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Zaongo SD, Chen Y. PSGL-1, a Strategic Biomarker for Pathological Conditions in HIV Infection: A Hypothesis Review. Viruses 2023; 15:2197. [PMID: 38005875 PMCID: PMC10674231 DOI: 10.3390/v15112197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/23/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
P-selectin glycoprotein ligand-1 (PSGL-1) has been established to be a cell adhesion molecule that is involved in the cellular rolling mechanism and the extravasation cascade, enabling the recruitment of immune cells to sites of inflammation. In recent years, researchers have established that PSGL-1 also functions as an HIV restriction factor. PSGL-1 has been shown to inhibit the HIV reverse transcription process and inhibit the infectivity of HIV virions produced by cells expressing PSGL-1. Cumulative evidence gleaned from contemporary literature suggests that PSGL-1 expression negatively affects the functions of immune cells, particularly T-cells, which are critical participants in the defense against HIV infection. Indeed, some researchers have observed that PSGL-1 expression and signaling provokes T-cell exhaustion. Additionally, it has been established that PSGL-1 may also mediate virus capture and subsequent transfer to permissive cells. We therefore believe that, in addition to its beneficial roles, such as its function as a proinflammatory molecule and an HIV restriction factor, PSGL-1 expression during HIV infection may be disadvantageous and may potentially predict HIV disease progression. In this hypothesis review, we provide substantial discussions with respect to the possibility of using PSGL-1 to predict the potential development of particular pathological conditions commonly seen during HIV infection. Specifically, we speculate that PSGL-1 may possibly be a reliable biomarker for immunological status, inflammation/translocation, cell exhaustion, and the development of HIV-related cancers. Future investigations directed towards our hypotheses may help to evolve innovative strategies for the monitoring and/or treatment of HIV-infected individuals.
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Affiliation(s)
| | - Yaokai Chen
- Department of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing 400036, China;
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2
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Zaongo SD, Liu Y, Harypursat V, Song F, Xia H, Ma P, Chen Y. P-Selectin Glycoprotein Ligand 1: A Potential HIV-1 Therapeutic Target. Front Immunol 2021; 12:710121. [PMID: 34434194 PMCID: PMC8380821 DOI: 10.3389/fimmu.2021.710121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 07/28/2021] [Indexed: 01/21/2023] Open
Abstract
Antiretroviral therapy (ART), which is a life-long therapeutic option, remains the only currently effective clinical method to treat HIV-1 infection. However, ART may be toxic to vital organs including the liver, brain, heart, and kidneys, and may result in systemic complications. In this context, to consider HIV-1 restriction factors from the innate immune system to explore novel HIV therapeutics is likely to be a promising investigative strategy. In light of this, P-selectin glycoprotein ligand 1 (PSGL-1) has recently become the object of close scrutiny as a recognized cell adhesion molecule, and has become a major focus of academic study, as researchers believe that PSGL-1 may represent a novel area of interest in the research inquiry into the field of immune checkpoint inhibition. In this article, we review PSGL-1's structure and functions during infection and/or inflammation. We also outline a comprehensive review of its role and potential therapeutic utility during HIV-1 infection as published in contemporary academic literature.
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Affiliation(s)
- Silvere D Zaongo
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China.,Basic Medicine College, Chongqing Medical University, Chongqing, China
| | - Yanqiu Liu
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Vijay Harypursat
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Fangzhou Song
- Basic Medicine College, Chongqing Medical University, Chongqing, China
| | - Huan Xia
- Department of Infectious Diseases, Tianjin Second People's Hospital, Tianjin, China.,School of Medicine, Nankai University, Tianjin, China
| | - Ping Ma
- Department of Infectious Diseases, Tianjin Second People's Hospital, Tianjin, China.,School of Medicine, Nankai University, Tianjin, China
| | - Yaokai Chen
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
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3
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Pritchard GH, Kedl RM, Hunter CA. The evolving role of T-bet in resistance to infection. Nat Rev Immunol 2020; 19:398-410. [PMID: 30846856 DOI: 10.1038/s41577-019-0145-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The identification of T-bet as a key transcription factor associated with the development of IFNγ-producing CD4+ T cells predicted a crucial role for T-bet in cell-mediated immunity and in resistance to many intracellular infections. This idea was reinforced by initial reports showing that T-bet-deficient mice were more susceptible to pathogens that survived within the lysosomal system of macrophages. However, subsequent studies revealed IFNγ-dependent, T-bet-independent pathways of resistance to diverse classes of microorganisms that occupy other intracellular niches. Consequently, a more complex picture has emerged of how T-bet and the related transcription factor eomesodermin (EOMES) coordinate many facets of the immune response to bona fide pathogens as well as commensals. This article provides an overview of the discovery and evolutionary relationship between T-bet and EOMES and highlights the studies that have uncovered broader functions of T-bet in innate and adaptive immunity and in the development of the effector and memory T cell populations that mediate long-term resistance to infection.
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Affiliation(s)
- Gretchen Harms Pritchard
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ross M Kedl
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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4
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Reyes AWB, Hong TG, Hop HT, Arayan LT, Huy TXN, Min W, Lee HJ, Lee KS, Kim S. The in vitro and in vivo protective effects of tannin derivatives against Salmonella enterica serovar Typhimurium infection. Microb Pathog 2017; 109:86-93. [PMID: 28552635 DOI: 10.1016/j.micpath.2017.05.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 11/30/2022]
Abstract
In this study, we investigated the protective effects of tannin-derived components, gallic acid (GA) and tannic acid (TA), in vitro and in vivo against Salmonella infection in mice. Both GA and TA showed antibacterial effects against Salmonella (S.) Typhimurium as well as inhibitory effects on the adherence, invasion, and intracellular growth of the pathogens in macrophages. Following a lethal dose of Salmonella infection in mice, reduced virulence in both GA- and TA-treated groups was observed based on reduced mortality rates. In the non-infected groups, the average weights of the spleens and livers of GA- or TA-treated mice were not significantly different with the control group. In addition, the average weights of these organs in all of the Salmonella-infected groups were not significantly different but the numbers of bacteria in the spleens and livers in both GA- and TA-treated mice were significantly reduced. The levels of cytokine production in non-infected mice revealed that GA-treated and TA-treated mice elicited an increased level of IFN-γ, and both IFN-γ and MCP-1, respectively, as compared with the PBS-treated group. These findings highlight the potential of GA and TA as alternatives for the treatment of salmonellosis and as supplements to conventional antimicrobial food additives.
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Affiliation(s)
- Alisha Wehdnesday Bernardo Reyes
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea; Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, College, Laguna, 4031, Philippines
| | - Tae Gyu Hong
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Huynh Tan Hop
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Lauren Togonon Arayan
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Tran Xuan Ngoc Huy
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Wongi Min
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Hu Jang Lee
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Kang Seok Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Suk Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Republic of Korea.
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5
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PSGL-1: A New Player in the Immune Checkpoint Landscape. Trends Immunol 2017; 38:323-335. [PMID: 28262471 DOI: 10.1016/j.it.2017.02.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/02/2017] [Accepted: 02/08/2017] [Indexed: 02/07/2023]
Abstract
P-selectin glycoprotein ligand-1 (PSGL-1) has long been studied as an adhesion molecule involved in immune cell trafficking and is recognized as a regulator of many facets of immune responses by myeloid cells. PSGL-1 also regulates T cell migration during homeostasis and inflammatory settings. However, recent findings indicate that PSGL-1 can also negatively regulate T cell function. Because T cell differentiation is finely tuned by multiple positive and negative regulatory signals that appropriately scale the magnitude of the immune response, PSGL-1 has emerged as an important checkpoint during this process. We summarize what is known regarding PSGL-1 structure and function and highlight how it may act as an immune checkpoint inhibitor in T cells.
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Gao P, Liu H, Huang H, Zhang Q, Strober W, Zhang F. The Inflammatory Bowel Disease-Associated Autophagy Gene Atg16L1T300A Acts as a Dominant Negative Variant in Mice. THE JOURNAL OF IMMUNOLOGY 2017; 198:2457-2467. [PMID: 28202618 DOI: 10.4049/jimmunol.1502652] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 01/16/2017] [Indexed: 11/19/2022]
Abstract
The basis of the increased risk for Crohn's disease conferred by the Atg16L1T300A polymorphism is incompletely understood. An important step forward came from the recent demonstration that the murine equivalent of Atg16L1T300A (Atg16L1T316A) exhibits increased susceptibility to caspase 3-mediated cleavage and resulting decreased levels of full-length Atg16L1 in macrophages. However, although this finding showed that this polymorphism is a loss-of-function abnormality, it did not address the possibility that this polymorphism also affects the function of a normal Atg16L1 allele in heterozygous mice. Therefore, we evaluated the function of the Atg16L1T300A polymorphism heterozygote and homozygote in knock-in (KI) mice. Surprisingly, we found that macrophages from both types of KI mice exhibit defective autophagic induction; accordingly, both types of mice exhibit defects in bacterial clearance coupled with increased inflammasome cytokine (IL-1β) responses. Furthermore, macrophages from both types of KI mice displayed defects in TNF-α-induced Atg16L1T300A cleavage, increased retention of bacteria, bacterial dissemination, and Salmonella-induced colitis. These studies suggested that chromosomes bearing the Atg16L1T300A polymorphism can interfere with the function of the wild-type (WT) Atg16L1 allele and, thus, that the Crohn's disease risk polymorphism is a dominant-negative variant with the potential to act as a disease factor, even when present on only one chromosome. This conclusion was supported by the finding that mice bearing a WT Atg16L1 allele and a null allele (Atg16L1KO/+ mice) exhibit normal autophagic function equivalent to that of WT mice.
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Affiliation(s)
- Ping Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongtao Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huarong Huang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qi Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Warren Strober
- Mucosal Immunity Section, Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
| | - Fuping Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; .,Savaid Medical School, University of Chinese Academy of Sciences, Beijing 101408, China
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7
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Blatt AZ, Saggu G, Kulkarni KV, Cortes C, Thurman JM, Ricklin D, Lambris JD, Valenzuela JG, Ferreira VP. Properdin-Mediated C5a Production Enhances Stable Binding of Platelets to Granulocytes in Human Whole Blood. THE JOURNAL OF IMMUNOLOGY 2016; 196:4671-4680. [PMID: 27183616 DOI: 10.4049/jimmunol.1600040] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/28/2016] [Indexed: 12/11/2022]
Abstract
Enhanced levels of platelet/granulocyte aggregates (PGAs) are found in patients suffering from many different inflammatory vascular diseases, and their formation in animal models of vascular disease is associated with increased thromboinflammation and worsened outcomes. The complement system, a part of the innate immune system, influences PGA formation, but the mechanisms for its effects are unknown. In this study, we have defined complement-mediated mechanisms that enhance PGA formation in human whole blood stimulated with thrombin receptor-activating peptide (TRAP) using ex vivo flow cytometry assays. We demonstrate that physiological properdin, a positive regulator of complement alternative pathway activity, increases PGA formation when added to TRAP-stimulated blood. All physiological properdin forms increase PGA formation, but properdin tetramers are the most efficient at increasing complement activity and PGA formation. Inhibition of endogenous properdin, either circulating in the blood or produced locally by leukocytes, impairs TRAP-mediated PGA formation to the same level as specific inhibition of either the alternative or classical pathway. Additionally, blocking the interaction of C5a with its cellular receptor prevents properdin-mediated increases in PGA formation. Adding either properdin tetramers or C5a to whole blood increases CD11b expression on granulocytes, and this increase is prevented by blockade of the C5a-C5a receptor axis. Finally, we demonstrate that the effects of properdin on PGA formation are tightly regulated by Factor H. Cumulatively, our data indicate that properdin enhances PGA formation via increased production of C5a, and that inhibition of properdin function has therapeutic potential to limit thromboinflammation in diseases characterized by increased PGA formation.
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Affiliation(s)
- Adam Z Blatt
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Gurpanna Saggu
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Koustubh V Kulkarni
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Claudio Cortes
- Department of Biomedical Sciences, Oakland University William Beaumont School of Medicine, Rochester, Michigan
| | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - Daniel Ricklin
- Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John D Lambris
- Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jesus G Valenzuela
- Vector Molecular Biology Section, LMVR, National Institute of Allergy and Infectious Diseases, NIH, Rockville, Maryland
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
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8
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PSGL-1 on Leukocytes is a Critical Component of the Host Immune Response against Invasive Pneumococcal Disease. PLoS Pathog 2016; 12:e1005500. [PMID: 26975045 PMCID: PMC4790886 DOI: 10.1371/journal.ppat.1005500] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/19/2016] [Indexed: 12/21/2022] Open
Abstract
Bacterial uptake by phagocytic cells is a vital event in the clearance of invading pathogens such as Streptococcus pneumoniae. A major role of the P-selectin glycoprotein ligand-1 (PSGL-1) on leukocytes against invasive pneumococcal disease is described in this study. Phagocytosis experiments using different serotypes demonstrated that PSGL-1 is involved in the recognition, uptake and killing of S. pneumoniae. Co-localization of several clinical isolates of S. pneumoniae with PSGL-1 was demonstrated, observing a rapid and active phagocytosis in the presence of PSGL-1. Furthermore, the pneumococcal capsular polysaccharide and the main autolysin of the bacterium ―the amidase LytA― were identified as bacterial ligands for PSGL-1. Experimental models of pneumococcal disease including invasive pneumonia and systemic infection showed that bacterial levels were markedly increased in the blood of PSGL-1−/− mice. During pneumonia, PSGL-1 controls the severity of pneumococcal dissemination from the lung to the bloodstream. In systemic infection, a major role of PSGL-1 in host defense is to clear the bacteria in the systemic circulation controlling bacterial replication. These results confirmed the importance of this receptor in the recognition and clearance of S. pneumoniae during invasive pneumococcal disease. Histological and cellular analysis demonstrated that PSGL-1−/− mice have increased levels of T cells migrating to the lung than the corresponding wild-type mice. In contrast, during systemic infection, PSGL-1−/− mice had increased numbers of neutrophils and macrophages in blood, but were less effective controlling the infection process due to the lack of this functional receptor. Overall, this study demonstrates that PSGL-1 is a novel receptor for S. pneumoniae that contributes to protection against invasive pneumococcal disease. S. pneumoniae is one of the most important and devastating human pathogens worldwide, mainly affecting young children, elderly people and immunocompromised patients. In terms of host immune defense against invasive pneumococcal isolates, professional phagocytes require receptor-mediated recognition of certain ligands on the bacterial surface for the uptake and clearance of the microorganism. In this study, we demonstrate that the P-selectin glycoprotein ligand-1 (PSGL-1) on leukocytes is involved in the phagocytosis process of S. pneumoniae by targeting the capsule and the surface protein LytA as pathogen-associated molecular patterns. To explore this process in more detail, we have used wild-type mice and mice deficient in PSGL-1 demonstrating that lack of PSGL-1 is detrimental for the host by increasing the susceptibility to the infection and the severity of the pneumococcal invasive disease. Overall, these data show the importance of PSGL-1 on leukocytes in host defense against S. pneumoniae and confirm that PSGL-1 plays a critical protective role against invasive bacterial disease.
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9
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Ruiz-Perez F, Nataro JP. Bacterial serine proteases secreted by the autotransporter pathway: classification, specificity, and role in virulence. Cell Mol Life Sci 2013; 71:745-70. [PMID: 23689588 DOI: 10.1007/s00018-013-1355-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 01/07/2023]
Abstract
Serine proteases exist in eukaryotic and prokaryotic organisms and have emerged during evolution as the most abundant and functionally diverse group. In Gram-negative bacteria, there is a growing family of high molecular weight serine proteases secreted to the external milieu by a fascinating and widely employed bacterial secretion mechanism, known as the autotransporter pathway. They were initially found in Neisseria, Shigella, and pathogenic Escherichia coli, but have now also been identified in Citrobacter rodentium, Salmonella, and Edwardsiella species. Here, we focus on proteins belonging to the serine protease autotransporter of Enterobacteriaceae (SPATEs) family. Recent findings regarding the predilection of serine proteases to host intracellular or extracellular protein-substrates involved in numerous biological functions, such as those implicated in cytoskeleton stability, autophagy or innate and adaptive immunity, have helped provide a better understanding of SPATEs' contributions in pathogenesis. Here, we discuss their classification, substrate specificity, and potential roles in pathogenesis.
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Affiliation(s)
- Fernando Ruiz-Perez
- Department of Pediatrics, School of Medicine, University of Virginia, P.O.Box 800326, MR4 Room 4012C, 409 Lane Road, Charlottesville, VA, 22908, USA,
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10
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Grassl GA, Faustmann M, Gill N, Zbytnuik L, Merkens H, So L, Rossi FM, McNagny KM, Finlay BB. CD34 mediates intestinal inflammation in Salmonella-infected mice. Cell Microbiol 2011; 12:1562-75. [PMID: 20497179 DOI: 10.1111/j.1462-5822.2010.01488.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
CD34 is a highly glycosylated sialomucin expressed on a variety of cells, ranging from vascular endothelial cells to haematopoietic stem cells. Depending on its glycosylation state, CD34 has been shown to promote or inhibit cell adhesion and migration; however, a functional role for CD34 in the gut has not been determined. Using a model of Salmonella-induced gastroenteritis, we investigated the role of CD34 in the context of infection. Upon oral infection, the number of CD34+ cells detected in the submucosa, vascular endothelium and lamina propria significantly increased in S. Typhimurium-infected C57Bl/6 mice. The pathology of S. Typhimurium-infected C57Bl/6 mice was characterized by recruitment of neutrophils to the site of inflammation, submucosal oedema and crypt destruction. In contrast, Cd34(-/-) mice showed a delayed pathology, a defect in inflammatory cell migration into the intestinal tissue and enhanced survival. Importantly, this was not due to a lack of chemotactic signals in Cd34(-/-) mice as these mice had either similar or significantly higher levels of pro-inflammatory cytokines and chemokines post infection when compared with infected C57/Bl6 control mice. In summary, we demonstrate a novel role for CD34 in enhancing migration of inflammatory cells and thereby exacerbating host-mediated immunopathology in the intestine of S. Typhimurium-infected mice.
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Affiliation(s)
- Guntram A Grassl
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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11
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Nuñez-Andrade N, Lamana A, Sancho D, Gisbert JP, Gonzalez-Amaro R, Sanchez-Madrid F, Urzainqui A. P-selectin glycoprotein ligand-1 modulates immune inflammatory responses in the enteric lamina propria. J Pathol 2011; 224:212-21. [PMID: 21432853 DOI: 10.1002/path.2850] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 11/30/2010] [Accepted: 12/21/2010] [Indexed: 12/22/2022]
Abstract
P-selectin glycoprotein ligand-1 (PSGL-1), a leukocyte adhesion receptor that interacts with selectins, induces a tolerogenic programme in bone marrow-derived dendritic cells (DCs), which in turn promotes the generation of T regulatory (Treg) lymphocytes. In the present study, we have used a mouse model of dextran sulphate sodium (DSS)-induced colitis and studied the characteristics of the inflammatory cell infiltrate in the lamina propria (LP), mesenteric lymph nodes (mLNs) and Peyer's patches (PPs) to assess the possible role of PSGL-1 in the modulation of the enteric immune response. We have found that untreated PSGL-1-deficient mice showed an altered proportion of innate and adaptive immune cells in mLNs and PPs as well as an activated phenotype of macrophages and DCs in the colonic LP that mainly produced pro-inflammatory cytokines. Administration of an anti-PSGL-1 antibody also reduced the total numbers of macrophages, DCs and B cells in the colonic LP, and induced a lower expression of MHC-II by DCs and macrophages. After DSS treatment, PSGL-1(-/-) mice developed colitis earlier and with higher severity than wild-type (WT) mice. Accordingly, the colonic LP of these animals showed an enhanced number of Th1 and Th17 lymphocytes, with enhanced synthesis of IL-1α, IL-6 and IL-22, and increased activation of LP macrophages. Together, our data indicate that PSGL-1 has a relevant homeostatic role in the gut-associated lymphoid tissue under steady-state conditions, and that this adhesion receptor is able to down-regulate the inflammatory phenomenon in DSS-induced colitis.
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Affiliation(s)
- Norman Nuñez-Andrade
- Departamento de Biología Vascular e Inflamación, CNIC, C/Melchor Fernández Almagro, 28034 Madrid, Spain
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12
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Role of Salmonella Pathogenicity Island 1 protein IacP in Salmonella enterica serovar typhimurium pathogenesis. Infect Immun 2011; 79:1440-50. [PMID: 21263021 DOI: 10.1128/iai.01231-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gram-negative bacteria, including Salmonella enterica serovar Typhimurium, exploit type III secretion systems (T3SSs) through which virulence proteins are delivered into the host cytosol to reinforce invasive and replicative niches in their host. Although many secreted effector proteins and membrane-bound structural proteins in the T3SS have been characterized, the functions of many cytoplasmic proteins still remain unknown. In this study, we found that IacP, encoded by Salmonella pathogenicity island 1, was important for nonphagocytic cell invasion and bacterial virulence. When the iacP gene was deleted from several Salmonella serovar Typhimurium strains, the invasion into INT-407 epithelial cells was significantly decreased compared to that of their parental strains, and retarded rearrangements of actin fibers were observed for the iacP mutant-infected cells. Although IacP had no effect on the secretion of type III translocon proteins, the levels of secretion of the effector proteins SopB, SopA, and SopD into the culture medium were decreased in the iacP mutant. In a mouse infection model, mice infected with the iacP mutant exhibited alleviated pathological signs in the intestine and survived longer than did wild-type-infected mice. Taken together, IacP plays a key role in Salmonella virulence by regulating the translocation of T3SS effector proteins.
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13
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Kum WWS, Lo BC, Deng W, Ziltener HJ, Finlay BB. Impaired innate immune response and enhanced pathology during Citrobacter rodentium infection in mice lacking functional P-selectin. Cell Microbiol 2010; 12:1250-71. [PMID: 20345490 DOI: 10.1111/j.1462-5822.2010.01466.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The selectin family of adhesion molecules mediates recruitment of immune cells to sites of inflammation which is critical for host resistance against infection. To characterize the role of selectins in host defence against Citrobacter rodentium infection, wild-type (WT) mice and mice lacking P-selectin glycoprotein ligand-1 (PSGL-1), P-, E- and L-selectin were infected using a Citrobacter-induced colitis model. Infected mice lacking PSGL-1 or P-selectin showed a more pronounced morbidity associated with higher bacterial load, elevated IL-12 p70, TNF-alpha, IFN-gamma, MCP-1 and IL-6 production, more severe inflammation and surprisingly higher leucocyte infiltration in the guts than WT control. Recruitment of neutrophils and macrophages and caecal inflammation were drastically reduced in infected P-selectin knockout mice receiving blocking monoclonal antibodies to ICAM-1 or LFA-1, indicating that these adhesion molecules may compensate for the loss of selectins in leucocyte recruitment. Furthermore, the adaptive immune response in mice lacking PSGL-1 or P-selectin remained functional since these infected mice were capable of eradicating the bacteria and being protected upon re-challenge with C. rodentium. These data demonstrate a definitive phenotypic impairment of innate response in mice lacking PSGL-1 or P-selectin, and suggest that these adhesion molecules are important in host innate immune response against Citrobacter infection.
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Affiliation(s)
- Winnie W S Kum
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
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