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da Silveira BP, Barhoumi R, Bray JM, Cole-Pfeiffer HM, Mabry CJ, Burghardt RC, Cohen ND, Bordin AI. Impact of surface receptors TLR2, CR3, and FcγRIII on Rhodococcus equi phagocytosis and intracellular survival in macrophages. Infect Immun 2024; 92:e0038323. [PMID: 38018994 PMCID: PMC10790823 DOI: 10.1128/iai.00383-23] [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: 09/21/2023] [Accepted: 10/26/2023] [Indexed: 11/30/2023] Open
Abstract
The virulence-associated protein A (VapA) produced by virulent Rhodococcus equi allows it to replicate in macrophages and cause pneumonia in foals. It is unknown how VapA interacts with mammalian cell receptors, but intracellular replication of avirulent R. equi lacking vapA can be restored by supplementation with recombinant VapA (rVapA). Our objectives were to determine whether the absence of the surface receptors Toll-like receptor 2 (TLR2), complement receptor 3 (CR3), or Fc gamma receptor III (FcγRIII) impacts R. equi phagocytosis and intracellular replication in macrophages, and whether rVapA restoration of virulence in R. equi is dependent upon these receptors. Wild-type (WT) murine macrophages with TLR2, CR3, or FcγRIII blocked or knocked out (KO) were infected with virulent or avirulent R. equi, with or without rVapA supplementation. Quantitative bacterial culture and immunofluorescence imaging were performed. Phagocytosis of R. equi was not affected by blockade or KO of TLR2 or CR3. Intracellular replication of virulent R. equi was not affected by TLR2, CR3, or FcγRIII blockade or KO; however, avirulent R. equi replicated in TLR2-/- and CR3-/- macrophages but not in WT and FcγRIII-/-. rVapA supplementation did not affect avirulent R. equi phagocytosis but promoted intracellular replication in WT and all KO cells. By demonstrating that TLR2 and CR3 limit replication of avirulent but not virulent R. equi and that VapA-mediated virulence is independent of TLR2, CR3, or FcγRIII, our study provides novel insights into the role of these specific surface receptors in determining the entry and intracellular fate of R. equi.
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Affiliation(s)
- Bibiana Petri da Silveira
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Rola Barhoumi
- Department of Veterinary Integrative Biosciences, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Jocelyne M. Bray
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Hannah M. Cole-Pfeiffer
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Cory J. Mabry
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Robert C. Burghardt
- Department of Veterinary Integrative Biosciences, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Noah D. Cohen
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Angela I. Bordin
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
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2
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Karam J, Blanchet FP, Vivès É, Boisguérin P, Boudehen YM, Kremer L, Daher W. Mycobacterium abscessus alkyl hydroperoxide reductase C promotes cell invasion by binding to tetraspanin CD81. iScience 2023; 26:106042. [PMID: 36818301 PMCID: PMC9929602 DOI: 10.1016/j.isci.2023.106042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/19/2022] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Mycobacterium abscessus (Mab) is an increasingly recognized pulmonary pathogen. How Mab is internalized by macrophages and establishes infection remains unknown. Here, we show that Mab uptake is significantly reduced in macrophages pre-incubated with neutralizing anti-CD81 antibodies or in cells in which the large extracellular loop (LEL) of CD81 has been deleted. Saturation of Mab with either soluble GST-CD81-LEL or CD81-LEL-derived peptides also diminished internalization of the bacilli. The mycobacterial alkyl hydroperoxide reductase C (AhpC) was unveiled as a major interactant of CD81-LEL. Pre-exposure of macrophages with soluble AhpC inhibited mycobacterial uptake whereas overexpression of AhpC in Mab enhanced its internalization. Importantly, pre-incubation of macrophages with anti-CD81-LEL antibodies inhibited phagocytosis of AhpC-coated beads, indicating that AhpC is a direct interactant of CD81-LEL. Conditional depletion of AhpC in Mab correlated with decreased internalization of Mab. These compelling data unravel a previously unexplored role for CD81/AhpC to promote uptake of pathogenic mycobacteria by host cells.
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Affiliation(s)
- Jona Karam
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Fabien P. Blanchet
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France,INSERM, IRIM, 34293 Montpellier, France
| | - Éric Vivès
- PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR, 9214 Montpellier, France
| | - Prisca Boisguérin
- PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR, 9214 Montpellier, France
| | - Yves-Marie Boudehen
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France,INSERM, IRIM, 34293 Montpellier, France,Corresponding author
| | - Wassim Daher
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France,INSERM, IRIM, 34293 Montpellier, France,Corresponding author
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3
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Negi K, Bhaskar A, Dwivedi VP. Progressive Host-Directed Strategies to Potentiate BCG Vaccination Against Tuberculosis. Front Immunol 2022; 13:944183. [PMID: 35967410 PMCID: PMC9365942 DOI: 10.3389/fimmu.2022.944183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
The pursuit to improve the TB control program comprising one approved vaccine, M. bovis Bacille Calmette-Guerin (BCG) has directed researchers to explore progressive approaches to halt the eternal TB pandemic. Mycobacterium tuberculosis (M.tb) was first identified as the causative agent of TB in 1882 by Dr. Robert Koch. However, TB has plagued living beings since ancient times and continues to endure as an eternal scourge ravaging even with existing chemoprophylaxis and preventive therapy. We have scientifically come a long way since then, but despite accessibility to the standard antimycobacterial antibiotics and prophylactic vaccine, almost one-fourth of humankind is infected latently with M.tb. Existing therapeutics fail to control TB, due to the upsurge of drug-resistant strains and increasing incidents of co-infections in immune-compromised individuals. Unresponsiveness to established antibiotics leaves patients with no therapeutic possibilities. Hence the search for an efficacious TB immunization strategy is a global health priority. Researchers are paving the course for efficient vaccination strategies with the radically advanced operation of core principles of protective immune responses against M.tb. In this review; we have reassessed the progression of the TB vaccination program comprising BCG immunization in children and potential stratagems to reinforce BCG-induced protection in adults.
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Affiliation(s)
| | | | - Ved Prakash Dwivedi
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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4
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Jiang S, Redelman-Sidi G. BCG in Bladder Cancer Immunotherapy. Cancers (Basel) 2022; 14:3073. [PMID: 35804844 PMCID: PMC9264881 DOI: 10.3390/cancers14133073] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 01/18/2023] Open
Abstract
BCG is a live attenuated strain of Mycobacterium bovis that is primarily used as a vaccine against tuberculosis. In the past four decades, BCG has also been used for the treatment of non-muscle invasive bladder cancer (NMIBC). In patients with NMIBC, BCG reduces the risk of tumor recurrence and decreases the likelihood of progression to more invasive disease. Despite the long-term clinical experience with BCG, its mechanism of action is still being elucidated. Data from animal models and from human studies suggests that BCG activates both the innate and adaptive arms of the immune system eventually leading to tumor destruction. Herein, we review the current data regarding the mechanism of BCG and summarize the evidence for its clinical efficacy and recommended indications and clinical practice.
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Affiliation(s)
- Song Jiang
- Urology Service, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Gil Redelman-Sidi
- Infectious Diseases Service, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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5
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Ahmed A, Rakshit S, Adiga V, Dias M, Dwarkanath P, D'Souza G, Vyakarnam A. A century of BCG: Impact on tuberculosis control and beyond. Immunol Rev 2021; 301:98-121. [PMID: 33955564 DOI: 10.1111/imr.12968] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/13/2021] [Accepted: 03/13/2021] [Indexed: 12/14/2022]
Abstract
BCG turns 100 this year and while it might not be the perfect vaccine, it has certainly contributed significantly towards eradication and prevention of spread of tuberculosis (TB). The search for newer and better vaccines for TB is an ongoing endeavor and latest results from trials of candidate TB vaccines such as M72AS01 look promising. However, recent encouraging data from BCG revaccination trials in adults combined with studies on mucosal and intravenous routes of BCG vaccination in non-human primate models have renewed interest in BCG for TB prevention. In addition, several well-demonstrated non-specific effects of BCG, for example, prevention of viral and respiratory infections, give BCG an added advantage. Also, BCG vaccination is currently being widely tested in human clinical trials to determine whether it protects against SARS-CoV-2 infection and/or death with detailed analyses and outcomes from several ongoing trials across the world awaited. Through this review, we attempt to bring together information on various aspects of the BCG-induced immune response, its efficacy in TB control, comparison with other candidate TB vaccines and strategies to improve its efficiency including revaccination and alternate routes of administration. Finally, we discuss the future relevance of BCG use especially in light of its several heterologous benefits.
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Affiliation(s)
- Asma Ahmed
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Srabanti Rakshit
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Vasista Adiga
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Mary Dias
- Division of Infectious Diseases, St John's Research Institute, Bangalore, India
| | | | - George D'Souza
- Division of Infectious Diseases, St John's Research Institute, Bangalore, India.,Department of Pulmonary Medicine, St John's Medical College, Bangalore, India
| | - Annapurna Vyakarnam
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India.,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, Guy's Hospital, King's College London, London, UK
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6
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Basak P, Sachdeva N, Dayal D. Can BCG vaccine protect against COVID-19 via trained immunity and tolerogenesis? Bioessays 2020; 43:e2000200. [PMID: 33169410 DOI: 10.1002/bies.202000200] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022]
Abstract
As the number of infections and mortalities from the SARS-CoV-2 pandemic continues to rise, the development of an effective therapy against COVID-19 becomes ever more urgent. A few reports showing a positive correlation between BCG vaccination and reduced COVID-19 mortality have ushered in some hope. BCG has been suggested to confer a broad level of nonspecific protection against several pathogens, mainly via eliciting "trained immunity" in innate immune cells. Secondly, BCG has also been proven to provide benefits in autoimmune diseases by inducing tolerogenicity. Being an acute inflammatory disease, COVID-19 requires a therapy that induces early priming of anti-viral immune responses and regulates aberrant hyperactivity of innate-immune cells. Here, we hypothesize that BCG can offer reliable spatiotemporal protection from COVID-19 by triggering trained immunity and tolerogenesis, through multiple cellular pathways. We propose further research on BCG-mediated immunoprotection, especially in vulnerable individuals, as a strategy to halt the progress of the SARS-CoV-2 pandemic. Also see the video abstract here https://youtu.be/P2D2RXfq6Vg.
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Affiliation(s)
- Preetam Basak
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Naresh Sachdeva
- Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Devi Dayal
- Department of Pediatrics, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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7
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Augenstreich J, Haanappel E, Sayes F, Simeone R, Guillet V, Mazeres S, Chalut C, Mourey L, Brosch R, Guilhot C, Astarie-Dequeker C. Phthiocerol Dimycocerosates From Mycobacterium tuberculosis Increase the Membrane Activity of Bacterial Effectors and Host Receptors. Front Cell Infect Microbiol 2020; 10:420. [PMID: 32923411 PMCID: PMC7456886 DOI: 10.3389/fcimb.2020.00420] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) synthesizes a variety of atypical lipids that are exposed at the cell surface and help the bacterium infect macrophages and escape elimination by the cell's immune responses. In the present study, we investigate the mechanism of action of one family of hydrophobic lipids, the phthiocerol dimycocerosates (DIM/PDIM), major lipid virulence factors. DIM are transferred from the envelope of Mtb to host membranes during infection. Using the polarity-sensitive fluorophore C-Laurdan, we visualized that DIM decrease the membrane polarity of a supported lipid bilayer put in contact with mycobacteria, even beyond the site of contact. We observed that DIM activate the complement receptor 3, a predominant receptor for phagocytosis of Mtb by macrophages. DIM also increased the activity of membrane-permeabilizing effectors of Mtb, among which the virulence factor EsxA. This is consistent with previous observations that DIM help Mtb disrupt host cell membranes. Taken together, our data show that transferred DIM spread within the target membrane, modify its physical properties and increase the activity of host cell receptors and bacterial effectors, diverting in a non-specific manner host cell functions. We therefore bring new insight into the molecular mechanisms by which DIM increase Mtb's capability to escape the cell's immune responses.
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Affiliation(s)
- Jacques Augenstreich
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Evert Haanappel
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Fadel Sayes
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR3525, Paris, France
| | - Roxane Simeone
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR3525, Paris, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Serge Mazeres
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Christian Chalut
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Roland Brosch
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR3525, Paris, France
| | - Christophe Guilhot
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
| | - Catherine Astarie-Dequeker
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS-UPS UMR 5089, Toulouse, France
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8
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Torres-Gomez A, Cabañas C, Lafuente EM. Phagocytic Integrins: Activation and Signaling. Front Immunol 2020; 11:738. [PMID: 32425937 PMCID: PMC7203660 DOI: 10.3389/fimmu.2020.00738] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/31/2020] [Indexed: 01/06/2023] Open
Abstract
Phagocytic integrins are endowed with the ability to engulf and dispose of particles of different natures. Evolutionarily conserved from worms to humans, they are involved in pathogen elimination and apoptotic and tumoral cell clearance. Research in the field of integrin-mediated phagocytosis has shed light on the molecular events controlling integrin activation and their effector functions. However, there are still some aspects of the regulation of the phagocytic process that need to be clarified. Here, we have revised the molecular events controlling phagocytic integrin activation and the downstream signaling driving particle engulfment, and we have focused particularly on αMβ2/CR3, αXβ2/CR4, and a brief mention of αVβ5/αVβ3integrins.
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Affiliation(s)
- Alvaro Torres-Gomez
- Department of Immunology, Ophthalmology and Otorhinolaryngology, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), Madrid, Spain
| | - Carlos Cabañas
- Department of Immunology, Ophthalmology and Otorhinolaryngology, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), Madrid, Spain.,Severo Ochoa Center for Molecular Biology (CSIC-UAM), Madrid, Spain
| | - Esther M Lafuente
- Department of Immunology, Ophthalmology and Otorhinolaryngology, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), Madrid, Spain
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9
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Hu Y, Lu S, Xi L. Murine Macrophage Requires CD11b to Recognize Talaromyces marneffei. Infect Drug Resist 2020; 13:911-920. [PMID: 32273736 PMCID: PMC7108879 DOI: 10.2147/idr.s237401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/10/2020] [Indexed: 01/17/2023] Open
Abstract
Introduction Talaromyces marneffei (T. marneffei) is an emerging pathogenic fungus. Macrophage-1 antigen (Mac-1, CR3, CD11b/CD18) is an important receptor on innate immune cells and can recognize pathogens. However, the importance of CR3 in phagocytosis of T. marneffei by macrophages and their responses to T. marneffei have not been clarified. Methods We show that interaction of mouse peritoneal macrophages (pMacs) or RAW264.7 macrophages with T. marneffei of its conidia spores and yeast cells enhances CR3 expression on macrophages. The phagocytosis rate was determined using flow cytometry, RT-PCR and Western blotting were used to detect CD11b expression, and the levels of IFN-γ, TNF-α, IL-2, IL-4, IL-6 and IL-10 in the co-culture supernatants were determined by ELISA. Results Incubation of mouse macrophages with T. marneffei promoted phagocytosis of T. marneffei, which was dramatically mitigated by pretreatment with anti-CD11b antibody or knockdown of CR3 expression on macrophages. Then, interferon γ, tumor necrosis factor α, IL-4, IL-10 and IL-12 production in macrophages incubation with heat-killed T. marneffei was detected. CD11b expression on mouse macrophages was upregulated by T. marneffei. Incubation of T. marneffei promoted phagocytosis of T. marneffei by macrophages and high levels of pro-inflammatory and anti-inflammatory cytokine production by macrophages, which were mitigated and abrogated by pre-treatment with anti-CD11b or knockdown of CD11b expression. Conclusion These data indicated that murine macrophage requires CD11b to recognize Talaromyces marneffei and their cytokine responses to heat-killed T. marneffei in vitro.
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Affiliation(s)
- Yongxuan Hu
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China.,Department of Dermatology and Venereology, The 3rd Affiliated Hospital of Southern Medical University, Guangzhou, People's Republic of China.,Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Guangzhou, People's Republic of China
| | - Sha Lu
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Liyan Xi
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China.,Dermatology Hospital of Southern Medical University, Guangzhou, People's Republic of China.,Department of Dermatology, Guangzhou First People's Hospital, The Second Affiliated Hospital of South China University of Technology, Guangzhou, People's Republic of China
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10
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Kumar V. The complement system, toll-like receptors and inflammasomes in host defense: three musketeers’ one target. Int Rev Immunol 2019; 38:131-156. [DOI: 10.1080/08830185.2019.1609962] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Vijay Kumar
- Children’s Health Queensland Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, St Lucia, Brisbane, QLD, Australia
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, ST Lucia, Brisbane, QLD, Australia
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11
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Oldenburg R, Demangel C. Pathogenic and immunosuppressive properties of mycobacterial phenolic glycolipids. Biochimie 2017; 141:3-8. [DOI: 10.1016/j.biochi.2017.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/15/2017] [Indexed: 01/29/2023]
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12
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Dockrell HM, Smith SG. What Have We Learnt about BCG Vaccination in the Last 20 Years? Front Immunol 2017; 8:1134. [PMID: 28955344 PMCID: PMC5601272 DOI: 10.3389/fimmu.2017.01134] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/28/2017] [Indexed: 12/18/2022] Open
Abstract
A number of new tuberculosis (TB) vaccines have been or are entering clinical trials, which include genetically modified mycobacteria, mycobacterial antigens delivered by viral vectors, or mycobacterial antigens in adjuvant. Some of these vaccines aim to replace the existing BCG vaccine but others will be given as a boosting vaccine following BCG vaccination given soon after birth. It is clear that the existing BCG vaccines provide incomplete and variable protection against pulmonary TB. This review will discuss what we have learnt over the last 20 years about how the BCG vaccine induces specific and non-specific immunity, what factors influence the immune responses induced by BCG, and progress toward identifying correlates of immunity against TB from BCG vaccination studies. There is still a lot to learn about the BCG vaccine and the insights gained can help the development of more protective vaccines.
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Affiliation(s)
- Hazel M Dockrell
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Steven G Smith
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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13
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Hajishengallis G, Lambris JD. More than complementing Tolls: complement-Toll-like receptor synergy and crosstalk in innate immunity and inflammation. Immunol Rev 2017; 274:233-244. [PMID: 27782328 DOI: 10.1111/imr.12467] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Complement and Toll-like receptors (TLRs) play key roles in the host immune response and are swiftly activated by infection or other types of immunological stress. This review focuses on the capacity of complement and TLRs to engage in signaling crosstalk, ostensibly to coordinate immune and inflammatory responses through synergistic or antagonistic (regulatory) interactions. However, overactivation or dysregulation of either system may lead-often synergistically-to exaggerated inflammation and host tissue injury. Intriguingly, moreover, certain pathogens can manipulate complement-TLR crosstalk pathways in ways that undermine host immunity and favor their persistence. In the setting of polymicrobial inflammatory disease, subversion of complement-TLR crosstalk by keystone pathogens can promote dysbiosis. Knowledge of the molecular mechanisms underlying complement-TLR crosstalk pathways can, therefore, be used productively for tailored therapeutic approaches, such as, to enhance host immunity, mitigate destructive inflammation, or counteract microbial subversion of the host response.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
| | - John D Lambris
- Perelman School of Medicine, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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14
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Moliva JI, Turner J, Torrelles JB. Immune Responses to Bacillus Calmette-Guérin Vaccination: Why Do They Fail to Protect against Mycobacterium tuberculosis? Front Immunol 2017; 8:407. [PMID: 28424703 PMCID: PMC5380737 DOI: 10.3389/fimmu.2017.00407] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/22/2017] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis (TB), is the current leading cause of death due to a single infectious organism. Although curable, the broad emergence of multi-, extensive-, extreme-, and total-drug resistant strains of M.tb has hindered eradication efforts of this pathogen. Furthermore, computational models predict a quarter of the world’s population is infected with M.tb in a latent state, effectively serving as the largest reservoir for any human pathogen with the ability to cause significant morbidity and mortality. The World Health Organization has prioritized new strategies for improved vaccination programs; however, the lack of understanding of mycobacterial immunity has made it difficult to develop new successful vaccines. Currently, Mycobacterium bovis bacillus Calmette–Guérin (BCG) is the only vaccine approved for use to prevent TB. BCG is highly efficacious at preventing meningeal and miliary TB, but is at best 60% effective against the development of pulmonary TB in adults and wanes as we age. In this review, we provide a detailed summary on the innate immune response of macrophages, dendritic cells, and neutrophils in response to BCG vaccination. Additionally, we discuss adaptive immune responses generated by BCG vaccination, emphasizing their specific contributions to mycobacterial immunity. The success of future vaccines against TB will directly depend on our understanding of mycobacterial immunity.
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Affiliation(s)
- Juan I Moliva
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Joanne Turner
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
| | - Jordi B Torrelles
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
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15
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Garza-Cuartero L, O'Sullivan J, Blanco A, McNair J, Welsh M, Flynn RJ, Williams D, Diggle P, Cassidy J, Mulcahy G. Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response. Parasite Immunol 2017; 38:387-402. [PMID: 27108767 PMCID: PMC6680181 DOI: 10.1111/pim.12326] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 04/18/2016] [Indexed: 01/06/2023]
Abstract
Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long‐standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co‐infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis‐specific Th1 immune response. We hypothesized that these changes in co‐infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co‐infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte‐derived macrophages (MDM) from F. hepatica‐infected cattle which is associated with suppression of pro‐inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica‐infected cattle is increased. These findings reflecting the bystander effect of helminth‐induced downregulation of pro‐inflammatory responses provide insights to understand host‐pathogen interactions in co‐infection.
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Affiliation(s)
- L Garza-Cuartero
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - J O'Sullivan
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - A Blanco
- Conway Institute, University College Dublin, Dublin, Ireland
| | - J McNair
- Veterinary Sciences Division, Agri-Food and Biosciences Institute, Belfast, UK
| | - M Welsh
- CSO, SISAF, The Innovation Centre, Belfast, UK
| | - R J Flynn
- School of Veterinary Science, University of Nottingham, Nottingham, UK
| | - D Williams
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - P Diggle
- Division of Medicine, Lancaster University, Lancaster, UK
| | - J Cassidy
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - G Mulcahy
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland.,Conway Institute, University College Dublin, Dublin, Ireland
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16
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Zwozdesky MA, Fei C, Lillico DME, Stafford JL. Imaging flow cytometry and GST pulldown assays provide new insights into channel catfish leukocyte immune-type receptor-mediated phagocytic pathways. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 67:126-138. [PMID: 27984101 DOI: 10.1016/j.dci.2016.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/26/2016] [Accepted: 10/26/2016] [Indexed: 06/06/2023]
Abstract
Channel catfish (Ictalurus punctatus) leukocyte immune-type receptors (IpLITRs) control various innate immune cell effector responses including the phagocytic process. This large immunoregulatory receptor family also consists of multiple receptor-types with variable signaling abilities that is dependent on their inherent or acquired tyrosine-containing cytoplasmic tail (CYT) regions. For example, IpLITR 2.6b associates with the immunoreceptor tyrosine-based activation motif (ITAM)-containing adaptor molecule IpFcRγ-L, and when expressed in mammalian cells it activates phagocytosis using a similar profile of intracellular signaling mediators that also regulate the prototypical mammalian Fc receptor (FcR) phagocytic pathway. Alternatively, IpLITR 1.1b contains a long tyrosine-containing CYT with multifunctional capabilities including both inhibitory and stimulatory actions. Recently, we demonstrated that IpLITR 1.1b activates a unique phagocytic pathway involving the generation of multiple plasma membrane extensions that rapidly capture extracellular targets and secure them on the cell surface in phagocytic cup-like structures. Occasionally, these captured targets are completely engulfed albeit at a significantly lower rate than what was observed for IpLITR 2.6b. While this novel IpLITR 1.1b phagocytic activity is insensitive to classical blockers of phagocytosis, its distinct target capture and engulfment actions depend on the engagement of the actin polymerization machinery. However, it is not known how this protein translates target recognition into intracellular signaling events during this atypical mode of phagocytosis. Using imaging flow cytometry and GST pulldown assays, the aims of this study were to specifically examine what regions of the IpLITR 1.1b CYT trigger phagocytosis and to establish what profile of intracellular signaling molecules likely participate in its actions. Our results show that in stably transfected AD293 cells, the membrane proximal and distal CYT segments of IpLITR 1.1b independently regulate its phagocytic activities. These CYT regions were also shown to differentially recruit various SH2 domain-containing intracellular mediators, which provides new information about the dynamic immunoregulatory abilities of IpLITR 1.1b. Overall, this work further advances our understanding of how certain immunoregulatory receptor-types link extracellular target binding events to the actin polymerization machinery during a non-classical mode of phagocytosis.
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Affiliation(s)
- Myron A Zwozdesky
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Chenjie Fei
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Dustin M E Lillico
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - James L Stafford
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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17
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Rafiq NBM, Lieu ZZ, Jiang T, Yu CH, Matsudaira P, Jones GE, Bershadsky AD. Podosome assembly is controlled by the GTPase ARF1 and its nucleotide exchange factor ARNO. J Cell Biol 2016; 216:181-197. [PMID: 28007915 PMCID: PMC5223603 DOI: 10.1083/jcb.201605104] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/26/2016] [Accepted: 11/28/2016] [Indexed: 01/07/2023] Open
Abstract
Podosomes represent a class of integrin-mediated cell-matrix adhesions formed by migrating and matrix-degrading cells. We demonstrate that in macrophage-like THP1 cells and fibroblasts stimulated to produce podosomes, down-regulation of the G-protein ARF1 or the ARF1 guanine nucleotide exchange factor, ARNO, by small, interfering RNA or pharmacological inhibitors led to striking podosome elimination. Concomitantly, treatments inducing podosome formation increased the level of guanosine triphosphate (GTP)-bound ARF1. ARNO was found to colocalize with the adhesive rings of podosomes, whereas ARF1 was localized to vesicular structures transiently contacting podosome rings. Inhibition of ARF1 led to an increase in RhoA-GTP levels and triggered assembly of myosin-IIA filaments in THP1 cells, whereas the suppression of myosin-IIA rescued podosome formation regardless of ARF1 inhibition. Finally, expression of constitutively active ARF1 in fibroblasts induced formation of putative podosome precursors: actin-rich puncta coinciding with matrix degradation sites and containing proteins of the podosome core but not of the adhesive ring. Thus, ARNO-ARF1 regulates formation of podosomes by inhibition of RhoA/myosin-II and promotion of actin core assembly.
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Affiliation(s)
- Nisha Bte Mohd Rafiq
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.,Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, England, UK
| | - Zi Zhao Lieu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Tingting Jiang
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Cheng-Han Yu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Paul Matsudaira
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Gareth E Jones
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, England, UK
| | - Alexander D Bershadsky
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore .,Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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18
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Sibilla P, Sereni A, Aguiari G, Banzi M, Manzati E, Mischiati C, Trombelli L, del Senno L. Effects of a Hydroxyapatite-based Biomaterial on Gene Expression in Osteoblast-like Cells. J Dent Res 2016; 85:354-8. [PMID: 16567558 DOI: 10.1177/154405910608500414] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Biostite® is a hydroxyapatite-derived biomaterial that is used in periodontal and bone reconstructive procedures due to its osteoconductive properties. Since the molecular effects of this biomaterial on osteoblasts are still unknown, we decided to assess whether it may specifically modulate osteoblast functions in vitro. We found that a brief exposure to Biostite® significantly reduced the proliferation of MG-63 and SaOS-2 osteoblast-like cells to ~ 50% of the plateau value. Furthermore, gene array analysis of MG-63 cells showed that Biostite® caused a differential expression of 37 genes which are involved in cell proliferation and interaction, and related to osteoblast differentiation and tissue regeneration. Results were confirmed by RT-PCR, Western blot, and by an increase in alkaline phosphatase (ALP) specific activity. Biostite® also increased levels of polycystin-2, a mechano-sensitive Ca2+ channel, a promising new marker of bone cell differentiation. Biostite®, therefore, may directly affect osteoblasts by enhancing chondro/osteogenic gene expression and cytoskeleton-related signaling pathways, which may contribute to its clinical efficacy.
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Affiliation(s)
- P Sibilla
- Department of Biochemistry and Molecular Biology, University of Ferrara, Italy
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19
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Humphreys D, Singh V, Koronakis V. Inhibition of WAVE Regulatory Complex Activation by a Bacterial Virulence Effector Counteracts Pathogen Phagocytosis. Cell Rep 2016; 17:697-707. [PMID: 27732847 PMCID: PMC5081413 DOI: 10.1016/j.celrep.2016.09.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/24/2016] [Accepted: 09/14/2016] [Indexed: 02/05/2023] Open
Abstract
To establish pathogenicity, bacteria must evade phagocytosis directed by remodeling of the actin cytoskeleton. We show that macrophages facilitate pathogen phagocytosis through actin polymerization mediated by the WAVE regulatory complex (WRC), small GTPases Arf and Rac1, and the Arf1 activator ARNO. To establish extracellular infections, enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherichia coli hijack the actin cytoskeleton by injecting virulence effectors into the host cell. Here, we find that the virulence effector EspG counteracts WRC-dependent phagocytosis, enabling EPEC and EHEC to remain extracellular. By reconstituting membrane-associated actin polymerization, we find that EspG disabled WRC activation through two mechanisms: EspG interaction with Arf6 blocked signaling to ARNO while EspG binding of Arf1 impeded collaboration with Rac1, thereby inhibiting WRC recruitment and activation. Investigating the mode of EspG interference revealed sites in Arf1 required for WRC activation and a mechanism facilitating pathogen evasion of innate host defenses.
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Affiliation(s)
- Daniel Humphreys
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
| | - Vikash Singh
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Vassilis Koronakis
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
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20
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Barratt-Due A, Pischke SE, Nilsson PH, Espevik T, Mollnes TE. Dual inhibition of complement and Toll-like receptors as a novel approach to treat inflammatory diseases-C3 or C5 emerge together with CD14 as promising targets. J Leukoc Biol 2016; 101:193-204. [PMID: 27581539 PMCID: PMC5166441 DOI: 10.1189/jlb.3vmr0316-132r] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/01/2016] [Accepted: 07/25/2016] [Indexed: 12/22/2022] Open
Abstract
Review of how targeting key upstream molecules at the recognition phase of innate immunity exert anti-inflammatory effects; a potential therapeutic regimen for inflammatory diseases. The host is protected by pattern recognition systems, including complement and TLRs, which are closely cross-talking. If improperly activated, these systems might induce tissue damage and disease. Inhibition of single downstream proinflammatory cytokines, such as TNF, IL-1β, and IL-6, have failed in clinical sepsis trials, which might not be unexpected, given the substantial amounts of mediators involved in the pathogenesis of this condition. Instead, we have put forward a hypothesis of inhibition at the recognition phase by “dual blockade” of bottleneck molecules of complement and TLRs. By acting upstream and broadly, the dual blockade could be beneficial in conditions with improper or uncontrolled innate immune activation threatening the host. Key bottleneck molecules in these systems that could be targets for inhibition are the central complement molecules C3 and C5 and the important CD14 molecule, which is a coreceptor for several TLRs, including TLR4 and TLR2. This review summarizes current knowledge of inhibition of complement and TLRs alone and in combination, in both sterile and nonsterile inflammatory processes, where activation of these systems is of crucial importance for tissue damage and disease. Thus, dual blockade might provide a general, broad-acting therapeutic regimen against a number of diseases where innate immunity is improperly activated.
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Affiliation(s)
- Andreas Barratt-Due
- Department of Immunology, Oslo University Hospital, and K. G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway.,Department of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
| | - Søren Erik Pischke
- Department of Immunology, Oslo University Hospital, and K. G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway.,Department of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
| | - Per H Nilsson
- Department of Immunology, Oslo University Hospital, and K. G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tom Eirik Mollnes
- Department of Immunology, Oslo University Hospital, and K. G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway; .,Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Research Laboratory Nordland Hospital, Bodø, Norway; and.,K. G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, Tromsø, Norway
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21
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PE_PGRS33 Contributes to Mycobacterium tuberculosis Entry in Macrophages through Interaction with TLR2. PLoS One 2016; 11:e0150800. [PMID: 26978522 PMCID: PMC4792380 DOI: 10.1371/journal.pone.0150800] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 02/20/2016] [Indexed: 01/01/2023] Open
Abstract
PE_PGRS represent a large family of proteins typical of pathogenic mycobacteria whose members are characterized by an N-terminal PE domain followed by a large Gly-Ala repeat-rich C-terminal domain. Despite the abundance of PE_PGRS-coding genes in the Mycobacterium tuberculosis (Mtb) genome their role and function in the biology and pathogenesis still remains elusive. In this study, we generated and characterized an Mtb H37Rv mutant (MtbΔ33) in which the structural gene of PE_PGRS33, a prototypical member of the protein family, was inactivated. We showed that this mutant entered macrophages with an efficiency up to ten times lower than parental or complemented strains, while its efficiency in infecting pneumocytes remained unaffected. Interestingly, the lack of PE_PGRS33 did not affect the intracellular growth of this mutant in macrophages. Using a series of functional deletion mutants of the PE_PGRS33 gene to complement the MtbΔ33 strain, we demonstrated that the PGRS domain is required to mediate cell entry into macrophages, with the key domain encompassing position 140–260 amino acids of PE_PGRS33. PE_PGRS33-mediated entry into macrophages was abolished in TLR2-deficient mice, as well as following treatment with wortmannin or an antibody against the complement receptor 3 (CR3), indicating that PE_PGRS33-mediated entry of Mtb in macrophages occurs through interaction with TLR2.
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22
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Liao TYA, Lau A, Joseph S, Hytönen V, Hmama Z. Improving the Immunogenicity of the Mycobacterium bovis BCG Vaccine by Non-Genetic Bacterial Surface Decoration Using the Avidin-Biotin System. PLoS One 2015; 10:e0145833. [PMID: 26716832 PMCID: PMC4696857 DOI: 10.1371/journal.pone.0145833] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 12/09/2015] [Indexed: 12/18/2022] Open
Abstract
Current strategies to improve the current BCG vaccine attempt to over-express genes encoding specific M. tuberculosis (Mtb) antigens and/or regulators of antigen presentation function, which indeed have the potential to reshape BCG in many ways. However, these approaches often face serious difficulties, in particular the efficiency and stability of gene expression via nucleic acid complementation and safety concerns associated with the introduction of exogenous DNA. As an alternative, we developed a novel non-genetic approach for rapid and efficient display of exogenous proteins on bacterial cell surface. The technology involves expression of proteins of interest in fusion with a mutant version of monomeric avidin that has the feature of reversible binding to biotin. Fusion proteins are then used to decorate the surface of biotinylated BCG. Surface coating of BCG with recombinant proteins was highly reproducible and stable. It also resisted to the freeze-drying shock routinely used in manufacturing conventional BCG. Modifications of BCG surface did not affect its growth in culture media neither its survival within the host cell. Macrophages phagocytized coated BCG bacteria, which efficiently delivered their surface cargo of avidin fusion proteins to MHC class I and class II antigen presentation compartments. Thereafter, chimeric proteins corresponding to a surrogate antigen derived from ovalbumin and the Mtb specific ESAT6 antigen were generated and tested for immunogenicity in vaccinated mice. We found that BCG displaying ovalbumin antigen induces an immune response with a magnitude similar to that induced by BCG genetically expressing the same surrogate antigen. We also found that BCG decorated with Mtb specific antigen ESAT6 successfully induces the expansion of specific T cell responses. This novel technology, therefore, represents a practical and effective alternative to DNA-based gene expression for upgrading the current BCG vaccine.
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Affiliation(s)
- Ting-Yu Angela Liao
- Division of Infectious Diseases, Department of Medicine and Vancouver Costal Health Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Alice Lau
- Division of Infectious Diseases, Department of Medicine and Vancouver Costal Health Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Sunil Joseph
- Division of Infectious Diseases, Department of Medicine and Vancouver Costal Health Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Vesa Hytönen
- Institute of Biomedical Technology, University of Tampere, Tampere, Finland
| | - Zakaria Hmama
- Division of Infectious Diseases, Department of Medicine and Vancouver Costal Health Research Institute, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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23
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Hmama Z, Peña-Díaz S, Joseph S, Av-Gay Y. Immunoevasion and immunosuppression of the macrophage by Mycobacterium tuberculosis. Immunol Rev 2015; 264:220-32. [PMID: 25703562 DOI: 10.1111/imr.12268] [Citation(s) in RCA: 200] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
By virtue of their position at the crossroads between the innate and adaptive immune response, macrophages play an essential role in the control of bacterial infections. Paradoxically, macrophages serve as the natural habitat to Mycobacterium tuberculosis (Mtb). Mtb subverts the macrophage's mechanisms of intracellular killing and antigen presentation, leading ultimately to the development of tuberculosis (TB) disease. Here, we describe mechanisms of Mtb uptake by the macrophage and address key macrophage functions that are targeted by Mtb-specific effector molecules enabling this pathogen to circumvent host immune response. The macrophage functions described in this review include fusion between phagosomes and lysosomes, production of reactive oxygen and nitrogen species, antigen presentation and major histocompatibility complex class II expression and trafficking, as well as autophagy and apoptosis. All these are Mtb-targeted key cellular pathways, normally working in concert in the macrophage to recognize, respond, and activate 'proper' immune responses. We further analyze and discuss major molecular interactions between Mtb virulence factors and key macrophage proteins and provide implications for vaccine and drug development.
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Affiliation(s)
- Zakaria Hmama
- Department of Medicine, Division of Infectious Diseases, Infection and Immunity Research Center, University of British Columbia, Vancouver, BC, Canada
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24
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Yu CH, Micaroni M, Puyskens A, Schultz TE, Yeo JC, Stanley AC, Lucas M, Kurihara J, Dobos KM, Stow JL, Blumenthal A. RP105 Engages Phosphatidylinositol 3-Kinase p110δ To Facilitate the Trafficking and Secretion of Cytokines in Macrophages during Mycobacterial Infection. THE JOURNAL OF IMMUNOLOGY 2015; 195:3890-900. [PMID: 26371254 DOI: 10.4049/jimmunol.1500017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 08/06/2015] [Indexed: 12/11/2022]
Abstract
Cytokines are key regulators of adequate immune responses to infection with Mycobacterium tuberculosis. We demonstrate that the p110δ catalytic subunit of PI3K acts as a downstream effector of the TLR family member RP105 (CD180) in promoting mycobacteria-induced cytokine production by macrophages. Our data show that the significantly reduced release of TNF and IL-6 by RP105(-/-) macrophages during mycobacterial infection was not accompanied by diminished mRNA or protein expression. Mycobacteria induced comparable activation of NF-κB and p38 MAPK signaling in wild-type (WT) and RP105(-/-) macrophages. In contrast, mycobacteria-induced phosphorylation of Akt was abrogated in RP105(-/-) macrophages. The p110δ-specific inhibitor, Cal-101, and small interfering RNA-mediated knockdown of p110δ diminished mycobacteria-induced TNF secretion by WT but not RP105(-/-) macrophages. Such interference with p110δ activity led to reduced surface-expressed TNF in WT but not RP105(-/-) macrophages, while leaving TNF mRNA and protein expression unaffected. Activity of Bruton's tyrosine kinase was required for RP105-mediated activation of Akt phosphorylation and TNF release by mycobacteria-infected macrophages. These data unveil a novel innate immune signaling axis that orchestrates key cytokine responses of macrophages and provide molecular insight into the functions of RP105 as an innate immune receptor for mycobacteria.
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Affiliation(s)
- Chien-Hsiung Yu
- The University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, Queensland 4102, Australia
| | - Massimo Micaroni
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andreas Puyskens
- The University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, Queensland 4102, Australia
| | - Thomas E Schultz
- The University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, Queensland 4102, Australia
| | - Jeremy Changyu Yeo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Amanda C Stanley
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Megan Lucas
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523; and
| | - Jade Kurihara
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523; and
| | - Karen M Dobos
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523; and
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Antje Blumenthal
- The University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, Queensland 4102, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
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25
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Spanos JP, Hsu NJ, Jacobs M. Microglia are crucial regulators of neuro-immunity during central nervous system tuberculosis. Front Cell Neurosci 2015; 9:182. [PMID: 26041993 PMCID: PMC4435040 DOI: 10.3389/fncel.2015.00182] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/27/2015] [Indexed: 01/11/2023] Open
Abstract
Mycobacterium tuberculosis (M. tuberculosis) infection of the central nervous system (CNS) is the most devastating manifestation of tuberculosis (TB), with both high mortality and morbidity. Although research has been fueled by the potential therapeutic target microglia offer against neurodegenerative inflammation, their part in TB infection of the CNS has not been fully evaluated nor elucidated. Yet, as both the preferential targets of M. tuberculosis and the immune-effector cells of the CNS, microglia are likely to be key determinants of disease severity and clinical outcomes. Following pathogen recognition, bacilli are internalized and capable of replicating within microglia. Cellular activation ensues, utilizing signaling molecules that may be neurotoxic. Central to initiating, orchestrating and modulating the tuberculous immune response is microglial secretion of cytokines and chemokines. However, the neurological environment is unique in that inflammatory signals, which appear to be damaging in the periphery, could be beneficial by governing neuronal survival, regeneration and differentiation. Furthermore, microglia are important in the recruitment of peripheral immune cells and central to defining the pro-inflammatory milieu of which neurotoxicity may result from many of the participating local or recruited cell types. Microglia are capable of both presenting antigen to infiltrating CD4(+) T-lymphocytes and inducing their differentiation-a possible correlate of protection against M. tuberculosis infection. Clarifying the nature of the immune effector molecules secreted by microglia, and the means by which other CNS-specific cell types govern microglial activation or modulate their responses is critical if improved diagnostic and therapeutic strategies are to be attained. Therefore, this review evaluates the diverse roles microglia play in the neuro-immunity to M. tuberculosis infection of the CNS.
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Affiliation(s)
- Jonathan Paul Spanos
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Nai-Jen Hsu
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Muazzam Jacobs
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa ; National Health Laboratory Service Johannesburg, South Africa
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Merritt PM, Nero T, Bohman L, Felek S, Krukonis ES, Marketon MM. Yersinia pestis targets neutrophils via complement receptor 3. Cell Microbiol 2014; 17:666-87. [PMID: 25359083 DOI: 10.1111/cmi.12391] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 10/18/2014] [Accepted: 10/28/2014] [Indexed: 01/20/2023]
Abstract
Yersinia species display a tropism for lymphoid tissues during infection, and the bacteria select innate immune cells for delivery of cytotoxic effectors by the type III secretion system. Yet, the mechanism for target cell selection remains a mystery. Here we investigate the interaction of Yersinia pestis with murine splenocytes to identify factors that participate in the targeting process. We find that interactions with primary immune cells rely on multiple factors. First, the bacterial adhesin Ail is required for efficient targeting of neutrophils in vivo. However, Ail does not appear to directly mediate binding to a specific cell type. Instead, we find that host serum factors direct Y. pestis to specific innate immune cells, particularly neutrophils. Importantly, specificity towards neutrophils was increased in the absence of bacterial adhesins because of reduced targeting of other cell types, but this phenotype was only visible in the presence of mouse serum. Addition of antibodies against complement receptor 3 and CD14 blocked target cell selection, suggesting that a combination of host factors participate in steering bacteria towards neutrophils during plague infection.
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Affiliation(s)
- Peter M Merritt
- Department of Biology, Indiana University, Bloomington, IN, USA
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Costalonga M, Herzberg MC. The oral microbiome and the immunobiology of periodontal disease and caries. Immunol Lett 2014; 162:22-38. [PMID: 25447398 DOI: 10.1016/j.imlet.2014.08.017] [Citation(s) in RCA: 381] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/31/2014] [Accepted: 08/08/2014] [Indexed: 12/22/2022]
Abstract
The composition of the oral microbiome differs from one intraoral site to another, reflecting in part the host response and immune capacity at each site. By focusing on two major oral infections, periodontal disease and caries, new principles of disease emerge. Periodontal disease affects the soft tissues and bone that support the teeth. Caries is a unique infection of the dental hard tissues. The initiation of both diseases is marked by an increase in the complexity of the microbiome. In periodontitis, pathobionts and keystone pathogens such as Porphyromonas gingivalis appear in greater proportion than in health. As a keystone pathogen, P. gingivalis impairs host immune responses and appears necessary but not sufficient to cause periodontitis. Historically, dental caries had been causally linked to Streptococcus mutans. Contemporary microbiome studies now indicate that singular pathogens are not obvious in either caries or periodontitis. Both diseases appear to result from a perturbation among relatively minor constituents in local microbial communities resulting in dysbiosis. Emergent consortia of the minor members of the respective microbiomes act synergistically to stress the ability of the host to respond and protect. In periodontal disease, host protection first occurs at the level of innate gingival epithelial immunity. Secretory IgA antibody and other salivary antimicrobial systems also act against periodontopathic and cariogenic consortia. When the gingival immune response is impaired, periodontal tissue pathology results when matrix metalloproteinases are released from neutrophils and T cells mediate alveolar bone loss. In caries, several species are acidogenic and aciduric and appear to work synergistically to promote demineralization of the enamel and dentin. Whereas technically possible, particularly for caries, vaccines are unlikely to be commercialized in the near future because of the low morbidity of caries and periodontitis.
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Affiliation(s)
- Massimo Costalonga
- Division of Periodontology, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, United States.
| | - Mark C Herzberg
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, United States; Mucosal and Vaccine Research Center, Minneapolis VA Medical Center, Minneapolis, MN 55417, United States
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Barth K, Remick DG, Genco CA. Disruption of immune regulation by microbial pathogens and resulting chronic inflammation. J Cell Physiol 2013; 228:1413-22. [PMID: 23255141 DOI: 10.1002/jcp.24299] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 11/27/2012] [Indexed: 12/23/2022]
Abstract
Activation of the immune response is a tightly regulated, coordinated effort that functions to control and eradicate exogenous microorganisms, while also responding to endogenous ligands. Determining the proper balance of inflammation is essential, as chronic inflammation leads to a wide array of host pathologies. Bacterial pathogens can instigate chronic inflammation via an extensive repertoire of evolved evasion strategies that perturb immune regulation. In this review, we discuss two model pathogens, Mycobacterium tuberculosis and Porphyromonas gingivalis, which efficiently escape various aspects of the immune system within professional and non-professional immune cell types to establish chronic inflammation.
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Affiliation(s)
- Kenneth Barth
- Department of Medicine Section of Infectious Disease, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Lamont EA, Xu WW, Sreevatsan S. Host-Mycobacterium avium subsp. paratuberculosis interactome reveals a novel iron assimilation mechanism linked to nitric oxide stress during early infection. BMC Genomics 2013; 14:694. [PMID: 24112552 PMCID: PMC3832399 DOI: 10.1186/1471-2164-14-694] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 10/02/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The initial interaction between host cell and pathogen sets the stage for the ensuing infection and ultimately determine the course of disease. However, there is limited knowledge of the transcripts utilized by host and pathogen and how they may impact one another during this critical step. The purpose of this study was to create a host-Mycobacterium avium subsp. paratuberculosis (MAP) interactome for early infection in an epithelium-macrophage co-culture system using RNA-seq. RESULTS Establishment of the host-MAP interactome revealed a novel iron assimilation system for carboxymycobactin. Iron assimilation is linked to nitric oxide synthase-2 production by the host and subsequent nitric oxide buildup. Iron limitation as well as nitric oxide is a prompt for MAP to enter into an iron sequestration program. This new iron sequestration program provides an explanation for mycobactin independence in some MAP strains grown in vitro as well as during infection within the host cell. Utilization of such a pathway is likely to aid MAP establishment and long-term survival within the host. CONCLUSIONS The host-MAP interactome identified a number of metabolic, DNA repair and virulence genes worthy for consideration as novel drug targets as well as future pathogenesis studies. Reported interactome data may also be utilized to conduct focused, hypothesis-driven research. Co-culture of uninfected bovine epithelial cells (MAC-T) and primary bovine macrophages creates a tolerant genotype as demonstrated by downregulation of inflammatory pathways. This co-culture system may serve as a model to investigate other bovine enteric pathogens.
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Affiliation(s)
- Elise A Lamont
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, Saint Paul, MN 55108, USA
| | - Wayne W Xu
- Minnesota Supercomputing Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - Srinand Sreevatsan
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, Saint Paul, MN 55108, USA
- Department of Veterinary Biomedical Sciences, University of Minnesota, Saint Paul, MN 55108, USA
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Hawley KL, Martín-Ruiz I, Iglesias-Pedraz JM, Berwin B, Anguita J. CD14 targets complement receptor 3 to lipid rafts during phagocytosis of Borrelia burgdorferi. Int J Biol Sci 2013; 9:803-10. [PMID: 23983613 PMCID: PMC3753444 DOI: 10.7150/ijbs.7136] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 08/03/2013] [Indexed: 12/03/2022] Open
Abstract
Phagocytosis of Borrelia burgdorferi, the causative agent of Lyme disease, is mediated partly by the interaction of the spirochete with Complement Receptor (CR) 3. CR3 requires the GPI-anchored protein, CD14, in order to efficiently internalize CR3-B. burgdorferi complexes. GPI-anchored proteins reside in cholesterol-rich membrane microdomains, and through its interaction with partner proteins, help initiate signaling cascades. Here, we investigated the role of CD14 on the internalization of B. burgdorferi mediated by CR3. We show that CR3 partly colocalizes with CD14 in lipid rafts. The use of the cholesterol-sequestering compound methyl-β-cyclodextran completely prevents the internalization of the spirochete in CHO cells that co-express CD14 and CR3, while no effect was observed in CD11b-deficient macrophages. These results show that lipid rafts are required for CR3-dependent, but not independent, phagocytosis of B. burgdorferi. Our results also suggest that CD14 interacts with the C-lectin domain of CR3, favoring the formation of multi-complexes that allow their internalization, and the use of β-glucan, a known ligand for the C-lectin domain of CR3, can compensate for the lack of CD14 in CHO cells that express CR3. These results provide evidence to understand the mechanisms that govern the interaction between CR3 and CD14 during the phagocytosis of B. burgdorferi.
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Affiliation(s)
- Kelly L Hawley
- Department of Veterinary and Animal Sciences, University of Massachusetts at Amherst, Amherst, MA 01003, USA
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Hajishengallis G, Lambris JD. Complement and dysbiosis in periodontal disease. Immunobiology 2013; 217:1111-6. [PMID: 22964237 DOI: 10.1016/j.imbio.2012.07.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 07/13/2012] [Accepted: 07/14/2012] [Indexed: 12/16/2022]
Abstract
Signaling crosstalk between complement and Toll-like receptors (TLRs) normally serves to coordinate host immunity. However, the periodontal bacterium Porphyromonas gingivalis expresses C5 convertase-like enzymatic activity and adeptly exploits complement-TLR crosstalk to subvert host defenses and escape elimination. Intriguingly, this defective immune surveillance leads to the remodeling of the periodontal microbiota to a dysbiotic state that causes inflammatory periodontitis. Understanding the mechanisms by which P. gingivalis modulates complement function to cause dysbiosis offers new targets for complement therapeutics.
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Affiliation(s)
- George Hajishengallis
- University of Pennsylvania School of Dental Medicine, Department of Microbiology, Philadelphia, PA 19104, USA.
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Barratt-Due A, Pischke SE, Brekke OL, Thorgersen EB, Nielsen EW, Espevik T, Huber-Lang M, Mollnes TE. Bride and groom in systemic inflammation--the bells ring for complement and Toll in cooperation. Immunobiology 2013; 217:1047-56. [PMID: 22964230 DOI: 10.1016/j.imbio.2012.07.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 07/19/2012] [Accepted: 07/19/2012] [Indexed: 01/08/2023]
Abstract
Attenuating the sepsis-induced systemic inflammatory response, with subsequent homeostatic imbalance, has for years been one of the main tasks in sepsis related research. Complement and the TLR family constitute two important upstream sensor and effector-systems of innate immunity. Although they act as partly independent branches of pattern recognition, recent evidence indicate a considerable cross-talk implying that they can either compensate, synergize or antagonize each other. Combined inhibition of these pathways is therefore a particularly interesting approach with a profound anti-inflammatory potential. In previous preclinical studies, we demonstrated that targeting the key molecules C3 or C5 of complement and CD14 of the TLR family had a vast anti-inflammatory effect on Gram-negative bacteria-induced inflammation and sepsis. In this review, we elucidate the significance of these key molecules as important targets for intervention in sepsis and systemic inflammatory response syndrome. Finally, we argue that a combined inhibition of complement and CD14 represent a potential general treatment regimen, beyond the limit of sepsis, including non-infectious systemic inflammation and ischemia reperfusion injury.
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Affiliation(s)
- Andreas Barratt-Due
- Department of Immunology, Oslo University Hospital Rikshospitalet, University of Oslo, Norway.
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Fine tuning inflammation at the front door: macrophage complement receptor 3-mediates phagocytosis and immune suppression for Francisella tularensis. PLoS Pathog 2013; 9:e1003114. [PMID: 23359218 PMCID: PMC3554622 DOI: 10.1371/journal.ppat.1003114] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 11/19/2012] [Indexed: 12/11/2022] Open
Abstract
Complement receptor 3 (CR3, CD11b/CD18) is a major macrophage phagocytic receptor. The biochemical pathways through which CR3 regulates immunologic responses have not been fully characterized. Francisella tularensis is a remarkably infectious, facultative intracellular pathogen of macrophages that causes tularemia. Early evasion of the host immune response contributes to the virulence of F. tularensis and CR3 is an important receptor for its phagocytosis. Here we confirm that efficient attachment and uptake of the highly virulent Type A F. tularensis spp. tularensis strain Schu S4 by human monocyte-derived macrophages (hMDMs) requires complement C3 opsonization and CR3. However, despite a>40-fold increase in uptake following C3 opsonization, Schu S4 induces limited pro-inflammatory cytokine production compared with non-opsonized Schu S4 and the low virulent F. novicida. This suggests that engagement of CR3 by opsonized Schu S4 contributes specifically to the immune suppression during and shortly following phagocytosis which we demonstrate by CD11b siRNA knockdown in hMDMs. This immune suppression is concomitant with early inhibition of ERK1/2, p38 MAPK and NF-κB activation. Furthermore, TLR2 siRNA knockdown shows that pro-inflammatory cytokine production and MAPK activation in response to non-opsonized Schu S4 depends on TLR2 signaling providing evidence that CR3-TLR2 crosstalk mediates immune suppression for opsonized Schu S4. Deletion of the CD11b cytoplasmic tail reverses the CR3-mediated decrease in ERK and p38 activation during opsonized Schu-S4 infection. The CR3-mediated signaling pathway involved in this immune suppression includes Lyn kinase and Akt activation, and increased MKP-1, which limits TLR2-mediated pro-inflammatory responses. These data indicate that while the highly virulent F. tularensis uses CR3 for efficient uptake, optimal engagement of this receptor down-regulates TLR2-dependent pro-inflammatory responses by inhibiting MAPK activation through outside-in signaling. CR3-linked immune suppression is an important mechanism involved in the pathogenesis of F. tularensis infection.
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1,25-Dihydroxyvitamin D3 promotes a sustained LPS-induced NF-κB-dependent expression of CD55 in human monocytic THP-1 cells. PLoS One 2012; 7:e49318. [PMID: 23152895 PMCID: PMC3495912 DOI: 10.1371/journal.pone.0049318] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 10/10/2012] [Indexed: 01/05/2023] Open
Abstract
The vitamin D3 system imposes immunosuppressive effects on monocytic cells, in part, by inhibiting NF-κB-dependent expression of proinflammatory mediators. CD55, a cell surface complement regulatory protein that promotes protective and anti-inflammatory properties, is reportedly an NF-κB target gene transiently induced in monocytic cells by the bacterial endotoxin LPS. CD55 is elevated on white cells in women experiencing preterm labor (a pathophysiology commonly associated with bacterial infection) and failure to maintain CD55 was associated with subsequent preterm delivery. We examined the influence of vitamin D3 signaling on LPS-induced expression of CD55 in human monocytic THP-1 cells using quantitative PCR, immunoblot, immunohistochemistry, and NF-κB activation pathway inhibitors. Non-NF-κB targets CD14 and CD11b, which modulate bacterial surveillance and eradication, respectively, were also examined. LPS produced a rapid transient 1.6-fold increase in CD55 mRNA. 1,25-D3 alone did not affect CD55 mRNA expression within the first 48 h. However, in 1,25-D3 pretreated cells, LPS produced a >4-fold immediate and sustained increase in CD55 mRNA and protein expression, which was blocked by NF-κB inhibitors. Our results unexpectedly suggest that vitamin D3 signaling may promote an anti-inflammatory response through an NF-κB-dependent increase in CD55 expression. As expected, LPS or 1,25-D3 alone led to sustained increases in CD14 and CD11b expression. In 1,25-D3 pretreated cells, LPS differentially regulated protein expression - CD14 (21-fold increase) and CD11b (a transient 2-fold decrease) - principally at the posttranscriptional level. The coordinated temporal expression of CD55, CD14 and CD11b would contribute to an anti-inflammatory response by providing protection against complement-mediated cell lysis during pathogen recognition and eradication. Overall, the vitamin D3 system may play a role coordinating an anti-inflammatory response pattern of the host complement immune system. This may be particularly important when considering the high rates of preterm births in blacks, a population that exhibits reduced circulating vitamin D3 levels.
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Abstract
Small GTP-binding proteins of the ADP-ribosylation factor (Arf) family control various cell functional responses including protein transport and recycling between different cellular compartments, phagocytosis, proliferation, cytoskeletal remodelling, and migration. The activity of Arfs is tightly regulated. GTPase-activating proteins (GAPs) inactivate Arfs by stimulating GTP hydrolysis, and guanine nucleotide exchange factors (GEFs) stimulate the conversion of inactive GDP-bound Arf to the active GTP-bound conformation. There is increasing evidence that Arf small GTPases contribute to cancer growth and invasion. Increased expression of Arf6 and of Arf-GEPs, or deregulation Arf-GAP functions have been correlated with enhanced invasive capacity of tumor cells and metastasis. The spatiotemporal specificity of Arf activation is dictated by their GEFs that integrate various signals in stimulated cells. Brefeldin A (BFA), which inactivates a subset of Arf-GEFs, has been very useful for assessing the function of Golgi-localized Arfs. However, specific inhibitors to investigate the individual function of BFA-sensitive and insensitive Arf-GEFs are lacking. In recent years, specific screens have been developed, and new inhibitors with improved selectivity and potency to study cell functional responses regulated by BFA-sensitive and BFA-insensitive Arf pathways have been identified. These inhibitors have been instrumental for our understanding of the spatiotemporal activation of Arf proteins in cells and demonstrate the feasibility of developing small molecules interfering with Arf activation to prevent tumor invasion and metastasis.
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Driss V, Hermann E, Legrand F, Loiseau S, Delbeke M, Kremer L, Guerardel Y, Dombrowicz D, Capron M. CR3-dependent negative regulation of human eosinophils by Mycobacterium bovis BCG lipoarabinomannan. Immunol Lett 2012; 143:202-7. [DOI: 10.1016/j.imlet.2012.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 02/16/2012] [Accepted: 02/16/2012] [Indexed: 01/21/2023]
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Mitogen-activated protein kinases mediate Mycobacterium tuberculosis–induced CD44 surface expression in monocytes. J Biosci 2012; 37:41-54. [DOI: 10.1007/s12038-011-9179-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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CD14 cooperates with complement receptor 3 to mediate MyD88-independent phagocytosis of Borrelia burgdorferi. Proc Natl Acad Sci U S A 2012; 109:1228-32. [PMID: 22232682 DOI: 10.1073/pnas.1112078109] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Phagocytosis of Borrelia burgdorferi, the causative agent of Lyme disease, is a poorly understood process, despite its importance during the host immune response to infection. B. burgdorferi has been shown to bind to different receptors on the surface of phagocytic cells, including the β(2) integrin, complement receptor 3 (CR3). However, whether these receptors mediate the phagocytosis of the spirochete remains unknown. We now demonstrate that CR3 mediates the phagocytosis of the spirochete by murine macrophages and human monocytes. Interaction of B. burgdorferi with the integrin is not sufficient, however, to internalize the spirochete; phagocytosis requires the interaction of CR3 with the GPI-anchored protein, CD14, independently of TLR/MyD88-induced or inside-out signals. Interestingly, the absence of CR3 leads to marked increases in the production of TNF in vitro and in vivo, despite reduced spirochetal uptake. Furthermore, the absence of CR3 during infection with B. burgdorferi results in the inefficient control of bacterial burdens in the heart and increased Lyme carditis. Overall, our data identify CR3 as a MyD88-independent phagocytic receptor for B. burgdorferi that also participates in the modulation of the proinflammatory output of macrophages. These data also establish a unique mechanism of CR3-mediated phagocytosis that requires the direct cooperation of GPI-anchored proteins.
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Natarajan PL, Narayanan S. Mitogen-activated protein kinases mediate the production of B-cell lymphoma 2 protein by Mycobacterium tuberculosis in monocytes. BIOCHEMISTRY (MOSCOW) 2011; 76:938-50. [PMID: 22022968 DOI: 10.1134/s0006297911080104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Changes in the levels of antiapoptotic protein B-cell lymphoma 2 (Bcl-2) protein has been reported in murine and human tuberculosis. We investigated the role of mitogen-activated protein kinase pathways in the production of Bcl-2 protein in THP-1 human monocytes infected with Mycobacterium tuberculosis H37Rv and H37Ra. Analysis of phosphorylation profiles of mitogen-activated protein kinase kinase-1, extracellular-signal regulated kinase 1/2, mitogen-activated protein kinase kinase 3/6, and p38 mitogen-activated protein kinase; B-cell lymphoma 2 kinetics; and tumor necrosis factor-α (TNF-α) secretion levels showed variation between the two strains. Mycobacterium tuberculosis H37Rv induced higher Bcl-2 and lower TNF-α levels, whereas H37Ra the reverse. The strains also differed in their usage of CD14 and human leukocyte antigen-DR receptors in mediating extracellular-signal regulated kinase 1/2 and p38 mitogen-activated protein kinase activation. Mycobacterium tuberculosis H37Rv- and H37Ra-induced Bcl-2 production was reduced by specific inhibitors of mitogen-activated protein kinase kinase-1 (PD98059) and p38 (SB203580), but increased by nuclear factor κB (NF-κB) inhibitor (BAY 11-7082). TNF-α production by both strains was reduced in the presence of specific inhibitors of mitogen-activated protein kinase kinase-1 (PD98059), p38 (SB203580), and NF-κB (BAY 11-7082). Furthermore, inhibition of NF-κB was accompanied by an increase in strain-induced extracellular-signal regulated kinase 1/2 phosphorylation. Collectively, these results indicate for the first time that the production of Bcl-2 and TNF-α by M. tuberculosis H37Rv/H37Ra-infected THP-1 human monocytes is mediated through mitogen-activated protein kinases and NF-κB.
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Affiliation(s)
- P L Natarajan
- Department of Immunology, Tuberculosis Research Centre, Chennai, India
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Karavitis J, Kovacs EJ. Macrophage phagocytosis: effects of environmental pollutants, alcohol, cigarette smoke, and other external factors. J Leukoc Biol 2011; 90:1065-78. [PMID: 21878544 DOI: 10.1189/jlb.0311114] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The ability of a pathogen to evade host immunity successfully, in contrast to the host's capacity to defend itself against a foreign invader, is a complex struggle, in which eradication of infection is dictated by a robust immunologic response. Often, there are external factors that can alter the outcome by tipping the scale to benefit pathogen establishment rather than resolution by the host's defense system. These external sources, such a cigarettes, alcohol, or environmental pollutants, can negatively influence the effectiveness of the immune system's response to a pathogen. The observed suppression of immune function can be attributed to dysregulated cytokine and chemokine production, the loss of migratory potential, or the inability to phagocytose pathogens by immune cells. This review will focus on the mechanisms involved during the toxin-induced suppression of phagocytosis. The accumulated data support the importance of studying the mechanisms of phagocytosis following exposure to these factors, in that this effect alone cannot only leave the host susceptible to infection but also promote alterations in many other macrophage functions necessary for pathogen clearance and restoration of homeostasis.
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Affiliation(s)
- John Karavitis
- Program of Cell Biology, Neurobiology and Anatomy, Loyola University Medical Center, Maywood, Illinois, USA
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Kim KH, Yang CS, Shin AR, Jeon SR, Park JK, Kim HJ, Jo EK. Mycobacterial Heparin-binding Hemagglutinin Antigen Activates Inflammatory Responses through PI3-K/Akt, NF-κB, and MAPK Pathways. Immune Netw 2011; 11:123-33. [PMID: 21637390 PMCID: PMC3100523 DOI: 10.4110/in.2011.11.2.123] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/04/2011] [Accepted: 04/14/2011] [Indexed: 01/08/2023] Open
Abstract
Background Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. Methods HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-κB, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. Results HBHA robustly activated the expression of mRNA and protein of both TNF-α and IL-6, and induced phosphorylation of NF-κB, Akt, and MAPKs in BMDMs. Both TNF-α and IL-6 production by HBHA was regulated by the NF-κB, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. Conclusion These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.
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Affiliation(s)
- Ki-Hye Kim
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon 301-747, Korea
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El azreq MA, Bourgoin SG. Cytohesin-1 regulates human blood neutrophil adhesion to endothelial cells through β2 integrin activation. Mol Immunol 2011; 48:1408-16. [PMID: 21511340 DOI: 10.1016/j.molimm.2011.03.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 03/21/2011] [Accepted: 03/22/2011] [Indexed: 12/23/2022]
Abstract
Cytohesin-1 is a guanine nucleotide exchange factor for ADP ribosylation factor 6 (Arf6) in human blood neutrophils and differentiated PLB-985 neutrophil-like cells. Cytohesin-1 regulates adhesion and the transendothelial migration of monocytes, dendritic cells and T lymphocytes through activation of the β2 integrin LFA-1. In this study we investigated the role of cytohesin-1 in neutrophil and neutrophil-like cell adhesion to HUVECs, immobilized ICAM-1, and the α4β1 and α5β1 integrin extracellular matrix ligand fibronectin. We show that cytohesin-1 knockdown or inhibition with secinH3 inhibits fMLF-mediated cell adhesion to HUVECs and immobilized ICAM-1, whereas cytohesin-1 over-expression has the opposing effect. Binding of PLB-985 cells to HUVECs correlated with expression of the high-affinity β2 integrin epitope recognized by mAb24. Adhesion to HUVECs was inhibited by soluble ICAM-1, anti-ICAM-1, anti-CD11a and anti-CD18, but not anti-CD11b, blocking antibodies. We also demonstrate that cytohesin-1 knockdown promotes fMLF-mediated cell adhesion to fibronectin whereas cytohesin-1 over-expression has the opposing effect. Crosstalk between β1 and β2 integrins also exists since inhibition of β1 integrin functions with blocking antibodies enhanced adhesion of PLB-985 over-expressing cytohesin-1 to ICAM-1. We suggest that cytohesin-1 is a key regulator of neutrophil adhesion to endothelial cells and to components of extracellular matrix, which may influence cell emigration through its dual opposing effect on β2 and β1 integrin activation.
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Affiliation(s)
- Mohammed-Amine El azreq
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ-CHUL, Québec, Canada
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Hajishengallis G, Lambris JD. Microbial manipulation of receptor crosstalk in innate immunity. Nat Rev Immunol 2011; 11:187-200. [PMID: 21350579 DOI: 10.1038/nri2918] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the arms race of host-microbe co-evolution, successful microbial pathogens have evolved ingenious ways to evade host immune responses. In this Review, we focus on 'crosstalk manipulation' - the microbial strategies that instigate, subvert or disrupt the molecular signalling crosstalk between receptors of the innate immune system. This proactive interference undermines host defences and contributes to microbial adaptive fitness and persistent infections. Understanding how pathogens exploit host receptor crosstalk mechanisms and infiltrate the host signalling network is essential for developing interventions to redirect the host response and achieve protective immunity.
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Affiliation(s)
- George Hajishengallis
- University of Louisville, Department of Microbiology and Immunology, Louisville, Kentucky 40292, USA.
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El Azreq MA, Garceau V, Bourgoin SG. Cytohesin-1 regulates fMLF-mediated activation and functions of the β2 integrin Mac-1 in human neutrophils. J Leukoc Biol 2011; 89:823-36. [PMID: 21233413 DOI: 10.1189/jlb.0410222] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The nucleotide exchange factor cytohesin-1 was previously reported to interact with the cytoplasmic domains of the integrin β-chain common to all β(2) integrins such as LFA-1 and Mac-1. We show here that cytohesin-1, which contributes to fMLF-induced functional responses in PMNs through activation of Arf6, restrains the activation of the β(2) integrin Mac-1 (αMβ(2)) in PMNs or dcAMP-differentiated PLB-985 cells. We found that the cytohesin-1 inhibitor SecinH3 or siRNA increased cell adhesion to immobilized fibrinogen and fMLF-mediated conformational changes of Mac-1, monitored using mAb CBRM1/5, specific for the activation epitope of the αM subunit. In contrast, PLB-985 cells overexpressing cytohesin-1 showed little adhesion to fibrinogen. The use of SecinH3 and siRNA also revealed that interference with cytohesin-1 signaling also enhanced phagocytosis of zymosan particles and chemotaxis toward fMLF in transwell migration assays. These increments of phagocytosis and chemotaxis in cells treated with SecinH3 and cytohesin-1 siRNA were reversed by a blocking mAb to the integrin-αM subunit. We provide evidence for increased polymerized cortical actin in cells treated with SecinH3 and that altered signaling through cytohesin-1 increased cell surface expression of FPRL-1 and impairs the late calcium mobilization response elicited by fMLF. The data provide evidence that stimulation with fMLF initiates a signaling cascade that restrains Mac-1 activation in PMNs. Such crosstalk between FPRL-1 and Mac-1 involves cytohesin-1. We suggest that cytohesin-1 may coordinate activation of the β(2) integrins to regulate PMN adhesion, phagocytosis, and chemotaxis.
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Affiliation(s)
- Mohammed-Amine El Azreq
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ-CHUL, Faculté de Médecine, Université Laval, Québec, Canada
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Stevens M, Van Poucke M, Peelman L, Rainard P, De Spiegeleer B, Rogiers C, Van de Walle G, Duchateau L, Burvenich C. Anaphylatoxin C5a-induced toll-like receptor 4 signaling in bovine neutrophils. J Dairy Sci 2011; 94:152-64. [DOI: 10.3168/jds.2010-3358] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 10/01/2010] [Indexed: 01/19/2023]
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Tabouret G, Astarie-Dequeker C, Demangel C, Malaga W, Constant P, Ray A, Honoré N, Bello NF, Perez E, Daffé M, Guilhot C. Mycobacterium leprae phenolglycolipid-1 expressed by engineered M. bovis BCG modulates early interaction with human phagocytes. PLoS Pathog 2010; 6:e1001159. [PMID: 20975946 PMCID: PMC2958813 DOI: 10.1371/journal.ppat.1001159] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 09/23/2010] [Indexed: 11/19/2022] Open
Abstract
The species-specific phenolic glycolipid 1 (PGL-1) is suspected to play a critical role in the pathogenesis of leprosy, a chronic disease of the skin and peripheral nerves caused by Mycobacterium leprae. Based on studies using the purified compound, PGL-1 was proposed to mediate the tropism of M. leprae for the nervous system and to modulate host immune responses. However, deciphering the biological function of this glycolipid has been hampered by the inability to grow M. leprae in vitro and to genetically engineer this bacterium. Here, we identified the M. leprae genes required for the biosynthesis of the species-specific saccharidic domain of PGL-1 and reprogrammed seven enzymatic steps in M. bovis BCG to make it synthesize and display PGL-1 in the context of an M. leprae-like cell envelope. This recombinant strain provides us with a unique tool to address the key questions of the contribution of PGL-1 in the infection process and to study the underlying molecular mechanisms. We found that PGL-1 production endowed recombinant BCG with an increased capacity to exploit complement receptor 3 (CR3) for efficient invasion of human macrophages and evasion of inflammatory responses. PGL-1 production also promoted bacterial uptake by human dendritic cells and dampened their infection-induced maturation. Our results therefore suggest that M. leprae produces PGL-1 for immune-silent invasion of host phagocytic cells.
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Affiliation(s)
- Guillaume Tabouret
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Catherine Astarie-Dequeker
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Caroline Demangel
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Wladimir Malaga
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Patricia Constant
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Aurélie Ray
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Nadine Honoré
- Institut Pasteur, Unité de Pathogénomique Mycobactérienne Intégrée, Paris, France
| | - Nana Fatimath Bello
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Esther Perez
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Mamadou Daffé
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Christophe Guilhot
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
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Lin JS, Huang JH, Hung LY, Wu SY, Wu-Hsieh BA. Distinct roles of complement receptor 3, Dectin-1, and sialic acids in murine macrophage interaction with Histoplasma yeast. J Leukoc Biol 2010; 88:95-106. [PMID: 20360401 DOI: 10.1189/jlb.1109717] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The yeast cells of dimorphic fungal pathogen Histoplasma reside primarily within the macrophages of an infected host; the interaction between the yeast and macrophage has a profound impact on host defense against the fungus. We used blocking antibodies and saccharides to identify the receptors that participate in the phagocytosis of and the cytokine response to Histoplasma. The phagocytosis and cytokine response results show that sialic acids on the macrophages were involved in the interaction between macrophages and Histoplasma. CR3, although not the only receptor involved, was responsible for phagocytosis and cytokine response. It is unclear which receptors other than CR3 are responsible for phagocytosis, but we did rule out the participation of TLR2, TLR4, MR, DC-SIGN/SIGNR1, FcgammaR, VLA-5, and Dectin-1. Even though Dectin-1 did not participate in phagocytosis, it collaborated with CR3 in the cytokine response to Histoplasma, suggesting that in the presence of phagocytic receptors, Histoplasma triggers cytokine signals through Dectin-1. Moreover, macrophage phagocytosis of and cytokine response to Histoplasma are Syk kinase-dependent. Our study delineated the distinct roles of CR3, Dectin-1, and sialic acids in the interaction with Histoplasma and suggested that multiple receptor use might be important to host defense against Histoplasma.
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Affiliation(s)
- Jr-Shiuan Lin
- Graduate Institute of Immunology, National Taiwan University College of Medicine, Taipei, Taiwan
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Hajishengallis G, Lambris JD. Crosstalk pathways between Toll-like receptors and the complement system. Trends Immunol 2010; 31:154-63. [PMID: 20153254 DOI: 10.1016/j.it.2010.01.002] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 01/09/2010] [Accepted: 01/14/2010] [Indexed: 02/08/2023]
Abstract
The Toll-like receptors (TLRs) and complement are key innate defense systems that are triggered rapidly upon infection. Although both systems have been investigated primarily as separate entities, an emerging body of evidence indicates extensive crosstalk between complement and TLR signaling pathways. Analysis of these data suggests that the complement-TLR interplay reinforces innate immunity or regulates excessive inflammation, through synergistic or antagonistic interactions, respectively. However, the facility of complement and TLRs for communication is exploited by certain pathogens as a means to modify the host response in ways that favor the persistence of the pathogens. Further elucidation of regulatory links between complement and TLRs is essential for understanding their complex roles in health and disease.
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Affiliation(s)
- George Hajishengallis
- University of Louisville School of Dentistry, Division of Oral Health and Systemic Disease, Louisville, KY, USA.
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Affiliation(s)
- Oana Popa‐Nita
- Centre de Recherche en Rhumatologie et Immunologie du Centre de Recherche du CHUL‐CHUQ, Department of Microbiology and Immunology, Faculty of Medicine, Laval University Québec Canada
| | - Paul H Naccache
- Centre de Recherche en Rhumatologie et Immunologie du Centre de Recherche du CHUL‐CHUQ, Department of Microbiology and Immunology, Faculty of Medicine, Laval University Québec Canada
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