immune cell types, including macrophages (MO), T cells and ILC3 did not result in intestinal immunity, while expression of MyD88 in intestinal epithelial cells (IEC) mainly enhanced epithelial barrier integrity. Together, our data suggest that MyD88 signaling in DC and IEC is both essential and sufficient to induce a full spectrum of host responses upon intestinal infection with C. rodentium.
Collapse
|
22
|
Dorward DA, Lucas CD, Doherty MK, Chapman GB, Scholefield EJ, Conway Morris A, Felton JM, Kipari T, Humphries DC, Robb CT, Simpson AJ, Whitfield PD, Haslett C, Dhaliwal K, Rossi AG. Novel role for endogenous mitochondrial formylated peptide-driven formyl peptide receptor 1 signalling in acute respiratory distress syndrome. Thorax 2017; 72:928-936. [PMID: 28469031 PMCID: PMC5738532 DOI: 10.1136/thoraxjnl-2017-210030] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/28/2017] [Accepted: 04/02/2017] [Indexed: 01/23/2023]
Abstract
Background Acute respiratory distress syndrome (ARDS) is an often fatal neutrophil-dominant lung disease. Although influenced by multiple proinflammatory mediators, identification of suitable therapeutic candidates remains elusive. We aimed to delineate the presence of mitochondrial formylated peptides in ARDS and characterise the functional importance of formyl peptide receptor 1 (FPR1) signalling in sterile lung inflammation. Methods Mitochondrial formylated peptides were identified in bronchoalveolar lavage fluid (BALF) and serum of patients with ARDS by liquid chromatography–tandem mass spectrometry. In vitro, human neutrophils were stimulated with mitochondrial formylated peptides and their effects assessed by flow cytometry and chemotaxis assay. Mouse lung injury was induced by mitochondrial formylated peptides or hydrochloric acid. Bone marrow chimeras determined the contribution of myeloid and parenchymal FPR1 to sterile lung inflammation. Results Mitochondrial formylated peptides were elevated in BALF and serum from patients with ARDS. These peptides drove neutrophil activation and chemotaxis through FPR1-dependent mechanisms in vitro and in vivo. In mouse lung injury, inflammation was attenuated in Fpr1−/− mice, effects recapitulated by a pharmacological FPR1 antagonist even when administered after the onset of injury. FPR1 expression was present in alveolar epithelium and chimeric mice demonstrated that both myeloid and parenchymal FPR1 contributed to lung inflammation. Conclusions We provide the first definitive evidence of mitochondrial formylated peptides in human disease and demonstrate them to be elevated in ARDS and important in a mouse model of lung injury. This work reveals mitochondrial formylated peptide FPR1 signalling as a key driver of sterile acute lung injury and a potential therapeutic target in ARDS.
Collapse
Affiliation(s)
- David A Dorward
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Christopher D Lucas
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Mary K Doherty
- Department of Diabetes and Cardiovascular Science, Division of Health Research, University of the Highlands and Islands, Inverness, UK
| | - Gavin B Chapman
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Emma J Scholefield
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | | | - Jennifer M Felton
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Tiina Kipari
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Duncan C Humphries
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Calum T Robb
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - A John Simpson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Phillip D Whitfield
- Department of Diabetes and Cardiovascular Science, Division of Health Research, University of the Highlands and Islands, Inverness, UK
| | - Christopher Haslett
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Kevin Dhaliwal
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Adriano G Rossi
- The MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
23
|
Metabolites: deciphering the molecular language between DCs and their environment. Semin Immunopathol 2016; 39:177-198. [PMID: 27921148 DOI: 10.1007/s00281-016-0609-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 11/14/2016] [Indexed: 02/07/2023]
Abstract
Dendritic cells (DCs) determine the outcome of the immune response based on signals they receive from the environment. Presentation of antigen under various contexts can lead to activation and differentiation of T cells for immunity or dampening of immune responses by establishing tolerance, primarily through the priming of regulatory T cells. Infections, inflammation and normal cellular interactions shape DC responses through direct contact or via cytokine signaling. Although it is widely accepted that DCs sense microbial components through pattern recognition receptors (PRRs), increasing evidence advocates for the existence of a set of signals that can profoundly shape DC function via PRR-independent pathways. This diverse group of host- or commensal-derived metabolites represents a newly appreciated code from which DCs can interpret environmental cues. In this review, we discuss the existing information on the effect of some of the most studied metabolites on DC function, together with the implications this may have in immune-mediated diseases.
Collapse
|