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Zhang Y, Lee C, Geng S, Wang J, Bohara U, Hou J, Yi Z, Li L. Immune-enhancing neutrophils reprogrammed by subclinical low-dose endotoxin in cancer treatment. EMBO Mol Med 2024:10.1038/s44321-024-00100-7. [PMID: 39009886 DOI: 10.1038/s44321-024-00100-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/17/2024] Open
Abstract
Despite the re-emergence of the pioneering "Coley's toxin" concept in anti-cancer immune therapies highlighted by check-point inhibitors and CAR-T approaches, fundamental mechanisms responsible for the immune-enhancing efficacy of low-dose "Coley's toxin" remain poorly understood. This study examines the novel reprogramming of immune-enhancing neutrophils by super-low dose endotoxin conducive for anti-cancer therapies. Through integrated analyses including scRNAseq and functional characterizations, we examined the efficacy of reprogrammed neutrophils in treating experimental cancer. We observed that neutrophils trained by super-low dose endotoxin adopt a potent immune-enhancing phenotype characterized by CD177loCD11bloCD80hiCD40hiDectin2hi. Both murine and human neutrophils trained by super-low dose endotoxin exhibit relieved suppression of adaptive T cells as compared to un-trained neutrophils. Functionally, neutrophils trained by super-low dose endotoxin can potently reduce tumor burden when transfused into recipient tumor-bearing mice. Mechanistically, Super-low dose endotoxin enables the generation of immune-enhancing neutrophils through activating STAT5 and reducing innate suppressor IRAK-M. Together, our data clarify the long-held mystery of "Coley's toxin" in rejuvenating anti-tumor immune defense, and provide a proof-of-concept in developing innate neutrophil-based anti-tumor therapeutics.
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Affiliation(s)
- Yao Zhang
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Christina Lee
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Shuo Geng
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Jing Wang
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Udipta Bohara
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Jacqueline Hou
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Ziyue Yi
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0910, USA.
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2
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Balasubramanian A, Hsu AY, Ghimire L, Tahir M, Devant P, Fontana P, Du G, Liu X, Fabin D, Kambara H, Xie X, Liu F, Hasegawa T, Xu R, Yu H, Chen M, Kolakowski S, Trauger S, Larsen MR, Wei W, Wu H, Kagan JC, Lieberman J, Luo HR. The palmitoylation of gasdermin D directs its membrane translocation and pore formation during pyroptosis. Sci Immunol 2024; 9:eadn1452. [PMID: 38530158 DOI: 10.1126/sciimmunol.adn1452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 03/20/2024] [Indexed: 03/27/2024]
Abstract
Plasma membrane perforation elicited by caspase cleavage of the gasdermin D (GSDMD) N-terminal domain (GSDMD-NT) triggers pyroptosis. The mechanisms underlying GSDMD membrane translocation and pore formation are not fully understood. Here, using a proteomic approach, we identified fatty acid synthase (FASN) as a GSDMD-binding partner. S-palmitoylation of GSDMD at Cys191/Cys192 (human/mouse), catalyzed by palmitoyl acyltransferases ZDHHC5 and ZDHHC9 and facilitated by reactive oxygen species (ROS), directly mediated membrane translocation of GSDMD-NT but not full-length GSDMD (GSDMD-FL). Palmitoylation of GSDMD-FL could be induced before inflammasome activation by stimuli such as lipopolysaccharide (LPS), consequently serving as an essential molecular event in macrophage priming. Inhibition of GSDMD palmitoylation suppressed macrophage pyroptosis and IL-1β release, mitigated organ damage, and enhanced the survival of septic mice. Thus, GSDMD-NT palmitoylation is a key regulatory mechanism controlling GSDMD membrane localization and activation, which may offer an additional target for modulating immune activity in infectious and inflammatory diseases.
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Affiliation(s)
- Arumugam Balasubramanian
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Alan Y Hsu
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Laxman Ghimire
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Muhammad Tahir
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
- Biomedical Mass Spectrometry and Systems Biology, University of Southern Denmark, Odense, Denmark
| | - Pascal Devant
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Pietro Fontana
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Gang Du
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Xing Liu
- Department of Pediatrics, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Dang Fabin
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hiroto Kambara
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Xuemei Xie
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Fei Liu
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Tomoya Hasegawa
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Rong Xu
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
| | - Hongbo Yu
- Department of Pathology and Laboratory Medicine, VA Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132, USA
| | - Mei Chen
- Harvard Center for Mass Spectrometry, Harvard University, Boston, MA 02115, USA
| | - Steven Kolakowski
- Harvard Center for Mass Spectrometry, Harvard University, Boston, MA 02115, USA
| | - Sunia Trauger
- Harvard Center for Mass Spectrometry, Harvard University, Boston, MA 02115, USA
| | - Martin Røssel Larsen
- Biomedical Mass Spectrometry and Systems Biology, University of Southern Denmark, Odense, Denmark
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Judy Lieberman
- Department of Pediatrics, Harvard Medical School, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Hongbo R Luo
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School and Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 811, Boston, MA 02115, USA
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3
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Wu Y, Caldwell B, Wang J, Zhang Y, Li L. Alleviation of monocyte exhaustion by BCG derivative mycolic acid. iScience 2024; 27:108978. [PMID: 38323001 PMCID: PMC10845070 DOI: 10.1016/j.isci.2024.108978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/27/2023] [Accepted: 01/16/2024] [Indexed: 02/08/2024] Open
Abstract
Monocyte exhaustion with sustained pathogenic inflammation and immune-suppression, a hallmark of sepsis resulting from systemic infections, presents a challenge with limited therapeutic solutions. This study identified Methoxy-Mycolic Acid (M-MA), a branched mycolic acid derived from Mycobacterium bovis Bacillus Calmette-Guérin (BCG), as a potent agent in alleviating monocyte exhaustion and restoring immune homeostasis. Co-treatment of monocytes with M-MA effectively blocked the expansion of Ly6Chi/CD38hi/PD-L1hi monocytes induced by LPS challenges and restored the expression of immune-enhancing CD86. M-MA treatment restored mitochondrial functions of exhausted monocytes and alleviated their suppressive activities on co-cultured T cells. Independent of TREM2, M-MA blocks Src-STAT1-mediated inflammatory polarization and reduces the production of immune suppressors TAX1BP1 and PLAC8. Whole genome methylation analyses revealed M-MA's ability to erase the methylation memory of exhausted monocytes, particularly restoring Plac8 methylation. Together, our data suggest M-MA as an effective agent in restoring monocyte homeostasis with a therapeutic potential for treating sepsis.
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Affiliation(s)
- Yajun Wu
- Department of Biological Sciences, Virginia Tech; Blacksburg, VA 24061-0910, USA
| | - Blake Caldwell
- Department of Biological Sciences, Virginia Tech; Blacksburg, VA 24061-0910, USA
| | - Jing Wang
- Department of Biological Sciences, Virginia Tech; Blacksburg, VA 24061-0910, USA
| | - Yao Zhang
- Department of Biological Sciences, Virginia Tech; Blacksburg, VA 24061-0910, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech; Blacksburg, VA 24061-0910, USA
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4
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Geng S, Wu Y, Li L. Immune Homeostasis Maintenance Through Advanced Immune Therapeutics to Target Atherosclerosis. Methods Mol Biol 2024; 2782:25-37. [PMID: 38622390 DOI: 10.1007/978-1-0716-3754-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Atherosclerosis remains the leading cause of coronary heart disease (CHD) with enormous health and societal tolls. Traditional drug development approaches have been focused on small molecule-based compounds that aim to lower plasma lipids and reduce systemic inflammation, two primary causes of atherosclerosis. However, despite the widely available lipid-lowering and anti-inflammatory small compounds and biologic agents, CHD prevalence still remains high. Based on recent advances revealing disrupted immune homeostasis during atherosclerosis pathogenesis, novel strategies aimed at rejuvenating immune homeostasis with engineered immune leukocytes are being developed. This chapter aims to assess basic and translational efforts on these emerging strategies for the effective development of atherosclerosis treatment, as well as key challenges in this important translational field.
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Affiliation(s)
- Shuo Geng
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Yajun Wu
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
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5
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Geng S, Lu R, Zhang Y, Wu Y, Xie L, Caldwell B, Pradhan K, Yi Z, Hou J, Xu F, Chen X, Li L. Monocytes reprogrammed by 4-PBA potently contribute to the resolution of inflammation and atherosclerosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.19.563200. [PMID: 37961551 PMCID: PMC10634693 DOI: 10.1101/2023.10.19.563200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Background Chronic inflammation initiated by inflammatory monocytes underlies the pathogenesis of atherosclerosis. However, approaches that can effectively resolve chronic low-grade inflammation targeting monocytes are not readily available. The small chemical compound 4-phenylbutyric acid (4-PBA) exhibits broad anti-inflammatory effects in reducing atherosclerosis. Selective delivery of 4-PBA reprogrammed monocytes may hold novel potential in providing targeted and precision therapeutics for the treatment of atherosclerosis. Methods Systems analyses integrating single-cell RNA-sequencing and complementary immunological approaches characterized key resolving characteristics as well as defining markers of reprogrammed monocytes trained by 4-PBA. Molecular mechanisms responsible for monocyte reprogramming was assessed by integrated biochemical and genetic approaches. The inter-cellular propagation of homeostasis resolution was evaluated by co-culture assays with donor monocytes trained by 4-PBA and recipient naïve monocytes. The in vivo effects of monocyte resolution and atherosclerosis prevention by 4-PBA were assessed with the high fat diet-fed ApoE -/- mouse model with i.p. 4-PBA administration. Furthermore, the selective efficacy of 4-PBA trained monocytes were examined by i.v. transfusion of ex vivo trained monocytes by 4-PBA into recipient high fat diet-fed ApoE -/- mice. Results In this study, we found that monocytes can be potently reprogrammed by 4-PBA into an immune-resolving state characterized by reduced adhesion and enhanced expression of anti-inflammatory mediator CD24. Mechanistically, 4-PBA reduced the expression of ICAM-1 via reducing peroxisome stress and attenuating SYK-mTOR signaling. Concurrently, 4-PBA enhanced the expression of resolving mediator CD24 through promoting PPARγ neddylation mediated by TOLLIP. 4-PBA trained monocytes can effectively propagate anti-inflammation activity to neighboring monocytes through CD24. Our data further demonstrated that 4-PBA trained monocytes effectively reduce atherosclerosis pathogenesis when administered in vivo . Conclusion Our study describes a robust and effective approach to generate resolving monocytes, characterizes novel mechanisms for targeted monocyte reprogramming, and offers a precision-therapeutics for atherosclerosis based on delivering reprogrammed resolving monocytes.
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Wang J, Zhang J, Wang J, Hu X, Ouyang L, Wang Y. Small-Molecule Modulators Targeting Toll-like Receptors for Potential Anticancer Therapeutics. J Med Chem 2023; 66:6437-6462. [PMID: 37163340 DOI: 10.1021/acs.jmedchem.2c01655] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Toll-like receptors (TLRs) are key components of the innate immune system and serve as a crucial link between innate and acquired immunity. In addition to immune function, TLRs are involved in other important pathological processes, including tumorigenesis. TLRs have dual regulatory effects on tumor immunity by activating nuclear factor κ-B signaling pathways, which induce tumor immune evasion or enhance the antitumor immune response. Therefore, TLRs have become a popular target for cancer prevention and treatment, and TLR agonists and antagonists offer considerable potential for drug development. The TLR7 agonist imiquimod (1) has been approved by the U.S. Food and Drug Administration as a treatment for malignant skin cancer. Herein, the structure, signaling pathways, and function of the TLR family are summarized, and the structure-activity relationships associated with TLR selective and multitarget modulators and their potential application in tumor therapy are systematically discussed.
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Affiliation(s)
- Jiayu Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, China
| | - Jifa Zhang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Xinyue Hu
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, China
| | - Liang Ouyang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yuxi Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
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Lajqi T, Köstlin-Gille N, Bauer R, Zarogiannis SG, Lajqi E, Ajeti V, Dietz S, Kranig SA, Rühle J, Demaj A, Hebel J, Bartosova M, Frommhold D, Hudalla H, Gille C. Training vs. Tolerance: The Yin/Yang of the Innate Immune System. Biomedicines 2023; 11:biomedicines11030766. [PMID: 36979747 PMCID: PMC10045728 DOI: 10.3390/biomedicines11030766] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
For almost nearly a century, memory functions have been attributed only to acquired immune cells. Lately, this paradigm has been challenged by an increasing number of studies revealing that innate immune cells are capable of exhibiting memory-like features resulting in increased responsiveness to subsequent challenges, a process known as trained immunity (known also as innate memory). In contrast, the refractory state of endotoxin tolerance has been defined as an immunosuppressive state of myeloid cells portrayed by a significant reduction in the inflammatory capacity. Both training as well tolerance as adaptive features are reported to be accompanied by epigenetic and metabolic alterations occurring in cells. While training conveys proper protection against secondary infections, the induction of endotoxin tolerance promotes repairing mechanisms in the cells. Consequently, the inappropriate induction of these adaptive cues may trigger maladaptive effects, promoting an increased susceptibility to secondary infections—tolerance, or contribute to the progression of the inflammatory disorder—trained immunity. This review aims at the discussion of these opposing manners of innate immune and non-immune cells, describing the molecular, metabolic and epigenetic mechanisms involved and interpreting the clinical implications in various inflammatory pathologies.
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Affiliation(s)
- Trim Lajqi
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
- Correspondence: (T.L.); (C.G.)
| | - Natascha Köstlin-Gille
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
- Department of Neonatology, University of Tübingen, D-72076 Tübingen, Germany
| | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, D-07745 Jena, Germany
| | - Sotirios G. Zarogiannis
- Department of Physiology, School of Health Sciences, Faculty of Medicine, University of Thessaly, GR-41500 Larissa, Greece
| | - Esra Lajqi
- Department of Radiation Oncology, Heidelberg University Hospital, D-69120 Heidelberg, Germany
| | - Valdrina Ajeti
- Department of Pharmacy, Alma Mater Europaea—Campus College Rezonanca, XK-10000 Pristina, Kosovo
| | - Stefanie Dietz
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
- Department of Neonatology, University of Tübingen, D-72076 Tübingen, Germany
| | - Simon A. Kranig
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
| | - Jessica Rühle
- Department of Neonatology, University of Tübingen, D-72076 Tübingen, Germany
| | - Ardian Demaj
- Faculty of Medical Sciences, University of Tetovo, MK-1200 Tetova, North Macedonia
| | - Janine Hebel
- Department of Neonatology, University of Tübingen, D-72076 Tübingen, Germany
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine Heidelberg, University of Heidelberg, D-69120 Heidelberg, Germany
| | - David Frommhold
- Klinik für Kinderheilkunde und Jugendmedizin, D-87700 Memmingen, Germany
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
| | - Christian Gille
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany
- Correspondence: (T.L.); (C.G.)
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8
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Lajqi T, Frommhold D, Gille C, Hudalla H. Induction of memory-like adaptive responses in murine neutrophils in vitro. Cell Immunol 2022; 376:104535. [DOI: 10.1016/j.cellimm.2022.104535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 01/02/2023]
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9
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Gut Microbiota-Derived Small Extracellular Vesicles Endorse Memory-like Inflammatory Responses in Murine Neutrophils. Biomedicines 2022; 10:biomedicines10020442. [PMID: 35203650 PMCID: PMC8962420 DOI: 10.3390/biomedicines10020442] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
Neutrophils are classically characterized as merely reactive innate effector cells. However, the microbiome is known to shape the education and maturation process of neutrophils, improving their function and immune-plasticity. Recent reports demonstrate that murine neutrophils possess the ability to exert adaptive responses after exposure to bacterial components such as LPS (Gram-negative bacteria) or LTA (Gram-positive bacteria). We now ask whether small extracellular vesicles (EVs) from the gut may directly mediate adaptive responses in neutrophils in vitro. Murine bone marrow-derived neutrophils were primed in vitro by small EVs of high purity collected from colon stool samples, followed by a second hit with LPS. We found that low-dose priming with gut microbiota-derived small EVs enhanced pro-inflammatory sensitivity as indicated by elevated levels of TNF-α, IL-6, ROS and MCP-1 and increased migratory and phagocytic activity. In contrast, high-dose priming resulted in a tolerant phenotype, marked by increased IL-10 and decreased transmigration and phagocytosis. Alterations in TLR2/MyD88 as well as TLR4/MyD88 signaling were correlated with the induction of adaptive cues in neutrophils in vitro. Taken together, our study shows that small EVs from stools can drive adaptive responses in neutrophils in vitro and may represent a missing link in the gut–immune axis.
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10
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Geng S, Pradhan K, Li L. Signal-Strength and History-Dependent Innate Immune Memory Dynamics in Health and Disease. Handb Exp Pharmacol 2022; 276:23-41. [PMID: 34085119 DOI: 10.1007/164_2021_485] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Innate immunity exhibits memory characteristics, reflected not only in selective recognition of external microbial or internal damage signals, but more importantly in history and signal-strength dependent reprogramming of innate leukocytes characterized by priming, tolerance, and exhaustion. Key innate immune cells such as monocytes and neutrophils can finely discern and attune to the duration and intensity of external signals through rewiring of internal signaling circuitries, giving rise to a vast array of discreet memory phenotypes critically relevant to managing tissue homeostasis as well as diverse repertoires of inflammatory conditions. This review will highlight recent advances in this rapidly expanding field of innate immune programming and memory, as well as its translational implication in the pathophysiology of selected inflammatory diseases.
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Affiliation(s)
- Shuo Geng
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Kisha Pradhan
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
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11
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Ahmed D, Humphrey A, Roy D, Sheridan ME, Versey Z, Jaworski A, Edwards A, Donner J, Abizaid A, Willmore W, Kumar A, Golshani A, Cassol E. HIF-1α Regulation of Cytokine Production following TLR3 Engagement in Murine Bone Marrow-Derived Macrophages Is Dependent on Viral Nucleic Acid Length and Glucose Availability. THE JOURNAL OF IMMUNOLOGY 2021; 207:2813-2827. [PMID: 34740958 DOI: 10.4049/jimmunol.2001282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 09/16/2021] [Indexed: 12/24/2022]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) is an important regulator of glucose metabolism and inflammatory cytokine production in innate immune responses. Viruses modulate HIF-1α to support viral replication and the survival of infected cells, but it is unclear if this transcription factor also plays an important role in regulating antiviral immune responses. In this study, we found that short and long dsRNA differentially engage TLR3, inducing distinct levels of proinflammatory cytokine production (TNF-α and IL-6) in bone marrow-derived macrophages from C57BL/6 mice. These responses are associated with differential accumulation of HIF-1α, which augments NF-κB activation. Unlike TLR4 responses, increased HIF-1α following TLR3 engagement is not associated with significant alterations in glycolytic activity and was more pronounced in low glucose conditions. We also show that the mechanisms supporting HIF-1α stabilization may differ following stimulation with short versus long dsRNA and that pyruvate kinase M2 and mitochondrial reactive oxygen species play a central role in these processes. Collectively, this work suggests that HIF-1α may fine-tune proinflammatory cytokine production during early antiviral immune responses, particularly when there is limited glucose availability or under other conditions of stress. Our findings also suggest we may be able to regulate the magnitude of proinflammatory cytokine production during antiviral responses by targeting proteins or molecules that contribute to HIF-1α stabilization.
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Affiliation(s)
- Duale Ahmed
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.,Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Allan Humphrey
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada.,Apoptosis Research Centre, The Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - David Roy
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | | | - Zoya Versey
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Allison Jaworski
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Alex Edwards
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - James Donner
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - William Willmore
- Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Ashok Kumar
- Department of Pathology, The Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; and.,Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Ashkan Golshani
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Edana Cassol
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada;
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12
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Pradhan K, Yi Z, Geng S, Li L. Development of Exhausted Memory Monocytes and Underlying Mechanisms. Front Immunol 2021; 12:778830. [PMID: 34777396 PMCID: PMC8583871 DOI: 10.3389/fimmu.2021.778830] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/14/2021] [Indexed: 01/04/2023] Open
Abstract
Pathogenic inflammation and immuno-suppression are cardinal features of exhausted monocytes increasingly recognized in septic patients and murine models of sepsis. However, underlying mechanisms responsible for the generation of exhausted monocytes have not been addressed. In this report, we examined the generation of exhausted primary murine monocytes through prolonged and repetitive challenges with high dose bacterial endotoxin lipopolysaccharide (LPS). We demonstrated that repetitive LPS challenges skew monocytes into the classically exhausted Ly6Chi population, and deplete the homeostatic non-classical Ly6Clo population, reminiscent of monocyte exhaustion in septic patients. scRNAseq analyses confirmed the expansion of Ly6Chi monocyte cluster, with elevation of pathogenic inflammatory genes previously observed in human septic patients. Furthermore, we identified CD38 as an inflammatory mediator of exhausted monocytes, associated with a drastic depletion of cellular NAD+; elevation of ROS; and compromise of mitochondria respiration, representative of septic monocytes. Mechanistically, we revealed that STAT1 is robustly elevated and sustained in LPS-exhausted monocytes, dependent upon the TRAM adaptor of the TLR4 pathway. TRAM deficient monocytes are largely resistant to LPS-mediated exhaustion, and retain the non-classical homeostatic features. Together, our current study addresses an important yet less-examined area of monocyte exhaustion, by providing phenotypic and mechanistic insights regarding the generation of exhausted monocytes.
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Affiliation(s)
- Kisha Pradhan
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Ziyue Yi
- Graduate Program of Genetics, Biotechnology and Computational Biology, Virginia Tech, Blacksburg, VA, United States
| | - Shuo Geng
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
- Graduate Program of Genetics, Biotechnology and Computational Biology, Virginia Tech, Blacksburg, VA, United States
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13
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Geng S, Zhang Y, Yi Z, Lu R, Li L. Resolving monocytes generated through TRAM deletion attenuate atherosclerosis. JCI Insight 2021; 6:e149651. [PMID: 34499622 PMCID: PMC8564896 DOI: 10.1172/jci.insight.149651] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/08/2021] [Indexed: 02/06/2023] Open
Abstract
Polarization of low-grade inflammatory monocytes facilitates the pathogenesis of atherosclerosis. However, underlying mechanisms as well as approaches for resolving monocyte polarization conducive to the regression of atherosclerosis are not well established. In this report, we demonstrate that TRIF-related adaptor molecule (TRAM) mediated monocyte polarization in vivo and in vitro. TRAM controlled monocyte polarization through activating Src family kinase c-SRC, which not only induces STAT1/STAT5-regulated inflammatory mediators CCR2 and SIRP-α but also suppresses PPARγ-regulated resolving mediator CD200R. Enhanced PPARγ and Pex5 due to TRAM deficiency facilitated peroxisome homeostasis and reduction of cellular reactive oxygen species, further contributing to the establishment of a resolving monocyte phenotype. TRAM-deficient monocytes propagated the resolving phenotype to neighboring monocytes through CD200R-mediated intercellular communication. At the translational level, we show that TRAM-deficient mice were resistant to high-fat diet-induced pathogenesis of atherosclerosis. We further document that intravenous transfusion of TRAM-deficient resolving monocytes into atherosclerotic mice potently reduced the progression of atherosclerosis. Together, our data reveal that targeting TRAM may facilitate the effective generation of resolving monocytes conducive for the treatment of atherosclerosis.
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Affiliation(s)
- Shuo Geng
- Department of Biological Sciences and
| | - Yao Zhang
- Department of Biological Sciences and
| | - Ziyue Yi
- Graduate Program of Genetics, Biotechnology and Computational Biology, Virginia Tech, Blacksburg, Virginia, USA
| | - Ran Lu
- Department of Biological Sciences and
| | - Liwu Li
- Department of Biological Sciences and
- Graduate Program of Genetics, Biotechnology and Computational Biology, Virginia Tech, Blacksburg, Virginia, USA
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14
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Lajqi T, Braun M, Kranig SA, Frommhold D, Pöschl J, Hudalla H. LPS Induces Opposing Memory-like Inflammatory Responses in Mouse Bone Marrow Neutrophils. Int J Mol Sci 2021; 22:ijms22189803. [PMID: 34575963 PMCID: PMC8469609 DOI: 10.3390/ijms22189803] [Citation(s) in RCA: 8] [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: 06/27/2021] [Revised: 08/23/2021] [Accepted: 09/07/2021] [Indexed: 01/03/2023] Open
Abstract
A growing body of evidence suggests that innate immune cells can respond in a memory-like (adaptive) fashion, which is referred to as trained immunity. Only few in vivo studies have shown training effects in neutrophils; however, no in vitro setup has been established to study the induction of trained immunity or tolerance in neutrophils by microbial agents. In light of their short lifespan (up to 48 h), we suggest to use the term trained sensitivity for neutrophils in an in vitro setting. Here, we firstly describe a feasible two-hit model, using different doses of lipopolysaccharide (LPS) in bone marrow neutrophils. We found that low doses (10 pg/mL) induce pro-inflammatory activation (trained sensitivity), whereas priming with high doses (100 ng/mL) leads to suppression of pro-inflammatory mediators such as TNF-α or IL-6 (tolerance) (p < 0.05). On a functional level, trained neutrophils displayed increased phagocytic activity and LFA-1 expression as well as migrational capacity and CD11a expression, whereas tolerant neutrophils show contrasting effects in vitro. Mechanistically, TLR4/MyD88/PI3Ks regulate the activation of p65, which controls memory-like responses in mouse bone marrow neutrophils (p < 0.05). Our results open a new window for further in vitro studies on memory-like inflammatory responses of short-lived innate immune cells such as neutrophils.
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Affiliation(s)
- Trim Lajqi
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
| | - Maylis Braun
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
| | - Simon Alexander Kranig
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
| | - David Frommhold
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
- Klinik für Kinderheilkunde und Jugendmedizin, D-87700 Memmingen, Germany
| | - Johannes Pöschl
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children’s Hospital, D-69120 Heidelberg, Germany; (T.L.); (M.B.); (S.A.K.); (D.F.); (J.P.)
- Correspondence: ; Tel.: +49-6221-56-1983; Fax: +49-6221-56-5626
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15
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Pradhan K, Geng S, Zhang Y, Lin RC, Li L. TRAM-Related TLR4 Pathway Antagonized by IRAK-M Mediates the Expression of Adhesion/Coactivating Molecules on Low-Grade Inflammatory Monocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 206:2980-2988. [PMID: 34031144 PMCID: PMC8278277 DOI: 10.4049/jimmunol.2000978] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 04/05/2021] [Indexed: 11/19/2022]
Abstract
Low-grade inflammatory monocytes critically contribute to the pathogenesis of chronic inflammatory diseases such as atherosclerosis. The elevated expression of coactivating molecule CD40 as well as key adhesion molecule CD11a is a critical signature of inflammatory monocytes from both human patients with coronary artery diseases as well as in animal models of atherosclerosis. In this study, we report that subclinical superlow-dose LPS, a key risk factor for low-grade inflammation and atherosclerosis, can potently trigger the induction of CD40 and CD11a on low-grade inflammatory monocytes. Subclinical endotoxin-derived monocytes demonstrate immune-enhancing effects and suppress the generation of regulatory CD8+CD122+ T cells, which further exacerbate the inflammatory environment conducive for chronic diseases. Mechanistically, subclinical endotoxemia activates TRAM-mediated signaling processes, leading to the activation of MAPK and STAT5, which is responsible for the expression of CD40 and CD11a. We also demonstrate that TRAM-mediated monocyte polarization can be suppressed by IRAK-M. IRAK-M-deficient monocytes have increased expression of TRAM, elevated induction of CD40 and CD11a by subclinical-dose endotoxin, and are more potent in suppressing the CD8 regulatory T cells. Mice with IRAK-M deficiency generate an increased population of inflammatory monocytes and a reduced population of CD8 T regulatory cells. In contrast, mice with TRAM deficiency exhibit a significantly reduced inflammatory monocyte population and an elevated CD8 T regulatory cell population. Together, our data reveal a competing intracellular circuitry involving TRAM and IRAK-M that modulate the polarization of low-grade inflammatory monocytes with an immune-enhancing function.
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Affiliation(s)
- Kisha Pradhan
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Shuo Geng
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Yao Zhang
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Rui-Ci Lin
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Liwu Li
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
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16
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Lee J, Geng S, Li S, Li L. Single Cell RNA-Seq and Machine Learning Reveal Novel Subpopulations in Low-Grade Inflammatory Monocytes With Unique Regulatory Circuits. Front Immunol 2021; 12:627036. [PMID: 33708217 PMCID: PMC7940189 DOI: 10.3389/fimmu.2021.627036] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/21/2021] [Indexed: 11/13/2022] Open
Abstract
Subclinical doses of LPS (SD-LPS) are known to cause low-grade inflammatory activation of monocytes, which could lead to inflammatory diseases including atherosclerosis and metabolic syndrome. Sodium 4-phenylbutyrate is a potential therapeutic compound which can reduce the inflammation caused by SD-LPS. To understand the gene regulatory networks of these processes, we have generated scRNA-seq data from mouse monocytes treated with these compounds and identified 11 novel cell clusters. We have developed a machine learning method to integrate scRNA-seq, ATAC-seq, and binding motifs to characterize gene regulatory networks underlying these cell clusters. Using guided regularized random forest and feature selection, our method achieved high performance and outperformed a traditional enrichment-based method in selecting candidate regulatory genes. Our method is particularly efficient in selecting a few candidate genes to explain observed expression pattern. In particular, among 531 candidate TFs, our method achieves an auROC of 0.961 with only 10 motifs. Finally, we found two novel subpopulations of monocyte cells in response to SD-LPS and we confirmed our analysis using independent flow cytometry experiments. Our results suggest that our new machine learning method can select candidate regulatory genes as potential targets for developing new therapeutics against low grade inflammation.
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Affiliation(s)
- Jiyoung Lee
- Ph.D. Program in Genetics, Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States.,School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Shuo Geng
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Song Li
- Ph.D. Program in Genetics, Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States.,School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Liwu Li
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
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17
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Ciupe SM, Boribong BP, Kadelka S, Jones CN. Bistable Mathematical Model of Neutrophil Migratory Patterns After LPS-Induced Epigenetic Reprogramming. Front Genet 2021; 12:633963. [PMID: 33708241 PMCID: PMC7940759 DOI: 10.3389/fgene.2021.633963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/27/2021] [Indexed: 11/17/2022] Open
Abstract
The highly controlled migration of neutrophils toward the site of an infection can be altered when they are trained with lipopolysaccharides (LPS), with high dose LPS enhancing neutrophil migratory pattern toward the bacterial derived source signal and super-low dose LPS inducing either migration toward an intermediary signal or dysregulation and oscillatory movement. Empirical studies that use microfluidic chemotaxis-chip devices with two opposing chemoattractants showed differential neutrophil migration after challenge with different LPS doses. The epigenetic alterations responsible for changes in neutrophil migratory behavior are unknown. We developed two mathematical models that evaluate the mechanistic interactions responsible for neutrophil migratory decision-making when exposed to competing chemoattractants and challenged with LPS. The first model, which considers the interactions between the receptor densities of two competing chemoattractants, their kinases, and LPS, displayed bistability between high and low ratios of primary to intermediary chemoattractant receptor densities. In particular, at equilibrium, we observe equal receptor densities for low LPS (< 15ng/mL); and dominance of receptors for the primary chemoattractant for high LPS (> 15ng/mL). The second model, which included additional interactions with an extracellular signal-regulated kinase in both phosphorylated and non-phosphorylated forms, has an additional dynamic outcome, oscillatory dynamics for both receptors, as seen in the data. In particular, it found equal receptor densities in the absence of oscillation for super-low and high LPS challenge (< 0.4 and 1.1 376 ng/mL). Predicting the mechanisms and the type of external LPS challenge responsible for neutrophils migration toward pro-inflammatory chemoattractants, migration toward pro-tolerant chemoattractants, or oscillatory movement is necessary knowledge in designing interventions against immune diseases, such as sepsis.
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Affiliation(s)
- Stanca M. Ciupe
- Department of Mathematics, Virginia Tech, Blacksburg, VA, United States
| | - Brittany P. Boribong
- Division of Pediatric Pulmonology, Massachusetts General Hospital, Boston, MA, United States
| | - Sarah Kadelka
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Caroline N. Jones
- Department of Bioengineering, University of Texas, Dallas, TX, United States
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18
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Lajqi T, Pöschl J, Frommhold D, Hudalla H. The Role of Microbiota in Neutrophil Regulation and Adaptation in Newborns. Front Immunol 2020; 11:568685. [PMID: 33133082 PMCID: PMC7550463 DOI: 10.3389/fimmu.2020.568685] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/31/2020] [Indexed: 12/16/2022] Open
Abstract
Newborns are highly susceptible to infections and mainly rely on innate immune functions. Reduced reactivity, delayed activation and subsequent failure to resolve inflammation however makes the neonatal immune system a very volatile line of defense. Perinatal microbiota, nutrition and different extra-uterine factors are critical elements that define long-term outcomes and shape the immune system during the neonatal period. Neutrophils are first responders and represent a vital component of the immune system in newborns. They have long been regarded as merely executive immune cells, however this notion is beginning to shift. Neutrophils are shaped by their surrounding and adaptive elements have been described. The role of “innate immune memory” and the main triangle connection microbiome—neutrophil—adaptation will be discussed in this review.
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Affiliation(s)
- Trim Lajqi
- Heidelberg University Children's Hospital, Department of Neonatology, Heidelberg, Germany
| | - Johannes Pöschl
- Heidelberg University Children's Hospital, Department of Neonatology, Heidelberg, Germany
| | - David Frommhold
- Klinik für Kinderheilkunde und Jugendmedizin, Memmingen, Germany
| | - Hannes Hudalla
- Heidelberg University Children's Hospital, Department of Neonatology, Heidelberg, Germany
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19
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Lajqi T, Stojiljkovic M, Williams DL, Hudalla H, Bauer M, Witte OW, Wetzker R, Bauer R, Schmeer C. Memory-Like Responses of Brain Microglia Are Controlled by Developmental State and Pathogen Dose. Front Immunol 2020; 11:546415. [PMID: 33101271 PMCID: PMC7546897 DOI: 10.3389/fimmu.2020.546415] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/14/2020] [Indexed: 01/01/2023] Open
Abstract
Microglia, the innate immune cells of the central nervous system, feature adaptive immune memory with implications for brain homeostasis and pathologies. However, factors involved in the emergence and regulation of these opposing responses in microglia have not been fully addressed. Recently, we showed that microglia from the newborn brain display features of trained immunity and immune tolerance after repeated contact with pathogens in a dose-dependent manner. Here, we evaluate the impact of developmental stage on adaptive immune responses of brain microglia after repeated challenge with ultra-low (1 fg/ml) and high (100 ng/ml) doses of the endotoxin LPS in vitro. We find that priming of naïve microglia derived from newborn but not mature and aged murine brain with ultra-low LPS significantly increased levels of pro-inflammatory mediators TNF-α, IL-6, IL-1β, MMP-9, and iNOS as well as neurotrophic factors indicating induction of trained immunity (p < 0.05). In contrast, stimulation with high doses of LPS led to a robust downregulation of pro-inflammatory cytokines and iNOS independent of the developmental state, indicating induced immune tolerance. Furthermore, high-dose priming with LPS upregulated anti-inflammatory mediators IL-10, Arg-1, TGF- β, MSR1, and IL-4 in newborn microglia (p < 0.05). Our data indicate pronounced plasticity of the immune response of neonate microglia compared with microglia derived from mature and aged mouse brain. Induced trained immunity after priming with ultra-low LPS doses may be responsible for enhanced neuro-inflammatory susceptibility of immature brain. In contrast, the immunosuppressed phenotype following high-dose LPS priming might be prone to attenuate excessive damage after recurrent systemic inflammation.
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Affiliation(s)
- Trim Lajqi
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany.,Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Milan Stojiljkovic
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - David L Williams
- Department of Surgery and Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Michael Bauer
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Otto W Witte
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany.,Jena Center for Healthy Aging, Jena University Hospital, Jena, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany
| | - Christian Schmeer
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
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20
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Ding F, Liu B, Niu C, Wang T, Wang Y, Geng G, Tian D, Dai J, Fu Z. Low-Dose LPS Induces Tolerogenic Treg Skewing in Asthma. Front Immunol 2020; 11:2150. [PMID: 33072079 PMCID: PMC7538595 DOI: 10.3389/fimmu.2020.02150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/07/2020] [Indexed: 12/23/2022] Open
Abstract
The mechanism(s) underlying endotoxin tolerance in asthma remain elusive. As the endotoxin lipopolysaccharide (LPS) affects the expression of the regulatory T-cell (Treg)-suppressive glucocorticoid-induced tumor necrosis factor receptor ligand (GITRL) on antigen-presenting dendritic cells (DCs), we hypothesized that LPS-induced changes in DC GITRL expression may impact Treg-mediated T-helper (Th) cell suppression and the induction of endotoxin tolerance. Here, we propose a novel mechanism by which low-dose LPS inhalation in neonatal mice induces endotoxin tolerance, thereby offering protection from later asthma development. Three-day old wild-type and Toll-like receptor 4 (TLR4)-deficient neonatal mice were exposed to low-dose LPS (1 μg) intranasally for 10 consecutive days prior to ovalbumin (OVA)-induced asthma to better understand the tolerogenic mechanism(s) of low-dose LPS pre-exposure. In vivo findings were validated using in vitro co-culturing studies of primary CD11c+ DCs and CD4+ T-cells with or without low-dose LPS pre-exposure before OVA stimulation. Low-dose LPS pre-exposure upregulated the Treg response and downregulated pathogenic Th2 and Th17 responses through promoting apoptosis of Th2 and Th17 cells. Low-dose LPS pre-exposure downregulated DC GITRL expression and T-cell GITR expression. Artificial DC GITRL expression abrogated the tolerogenic Treg-skewing effect of low-dose LPS pre-exposure. Low-dose LPS pre-exposure inhibited TRIF/IRF3/IFNβ signaling and upregulated expression of tolerogenic TRIF/IRF3/IFNβ negative regulators in a TLR4-dependent manner. This tolerogenic DC GITRL downregulation was attributable to TRIF/IRF3/IFNβ signaling inhibition. Low-dose LPS pre-exposure produces tolerogenic Treg skewing in neonatal asthmatic mice, a phenomenon attributable to TLR4-dependent TRIF/IRF3/IFNβ-mediated DC GITRL downregulation.
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Affiliation(s)
- Fengxia Ding
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Bo Liu
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Department of Cardiothoracic Surgery, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Chao Niu
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Ting Wang
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Yaping Wang
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Gang Geng
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Daiyin Tian
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Jihong Dai
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
| | - Zhou Fu
- Department of Pediatric Respiratory Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Chongqing Key Laboratory of Child Infection and Immunity, Chongqing, China
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21
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Lin R, Zhang Y, Pradhan K, Li L. TICAM2-related pathway mediates neutrophil exhaustion. Sci Rep 2020; 10:14397. [PMID: 32873853 PMCID: PMC7463027 DOI: 10.1038/s41598-020-71379-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/14/2020] [Indexed: 12/15/2022] Open
Abstract
Pathogenic inflammation and immune suppression are the cardinal features that underlie the pathogenesis of severe systemic inflammatory syndrome and sepsis. Neutrophil exhaustion may play a key role during the establishment of pathogenic inflammation and immune suppression through elevated expression of inflammatory adhesion molecules such as ICAM1 and CD11b as well as immune-suppressors such as PD-L1. However, the mechanism of neutrophil exhaustion is not well understood. We demonstrated that murine primary neutrophils cultured in vitro with the prolonged lipopolysaccharides (LPS) stimulation can effectively develop an exhaustive phenotype resembling human septic neutrophils with elevated expression of ICAM1, CD11b, PD-L1 as well as enhanced swarming and aggregation. Mechanistically, we observed that TICAM2 is involved in the generation of neutrophil exhaustion, as TICAM2 deficient neutrophils have the decreased expression of ICAM1, CD11b, PD-L1, and the reduced aggregation following the prolonged LPS challenge as compared to wild type (WT) neutrophils. LPS drives neutrophil exhaustion through TICAM2 mediated activation of Src family kinases (SFK) and STAT1, as the application of SFK inhibitor Dasatinib blocks neutrophil exhaustion triggered by the prolonged LPS challenge. Functionally, TICAM2 deficient mice were protected from developing severe systemic inflammation and multi-organ injury following the chemical-induced mucosal damage. Together, our data defined a key role of TICAM2 in facilitating neutrophil exhaustion and that targeting TICAM2 may be a potential approach to treating the severe systemic inflammation.
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Affiliation(s)
- RuiCi Lin
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, VA, 24061, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Yao Zhang
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Kisha Pradhan
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Liwu Li
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, VA, 24061, USA.
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.
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22
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Rahtes A, Li L. Polarization of Low-Grade Inflammatory Monocytes Through TRAM-Mediated Up-Regulation of Keap1 by Super-Low Dose Endotoxin. Front Immunol 2020; 11:1478. [PMID: 32765513 PMCID: PMC7378438 DOI: 10.3389/fimmu.2020.01478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/08/2020] [Indexed: 12/19/2022] Open
Abstract
Subclinical endotoxemia [low levels of bacterial endotoxin (LPS) in the blood stream] has been correlated with chronic inflammatory diseases, with less-understood mechanisms. We have previously shown that chronic exposure to super low doses of LPS polarizes monocytes/macrophages to a pro-inflammatory state characterized by up-regulation of pro-inflammatory regulators such as p62 and simultaneous down-regulation of anti-inflammatory/resolving regulators such as Nrf2. Building upon this observation, here we show that chronic exposure to super-low doses of LPS leads to accumulation of the Nrf2-inhibitory protein Keap1 in murine monocytes. This is accompanied by increases of p62 and MLKL, consistent with a disruption of autolysosome function in polarized monocytes challenged by super-low dose LPS. Monocytes subjected to persistent super-low dose LPS challenge also accumulate higher levels of IKKβ. As a consequence, SLD-LPS challenge leads to an inflammatory monocyte state represented by higher expression of the inflammatory marker Ly6C as well as lower expression of the anti-inflammatory marker CD200R. Further analysis revealed that Keap1 levels are significantly enriched in the Ly6Chi pro-inflammatory monocyte population. Finally, we show that the TLR4 signaling adaptor TRAM is essential for these effects. Together our study provides novel insight into signaling mechanisms behind low-grade inflammatory monocyte polarization unique to chronic super-low dose LPS exposure.
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Affiliation(s)
- Allison Rahtes
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
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23
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Perros AJ, Flower RL, Dean MM. Inverse Relationship Between Lipopolysaccharide Concentration and Monocyte and Dendritic Cells Inflammatory Response. J Interferon Cytokine Res 2020; 40:349-356. [PMID: 32460585 DOI: 10.1089/jir.2019.0244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dendritic cells (DCs) and monocytes are key immunoregulatory cells that link the innate and adaptive immune response. However, understanding of human cell-specific responses to different doses of stimuli including lipopolysaccharide (LPS) is limited. This study investigated the monocyte and classical DC (cDC)-specific, as well as the overall inflammatory response after exposure to varying doses of LPS. Fresh peripheral whole blood (n = 8) was used in an in vitro peripheral blood culture model to assess cDC and monocyte responses in coculture with varying doses of LPS (0.25, 0.5, 0.75, 1 μg/mL). cDC and monocyte cytokine responses were measured through flow cytometry. Supernatants collected from the in vitro model were used in a cytometric bead array to assess the overall inflammatory response. Exposure to all doses of LPS tested increased monocyte, cDC, and the overall leukocyte response. A dose-dependent reduction in cDC and monocyte cytokine production was also evident with higher LPS doses. This study demonstrates that cell-subset-specific responses are more susceptible to LPS exposure compared with the overall inflammatory response. Therefore, assays that assess cell-specific immune responses may be more beneficial to identify underlying pathophysiology of infection and inflammation.
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Affiliation(s)
- Alexis J Perros
- Research and Development, Australian Red Cross Lifeblood, Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia.,Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Robert L Flower
- Research and Development, Australian Red Cross Lifeblood, Brisbane, Queensland, Australia.,Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Melinda M Dean
- Research and Development, Australian Red Cross Lifeblood, Brisbane, Queensland, Australia.,Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia.,School of Health and Sport Sciences, University of the Sunshine Coast, Petrie, Queensland, Australia
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24
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25
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Li L, McCall C, Hu X. Editorial: Innate Immunity Programming and Memory in Resolving and Non-Resolving Inflammation. Front Immunol 2020; 11:177. [PMID: 32117304 PMCID: PMC7026667 DOI: 10.3389/fimmu.2020.00177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 11/17/2022] Open
Affiliation(s)
- Liwu Li
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Charles McCall
- Department of Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Xiaoyu Hu
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing, China
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26
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Lérias JR, de Sousa E, Paraschoudi G, Martins J, Condeço C, Figueiredo N, Carvalho C, Dodoo E, Maia A, Castillo-Martin M, Beltrán A, Ligeiro D, Rao M, Zumla A, Maeurer M. Trained Immunity for Personalized Cancer Immunotherapy: Current Knowledge and Future Opportunities. Front Microbiol 2020; 10:2924. [PMID: 31998254 PMCID: PMC6967396 DOI: 10.3389/fmicb.2019.02924] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/04/2019] [Indexed: 12/17/2022] Open
Abstract
Memory formation, guided by microbial ligands, has been reported for innate immune cells. Epigenetic imprinting plays an important role herein, involving histone modification after pathogen-/danger-associated molecular patterns (PAMPs/DAMPs) recognition by pattern recognition receptors (PRRs). Such "trained immunity" affects not only the nominal target pathogen, yet also non-related targets that may be encountered later in life. The concept of trained innate immunity warrants further exploration in cancer and how these insights can be implemented in immunotherapeutic approaches. In this review, we discuss our current understanding of innate immune memory and we reference new findings in this field, highlighting the observations of trained immunity in monocytic and natural killer cells. We also provide a brief overview of trained immunity in non-immune cells, such as stromal cells and fibroblasts. Finally, we present possible strategies based on trained innate immunity that may help to devise host-directed immunotherapies focusing on cancer, with possible extension to infectious diseases.
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Affiliation(s)
- Joana R Lérias
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Eric de Sousa
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | | | - João Martins
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Carolina Condeço
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Nuno Figueiredo
- Digestive Unit, Champalimaud Clinical Centre, Lisbon, Portugal
| | - Carlos Carvalho
- Digestive Unit, Champalimaud Clinical Centre, Lisbon, Portugal
| | - Ernest Dodoo
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Andreia Maia
- Molecular and Experimental Pathology Laboratory, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Mireia Castillo-Martin
- Molecular and Experimental Pathology Laboratory, Champalimaud Centre for the Unknown, Lisbon, Portugal.,Department of Pathology, Champalimaud Clinical Centre, Lisbon, Portugal
| | - Antonio Beltrán
- Department of Pathology, Champalimaud Clinical Centre, Lisbon, Portugal
| | - Dário Ligeiro
- Lisbon Centre for Blood and Transplantation, Instituto Português do Sangue e Transplantação, Lisbon, Portugal
| | - Martin Rao
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Alimuddin Zumla
- Division of Infection and Immunity, NIHR Biomedical Research Centre, UCL Hospitals, NHS Foundation Trust, University College London, London, United Kingdom
| | - Markus Maeurer
- ImmunoSurgery Unit, Champalimaud Centre for the Unknown, Lisbon, Portugal
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27
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Lajqi T, Lang GP, Haas F, Williams DL, Hudalla H, Bauer M, Groth M, Wetzker R, Bauer R. Memory-Like Inflammatory Responses of Microglia to Rising Doses of LPS: Key Role of PI3Kγ. Front Immunol 2019; 10:2492. [PMID: 31781091 PMCID: PMC6856213 DOI: 10.3389/fimmu.2019.02492] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/07/2019] [Indexed: 12/28/2022] Open
Abstract
Trained immunity and immune tolerance have been identified as long-term response patterns of the innate immune system. The causes of these opposing reactions remain elusive. Here, we report about differential inflammatory responses of microglial cells derived from neonatal mouse brain to increasing doses of the endotoxin LPS. Prolonged priming with ultra-low LPS doses provokes trained immunity, i.e., increased production of pro-inflammatory mediators in comparison to the unprimed control. In contrast, priming with high doses of LPS induces immune tolerance, implying decreased production of inflammatory mediators and pronounced release of anti-inflammatory cytokines. Investigation of the signaling processes and cell functions involved in these memory-like immune responses reveals the essential role of phosphoinositide 3-kinase γ (PI3Kγ), one of the phosphoinositide 3-kinase species highly expressed in innate immune cells. Together, our data suggest profound influence of preceding contacts with pathogens on the immune response of microglia. The impact of these interactions—trained immunity or immune tolerance—appears to be shaped by pathogen dose.
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Affiliation(s)
- Trim Lajqi
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany.,Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Guang-Ping Lang
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany
| | - Fabienne Haas
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany
| | - David L Williams
- Department of Surgery and Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Michael Bauer
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Marco Groth
- Leibniz Institute on Aging-Fritz Lipmann Institute, CF DNA Sequencing, Jena, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany
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28
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Abstract
The endotoxin hypothesis of neurodegeneration is the hypothesis that endotoxin causes or contributes to neurodegeneration. Endotoxin is a lipopolysaccharide (LPS), constituting much of the outer membrane of gram-negative bacteria, present at high concentrations in gut, gums and skin and in other tissue during bacterial infection. Blood plasma levels of endotoxin are normally low, but are elevated during infections, gut inflammation, gum disease and neurodegenerative disease. Adding endotoxin at such levels to blood of healthy humans induces systemic inflammation and brain microglial activation. Adding high levels of endotoxin to the blood or body of rodents induces microglial activation, priming and/or tolerance, memory deficits and loss of brain synapses and neurons. Endotoxin promotes amyloid β and tau aggregation and neuropathology, suggesting the possibility that endotoxin synergises with different aggregable proteins to give different neurodegenerative diseases. Blood and brain endotoxin levels are elevated in Alzheimer's disease, which is accelerated by systemic infections, including gum disease. Endotoxin binds directly to APOE, and the APOE4 variant both sensitises to endotoxin and predisposes to Alzheimer's disease. Intestinal permeability increases early in Parkinson's disease, and injection of endotoxin into mice induces α-synuclein production and aggregation, as well as loss of dopaminergic neurons in the substantia nigra. The gut microbiome changes in Parkinson's disease, and changing the endotoxin-producing bacterial species can affect the disease in patients and mouse models. Blood endotoxin is elevated in amyotrophic lateral sclerosis, and endotoxin promotes TDP-43 aggregation and neuropathology. Peripheral diseases that elevate blood endotoxin, such as sepsis, AIDS and liver failure, also result in neurodegeneration. Endotoxin directly and indirectly activates microglia that damage neurons via nitric oxide, oxidants and cytokines, and by phagocytosis of synapses and neurons. The endotoxin hypothesis is unproven, but if correct, then neurodegeneration may be reduced by decreasing endotoxin levels or endotoxin-induced neuroinflammation.
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Affiliation(s)
- Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK.
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29
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Khan HN, Perlee D, Schoenmaker L, van der Meer A, Franitza M, Toliat MR, Nürnberg P, Zwinderman AH, van der Poll T, Scicluna BP. Leukocyte transcriptional signatures dependent on LPS dosage in human endotoxemia. J Leukoc Biol 2019; 106:1153-1160. [PMID: 31280495 PMCID: PMC6852106 DOI: 10.1002/jlb.4a0219-050r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/29/2019] [Accepted: 06/15/2019] [Indexed: 12/18/2022] Open
Abstract
The host immune response is characterized by a complex interplay of signal‐specific cellular transcriptional responses. The magnitude of the immune response is dependent on the strength of the external stimulus. Knowledge on leukocyte transcriptional responses altered in response to different stimulus dosages in man is lacking. Here, we sought to identify leukocyte transcriptional signatures dependent on LPS dose in humans. Healthy human volunteers were administered 1 ng/kg (n = 7), 2 ng/kg (n = 6), or 4 ng/kg (n = 7) LPS intravenously. Blood was collected before (pre‐LPS) and 4 h after LPS administration. Total RNA was analyzed by microarrays and generalized linear models. Pathway analysis was performed by using Ingenuity pathway analysis. Leukocyte transcriptomes altered per LPS dosage were predominantly shared, with 47% common signatures relative to pre‐LPS. A univariate linear model identified a set of 3736 genes that exhibited a dependency on differing LPS dosages. Neutrophil, monocyte, and lymphocyte counts explained 38.9% of the variance in the LPS dose‐dependent gene set. A multivariate linear model including leukocyte composition delineated a set of 295 genes with a dependency on LPS dose. Evaluation of the 295 gene signature in patients with sepsis due to abdominal infections showed significant correlations. Promoter regions of the LPS dose gene set were enriched for YY1, EGR1, ELK1, GABPA, KLF4, and REL transcription factor binding sites. Intravenous injection of 1, 2, or 4 ng/kg LPS was accompanied by both shared and distinct leukocyte transcriptional alterations. These data may assist in assessing the severity of the insult in patients with abdominal sepsis.
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Affiliation(s)
- Hina N. Khan
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Clinical EpidemiologyBiostatistics and BioinformaticsAmsterdam University Medical Centers, Academic Medical CenterAmsterdamThe Netherlands
| | - Desiree Perlee
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Lieke Schoenmaker
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Anne‐Jan van der Meer
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Marek Franitza
- Cologne Center for Genomics (CCG)University of CologneCologneGermany
| | | | - Peter Nürnberg
- Cologne Center for Genomics (CCG)University of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
- Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
| | - Aeilko H. Zwinderman
- Department of Clinical EpidemiologyBiostatistics and BioinformaticsAmsterdam University Medical Centers, Academic Medical CenterAmsterdamThe Netherlands
| | - Tom van der Poll
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- Division of Infectious DiseasesAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Brendon P. Scicluna
- Center for Experimental Molecular MedicineAmsterdam University Medical CentersAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Clinical EpidemiologyBiostatistics and BioinformaticsAmsterdam University Medical Centers, Academic Medical CenterAmsterdamThe Netherlands
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30
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Boribong BP, Lenzi MJ, Li L, Jones CN. Super-Low Dose Lipopolysaccharide Dysregulates Neutrophil Migratory Decision-Making. Front Immunol 2019; 10:359. [PMID: 30915068 PMCID: PMC6422936 DOI: 10.3389/fimmu.2019.00359] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/12/2019] [Indexed: 12/30/2022] Open
Abstract
Neutrophils are the first responders to infection and play a pivotal role in many inflammatory diseases, including sepsis. Recent studies have shown that lipopolysaccharide (LPS), a classical pattern recognition molecule, dynamically programs innate immune responses. In this study, we show that pre-treatment with super-low levels of LPS [1 ng/mL] significantly dysregulate neutrophil migratory phenotypes, including spontaneous migration and altering neutrophil decision-making. To quantify neutrophil migratory decision-making with single-cell resolution, we developed a novel microfluidic competitive chemotaxis-chip (μC3) that exposes cells in a central channel to competing chemoattractant gradients. In this reductionist approach, we use two chemoattractants: a pro-resolution (N-Formyl-Met-Leu-Phe, fMLP) and pro-inflammatory (Leukotriene B4, LTB4) chemoattractant to model how a neutrophil makes a decision to move toward an end target chemoattractant (e.g., bacterial infection) vs. an intermediary chemoattractant (e.g., inflammatory signal). We demonstrate that naïve neutrophils migrate toward the primary end target signal in higher percentages than toward the secondary intermediary signal. As expected, we found that training with high dose LPS [100 ng/mL] influences a higher percentage of neutrophils to migrate toward the end target signal, while reducing the percentage of neutrophils that migrate toward the intermediary signal. Surprisingly, super-low dose LPS [1 ng/mL] significantly changes the ratios of migrating cells and an increased percentage of cells migrate toward the intermediary signal. Significantly, there was also an increase in the numbers of spontaneously migrating neutrophils after treatment with super-low dose LPS. These results shed light onto the directional migratory decision-making of neutrophils exposed to inflammatory training signals. Understanding these mechanisms may lead to the development of pro-resolution therapies that correct the neutrophil compass and reduce off-target organ damage.
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Affiliation(s)
- Brittany P Boribong
- Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Mark J Lenzi
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Liwu Li
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Caroline N Jones
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
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31
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Geng S, Zhang Y, Lee C, Li L. Novel reprogramming of neutrophils modulates inflammation resolution during atherosclerosis. SCIENCE ADVANCES 2019; 5:eaav2309. [PMID: 30775441 PMCID: PMC6365109 DOI: 10.1126/sciadv.aav2309] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/21/2018] [Indexed: 05/04/2023]
Abstract
Nonresolving inflammation perpetuated by innate leukocytes is involved in the pathogenesis of unstable atherosclerosis. However, the role and regulation of neutrophils related to nonresolving inflammation and atherosclerosis are poorly understood. We report herein that chronic subclinical endotoxemia, a risk factor for atherosclerosis, skewed neutrophils into a nonresolving inflammatory state with elevated levels of inflammatory mediators (Dectin-1, MMP9, and LTB4) and reduced levels of homeostatic mediators (LRRC32, TGFβ, and FPN). The polarization of neutrophils was due to ROS-mediated activation of oxCAMKII, caused by altered peroxisome homeostasis and reduced lysosome fusion. Application of 4-phenylbutyrate (4-PBA) enhanced peroxisome homeostasis of neutrophils, reduced oxCAMKII, and rebalanced the expression profiles of pro- and anti-inflammatory mediators. Adoptive transfer of neutrophils programmed by subclinical endotoxemia rendered exacerbated atherosclerosis. In contrast, transfer of ex vivo programmed neutrophils by 4-PBA reduced the pathogenesis of atherosclerosis. Our data define novel neutrophil dynamics associated with the progression and regression of atherosclerosis.
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32
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Picomolar concentrations of oligomeric alpha-synuclein sensitizes TLR4 to play an initiating role in Parkinson's disease pathogenesis. Acta Neuropathol 2019; 137:103-120. [PMID: 30225556 PMCID: PMC6338693 DOI: 10.1007/s00401-018-1907-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 09/03/2018] [Accepted: 09/03/2018] [Indexed: 12/11/2022]
Abstract
Despite the wealth of genomic and transcriptomic data in Parkinson’s disease (PD), the initial molecular events are unknown. Using LD score regression analysis, we show significant enrichment in PD heritability within regulatory sites for LPS-activated monocytes and that TLR4 expression is highest within human substantia nigra, the most affected brain region, suggesting a role for TLR4 inflammatory responses. We then performed extended incubation of cells with physiological concentrations of small alpha-synuclein oligomers observing the development of a TLR4-dependent sensitized inflammatory response with time, including TNF-α production. ROS and cell death in primary neuronal cultures were significantly reduced by TLR4 antagonists revealing that an indirect inflammatory mechanism involving cytokines produced by glial cells makes a major contribution to neuronal death. Prolonged exposure to low levels of alpha-synuclein oligomers sensitizes TLR4 responsiveness in astrocytes and microglial, explaining how they become pro-inflammatory, and may be an early causative event in PD.
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33
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Monguió-Tortajada M, Franquesa M, Sarrias MR, Borràs FE. Low doses of LPS exacerbate the inflammatory response and trigger death on TLR3-primed human monocytes. Cell Death Dis 2018; 9:499. [PMID: 29717111 PMCID: PMC5931601 DOI: 10.1038/s41419-018-0520-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 12/18/2022]
Abstract
TLR sensing of pathogens triggers monocyte activation to initiate the host innate immune response to infection. Monocytes can dynamically adapt to different TLR agonists inducing different patterns of inflammatory response, and the sequence of exposure to TLRs can dramatically modulate cell activation. Understanding the interactions between TLR signalling that lead to synergy, priming and tolerance to TLR agonists may help explain how prior infections and inflammatory conditioning can regulate the innate immune response to subsequent infections. Our goal was to investigate the role of MyD88-independent/dependent TLR priming on modulating the monocyte response to LPS exposure. We stimulated human blood monocytes with agonists for TLR4 (LPS), TLR3 (poly(I:C)) and TLR7/8 (R848) and subsequently challenged them to low doses of endotoxin. The different TLR agonists promoted distinct inflammatory signatures in monocytes. Upon subsequent LPS challenge, LPS- and R848-primed monocytes did not enhance the previous response, whereas poly(I:C)-primed monocytes exhibited a significant inflammatory response concomitant with a sharp reduction on cell viability. Our results show that TLR3-primed monocytes are prompted to cell death by apoptosis in the presence of low endotoxin levels, concurrent with the production of high levels of TNFα and IL6. Of note, blocking of TNFR I/II in those monocytes did reduce TNFα production but did not abrogate cell death. Instead, direct signalling through TLR4 was responsible of such effect. Collectively, our study provides new insights on the effects of cross-priming and synergism between TLR3 and TLR4, identifying the selective induction of apoptosis as a strategy for TLR-mediated host innate response.
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Affiliation(s)
- Marta Monguió-Tortajada
- REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Marcella Franquesa
- REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain
- Nephrology Service, Germans Trias i Pujol University Hospital, Badalona, Spain
| | - Maria-Rosa Sarrias
- Innate Immunity Group, Health Sciences Research Institute Germans Trias i Pujol, Badalona, Spain
- Network for Biomedical Research in Hepatic and Digestive Diseases (CIBERehd), Badalona, Spain
| | - Francesc E Borràs
- REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain.
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Spain.
- Nephrology Service, Germans Trias i Pujol University Hospital, Badalona, Spain.
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34
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Jiang P, Guo Y, Dang R, Yang M, Liao D, Li H, Sun Z, Feng Q, Xu P. Salvianolic acid B protects against lipopolysaccharide-induced behavioral deficits and neuroinflammatory response: involvement of autophagy and NLRP3 inflammasome. J Neuroinflammation 2017; 14:239. [PMID: 29212498 PMCID: PMC5719935 DOI: 10.1186/s12974-017-1013-4] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/27/2017] [Indexed: 01/01/2023] Open
Abstract
Background The NLRP3 inflammasome activation and neuroinflammation are known to be involved in the pathology of depression, whereas autophagy has multiple effects on immunity, which is partly mediated by the regulation of inflammasome and clearance of proinflammatory cytokines. Given the emerging evidence that autophagy dysfunction plays an essential role in depression, it is very likely that autophagy may interact with the inflammatory process in the development and treatment of depression. Salvianolic acid B (SalB), a naturally occurring compound extracted from Salvia miltiorrhiza, contains anti-inflammatory and antidepression properties and has recently been proven to modulate autophagy. In this study, we sought to investigate whether autophagy is involved in the inflammation-induced depression and the antidepressant effects of SalB. Methods The effects of prolonged lipopolysaccharide (LPS) treatment and SalB administration on behavioral changes, neuroinflammation, autophagic markers and NLRP3 activation in rat hippocampus were determined by using behavioral tests, real-time PCR analysis, western blot, and immunostaining. Results Our data showed that periphery immune challenge by LPS for 2 weeks successfully induced the rats to a depression-like state, accompanied with enhanced expression of pro-inflammatory cytokines and NLRP3 inflammasome activation. Interestingly, autophagic markers, including Beclin-1, and the ratio of LC3II to LC3I were suppressed following prolonged LPS exposure. Meanwhile, co-treatment with SalB showed robust antidepressant effects and ameliorated the LPS-induced neuroinflammation. Additionally, SalB restored the compromised autophagy and overactivated NLRP3 inflammasome in LPS-treated rats. Conclusions Collectively, these data suggest that autophagy may interact with NLRP3 activation to contribute to the development of depression, whereas SalB can promote autophagy and induce the clearance of NLRP3, thereby resulting in neuroprotective and antidepressant actions.
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Affiliation(s)
- Pei Jiang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China
| | - Yujin Guo
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China
| | - Ruili Dang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China.
| | - Mengqi Yang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China
| | - Dehua Liao
- Department of Pharmacy, Hunan Cancer Hospital, Central South University, Changsha, China
| | - Huande Li
- Institute of Clinical Pharmacy & Pharmacology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhen Sun
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China
| | - Qingyan Feng
- Department of Neurology, Jining First People's Hospital, Jining Medical University, Jining, China
| | - Pengfei Xu
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining, China.
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35
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Neutrophil programming dynamics and its disease relevance. SCIENCE CHINA-LIFE SCIENCES 2017; 60:1168-1177. [PMID: 28971361 DOI: 10.1007/s11427-017-9145-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 07/21/2017] [Indexed: 12/27/2022]
Abstract
Neutrophils are traditionally considered as first responders to infection and provide antimicrobial host defense. However, recent advances indicate that neutrophils are also critically involved in the modulation of host immune environments by dynamically adopting distinct functional states. Functionally diverse neutrophil subsets are increasingly recognized as critical components mediating host pathophysiology. Despite its emerging significance, molecular mechanisms as well as functional relevance of dynamically programmed neutrophils remain to be better defined. The increasing complexity of neutrophil functions may require integrative studies that address programming dynamics of neutrophils and their pathophysiological relevance. This review aims to provide an update on the emerging topics of neutrophil programming dynamics as well as their functional relevance in diseases.
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Kowalski EJA, Li L. Toll-Interacting Protein in Resolving and Non-Resolving Inflammation. Front Immunol 2017; 8:511. [PMID: 28529512 PMCID: PMC5418219 DOI: 10.3389/fimmu.2017.00511] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 04/18/2017] [Indexed: 12/17/2022] Open
Abstract
Innate leukocytes manifest dynamic and distinct inflammatory responses upon challenges with rising dosages of pathogen-associated molecular pattern molecules such as lipopolysaccharide (LPS). To differentiate signal strengths, innate leukocytes may utilize distinct intracellular signaling circuitries modulated by adaptor molecules. Toll-interacting protein (Tollip) is one of the critical adaptor molecules potentially playing key roles in modulating the dynamic adaptation of innate leukocytes to varying dosages of external stimulants. While Tollip may serve as a negative regulator of nuclear factor κ of activated B cells signaling pathway in cells challenged with higher dosages of LPS, it acts as a positive regulator for low-grade chronic inflammation in leukocytes programmed by subclinical low-dosages of LPS. This review aims to discuss recent progress in our understanding of complex innate leukocyte dynamics and its relevance in the pathogenesis of resolving versus non-resolving chronic inflammatory diseases.
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Affiliation(s)
- Elizabeth J A Kowalski
- Department of Biological Sciences, Virginia Polytechnic State University, Blacksburg, VA, USA
| | - Liwu Li
- Department of Biological Sciences, Virginia Polytechnic State University, Blacksburg, VA, USA
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Lee C, Geng S, Zhang Y, Rahtes A, Li L. Programming and memory dynamics of innate leukocytes during tissue homeostasis and inflammation. J Leukoc Biol 2017; 102:719-726. [PMID: 28476750 DOI: 10.1189/jlb.6mr0117-027rr] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/06/2017] [Accepted: 04/07/2017] [Indexed: 12/24/2022] Open
Abstract
The field of innate immunity is witnessing a paradigm shift regarding "memory" and "programming" dynamics. Past studies of innate leukocytes characterized them as first responders to danger signals with no memory. However, recent findings suggest that innate leukocytes, such as monocytes and neutrophils, are capable of "memorizing" not only the chemical nature but also the history and dosages of external stimulants. As a consequence, innate leukocytes can be dynamically programmed or reprogrammed into complex inflammatory memory states. Key examples of innate leukocyte memory dynamics include the development of primed and tolerant monocytes when "programmed" with a variety of inflammatory stimulants at varying signal strengths. The development of innate leukocyte memory may have far-reaching translational implications, as programmed innate leukocytes may affect the pathogenesis of both acute and chronic inflammatory diseases. This review intends to critically discuss some of the recent studies that address this emerging concept and its implication in the pathogenesis of inflammatory diseases.
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Affiliation(s)
- Christina Lee
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; and.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Shuo Geng
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; and
| | - Yao Zhang
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; and
| | - Allison Rahtes
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; and
| | - Liwu Li
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; and
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