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Oscillatory Shear Stress Induces Oxidative Stress via TLR4 Activation in Endothelial Cells. Mediators Inflamm 2019; 2019:7162976. [PMID: 31316302 PMCID: PMC6604343 DOI: 10.1155/2019/7162976] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/29/2019] [Accepted: 05/13/2019] [Indexed: 01/25/2023] Open
Abstract
Background Oscillatory shear stress (OSS) disrupts endothelial homeostasis and promotes oxidative stress, which can lead to atherosclerosis. In atherosclerotic lesions, Toll-like receptor 4 (TLR4) is highly expressed. However, the molecular mechanism by which TLR4 modulates oxidative changes and the cell signaling transudation upon OSS is yet to be determined. Methods and Results Carotid artery constriction (CAC) surgery and a parallel-plate flow chamber were used to modulate shear stress. The results showed that OSS significantly increased the oxidative burden, and this was partly due to TLR4 activation. OSS activated NOX2 and had no significant influence to NOX1 or NOX4 in endothelial cells (ECs). OSS phosphorylated caveolin-1, promoted its binding with endothelial nitric oxide synthase (eNOS), and resulted in deactivation of eNOS. TLR4 inhibition restored levels of nitric oxide (NO) and superoxide dismutase (SOD) in OSS-exposed cells. Conclusion TLR4 modulates OSS-induced oxidative stress by activating NOX2 and suppressing eNOS.
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152
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Kramer S, Langhanki J, Krumb M, Opatz T, Bros M, Zentel R. HPMA‐Based Nanocarriers for Effective Immune System Stimulation. Macromol Biosci 2019; 19:e1800481. [DOI: 10.1002/mabi.201800481] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/22/2019] [Indexed: 01/25/2023]
Affiliation(s)
- Stefan Kramer
- Institute of Organic ChemistryJohannes Gutenberg‐University Mainz Duesbergweg 10–14 ,55128 Mainz Germany
| | - Jens Langhanki
- Institute of Organic ChemistryJohannes Gutenberg‐University Mainz Duesbergweg 10–14 ,55128 Mainz Germany
| | - Matthias Krumb
- Institute of Organic ChemistryJohannes Gutenberg‐University Mainz Duesbergweg 10–14 ,55128 Mainz Germany
| | - Till Opatz
- Institute of Organic ChemistryJohannes Gutenberg‐University Mainz Duesbergweg 10–14 ,55128 Mainz Germany
| | - Matthias Bros
- Department of DermatologyUniversity Medical CenterJohannes Gutenberg‐University Mainz Obere Zahlbacher Straße 63 ,55131 Mainz Germany
| | - Rudolf Zentel
- Institute of Organic ChemistryJohannes Gutenberg‐University Mainz Duesbergweg 10–14 ,55128 Mainz Germany
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153
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Saxena M, Sabado RL, La Mar M, Mohri H, Salazar AM, Dong H, Correa Da Rosa J, Markowitz M, Bhardwaj N, Miller E. Poly-ICLC, a TLR3 Agonist, Induces Transient Innate Immune Responses in Patients With Treated HIV-Infection: A Randomized Double-Blinded Placebo Controlled Trial. Front Immunol 2019; 10:725. [PMID: 31024557 PMCID: PMC6467168 DOI: 10.3389/fimmu.2019.00725] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/18/2019] [Indexed: 01/31/2023] Open
Abstract
Objective: Toll-like receptor-3 agonist Poly-ICLC has been known to activate immune cells and induce HIV replication in pre-clinical experiments. In this study we investigated if Poly-ICLC could be used for disrupting HIV latency while simultaneously enhancing innate immune responses. Design: This was a randomized, placebo-controlled, double-blinded trial in aviremic, cART-treated HIV-infected subjects. Participants (n = 15) were randomized 3:1 to receive two consecutive daily doses of Poly-ICLC (1.4 mg subcutaneously) vs. placebo. Subjects were observed for adverse events, immune activation, and viral replication. Methods: Besides primary outcomes of safety and tolerability, several longitudinal immune parameters were evaluated including immune cell phenotype and function via flowcytometry, ELISA, and transcriptional profiling. PCR assays for plasma HIV-1 RNA, CD4+ T cell-associated HIV-1 RNA, and proviral DNA were performed to measure HIV reservoirs and latency. Results: Poly-ICLC was overall safe and well-tolerated. Poly-ICLC-related adverse events were Grade 1/2, with the exception of one Grade 3 neutropenia which was short-lived. Mild Injection site reactions were observed in nearly all participants in the Poly-ICLC arm. Transcriptional analyses revealed upregulation of innate immune pathways in PBMCs following Poly-ICLC treatment, including strong interferon signaling accompanied by transient increases in circulating IP-10 (CXCL10) levels. These responses generally peaked by 24–48 h after the first injection and returned to baseline by day 8. CD4+ T cell number and phenotype were unchanged, plasma viral control was maintained and no significant effect on HIV reservoirs was observed. Conclusions: These finding suggest that Poly-ICLC could be safely used for inducing transient innate immune responses in treated HIV+ subjects indicating promise as an adjuvant for HIV therapeutic vaccines. Trial Registration:www.ClinicalTrials.gov, identifier: NCT02071095.
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Affiliation(s)
- Mansi Saxena
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Rachel L Sabado
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Melissa La Mar
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, NY, United States
| | - Hiroshi Mohri
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, NY, United States
| | | | - Hanqing Dong
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Joel Correa Da Rosa
- Laboratory of Investigative Dermatology, The Rockefeller University, New York, NY, United States
| | - Martin Markowitz
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, NY, United States
| | - Nina Bhardwaj
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Elizabeth Miller
- Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Laboratory of Investigative Dermatology, The Rockefeller University, New York, NY, United States
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154
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Neubert P, Schröder A, Müller DN, Jantsch J. Interplay of Na + Balance and Immunobiology of Dendritic Cells. Front Immunol 2019; 10:599. [PMID: 30984179 PMCID: PMC6449459 DOI: 10.3389/fimmu.2019.00599] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/06/2019] [Indexed: 12/12/2022] Open
Abstract
Local Na+ balance emerges as an important factor of tissue microenvironment. On the one hand, immune cells impact on local Na+ levels. On the other hand, Na+ availability is able to influence immune responses. In contrast to macrophages, our knowledge of dendritic cells (DCs) in this state of affair is rather limited. Current evidence suggests that the impact of increased Na+ on DCs is context dependent. Moreover, it is conceivable that DC immunobiology might also be influenced by Na+-rich-diet-induced changes of the gut microbiome.
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Affiliation(s)
- Patrick Neubert
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Agnes Schröder
- Department of Orthodontics, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Dominik N Müller
- Experimental and Clinical Research Center, A Joint Cooperation of Max-Delbrück Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Berlin, Germany.,Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
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155
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Palikhe S, Ohashi W, Sakamoto T, Hattori K, Kawakami M, Andoh T, Yamazaki H, Hattori Y. Regulatory Role of GRK2 in the TLR Signaling-Mediated iNOS Induction Pathway in Microglial Cells. Front Pharmacol 2019; 10:59. [PMID: 30778300 PMCID: PMC6369205 DOI: 10.3389/fphar.2019.00059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/18/2019] [Indexed: 12/31/2022] Open
Abstract
G protein-coupled receptor kinase 2 (GRK2) is a ubiquitous member of the GRK family that restrains cellular activation by G protein-coupled receptor (GPCR) phosphorylation leading to receptor desensitization and internalization, but has been identified to regulate a variety of signaling molecules, among which may be associated with inflammation. In this study, we attempted to establish the regulatory role of GRK2 in the Toll-like receptor (TLR) signaling pathway for inducible nitric oxide synthase (iNOS) expression in microglial cells. When mouse MG6 cells were stimulated with the TLR4 ligands lipopolysaccharide (LPS) and paclitaxel, we found that interferon regulatory factor 1 (IRF1) protein expression and activation was upregulated, transcription of interferon-β (IFN-β) was accelerated, induction/activation of STAT1 and activation of STAT3 were promoted, and subsequently iNOS expression was upregulated. The ablation of GRK2 by small interfering RNAs (siRNAs) not only eliminated TLR4-mediated upregulation of IRF1 protein expression and nuclear translocation but also suppressed the activation of the STAT pathway, resulting in negating the iNOS upregulation. The TLR3-mediated changes in IRF1 and STAT1/3, leading to iNOS induction, were also abrogated by siRNA knockdown of GRK2. Furthermore, transfection of GRK2 siRNA blocked the exogenous IFN-β supplementation-induced increases in phosphorylation of STAT1 as well as STAT3 and abrogated the augmentation of iNOS expression in the presence of exogenous IFN-β. Taken together, our results show that GRK2 regulates the activation of IRF1 as well as the activation of the STAT pathway, leading to upregulated transcription of iNOS in activated microglial cells. Modulation of the TLR signaling pathway via GRK2 in microglia may be a novel therapeutic target for treatment of neuroinflammatory disorders.
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Affiliation(s)
- Sailesh Palikhe
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Wakana Ohashi
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takuya Sakamoto
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Kohshi Hattori
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, Tokyo, Japan
| | - Masaaki Kawakami
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Hiromi Yamazaki
- Faculty of Nursing Science, Tsuruga Nursing University, Tsuruga, Japan
| | - Yuichi Hattori
- Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- The Research Institute of Cancer Prevention, Health Sciences University of Hokkaido, Tobetsu, Japan
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156
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The central adaptor molecule TRIF influences L. sigmodontis worm development. Parasitol Res 2019; 118:539-549. [PMID: 30643971 DOI: 10.1007/s00436-018-6159-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022]
Abstract
Worldwide approximately 68 million people are infected with lymphatic filariasis (Lf), provoked by Wuchereria bancrofti, Brugia malayi and Brugia timori. This disease can lead to massive swelling of the limbs (elephantiasis) and disfigurement of the male genitalia (hydrocele). Filarial induced immune regulation is characterised by dominant type 2 helper T cell and regulatory immune responses. In vitro studies have provided evidence that signalling via Toll-like receptor-mediated pathways is triggered by filarial associated factors. Nevertheless, until now, less is known about the role of the adapter molecule TRIF during in vivo infections. Here, we used the rodent-specific nematode Litomosoides sigmodontis to investigate the role of TLR signalling and the corresponding downstream adapter and regulatory molecules TRIF, MyD88, IRF1 and IRF3 during an ongoing infection in semi-susceptible C57BL/6 mice. Interestingly, lack of the central adapter molecule TRIF led to higher worm burden and reduced overall absolute cell numbers in the thoracic cavity (the site of infection) 30 days post-infection. In addition, frequencies of macrophages and lymphocytes in the TC were increased in infected TRIF-/- C57BL/6 mice, whereas frequencies of eosinophils, CD4+ and CD8+ T cells were reduced. Nevertheless, cytokine levels and regulatory T cell populations remained comparable between TRIF-deficient and wildtype C57BL/6 mice upon 30 days of L. sigmodontis infection. In summary, this study revealed a crucial role of the adapter molecule TRIF on worm recovery and immune cell recruitment into the site of infection 30 days upon L. sigmodontis infection in C57BL/6 mice.
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157
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Kumar G, Arya SB, Tuli A. Method for Studying the Effect of Gene Silencing on Bacterial Infection-induced ERK1/2 Signaling in Bone-marrow Derived Macrophages. Bio Protoc 2018; 8:e3123. [PMID: 30627594 DOI: 10.21769/bioprotoc.3123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Macrophages are highly phagocytic cells that utilize various pathogen recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs). These PAMPs can be present within the microbe, such as bacterial CpG DNA, and are recognized by Toll-like receptor 9 (TLR9), a PRR present on the endosomal membrane of macrophages. PAMPs can also be present on the surface of microbes, such as Lipopolysaccharide (LPS), which decorates the outer membrane of gram-negative bacteria like Salmonella typhimurium and Escherichia coli. LPS is recognized by TLR4 present on the plasma membrane of macrophages, and LPS-TLR4 association leads to activation of signaling cascades including MAPK phosphorylation, which in turn promotes macrophage activation and microbial killing. This protocol describes the method for studying the role of a gene of interest in Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) signaling, induced by bacterial infection in primary bone-marrow derived macrophages (BMDMs).
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Affiliation(s)
- Gaurav Kumar
- Division of Cell Biology and Immunology, CSIR-Institute of Microbial Technology (IMTECH), Chandigarh, India
| | - Subhash B Arya
- Division of Cell Biology and Immunology, CSIR-Institute of Microbial Technology (IMTECH), Chandigarh, India
| | - Amit Tuli
- Division of Cell Biology and Immunology, CSIR-Institute of Microbial Technology (IMTECH), Chandigarh, India
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158
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Abstract
Sepsis was known to ancient Greeks since the time of great physician Hippocrates (460-377 BC) without exact information regarding its pathogenesis. With time and medical advances, it is now considered as a condition associated with organ dysfunction occurring in the presence of systemic infection as a result of dysregulation of the immune response. Still with this advancement, we are struggling for the development of target-based therapeutic approach for the management of sepsis. The advancement in understanding the immune system and its working has led to novel discoveries in the last 50 years, including different pattern recognition receptors. Inflammasomes are also part of these novel discoveries in the field of immunology which are <20 years old in terms of their first identification. They serve as important cytosolic pattern recognition receptors required for recognizing cytosolic pathogens, and their pathogen-associated molecular patterns play an important role in the pathogenesis of sepsis. The activation of both canonical and non-canonical inflammasome signaling pathways is involved in mounting a proinflammatory immune response via regulating the generation of IL-1β, IL-18, IL-33 cytokines and pyroptosis. In addition to pathogens and their pathogen-associated molecular patterns, death/damage-associated molecular patterns and other proinflammatory molecules involved in the pathogenesis of sepsis affect inflammasomes and vice versa. Thus, the present review is mainly focused on the inflammasomes, their role in the regulation of immune response associated with sepsis, and their targeting as a novel therapeutic approach.
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Affiliation(s)
- Vijay Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, Brisbane, Australia,
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Australia,
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159
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Karkhah A, Ebrahimpour S, Rostamtabar M, Koppolu V, Darvish S, Vasigala VKR, Validi M, Nouri HR. Helicobacter pylori evasion strategies of the host innate and adaptive immune responses to survive and develop gastrointestinal diseases. Microbiol Res 2018; 218:49-57. [PMID: 30454658 DOI: 10.1016/j.micres.2018.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/09/2018] [Accepted: 09/28/2018] [Indexed: 02/08/2023]
Abstract
Helicobacter pylori (H. pylori) is a bacterial pathogen that resides in more than half of the human population and has co-evolved with humans for more than 58,000 years. This bacterium is orally transmitted during childhood and is a key cause of chronic gastritis, peptic ulcers and two malignant cancers including MALT (mucosa-associated lymphoid tissue) lymphoma and adenocarcinoma. Despite the strong innate and adaptive immune responses, H. pylori has a long-term survival in the gastric mucosa. In addition to the virulence factors, survival of H. pylori is strongly influenced by the ability of bacteria to escape, disrupt and manipulate the host immune system. This bacterium can escape from recognition by innate immune receptors via altering its surface molecules. Moreover, H. pylori subverts adaptive immune response by modulation of effector T cell. In this review, we discuss the immune-pathogenicity of H. pylori by focusing on its ability to manipulate the innate and acquired immune responses to increase its survival in the gastric mucosa, leading up to gastrointestinal disorders. We also highlight the mechanisms that resulted to the persistence of H. pylori in gastric mucosa.
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Affiliation(s)
- Ahmad Karkhah
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran; Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Soheil Ebrahimpour
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Maryam Rostamtabar
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran
| | - Veerendra Koppolu
- Scientist Biopharmaceutical Development Medimmune Gaithersburg, MD, 20878 USA
| | - Sorena Darvish
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran
| | | | - Majid Validi
- Clinical Biochemistry Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Hamid Reza Nouri
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran; Immunoregulation Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
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160
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Shmueli A, Shalit T, Okun E, Shohat-Ophir G. The Toll Pathway in the Central Nervous System of Flies and Mammals. Neuromolecular Med 2018; 20:419-436. [PMID: 30276585 DOI: 10.1007/s12017-018-8515-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 09/26/2018] [Indexed: 12/20/2022]
Abstract
Toll receptors, first identified to regulate embryogenesis and immune responses in the adult fly and subsequently defined as the principal sensors of infection in mammals, are increasingly appreciated for their impact on the homeostasis of the central as well as the peripheral nervous systems. Whereas in the context of immunity, the fly Toll and the mammalian TLR pathways have been researched in parallel, the expression pattern and functionality have largely been researched disparately. Herein, we provide data on the expression pattern of the Toll homologues, signaling components, and downstream effectors in ten different cell populations of the adult fly central nervous system (CNS). We have compared the expression of the different Toll pathways in the fly to the expression of TLRs in the mouse brain and discussed the implications with respect to commonalities, differences, and future perspectives.
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Affiliation(s)
- Anat Shmueli
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Tali Shalit
- The Mantoux Bioinformatics institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Eitan Okun
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
- The Paul Feder Laboratory on Alzheimer's Disease Research, Ramat-Gan, Israel.
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Building 901, room 315, Ramat-Gan, 5290000, Israel.
| | - Galit Shohat-Ophir
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel.
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161
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Ruhl T, Kim BS, Beier JP. Cannabidiol restores differentiation capacity of LPS exposed adipose tissue mesenchymal stromal cells. Exp Cell Res 2018; 370:653-662. [DOI: 10.1016/j.yexcr.2018.07.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 07/17/2018] [Accepted: 07/19/2018] [Indexed: 02/01/2023]
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162
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Modulation of Apoptosis by Cytotoxic Mediators and Cell-Survival Molecules in Sjögren's Syndrome. Int J Mol Sci 2018; 19:ijms19082369. [PMID: 30103522 PMCID: PMC6121505 DOI: 10.3390/ijms19082369] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 12/11/2022] Open
Abstract
The pathogenesis of Sjögren’s syndrome (SS) involves multiple factors including genetic background, cell death, and exocrine dysfunction. We here discuss apoptotic control in exocrine glands in SS by showing various pro- and anti-apoptotic pathways. Although the membrane-bound and soluble form of the Fas/Fas ligand system is a leading player with activation of the death domain and caspase 8/3 cleavage, the role of soluble Fas/FasL (including its polymorphism) in apoptosis is controversial. The tumor necrosis factor related apoptosis-inducing ligand (TRAIL)-mediated apoptosis of salivary gland epithelial cells (SGECs) involves a mitochondrial pathway that includes caspase 9 cleavage. The involvement of innate immunity cells such as toll-like receptors (TLRs) has been investigated; TLR2-4 and TLR7-9 are associated with the induction of inflammation in exocrine glands of SS patients. TLR3 has the potential to induce the apoptosis of SS patients’ SGECs. Linkage of epidermal growth factor (EGF) was shown in exocrine glands in SS, and it inhibited the Fas/FasL system with the help of cell-survival factors. TLR3 has dual actions to cause inflammation as well as apoptosis, which are inhibited by EGF. In conclusion, apoptosis in exocrine glands of SS patients is tightly controlled by balance of pro-apoptotic signals and growth factor.
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163
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Martin B, Decroly É. Mécanismes d’échappement des filovirus à l’immunité innée. Med Sci (Paris) 2018; 34:671-677. [DOI: 10.1051/medsci/20183408013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Le virus Ébola est un pathogène émergent important en Afrique où il a été responsable de plusieurs épidémies de fièvres hémorragiques associées à un taux de mortalité extrêmement élevée (jusqu’à 90 %). La pathogenèse des filovirus est, entre autres, liée à une réponse antivirale inadaptée. Cette famille de virus a en effet développé des stratégies d’échappement aux mécanismes précoces de l’immunité innée. Il en résulte une réplication virale massive qui induit une réponse immunitaire inappropriée à l’origine d’une réaction inflammatoire aiguë associée au syndrome hémorragique. Dans cette revue, nous décrivons les mécanismes utilisés par les filovirus, tels que le virus Ébola, pour échapper à la réponse immunitaire innée.
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164
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Diogenes A, Hargreaves KM. Microbial Modulation of Stem Cells and Future Directions in Regenerative Endodontics. J Endod 2018; 43:S95-S101. [PMID: 28844309 DOI: 10.1016/j.joen.2017.07.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Regenerative endodontic procedures (REPs) have been shown to promote the resolution of signs and symptoms of disease and increase survival compared with traditional treatment procedures. However, there is still variable predictability of continued root development and evidence that the tissues formed do not recapitulate the native pulp-dentin complex. There is growing evidence that the apical papilla is capable of surviving prolonged endodontic infection and apical periodontitis and that it represents a rich source of undifferentiated mesenchymal stem cells in REPs. The survival and proper differentiation of stem cells transferred into infected root canals are fraught with challenges. Residual antigens, such as lipopolysaccharides, have been shown to be present in dentin even after adequate chemomechanical debridement. These antigens have a profound effect on stem cell fate by modulating their proliferative capacity and postdifferentiation phenotype. Thus, root canals must be detoxified in addition to disinfection. There is a strong need for translational studies that incorporate all aspects of tissue engineering in endodontics in models that include an existing infection to promote further advancement of the field. This is particularly important to make REPs more predictable when treating immature teeth in young patients. Importantly, regenerative procedures could eventually promote tooth longevity in our aging population. Lessons learned from translational studies that best mimic the clinical challenges could be evaluated in pragmatic clinical trials to determine the effectiveness of these procedures to promote desirable patient-centered outcomes.
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Affiliation(s)
- Anibal Diogenes
- Department of Endodontics at University of Texas Health Science Center at San Antonio, San Antonio, Texas.
| | - Kenneth M Hargreaves
- Department of Endodontics at University of Texas Health Science Center at San Antonio, San Antonio, Texas
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165
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Ebner S, Trieb M, Schönfeld M, Wietzorrek G, Santos-Sierra S. Decoy peptides derived from the extracellular domain of toll-like receptor 2 (TLR2) show anti-inflammatory properties. Bioorg Med Chem 2018; 26:4615-4623. [PMID: 30093346 DOI: 10.1016/j.bmc.2018.07.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 06/19/2018] [Accepted: 07/07/2018] [Indexed: 02/06/2023]
Abstract
Toll-like receptor 2 (TLR2) recognizes bacterial derived- and synthetic-lipopeptides after dimerization with TLR1 or TLR6. Hyper-activation of TLR2 has been described in several inflammatory diseases and the discovery of inhibitors of its pro-inflammatory activity represent potential starting points to develop therapeutics in such pathologies. We designed peptides derived from the TLR2 sequence comprising amino acid residues involved in ligand binding (Pam3CSK4) or heterodimerization (TLR2/TLR1) as pointed out by structural data.2 We identified several peptides (P13, P13(LL), P16, P16(LL)) which inhibited TLR2/1 signaling in HEK293-TLR2 cells (MAPK activation and NF-kB activity). Moreover, P13L and P16L decreased TNFα release in human primary PBMCs and mouse macrophages. The peptides were selective for TLR2/1 as they did not inhibit the activity of other TLRs tested. P13L and P16L inhibited the internalization of Pam3CSK4 fluorescently labeled in macrophages and the heterodimerization of TLR2 with TLR1 as demonstrated by immunoprecipitation studies. Our data demonstrate that peptides derived from the region comprising the leucine-rich repeats (LRR) 11 and 13 in the extracellular domain of TLR2 are good starting points to develop more potent anti-inflammatory peptides with TLR2 inhibitory activity.
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Affiliation(s)
- S Ebner
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University Innsbruck, Innrain 66, A-6020 Innsbruck, Austria
| | - M Trieb
- Biochemical Pharmacology Institute, Medical University Innsbruck, Peter Mayr Str. 1, A-6020 Innsbruck, Austria
| | - M Schönfeld
- Biochemical Pharmacology Institute, Medical University Innsbruck, Peter Mayr Str. 1, A-6020 Innsbruck, Austria
| | - G Wietzorrek
- Section of Molecular and Cellular Pharmacology, Medical University Innsbruck, Peter Mayr Str. 1, A-6020 Innsbruck, Austria
| | - S Santos-Sierra
- Biochemical Pharmacology Institute, Medical University Innsbruck, Peter Mayr Str. 1, A-6020 Innsbruck, Austria.
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166
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Abstract
Pattern recognition receptors (PRRs) survey intra- and extracellular spaces for pathogen-associated molecular patterns (PAMPs) within microbial products of infection. Recognition and binding to cognate PAMP ligand by specific PRRs initiates signaling cascades that culminate in a coordinated intracellular innate immune response designed to control infection. In particular, our immune system has evolved specialized PRRs to discriminate viral nucleic acid from host. These are critical sensors of viral RNA to trigger innate immunity in the vertebrate host. Different families of PRRs of virus infection have been defined and reveal a diversity of PAMP specificity for wide viral pathogen coverage to recognize and extinguish virus infection. In this review, we discuss recent insights in pathogen recognition by the RIG-I-like receptors, related RNA helicases, Toll-like receptors, and other RNA sensor PRRs, to present emerging themes in innate immune signaling during virus infection.
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Affiliation(s)
- Kwan T Chow
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
| | - Michael Gale
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
| | - Yueh-Ming Loo
- Center for Innate Immunity and Immune Disease and Department of Immunology, University of Washington, Seattle, Washington 98109, USA; , ,
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167
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Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis. Clin Transl Gastroenterol 2018; 9:147. [PMID: 29691386 PMCID: PMC5915448 DOI: 10.1038/s41424-018-0017-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/16/2018] [Accepted: 02/22/2018] [Indexed: 12/19/2022] Open
Abstract
Objectives Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy. Methods Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence. Results Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1β, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation. Conclusions Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.
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168
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Wallet SM, Puri V, Gibson FC. Linkage of Infection to Adverse Systemic Complications: Periodontal Disease, Toll-Like Receptors, and Other Pattern Recognition Systems. Vaccines (Basel) 2018; 6:E21. [PMID: 29621153 PMCID: PMC6027258 DOI: 10.3390/vaccines6020021] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/25/2018] [Accepted: 03/30/2018] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptors (TLRs) are a group of pattern recognition receptors (PRRs) that provide innate immune sensing of conserved pathogen-associated molecular patterns (PAMPs) to engage early immune recognition of bacteria, viruses, and protozoa. Furthermore, TLRs provide a conduit for initiation of non-infectious inflammation following the sensing of danger-associated molecular patterns (DAMPs) generated as a consequence of cellular injury. Due to their essential role as DAMP and PAMP sensors, TLR signaling also contributes importantly to several systemic diseases including cardiovascular disease, diabetes, and others. The overlapping participation of TLRs in the control of infection, and pathogenesis of systemic diseases, has served as a starting point for research delving into the poorly defined area of infection leading to increased risk of various systemic diseases. Although conflicting studies exist, cardiovascular disease, diabetes, cancer, rheumatoid arthritis, and obesity/metabolic dysfunction have been associated with differing degrees of strength to infectious diseases. Here we will discuss elements of these connections focusing on the contributions of TLR signaling as a consequence of bacterial exposure in the context of the oral infections leading to periodontal disease, and associations with metabolic diseases including atherosclerosis and type 2 diabetes.
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Affiliation(s)
- Shannon M Wallet
- Department of Oral Biology, College of Dental Medicine, University of Florida, Gainesville, FL 32610, USA.
| | - Vishwajeet Puri
- Department of Biomedical Sciences and Diabetes Institute, Ohio University, Athens, OH 45701, USA.
| | - Frank C Gibson
- Department of Oral Biology, College of Dental Medicine, University of Florida, Gainesville, FL 32610, USA.
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169
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Kim AY, Shim HJ, Shin HM, Lee YJ, Nam H, Kim SY, Youn HS. Andrographolide suppresses TRIF-dependent signaling of toll-like receptors by targeting TBK1. Int Immunopharmacol 2018. [DOI: 10.1016/j.intimp.2018.02.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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170
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Obesity, Inflammation, Toll-Like Receptor 4 and Fatty Acids. Nutrients 2018; 10:nu10040432. [PMID: 29601492 PMCID: PMC5946217 DOI: 10.3390/nu10040432] [Citation(s) in RCA: 414] [Impact Index Per Article: 69.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/24/2018] [Accepted: 03/28/2018] [Indexed: 02/06/2023] Open
Abstract
Obesity leads to an inflammatory condition that is directly involved in the etiology of cardiovascular diseases, type 2 diabetes mellitus, and certain types of cancer. The classic inflammatory response is an acute reaction to infections or to tissue injuries, and it tends to move towards resolution and homeostasis. However, the inflammatory process that was observed in individuals affected by obesity and metabolic syndrome differs from the classical inflammatory response in certain respects. This inflammatory process manifests itself systemically and it is characterized by a chronic low-intensity reaction. The toll-like receptor 4 (TLR4) signaling pathway is acknowledged as one of the main triggers of the obesity-induced inflammatory response. The aim of the present review is to describe the role that is played by the TLR4 signaling pathway in the inflammatory response and its modulation by saturated and omega-3 polyunsaturated fatty acids. Studies indicate that saturated fatty acids can induce inflammation by activating the TLR4 signaling pathway. Conversely, omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid and docosahexaenoic acid, exert anti-inflammatory actions through the attenuation of the activation of the TLR4 signaling pathway by either lipopolysaccharides or saturated fatty acids.
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171
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Avenoso A, D'Ascola A, Scuruchi M, Mandraffino G, Calatroni A, Saitta A, Campo S, Campo GM. The proteoglycan biglycan mediates inflammatory response by activating TLR-4 in human chondrocytes: Inhibition by specific siRNA and high polymerized Hyaluronan. Arch Biochem Biophys 2018; 640:75-82. [PMID: 29339093 DOI: 10.1016/j.abb.2018.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 02/07/2023]
Abstract
Cartilage degeneration are hallmarks of wear, tear, mechanical and inflammatory damage of the joint cartilage. Tissue degradation as well as compromising the integrity and function of the organ, produces different intermediates, directly able to stimulate further inflammatory effect, therefore, amplifying the inflammation response. Biglycan is a soluble component of the extracellular matrix that is released during tissue injury. It has been reported that released biglycan is an endogenous ligand for TLR-2/4 in some cell type. We studied the role of biglycan in an experimental model of biglycan-induced inflammatory response in human chondrocytes and the effect of high polymerized HA on reducing its activity. Exposition of chondrocytes to LPS generated cell injury, including high levels of biglycan. Chondrocyte treatment with biglycan produces a high mRNA expression of several detrimental inflammation mediators such as IL-1β, IL-6, MMP-13, and IL-17, as well as NF-kB and TLR-4 activation. Administration of high polymerized HA to chondrocytes exposed to biglycan was able to attenuate the inflammatory response by decreasing the expression of the inflammatory mediators. Involvement of the TLR-4 in the mediation of the biglycan action was confirmed using a specific silent agent (siRNA). Taken together, these data could be used to develop new anti-inflammatory approaches.
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Affiliation(s)
- Angela Avenoso
- Department of Biomedical and Dental Sciences and Morphofunctional Images, Policlinico Universitario, University of Messina, 98125 Messina, Italy
| | - Angela D'Ascola
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy
| | - Michele Scuruchi
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy
| | - Giuseppe Mandraffino
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy
| | - Alberto Calatroni
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy
| | - Antonino Saitta
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy
| | - Salvatore Campo
- Department of Biomedical and Dental Sciences and Morphofunctional Images, Policlinico Universitario, University of Messina, 98125 Messina, Italy
| | - Giuseppe M Campo
- Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, 98125 Messina, Italy.
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172
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Mitigating the Impact of Antibacterial Drug Resistance through Host-Directed Therapies: Current Progress, Outlook, and Challenges. mBio 2018; 9:mBio.01932-17. [PMID: 29382729 PMCID: PMC5790911 DOI: 10.1128/mbio.01932-17] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Increasing incidences of multidrug resistance in pathogenic bacteria threaten our ability to treat and manage bacterial infection. The development and FDA approval of novel antibiotics have slowed over the past decade; therefore, the adoption and improvement of alternative therapeutic strategies are critical for addressing the threat posed by multidrug-resistant bacteria. Host-directed therapies utilize small-molecule drugs and proteins to alter the host response to pathogen infection. Here, we highlight strategies for modulating the host inflammatory response to enhance bacterial clearance, small-molecule potentiation of innate immunity, and targeting of host factors that are exploited by pathogen virulence factors. Application of state-of-the-art "omic" technologies, including proteomics, transcriptomics, and image-omics (image-based high-throughput phenotypic screening), combined with powerful bioinformatics tools will enable the modeling of key signaling pathways in the host-pathogen interplay and aid in the identification of host proteins for therapeutic targeting and the discovery of host-directed small molecules that will regulate bacterial infection. We conclude with an outlook on research needed to overcome the challenges associated with transitioning host-directed therapies into a clinical setting.
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173
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Regan T, Gill AC, Clohisey SM, Barnett MW, Pariante CM, Harrison NA, Hume DA, Bullmore ET, Freeman TC. Effects of anti-inflammatory drugs on the expression of tryptophan-metabolism genes by human macrophages. J Leukoc Biol 2018; 103:681-692. [PMID: 29377288 PMCID: PMC5918594 DOI: 10.1002/jlb.3a0617-261r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 11/04/2017] [Accepted: 11/27/2017] [Indexed: 12/17/2022] Open
Abstract
Several lines of evidence link macrophage activation and inflammation with (monoaminergic) nervous systems in the etiology of depression. IFN treatment is associated with depressive symptoms, whereas anti‐TNFα therapies elicit positive mood. This study describes the actions of 2 monoaminergic antidepressants (escitalopram, nortriptyline) and 3 anti‐inflammatory drugs (indomethacin, prednisolone, and anti‐TNFα antibody) on the response of human monocyte‐derived macrophages (MDMs) from 6 individuals to LPS or IFN‐α. Expression profiling revealed robust changes in the MDM transcriptome (3294 genes at P < 0.001) following LPS challenge, whereas a more limited subset of genes (499) responded to IFNα. Contrary to published reports, administered at nontoxic doses, neither monoaminergic antidepressant significantly modulated the transcriptional response to either inflammatory challenge. Each anti‐inflammatory drug had a distinct impact on the expression of inflammatory cytokines and on the profile of inducible gene expression—notably on the regulation of enzymes involved in metabolism of tryptophan. Inter alia, the effect of anti‐TNFα antibody confirmed a predicted autocrine stimulatory loop in human macrophages. The transcriptional changes were predictive of tryptophan availability and kynurenine synthesis, as analyzed by targeted metabolomic studies on cellular supernatants. We suggest that inflammatory processes in the brain or periphery could impact on depression by altering the availability of tryptophan for serotonin synthesis and/or by increasing production of neurotoxic kynurenine.
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Affiliation(s)
- Tim Regan
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Scotland, UK
| | - Andrew C Gill
- School of Chemistry, Joseph Banks Laboratories, University of Lincoln, Green Lane, Lincoln, Lincolnshire, UK
| | - Sara M Clohisey
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Scotland, UK
| | - Mark W Barnett
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Scotland, UK
| | - Carmine M Pariante
- Stress, Psychiatry and Immunology Department of Psychological Medicine, Institute of Psychiatry, Kings College London, London, UK
| | - Neil A Harrison
- Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | | | - David A Hume
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Scotland, UK
| | - Edward T Bullmore
- Department of Psychiatry, University of Cambridge, Cambridge, UK.,Cambridgeshire & Peterborough NHS Foundation Trust, Cambridge, UK.,ImmunoPsychiatry, Immuno-Inflammation Therapeutic Area Unit, GlaxoSmithKline R&D, Stevenage, UK
| | - Tom C Freeman
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Scotland, UK
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174
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Stocks CJ, Schembri MA, Sweet MJ, Kapetanovic R. For when bacterial infections persist: Toll-like receptor-inducible direct antimicrobial pathways in macrophages. J Leukoc Biol 2018; 103:35-51. [PMID: 29345056 DOI: 10.1002/jlb.4ri0917-358r] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 12/18/2022] Open
Abstract
Macrophages are linchpins of innate immunity, responding to invading microorganisms by initiating coordinated inflammatory and antimicrobial programs. Immediate antimicrobial responses, such as NADPH-dependent reactive oxygen species (ROS), are triggered upon phagocytic receptor engagement. Macrophages also detect and respond to microbial products through pattern recognition receptors (PRRs), such as TLRs. TLR signaling influences multiple biological processes including antigen presentation, cell survival, inflammation, and direct antimicrobial responses. The latter enables macrophages to combat infectious agents that persist within the intracellular environment. In this review, we summarize our current understanding of TLR-inducible direct antimicrobial responses that macrophages employ against bacterial pathogens, with a focus on emerging evidence linking TLR signaling to reprogramming of mitochondrial functions to enable the production of direct antimicrobial agents such as ROS and itaconic acid. In addition, we describe other TLR-inducible antimicrobial pathways, including autophagy/mitophagy, modulation of nutrient availability, metal ion toxicity, reactive nitrogen species, immune GTPases (immunity-related GTPases and guanylate-binding proteins), and antimicrobial peptides. We also describe examples of mechanisms of evasion of such pathways by professional intramacrophage pathogens, with a focus on Salmonella, Mycobacteria, and Listeria. An understanding of how TLR-inducible direct antimicrobial responses are regulated, as well as how bacterial pathogens subvert such pathways, may provide new opportunities for manipulating host defence to combat infectious diseases.
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Affiliation(s)
- Claudia J Stocks
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark A Schembri
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
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175
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Abstract
Sepsis is a life-threatening organ dysfunction due to a dysregulated host response to infection. Both hyperinflammation and immune suppression ensue, to an extent that is harmful to the host. The inflammatory balance is disturbed, and this is associated with a failure to return to homeostasis. All pathogens with sufficient load and virulence can cause sepsis, after they succeed to adhere and pass the mucosal barrier of the host. The host defense system can recognize molecular components of invading pathogens, called pathogen-associated molecular patterns (PAMPs), with specialized receptors known as pattern recognition receptors (PRRs). Through several signaling pathways, overstimulation of PRRs has proinflammatory and immune suppressive consequences. Hyperinflammation is characterized by activation of target genes coding for proinflammatory cytokines (leukocyte activation), inefficient use of the complement system, activation of the coagulation system, and concurrent downregulation of anticoagulant mechanisms and necrotic cell death. The release of endogenous molecules by injured cells, called danger-associated molecular patterns (DAMPs) or alarmins, leads to deterioration in a vicious cycle by further stimulation of PRRs. Features of immune suppression are massive apoptosis and thereby depletion of immune cells, reprogramming of monocytes and macrophages to a state of a decreased capacity to release proinflammatory cytokines and a disturbed balance in cellular metabolic processes.
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176
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Queval CJ, Brosch R, Simeone R. The Macrophage: A Disputed Fortress in the Battle against Mycobacterium tuberculosis. Front Microbiol 2017; 8:2284. [PMID: 29218036 PMCID: PMC5703847 DOI: 10.3389/fmicb.2017.02284] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/06/2017] [Indexed: 01/09/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the etiological agent of human tuberculosis (TB), has plagued humans for thousands of years. TB still remains a major public health problem in our era, causing more than 4,400 deaths worldwide every day and killing more people than HIV. After inhaling Mtb-contaminated aerosols, TB primo-infection starts in the terminal lung airways, where Mtb is taken up by alveolar macrophages. Although macrophages are known as professional killers for pathogens, Mtb has adopted remarkable strategies to circumvent host defenses, building suitable conditions to survive and proliferate. Within macrophages, Mtb initially resides inside phagosomes, where its survival mostly depends on its ability to take control of phagosomal processing, through inhibition of phagolysosome biogenesis and acidification processes, and by progressively getting access to the cytosol. Bacterial access to the cytosolic space is determinant for specific immune responses and cell death programs, both required for the replication and the dissemination of Mtb. Comprehension of the molecular events governing Mtb survival within macrophages is fundamental for the improvement of vaccine-based and therapeutic strategies in order to help the host to better defend itself in the battle against the fierce invader Mtb. In this mini-review, we discuss recent research exploring how Mtb conquers and transforms the macrophage into a strategic base for its survival and dissemination as well as the associated defense strategies mounted by host.
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Affiliation(s)
| | | | - Roxane Simeone
- Unit for Integrated Mycobacterial Pathogenomics, Institut Pasteur, Paris, France
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177
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Kim E, Leung H, Akhtar N, Li J, Barta JR, Wang Y, Yang C, Kiarie E. Growth performance and gastrointestinal responses of broiler chickens fed corn-soybean meal diet without or with exogenous epidermal growth factor upon challenge with Eimeria. Poult Sci 2017; 96:3676-3686. [PMID: 28938785 PMCID: PMC5850350 DOI: 10.3382/ps/pex192] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/13/2017] [Indexed: 01/23/2023] Open
Abstract
Epidermal growth factor (EGF), a protein known for its mitogenic and anti-apoptotic effects was fed to broiler chickens to evaluate growth performance, gastrointestinal measurements, and apparent retention (AR) of components upon challenge with Eimeria. A total of 216, d old male broiler chicks (Ross 708) were placed in cages (6 birds/cage) and allocated to treatments. The treatments were: 1) control (Lactotobacilli lactis fermentation supernatant without EGF), 2) 80 μg of EGF/kg BW/d, and 3) 160 μg of EGF/kg BW/d. A basal antibiotic-free corn-soybean diet containing TiO2 was used. Birds were offered fresh feed with respective treatments on daily basis and had free access to drinking water for 14 d. On d 5, birds (6 replicates per treatment) were challenged with 1 mL of E. acervulina and E. maxima mixture via oral gavage and the other 6 replicates were given sham. Growth performance was measured in pre- (d 0 to 5) and post- (d 6 to 14) challenge periods. Two birds per cage were necropsied on d 10 for intestinal lesion scores and tissue samples for histomorphology and expression of select intestinal genes. Excreta samples for AR of components and oocyst shedding were taken d 10 to 13 and all birds were necropsied on d 14 for gastrointestinal weight. The EGF linearly (P < 0.05) increased BWG before challenge. There was no EGF and Eimeria interaction (P > 0.05) on growth performance, AR of GE, and intestinal histomorphology; the main effects were such that Eimeria depressed (P < 0.01) BWG, FCR, AR of DM, crude fat, and GE, and villi height to crypt depth ratio. An interaction between EGF and Eimeria (P < 0.05) on indices of gut function was such that EGF improved expression of genes for nutrient transporters and tight junction proteins in Eimeria challenged birds whilst no effect in non-challenged control. In conclusion, Eimeria challenge reduced growth performance and impaired gut function; EGF showed beneficial effects on growth pre-challenge and improved indices of gut function upon Eimeria challenge.
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Affiliation(s)
- E. Kim
- Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
| | - H. Leung
- Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
| | - N. Akhtar
- Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
| | - J. Li
- Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
| | - J. R. Barta
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1
| | - Y. Wang
- Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - C. Yang
- Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - E. Kiarie
- Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
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178
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Fros JJ, Dietrich I, Alshaikhahmed K, Passchier TC, Evans DJ, Simmonds P. CpG and UpA dinucleotides in both coding and non-coding regions of echovirus 7 inhibit replication initiation post-entry. eLife 2017; 6:e29112. [PMID: 28960178 PMCID: PMC5659819 DOI: 10.7554/elife.29112] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/28/2017] [Indexed: 12/23/2022] Open
Abstract
Most vertebrate and plant RNA and small DNA viruses suppress genomic CpG and UpA dinucleotide frequencies, apparently mimicking host mRNA composition. Artificially increasing CpG/UpA dinucleotides attenuates viruses through an entirely unknown mechanism. Using the echovirus 7 (E7) model in several cell types, we show that the restriction in E7 replication in mutants with increased CpG/UpA dinucleotides occurred immediately after viral entry, with incoming virions failing to form replication complexes. Sequences of CpG/UpA-high virus stocks showed no evidence of increased mutational errors that would render them replication defective, these viral RNAs were not differentially sequestered in cytoplasmic stress granules nor did they induce a systemic antiviral state. Importantly, restriction was not mediated through effects on translation efficiency since replicons with high CpG/UpA sequences inserted into a non-coding region were similarly replication defective. Host-cells thus possess intrinsic defence pathways that prevent replication of viruses with increased CpG/UpA frequencies independently of codon usage.
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Affiliation(s)
- Jelke Jan Fros
- Peter Medawar Building for Pathogen Research, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Isabelle Dietrich
- Peter Medawar Building for Pathogen Research, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Kinda Alshaikhahmed
- Peter Medawar Building for Pathogen Research, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Tim Casper Passchier
- Peter Medawar Building for Pathogen Research, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - David John Evans
- Biomedical Sciences Research ComplexUniversity of St AndrewsSt AndrewsUnited Kingdom
| | - Peter Simmonds
- Peter Medawar Building for Pathogen Research, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
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179
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Keck J, Gupta R, Christenson LK, Arulanandam BP. MicroRNA mediated regulation of immunity against gram-negative bacteria. Int Rev Immunol 2017; 36:287-299. [PMID: 28800263 PMCID: PMC6904929 DOI: 10.1080/08830185.2017.1347649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Evidence over the last couple decades has comprehensively established that short, highly conserved, non-coding RNA species called microRNA (miRNA) exhibit the ability to regulate expression and function of host genes at the messenger RNA (mRNA) level. MicroRNAs play key regulatory roles in immune cell development, differentiation, and protective function. Intrinsic host immune response to invading pathogens rely on intricate orchestrated events in the development of innate and adaptive arms of immunity. We discuss the involvement of miRNAs in regulating these processes against gram negative pathogens in this review.
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Affiliation(s)
- Jonathon Keck
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
| | - Lane K. Christenson
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Bernard P. Arulanandam
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
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180
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Pal B, Das B. In vitro Culture of Naïve Human Bone Marrow Mesenchymal Stem Cells: A Stemness Based Approach. Front Cell Dev Biol 2017; 5:69. [PMID: 28884113 PMCID: PMC5572382 DOI: 10.3389/fcell.2017.00069] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 07/28/2017] [Indexed: 12/11/2022] Open
Abstract
Human bone marrow derived mesenchymal stem cells (BM-MSCs) resides in their niches in close proximity to hematopoietic stem cells (HSCs). These naïve MSCs have tremendous potential in regenerative therapeutics, and may also be exploited by cancer and infectious disease agents. Hence, it is important to study the physiological and pathological roles of naïve MSC. However, our knowledge of naïve MSCs is limited by lack of appropriate isolation and in vitro culture methods. Established culture methods use serum rich media, and serial passaging for retrospective isolation of MSCs. These primed MSCs may not reflect the true physiological and pathological roles of naive MSCs (Figure 1). Therefore, there is a strong need for direct isolation and in vitro culture of naïve MSCs to study their stemness (self-renewal and undifferentiated state) and developmental ontogeny. We have taken a niche-based approach on stemness to better maintain naïve MSCs in vitro. In this approach, stemness is broadly divided as niche dependent (extrinsic), niche independent (intrinsic) and niche modulatory (altruistic or competitive). Using this approach, we were able to maintain naïve CD271+/CD133+ BM-MSCs for 2 weeks. Furthermore, this in vitro culture system helped us to identify naïve MSCs as a protective niche site for Mycobacterium tuberculosis, the causative organism of pulmonary tuberculosis. In this review, we discuss the in vitro culture of primed vs. naïve human BM derived MSCs with a special focus on how a stemness based approach could facilitate the study of naïve BM-MSCs.
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Affiliation(s)
- Bidisha Pal
- Department of Immunology and Infectious Diseases, The Forsyth InstituteCambridge, MA, United States
- Department of Stem Cell Biology, KaviKrishna Laboratory, Guwahati Biotech Park, Indian Institute of TechnologyGuwahati, India
| | - Bikul Das
- Department of Immunology and Infectious Diseases, The Forsyth InstituteCambridge, MA, United States
- Department of Stem Cell Biology, KaviKrishna Laboratory, Guwahati Biotech Park, Indian Institute of TechnologyGuwahati, India
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Uniting the neurodevelopmental and immunological hypotheses: Neuregulin 1 receptor ErbB and Toll-like receptor activation in first-episode schizophrenia. Sci Rep 2017. [PMID: 28646138 PMCID: PMC5482801 DOI: 10.1038/s41598-017-03736-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Current pathophysiological models of schizophrenia focus on neurodevelopmental and immunological mechanisms. We investigated a molecular pathway traditionally linked to the neurodevelopmental hypothesis (neuregulin 1 - ErbB), and pathogen-associated pattern recognition receptors associated with the immune hypothesis (Toll-like receptors, TLRs). We recruited 42 first-episode, drug-naïve patients with schizophrenia and 42 matched healthy control subjects. In monocytes TLR4/TLR5 and ErbB expressions were measured with flow-cytometry. Pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and the anti-inflammatory cytokine IL-10 were determined following the stimulation of TLR4/TLR5 and ErbB. Results revealed increased TLR4/TLR5 and decreased ErbB4 expression in schizophrenia relative to the control subjects. The expression of ErbB2 and ErbB3 receptors was unaltered in schizophrenia. TLR4 stimulation resulted in lower pro-inflammatory cytokine production in schizophrenia compared to the control levels, whereas the stimulation of ErbB by neuregulin 1 led to higher pro-inflammatory cytokine levels in patients with schizophrenia relative to the control group. In healthy controls, ErbB activation was associated with a marked production of IL-10, which was dampened in schizophrenia. These results indicate that the stimulation of TLR4 and ErbB induces opposite pro-inflammatory cytokine responses in schizophrenia.
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182
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Abstract
Apoptosis is an important component of normal tissue physiology, and the prompt removal of apoptotic cells is equally essential to avoid the undesirable consequences of their accumulation and disintegration. Professional phagocytes are highly specialized for engulfing apoptotic cells. The recent ability to track cells that have undergone apoptosis in situ has revealed a division of labor among the tissue resident phagocytes that sample them. Macrophages are uniquely programmed to process internalized apoptotic cell-derived fatty acids, cholesterol and nucleotides, as a reflection of their dominant role in clearing the bulk of apoptotic cells. Dendritic cells carry apoptotic cells to lymph nodes where they signal the emergence and expansion of highly suppressive regulatory CD4 T cells. A broad suppression of inflammation is executed through distinct phagocyte-specific mechanisms. A clever induction of negative regulatory nodes is notable in dendritic cells serving to simultaneously shut down multiple pathways of inflammation. Several of the genes and pathways modulated in phagocytes in response to apoptotic cells have been linked to chronic inflammatory and autoimmune diseases such as atherosclerosis, inflammatory bowel disease and systemic lupus erythematosus. Our collective understanding of old and new phagocyte functions after apoptotic cell phagocytosis demonstrates the enormity of ways to mediate immune suppression and enforce tissue homeostasis.
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Affiliation(s)
- J Magarian Blander
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Joan and Sanford I. Weill Department of Medicine, Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY, USA
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