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Kandel SR, Luo X, He JJ. Nef inhibits HIV transcription and gene expression in astrocytes and HIV transmission from astrocytes to CD4 + T cells. J Neurovirol 2022; 28:552-565. [PMID: 36001227 DOI: 10.1007/s13365-022-01091-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/07/2022] [Accepted: 07/27/2022] [Indexed: 01/13/2023]
Abstract
HIV infects astrocytes in a restricted manner but leads to abundant expression of Nef, a major viral factor for HIV replication and disease progression. However, the roles of Nef in HIV gene expression and replication in astrocytes and viral transfer from astrocytes to CD4+ T cells remain largely unclear. In this study, we attempted to address these issues by transfecting human primary astrocytes with HIV molecular clones with intact Nef and without Nef (a nonsense Nef mutant) and comparing gene expression and replication in astrocytes and viral transfer from astrocytes to CD4+ T cells MT4. First, we found that lack of Nef expression led to increased extracellular virus production from astrocytes and intracellular viral protein and RNA expression in astrocytes. Using a HIV LTR-driven luciferase reporter gene assay, we showed that ectopic Nef expression alone inhibited the HIV LTR promoter activity in astrocytes. Consistent with the previously established function of Nef, we showed that the infectivity of HIV derived from astrocytes with Nef expression was significantly higher than that with no Nef expression. Next, we performed the co-culture assay to determine HIV transfer from astrocytes transfected to MT4. We showed that lack of Nef expression led to significant increase in HIV transfer from astrocytes to MT4 using two HIV clones. We also used Nef-null HIV complemented with Nef in trans in the co-culture assay and demonstrated that Nef expression led to significantly decreased HIV transfer from astrocytes to MT4. Taken together, these findings support a negative role of Nef in HIV replication and pathogenesis in astrocytes.
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Affiliation(s)
- Suresh R Kandel
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University, North Chicago, IL, 60064, USA.,Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL, 60064, USA.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, 3333 Green Bay Road, North Chicago, IL, 60064, USA
| | - Xiaoyu Luo
- Gladstone Institute of Virology, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Johnny J He
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University, North Chicago, IL, 60064, USA. .,Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL, 60064, USA. .,School of Graduate and Postdoctoral Studies, Rosalind Franklin University, 3333 Green Bay Road, North Chicago, IL, 60064, USA.
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Negi N, Das BK. CNS: Not an immunoprivilaged site anymore but a virtual secondary lymphoid organ. Int Rev Immunol 2017; 37:57-68. [DOI: 10.1080/08830185.2017.1357719] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Neema Negi
- Department of Molecular Biology, Umea University, Umea, Sweden
| | - Bimal K. Das
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar (West), New Delhi, India
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3
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Falasca K, Reale M, Ucciferri C, Di Nicola M, Di Martino G, D'Angelo C, Coladonato S, Vecchiet J. Cytokines, Hepatic Fibrosis, and Antiretroviral Therapy Role in Neurocognitive Disorders HIV Related. AIDS Res Hum Retroviruses 2017; 33:246-253. [PMID: 27615271 DOI: 10.1089/aid.2016.0138] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The HIV may trigger a process of neuronal loss and axonal degeneration throughout the brain, which is carried on by the immune system releasing of proinflammatory cytokines, so that chronic inflammation associated with dysregulated innate immune response, glial cell dysfunction, and adverse antiretroviral therapy (ART) effect play an important role causing milder HIV-associated neurocognitive disorders or asymptomatic neurocognitive impairment. All patients have been tested for neurocognitive functioning through a comprehensive, five-domain neuropsychological battery performed in the study. Human cytokine (interleukin [IL]-6, IL-8, IL-18, and tumor necrosis factor [TNF]-α) and brain-derived neurotrophic factor serum levels were quantified using ELISAs, and the hepatic fibrosis was estimated using the noninvasive Fibrosis 4 (FIB-4) score. The study showed a group of 40 HIV-infected individuals and it was observed that almost 40% of HIV+ individuals, even if clinically asymptomatic, displayed some degree of neurocognitive dysfunction, compared to normative performance standards, at least in two cognitive areas. The functions affected the most were memory, attention, executive function, and psychomotor processing speed. Three cytokines (IL-6, IL-8, and IL-18) to be significantly linked to test results in specific neurocognitive domain were found. Treatments with nucleoside reverse transcriptase inhibitor plus non-nucleoside reverse transcriptase inhibitor alone were instead associated with poor neurocognitive outcome, especially in verbal fluency, fine motility, and Zung Depression Scale. Elevated value of FIB-4 score showed an opposite connection with cognitive performance as well, underlining the direct association between hepatic steatosis and neurocognitive deficit. The cytokine panel and the FIB-4 score can predict presence or worsening of neurocognitive functions in HIV-infected individuals. An ART switch can be suggested according to the neurocognitive domain involved the most, advising a therapy with protease inhibitors or/and integrase inhibitors to improve fluency, executive functions, and to prevent depression.
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Affiliation(s)
- Katia Falasca
- Clinic of Infectious Diseases, Department of Medicine and Science of Aging, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Marcella Reale
- Unit of Immunodiagnostic and Molecular Pathology, Department of Medical, Oral, and Biotechnological Sciences, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Claudio Ucciferri
- Clinic of Infectious Diseases, Department of Medicine and Science of Aging, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
- Unit of Immunodiagnostic and Molecular Pathology, Department of Medical, Oral, and Biotechnological Sciences, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
- Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
| | - Marta Di Nicola
- Laboratory of Biostatistics, Department of Medical, Oral, and Biotechnological Sciences, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Giuseppe Di Martino
- Division of Hygene, Epidemiology and Public Health, Department of Medicine and Science of Aging, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Chiara D'Angelo
- Unit of Immunodiagnostic and Molecular Pathology, Department of Medical, Oral, and Biotechnological Sciences, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Simona Coladonato
- Clinic of Infectious Diseases, Department of Medicine and Science of Aging, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
| | - Jacopo Vecchiet
- Clinic of Infectious Diseases, Department of Medicine and Science of Aging, University “G. d'Annunzio” Chieti-Pescara, Chieti, Italy
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4
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Correia S, Cohen R, Gongvatana A, Ross S, Olchowski J, Devlin K, Tashima K, Navia B, Delamonte S. Relationship of plasma cytokines and clinical biomarkers to memory performance in HIV. J Neuroimmunol 2013; 265:117-23. [PMID: 24210837 DOI: 10.1016/j.jneuroim.2013.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 08/15/2013] [Accepted: 09/10/2013] [Indexed: 11/26/2022]
Abstract
Chronic systemic immune activation and inflammatory processes have been linked to brain dysfunction in medically stable HIV-infected people. We investigated the association between verbal memory performance and plasma concentrations of 13 cytokines measured using multiplexed bead array immunoassay in 74 HIV-seropositive individuals and 50 HIV-seronegative controls. Memory performance was positively related to levels of IL-8 and IFN-γ, and negatively related to IL-10 and IL-18 and to hepatitis C infection. Memory performance was not significantly related to HIV disease markers. The results indicate the importance of systemic immune and inflammatory markers to neurocognitive function in chronic and stable HIV disease.
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Affiliation(s)
- Stephen Correia
- Department of Psychiatry and Human Behavior, Alpert Medical School, Brown University, Providence, RI, USA
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Cohen RA, de la Monte S, Gongvatana A, Ombao H, Gonzalez B, Devlin KN, Navia B, Tashima KT. Plasma cytokine concentrations associated with HIV/hepatitis C coinfection are related to attention, executive and psychomotor functioning. J Neuroimmunol 2011; 233:204-10. [PMID: 21146232 PMCID: PMC3074016 DOI: 10.1016/j.jneuroim.2010.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/06/2010] [Accepted: 11/16/2010] [Indexed: 01/26/2023]
Abstract
Cytokine disturbances have been linked to brain dysfunction among HIV-infected people. Past studies have not simultaneously examined a large set of cytokine measures and their relationships to HIV-associated neurocognitive deficits. We hypothesized that performance on measures of attention and executive and psychomotor functions would be associated with plasma cytokine concentrations in HIV-infected individuals. Plasma samples drawn from 30 HIV-infected and 37 HIV seronegative individuals were analyzed via xMAP multiplexed bead array immunoassay to determine concentrations of 13 cytokines. Performance on Trail Making A/B, Stroop Test, Letter-Number Sequencing, Digit Symbol Coding, Symbol Search, and Grooved Pegboard tests was assessed. Statistical analyses were performed to examine group differences in cytokine concentrations, and associations between cytokine and HIV clinical variables and neurocognitive performance. Significant HIV effects were found on 7 of the 13 cytokines, primarily with respect to interleukins. HIV clinical factors (CD4 and HIV RNA levels, duration of illness, antiretroviral treatment) and hepatitis C status were associated with specific plasma cytokine concentrations. Neurocognitive measures were associated with cytokine concentrations, most consistently among the interleukins and IP-10. Generally, cytokine concentrations were among the strongest predictors of neurocognitive function relative to other clinical factors, which reinforces their potential importance in examining the neuropathological processes of HIV. The findings also point to the potential value of simultaneously examining a panel of biomarkers. The current results suggest that a complex relationship likely exists among cytokines [how?] and that these relationships are mediated not only by HIV infection but also by antiretroviral treatment and other comorbid conditions.
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Affiliation(s)
- Ronald A Cohen
- Department of Psychiatry and Human Behavior, Brown University School of Medicine, Providence, RI, USA.
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6
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Lentz MR, Degaonkar M, Mohamed MA, Kim H, Conant K, Halpern EF, Sacktor N, Barker PB, Pomper MG. Exploring the relationship of macrophage colony-stimulating factor levels on neuroaxonal metabolism and cognition during chronic human immunodeficiency virus infection. J Neurovirol 2011; 16:368-76. [PMID: 20839921 DOI: 10.3109/13550284.2010.513029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Macrophage colony-stimulating factor (M-CSF) promotes macrophage differentiation, increases susceptibility of macrophages to viral infection, and enhances human immunodeficiency virus (HIV) replication in infected macrophages. Given the current model of HIV neuropathogenesis, which involves monocyte trafficking into the central nervous system, immune factors linked with macrophage maturation and survival may be associated with cognitive decline (measured by neuropsychological z-score [NPZ-8] or Memorial Sloan-Kettering [MSK] score) and alterations in a marker of neuronal integrity, N-acetylaspartate (NAA). Fifty-four chronically infected HIV+ subjects underwent neuropsychological assessment, magnetic resonance spectroscopic imaging, and quantification of M-CSF in plasma and cerebrospinal fluid (CSF) at baseline. Thirty-nine of those subjects underwent further examination at 3 and 10 months after initiation of combination antiretroviral therapy (ART) regimens. Within 3 months of therapy use, CSF M-CSF and viral RNA levels were reduced, whereas NAA concentrations in many brain regions were increased. Neither baseline levels nor the change in M-CSF levels had the ability to predict changes in NAA levels observed after 10 months of combination ART use. At study entry those with the lowest M-CSF levels in the CSF had the least cognitive impairment (NPZ-8). Those who had higher baseline CSF M-CSF levels and exhibited larger decreases in M-CSF after therapy, tended to have greater cognitive improvement after 10 months. Increased prevalence of M-CSF in the setting of HIV infection could contribute to neuronal injury and may be predictive of cognitive impairment.
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Affiliation(s)
- Margaret R Lentz
- Department of Neuroradiology and the A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
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8
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The role of microglia in central nervous system immunity and glioma immunology. J Clin Neurosci 2009; 17:6-10. [PMID: 19926287 DOI: 10.1016/j.jocn.2009.05.006] [Citation(s) in RCA: 252] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 05/11/2009] [Accepted: 05/17/2009] [Indexed: 12/25/2022]
Abstract
The central nervous system (CNS) historically has been considered an immune-privileged organ, lacking a lymphatic system and shielded from the circulatory system by the blood-brain barrier. Microglia are an abundant portion of the CNS cell population, comprising 5% to 20% of the total glial cell population, and are as numerous as neurons. A crucial function of microglia is the ability to generate significant innate and adaptive immune responses. Microglia are involved in first line innate immunity of the CNS. Proper antigen presentation is critical in the generation of specific, durable responses by the adaptive immune system, and requires interaction between the T cell receptor and processed antigen peptide presented on major histocompatibility complex (MHC) molecules by the antigen presenting cells (APC). Microglia also have a large regulatory role in CNS immunity. Histopathologic studies of glioma tissue have consistently shown high levels of infiltrating microglia. Microglia are also localized diffusely throughout the tumor, rather than to the areas of necrosis, and phagocytosis of glioma cells or debris by microglia is not observed. Recent evidence indicates that glioma-infiltrating microglia/macrophages might be promoting tumor growth by facilitating immunosuppression of the tumor microenvironment. When activated, microglia can be potent immune effector cells, able to perform a broad range of functions, and they mediate both innate and adaptive responses during CNS injury and disease while remaining quiescent in the steady state. Their versatility in bridging the gap between the immune-privileged CNS and the peripheral immune system, in addition to their significant numbers in gliomas, makes them an attractive candidate in immunotherapy for gliomas. An enhanced understanding of microglia-glioma interaction may provide better methods to manipulate the glioma microenvironment to allow the generation of a specific and durable anti-glioma immunity. The role of microglia in CNS immunity is reviewed, with a focus on key advances made in glioma immunology.
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9
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Cosenza-Nashat M, Zhao ML, Marshall HD, Si Q, Morgello S, Lee SC. Human immunodeficiency virus infection inhibits granulocyte-macrophage colony-stimulating factor-induced microglial proliferation. J Neurovirol 2008; 13:536-48. [PMID: 18097885 DOI: 10.1080/13550280701549417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
It is well known that infection by the human immunodeficiency virus (HIV) dysregulates cell physiology, but little information is available on the consequences of HIV infection in primary macrophages and microglia. The authors examined the relationship between cell proliferation and HIV infection in primary cultures of microglia and in human central nervous system (CNS). In cultures infected with HIV (ADA and BaL), granulocyte-macrophage colony-stimulating factor (GM-CSF)-mediated cell proliferation was reduced in productively infected (p24+) cells as compared to p24- cells. The reduction was observed with both Ki67 and BrdU labeling, suggesting a G1/S block. The reduction was insignificant when microglia were infected with a Vpr- mutant virus. In human CNS, proliferating (Ki67+) cells were rare but were increased in the HIV+ and HIV encephalitis (HIVE) groups compared to the HIV- group. A positive correlation between GM-CSF immunoreactivity and Ki67 counts, implicating GM-CSF as a growth factor in human CNS was found. The relationship between total macrophage (CD68+) proliferation and infected macrophage (p24+) proliferation was assessed in HIVE by double labeling. Whereas 1.2% of total CD68+ cells were Ki67+, only 0.5% of HIV p24+ cells were Ki67+ (P < .05). Furthermore, staining for CD45RB (as opposed to CD68) facilitated the identification of Ki67+ microglia, indicating that CD68 could underestimate proliferating microglia. The authors conclude that although there is increased expression of GM-CSF and increased cell proliferation in the CNS of HIV-seropositive individuals, cell proliferation in the productively infected population is actually suppressed. These data suggest that there might be a viral gain in the suppressed host cell proliferation.
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Affiliation(s)
- Melissa Cosenza-Nashat
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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10
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Increased in vivo activation of microglia and astrocytes in the brains of mice transgenic for an infectious R5 human immunodeficiency virus type 1 provirus and for CD4-specific expression of human cyclin T1 in response to stimulation by lipopolysaccharides. J Virol 2008; 82:5562-72. [PMID: 18353948 DOI: 10.1128/jvi.02618-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Inflammatory mediators and viral products produced by human immunodeficiency virus (HIV)-infected microglia and astrocytes perturb the function and viability of adjacent uninfected neuronal and glial cells and contribute to the pathogenesis of HIV-associated neurocognitive disorders (HAND). In vivo exposure to lipopolysaccharide (LPS) activates parenchymal microglia and astrocytes and induces cytokine and chemokine production in the brain. HIV-infected individuals display increased circulating LPS levels due to microbial translocation across a compromised mucosa barrier. We hypothesized that HIV-infected microglia and astrocytes display increased sensitivity to the proinflammatory effects of LPS, and this combines with the increased levels of systemic LPS in HIV-infected individuals to contribute to the development of HAND. To examine this possibility, we determined the in vivo responsiveness of HIV-infected microglia and astrocytes to LPS using our mouse model, JR-CSF/human cyclin T1 (JR-CSF/hu-cycT1) mice, which are transgenic for both an integrated full-length infectious HIV type 1 (HIV-1) provirus derived from the primary R5-tropic clinical isolate HIV-1(JR-CSF) regulated by the endogenous HIV-1 long terminal repeat and the hu-cycT1 gene under the control of a CD4 promoter. In the current report, we demonstrated that in vivo-administered LPS more potently activated JR-CSF/hu-cycT1 mouse microglia and astrocytes and induced a significantly higher degree of monocyte chemoattractant protein production by JR-CSF/hu-cycT1 astrocytes compared to that of the in vivo LPS response of control littermate mouse microglia and astrocytes. These results indicate that HIV infection increases the sensitivity of microglia and astrocytes to inflammatory stimulation and support the use of these mice as a model to investigate various aspects of the in vivo mechanism of HIV-induced neuronal dysfunction.
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Haine V, Fischer-Smith T, Rappaport J. Macrophage colony-stimulating factor in the pathogenesis of HIV infection: potential target for therapeutic intervention. J Neuroimmune Pharmacol 2007; 1:32-40. [PMID: 18040789 DOI: 10.1007/s11481-005-9003-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Macrophage colony stimulating factor (M-CSF) appears to play a major role in promoting and maintaining reservoirs of human immunodeficiency virus type 1 (HIV-1) in infected individuals. HIV-1 infection induces production of M-CSF by macrophages, which in turn promotes further infection of macrophages via increases in CD4 and CCR5 receptors, as well as increases in virus gene expression. M-CSF promotes the ontogeny and survival of macrophages, contributing to both the number and longevity of these infected cells. M-CSF dysregulation promotes the differentiation of monocytes toward macrophages and osteoclasts and at the same time may inhibit differentiation toward dendritic cells, resulting in immune impairment. The potential role of M-CSF in HIV-associated end organ diseases including HIV-associated dementia, HIV-associated nephropathy, and osteoporosis is discussed. This review emphasizes the need for developing M-CSF antagonists for treatment of HIV-1-infected patients.
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Affiliation(s)
- Valerie Haine
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, 1900 N. 12th Street, Philadelphia, PA 19122, USA
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12
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Zaheer A, Zaheer S, Sahu SK, Knight S, Khosravi H, Mathur SN, Lim R. A novel role of glia maturation factor: induction of granulocyte-macrophage colony-stimulating factor and pro-inflammatory cytokines. J Neurochem 2007; 101:364-76. [PMID: 17250654 DOI: 10.1111/j.1471-4159.2006.04385.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The glia maturation factor (GMF), which was discovered in our laboratory, is a highly conserved protein predominantly localized in astrocytes. GMF is an intracellular regulator of stress-related signal transduction. We now report that the overexpression of GMF in astrocytes leads to the destruction of primary oligodendrocytes by interactions between highly purified cultures of astrocytes, microglia, and oligodendrocytes. We infected astrocytes with a replication-defective adenovirus carrying the GMF cDNA. The overexpression of GMF caused the activation of p38 MAP kinase and transcription factor NF-kappaB, as well as the induction of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA and protein in astrocytes. Small interfering RNA-mediated GMF knockdown completely blocked the GMF-dependent activation of p38 mitogen-activated protein kinase (MAPK), NF-kappaB, and enhanced expression of GM-CSF by astrocytes. Inhibition of p38 MAPK or NF-kappaB by specific inhibitors prevented GM-CSF production. The cell-free conditioned medium from overexpressing GMF astrocytes contained 320 +/- 33 pg/mL of GM-CSF, which was responsible for enhanced production and secretion of TNF-alpha, IL-1beta, IL-6, and IP-10 by microglia. Presence of these inflammatory cytokines in the conditioned medium from microglia efficiently destroyed oligodendrocytes in culture. These results suggest that GMF-induced production of GM-CSF in astrocytes is depending on p38 MAPK and NF-kappaB activation. The GM-CSF-dependent expression and secretion of inflammatory cytokine/chemokine, TNF-alpha, IL-1beta, IL-6, and IP-10, is cytotoxic to oligodendrocytes, the myelin-forming cells in the central nervous system, and as well as neurons. Our results suggest a novel pathway of GMF-initiated cytotoxicity of brain cells, and implicate its involvement in inflammatory diseases such as multiple sclerosis.
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Affiliation(s)
- Asgar Zaheer
- Veterans Affair Medical Center, Iowa City, Iowa, USA.
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13
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Block ML, Hong JS. Microglia and inflammation-mediated neurodegeneration: multiple triggers with a common mechanism. Prog Neurobiol 2005; 76:77-98. [PMID: 16081203 DOI: 10.1016/j.pneurobio.2005.06.004] [Citation(s) in RCA: 1129] [Impact Index Per Article: 59.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 06/21/2005] [Accepted: 06/28/2005] [Indexed: 12/21/2022]
Abstract
Inflammation, a common denominator among the diverse list of neurodegenerative diseases, has recently been implicated as a critical mechanism responsible for the progressive nature of neurodegeneration. Microglia are the resident innate immune cells in the central nervous system and produce a barrage of factors (IL-1, TNFalpha, NO, PGE2, superoxide) that are toxic to neurons. Evidence supports that the unregulated activation of microglia in response to environmental toxins, endogenous proteins, and neuronal death results in the production of toxic factors that propagate neuronal injury. In the following review, we discuss the common thread of microglial activation across numerous neurodegenerative diseases, define current perceptions of how microglia are damaging neurons, and explain how the microglial response to neuronal damage results in a self-propelling cycle of neuron death.
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Affiliation(s)
- Michelle L Block
- Neuropharmacology Section, MD F1-01, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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Abstract
During the clinical course of acquired immune deficiency syndrome, infection of the CNS by human immunodeficiency virus-1 (HIV-1) may ultimately result in the impairment of cognitive, behavioral and motor functions. Viral neuropathogenesis involves inflammatory molecules and neurotoxins produced from infected and immune-activated lymphocytes, microglial cells and astrocytes. Here, we discuss the current understanding of HIV-1 infection of the CNS and various cell culture systems from the developing human brain in order to study the neurobiology of HIV-1 infection, the mechanisms contributing to HIV-1 infection, and disease progression.
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Affiliation(s)
- P Seth
- Molecular and Cellular Neuroscience, National Brain Research Centre, Manesar, India
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Henze C, Hartmann A, Lescot T, Hirsch EC, Michel PP. Proliferation of microglial cells induced by 1-methyl-4-phenylpyridinium in mesencephalic cultures results from an astrocyte-dependent mechanism: role of granulocyte macrophage colony-stimulating factor. J Neurochem 2005; 95:1069-77. [PMID: 16135085 DOI: 10.1111/j.1471-4159.2005.03416.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is evidence that an inflammatory microglial reaction participates in the pathophysiology of dopaminergic neuronal death in Parkinson's disease and in animal models of the disease. However, this phenomenon remains incompletely characterized. Using an in vitro model of neuronal/glial mesencephalic cultures, we show that the dopaminergic neurotoxin 1-methyl-4-phenylpyridinium (MPP+) stimulates the proliferation of microglial cells at concentrations that selectively reduce the survival of DA neurones. The mitogenic action of MPP+ was not the mere consequence of neuronal cell demise as the toxin produced the same effect in a model system of neuronal/glial cortical cultures, where target DA neurones are absent. Consistent with this observation, the proliferative effect of MPP+ was also detectable in neurone-free microglial/astroglial cultures. It disappeared, however, when MPP+ was added to pure microglial cell cultures suggesting that astrocytes played a key role in the mitogenic mechanism. Accordingly, the proliferation of microglial cells in response to MPP+ treatment was mimicked by granulocyte macrophage colony-stimulating factor (GM-CSF), a proinflammatory cytokine produced by astrocytes and was blocked by a neutralizing antibody to GM-CSF. Thus, we conclude that the microglial reaction observed following MPP+ exposure depends on astrocytic factors, e.g. GM-CSF, a finding that may have therapeutic implications.
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Affiliation(s)
- Carmen Henze
- INSERM U 679, Experimental Neurology and Therapeutics, Hôpital de la Salpêtrière, Paris, France
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Ghorpade A, Persidsky Y, Swindells S, Borgmann K, Persidsky R, Holter S, Cotter R, Gendelman HE. Neuroinflammatory responses from microglia recovered from HIV-1-infected and seronegative subjects. J Neuroimmunol 2005; 163:145-56. [PMID: 15869805 DOI: 10.1016/j.jneuroim.2005.01.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 01/12/2005] [Accepted: 01/25/2005] [Indexed: 11/25/2022]
Abstract
Microglial and macrophage infection and immune activation underlie the pathogenesis of HIV-1-associated dementia (HAD). To assess microglial function in HAD, we isolated cells from brain tissues recovered from an HIV-1-infected patient within 4 h of death. Brain tissue from seronegative patients served as controls. Regional neuropathology was correlated to microglial function. HIV-1-patient microglia formed multinucleated giant cells and produced progeny virions. These microglia secreted reduced basal and LPS-stimulated TNF-alpha levels compared to controls. Monocytes from seronegative donors paralleled these diminished immune responses following repeated LPS-activation. These results demonstrate changes in innate microglial function following viral infection or chronic immune activation.
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Affiliation(s)
- Anuja Ghorpade
- Laboratory of Cellular Neuroimmunology, 985215 Nebraska Medical Center, Omaha, NE, 68198-5215, USA.
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17
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Suh HS, Kim MO, Lee SC. Inhibition of granulocyte-macrophage colony-stimulating factor signaling and microglial proliferation by anti-CD45RO: role of Hck tyrosine kinase and phosphatidylinositol 3-kinase/Akt. THE JOURNAL OF IMMUNOLOGY 2005; 174:2712-9. [PMID: 15728479 DOI: 10.4049/jimmunol.174.5.2712] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Increasing evidence suggests that CD45, a transmembrane protein tyrosine phosphatase, is an important modulator of macrophage activation. Microglia, resident brain macrophages, express CD45 and proliferate under pathologic conditions. In this study, we examined the role of CD45 in modulating GM-CSF-induced proliferation and signal transduction in primary human microglial cultures. Soluble, but not immobilized anti-CD45RO induced tyrosine phosphatase activity and inhibited GM-CSF-induced microglial proliferation. Microglial proliferation was also inhibited by PP2 (Src inhibitor), LY294002 (PI3K inhibitor), and U0126 (MEK inhibitor). GM-CSF induced phosphorylation of Jak2, Stat5, Hck (the myeloid-restricted Src kinase), Akt, Stat3, and Erk MAPKs in microglia. Of these, anti-CD45RO inhibited phosphorylation of Hck and Akt, and PP2 inhibited phosphorylation of Hck and Akt. In a macrophage cell line stably overexpressing wild-type or kinase-inactive Hck, GM-CSF increased proliferation of the control (empty vector) and wild-type but not kinase-inactive cells, and this was inhibited by anti-CD45RO. Together, these results demonstrate that, in macrophages, Hck tyrosine kinase is activated by GM-CSF, and that Hck plays a pivotal role in cell proliferation and survival by activating the PI3K/Akt pathway. Ab-mediated activation of macrophage and microglial CD45 tyrosine phosphatase may have therapeutic implications for CNS inflammatory diseases.
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Affiliation(s)
- Hyeon-Sook Suh
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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18
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Bolin LM, Zhaung A, Strychkarska-Orczyk I, Nelson E, Huang I, Malit M, Nguyen Q. Differential inflammatory activation of IL-6 (−/−) astrocytes. Cytokine 2005; 30:47-55. [PMID: 15804595 DOI: 10.1016/j.cyto.2004.11.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Revised: 11/22/2004] [Accepted: 11/29/2004] [Indexed: 10/25/2022]
Abstract
IL-6 is a major immunomodulatory cytokine with neuroprotective activity. The absence of interleukin-6 (IL-6) results in increased vulnerability of dopaminergic neurons to the neurotoxicant, MPTP, and a compromised reactive microgliosis. To determine how astrogliosis may contribute to nigrostriatal degeneration in IL-6 (-/-) mice, the inflammatory profiles of astrocytes of IL-6 genotype were compared. Fourteen cytokines and four chemokines were simultaneously assayed in the supernatants of LPS-stimulated primary astrocyte cultures. In a time course of 6, 18 and 48 h and LPS stimulations of 0, 0.1, 1, 10 and 100 ng/ml, IL-6 (-/-) astrocytes secreted significantly greater amounts of the pro-inflammatory cytokines IL-1alpha, IL-1beta and TNFalpha than did IL-6 (+/+) cells. Elevated levels of IL-10 and IL-12p40 were only detected at 48 h post-stimulation with greater IL-10 in IL-6 (-/-) supernatants and greater IL-12p40 in IL-6 (+/+) supernatants. IL-6 (+/+) astrocytes produced more G-CSF and GM-CSF when compared with IL-6 (-/-) astrocytes. Chemokine levels were greater in supernatants of IL-6 (+/+) astrocytes than IL-6 (-/-) cells prior to 48 h post-stimulation. At that time, higher levels of MIP-1alpha were maintained in IL-6 (+/+) supernatant, while similar levels of MCP-1 in supernatants of both IL-6 (+/+) and IL-6 (-/-) cells were measured. Additionally, LPS (100 ng/ml) resulted in greater levels of KC and Rantes in IL-6 (-/-) astrocyte supernatants compared with IL-6 (+/+) supernatants at that time. These results suggest that the autocrine modulatory activities of IL-6 affect multiple cytokine secretory pathways, which could participate in neurodegenerative processes.
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Affiliation(s)
- L M Bolin
- The Parkinson's Institute, 1170 Morse Avenue, Sunnyvale, CA 94089-1605, USA.
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19
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Speth C, Dierich MP, Sopper S. HIV-infection of the central nervous system: the tightrope walk of innate immunity. Mol Immunol 2005; 42:213-28. [PMID: 15488609 DOI: 10.1016/j.molimm.2004.06.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection of the central nervous system (CNS) by HIV is a frequent and sometimes very early event in the course of HIV pathogenesis. Possible consequences are diverse symptoms of neurological dysfunction, but also the establishment of a lifelong latent viral reservoir in the brain. Whereas in the periphery innate and adaptive immunity are equal partners, the blood-brain barrier (BBB) with its restricted access of peripheral immune effectors shifts this balance in favour of the local innate immunity. Four main elements of cerebral innate immunity are discussed in the present article, including two cell types with immunological functions and two soluble immune systems: (1) the stimulation of microglial cells as the predominant brain-resident immune cell and the main local reservoir for the virus; (2) the reaction of astrocytes in response to viral infection; (3) the activation of the local complement system as important soluble immune cascade; and (4) the role of chemokines and cytokines which help to conduct and cross-link the interplay between the different immune elements. These components of the cerebral innate immunity do not act separately from each other but form a functional immunity network. A dual role of these components with both harmful and protective effects further enhances the complexity of the mutual interactions.
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Affiliation(s)
- Cornelia Speth
- Institute of Hygiene and Social Medicine, Medical University Innsbruck and Ludwig-Boltzmann-Institute for AIDS Research, Fritz-Pregl-Str. 3, A-6020 Innsbruck, Austria.
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20
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Si Q, Cosenza M, Kim MO, Zhao ML, Brownlee M, Goldstein H, Lee S. A novel action of minocycline: inhibition of human immunodeficiency virus type 1 infection in microglia. J Neurovirol 2004; 10:284-92. [PMID: 15385251 DOI: 10.1080/13550280490499533] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection of the brain produces a characteristic disease called acquired immunodeficiency syndrome (AIDS) dementia in which productive infection and inflammatory activation of microglia and macrophages play a central role. In this report, the authors demonstrate that minocycline (MC), a second-generation tetracycline with proven safety and penetration to the central nervous system, potently inhibited viral production from microglia. Inhibition of viral release was sustained through the entire course of infection and even when the drug exposure was limited to the first day of infection. Minocycline was effective even at low viral doses, and against R5- and X4R5-HIV, as well as in single-cycle reporter virus assays. Electrophoretic mobility shift analysis showed that minocycline inhibited nuclear factor (NF)-kappaB activation in microglia. HIV-1 long terminal repeat (LTR)-promoter activity in U38 cells was also inhibited. These results, combined with recently demonstrated in vivo anti-inflammatory effects of MC on microglia, suggest a potential utility for MC as an effective adjunct therapy for AIDS dementia.
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Affiliation(s)
- Qiusheng Si
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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21
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Albright AV, González-Scarano F. Microarray analysis of activated mixed glial (microglia) and monocyte-derived macrophage gene expression. J Neuroimmunol 2004; 157:27-38. [PMID: 15579277 DOI: 10.1016/j.jneuroim.2004.09.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Since macrophage activation can now be studied at a global level using modern microarray and proteomic analyses, discovery of novel macrophage activation genes is inevitable and important for understanding HIV-associated dementia (HAD). We isolated two different types of primary human macrophages: microglia and monocyte-derived macrophages (MDM) from brain tissue and whole blood, respectively. The microarray analysis of differentially regulated macrophage activation genes reported here supports our previous assertions that the mixed glia (MIX) cultured in starvation conditions (DMEM alone) are a non-activated, or "quiescent", tissue culture model for studying macrophage activation in the brain. Transcript levels from these quiescent cultures provided a background level of gene expression and allowed for the identification of upregulated macrophage activation genes in the MIX brain cultures upon treatment with an array of soluble activation factors: serum components, cytokines, and growth factors. We found that 914 genes in the MIX cultures and 734 genes in the MDM cultures had a greater than twofold increase in expression. We discovered 180 genes with expression that was increased more than twofold in both culture types. Microarray-specific statistical analyses were performed to complement fold change analysis: significance analysis of microarrays (SAM) and Partek Pro. In the MIX cultures, we detected over a 100-fold increase in IL-1beta and TIMP1 transcription; Caspase 9, S100A8 and 9, MMP12, IL-8, monocyte chemotactic protein 1 (MCP1), MRC-1, and IL-6 were also upregulated. Activation of starved MDM cultures resulted in fewer upregulated genes compared to MIX cultures. Genes upregulated in both MIX and MDM included CCL2 (MCP1), CCL7, CXCL5, TNFSF14, kinases, and phosphatases. These microarray data may provide leads for identifying previously unknown neurotoxins, disease biomarkers, and pathways responsible for the neuronal apoptosis observed in HAD and for the eventual identification of therapeutic targets and treatments.
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Affiliation(s)
- Andrew V Albright
- Department of Neurology, University of Pennsylvania, 255 Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104-6146, USA.
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22
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Rock RB, Gekker G, Hu S, Sheng WS, Cheeran M, Lokensgard JR, Peterson PK. Role of microglia in central nervous system infections. Clin Microbiol Rev 2004; 17:942-64, table of contents. [PMID: 15489356 PMCID: PMC523558 DOI: 10.1128/cmr.17.4.942-964.2004] [Citation(s) in RCA: 500] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The nature of microglia fascinated many prominent researchers in the 19th and early 20th centuries, and in a classic treatise in 1932, Pio del Rio-Hortega formulated a number of concepts regarding the function of these resident macrophages of the brain parenchyma that remain relevant to this day. However, a renaissance of interest in microglia occurred toward the end of the 20th century, fueled by the recognition of their role in neuropathogenesis of infectious agents, such as human immunodeficiency virus type 1, and by what appears to be their participation in other neurodegenerative and neuroinflammatory disorders. During the same period, insights into the physiological and pathological properties of microglia were gained from in vivo and in vitro studies of neurotropic viruses, bacteria, fungi, parasites, and prions, which are reviewed in this article. New concepts that have emerged from these studies include the importance of cytokines and chemokines produced by activated microglia in neurodegenerative and neuroprotective processes and the elegant but astonishingly complex interactions between microglia, astrocytes, lymphocytes, and neurons that underlie these processes. It is proposed that an enhanced understanding of microglia will yield improved therapies of central nervous system infections, since such therapies are, by and large, sorely needed.
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Affiliation(s)
- R Bryan Rock
- Neuroimmunology Laboratory, Minneapolis Medical Research Foundation, and University of Minnesota Medical School, USA
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23
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Albright AV, Vos RM, González-Scarano F. Low-level HIV replication in mixed glial cultures is associated with alterations in the processing of p55(Gag). Virology 2004; 325:328-39. [PMID: 15246272 DOI: 10.1016/j.virol.2004.04.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Revised: 04/22/2004] [Accepted: 04/28/2004] [Indexed: 10/26/2022]
Abstract
We report a novel long-lived infection model in human mixed glial cultures (microglia) whereby cells harbor replication-competent HIV-1 for up to 2.5 months after infection; a model that potentially mimics latency within the central nervous system (CNS). Infection of mixed glial cultures in the presence of serum, cytokines, and growth factors (activating conditions) resulted in a robust productive infection of microglial cells as previously described for purified microglia. In contrast, similar mixed glial cells cultured in serum-free medium without cytokines or growth factors (mirroring a nonactivated CNS) supported HIV-1 entry, reverse transcription, integration, and transcription, yet released little or no infectious virus. We found instead that nonactivated mixed glial cells expressed almost 10-fold less Gag protein, but more importantly, analysis of the intracellular Gag products in quiescent cells showed an aberrant p55/p24 Gag processing phenotype that appeared to be due to the premature activity of the viral protease. These results suggest that the cellular environment in nonactivated microglia cells in these mixed glial cultures is not conducive to proper Gag processing and virus release. This long-lived infection model will be useful in identifying factors that are key for viral maturation in cells of the macrophage lineage.
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Affiliation(s)
- Andrew V Albright
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104-6146, USA
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24
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Si Q, Zhao ML, Morgan ACA, Brosnan CF, Lee SC. 15-Deoxy-Δ12,14-Prostaglandin J2 Inhibits IFN-Inducible Protein 10/CXC Chemokine Ligand 10 Expression in Human Microglia: Mechanisms and Implications. THE JOURNAL OF IMMUNOLOGY 2004; 173:3504-13. [PMID: 15322215 DOI: 10.4049/jimmunol.173.5.3504] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Regulation of cytokine and chemokine expression in microglia may have implications for CNS inflammatory disorders. In this study we examined the role of the cyclopentenone PG 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) in microglial inflammatory activation in primary cultures of human fetal microglia. 15d-PGJ(2) potently inhibited the expression of microglial cytokines (IL-1, TNF-alpha, and IL-6). We found that 15d-PGJ(2) had differential effects on the expression of two alpha-chemokines; whereas the Glu-Lys-Arg (ELR)(-) chemokine IFN-inducible protein-10/CXCL10 was inhibited, the ELR(+) chemokine IL-8/CXCL8 was not inhibited. These findings were shown in primary human microglia and the human monocytic cells line THP-1 cells, using diverse cell stimuli such as bacterial endotoxin, proinflammatory cytokines (IL-1 and TNF-alpha), IFN-beta, and HIV-1. Furthermore, IL-8/CXCL8 expression was induced by 15d-PGJ(2) alone or in combination with TNF-alpha or HIV-1. Combined results from EMSA, Western blot analysis, and immunocytochemistry showed that 15d-PGJ(2) inhibited NF-kappaB, Stat1, and p38 MAPK activation in microglia. Adenoviral transduction of super-repressor IkappaBalpha, dominant negative MKK6, and dominant negative Ras demonstrated that NF-kappaB and p38 MAPK were involved in LPS-induced IFN-inducible protein 10/CXCL10 production. Interestingly, although LPS-induced IL-8/CXCL8 was dependent on NF-kappaB, the baseline or 15d-PGJ(2)-mediated IL-8/CXCL8 production was NF-kappaB independent. Our results demonstrate that 15d-PGJ(2) has opposing effects on the expression of two alpha-chemokines. These data may have implications for CNS inflammatory diseases.
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Affiliation(s)
- Qiusheng Si
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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25
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Ambrosini E, Aloisi F. Chemokines and glial cells: a complex network in the central nervous system. Neurochem Res 2004. [PMID: 15139300 DOI: 10.1023/b: nere.0000021246.96864.89] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Chemokines are small secreted proteins that are essential for the recruitment and activation of specific leukocyte subsets at sites of inflammation and for the development and homeostasis of lymphoid and nonlymphoid tissues. During the past decade, chemokines and their receptors have also emerged as key signaling molecules in neuroinflammatory processes and in the development and functioning of the central nervous system. Neurons and glial cells, including astrocytes, oligodendrocytes, and microglia, have been identified as cellular sources and/or targets of chemokines produced in the central nervous system in physiological and pathological conditions. In this article, we provide an update of chemokines and chemokine receptors expressed by glial cells focusing on their biological functions and implications in neurological diseases.
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Affiliation(s)
- Elena Ambrosini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
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26
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Jaworowski A, Maslin CLV, Wesselingh SL. The use of growth factors and cytokines to treat opportunistic infections in HIV-1 disease. Sex Health 2004; 1:161-74. [PMID: 16335304 DOI: 10.1071/sh03022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The success of highly active antiretroviral therapy (HAART) in reducing AIDS-related mortality means that in regions where HAART is available, HIV infection may now be regarded as a chronic disease. However the inability of HAART to eliminate HIV-1 from various anatomical and cellular reservoirs within the body means that HIV-infected individuals require life-long treatment with therapy that can have significant side effects. Management of HIV disease is therefore increasingly focused on drug-related toxicities and the improvement of current HAART regimens. Here we review the potential use of immunomodulatory cytokines to directly or indirectly stimulate the mononuclear phagocyte system as adjuncts to current HIV treatment as well as their use in the management of opportunistic infections in individuals who develop immunodeficiency. We argue that cytokines, which stimulate mononuclear phagocyte activity against opportunistic pathogens, may be useful for the treatment of individuals who develop recurrent opportunistic infections. Cytokines may act synergistically with antimicrobial agents to improve outcomes, which is of particular importance since recurrent infections frequently result in resistance to standard antimicrobial treatments. Before their use can be advocated however, given their toxicity and significant cost, the potential benefits of cytokines must be demonstrated in larger clinical trials.
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Affiliation(s)
- Anthony Jaworowski
- AIDS Pathogenesis and Clinical Research Program, The Burnet Institute for Medical Research and Public Health, Melbourne, Australia.
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27
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Si Q, Kim MO, Zhao ML, Landau NR, Goldstein H, Lee S. Vpr- and Nef-dependent induction of RANTES/CCL5 in microglial cells. Virology 2002; 301:342-53. [PMID: 12359436 DOI: 10.1006/viro.2002.1613] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microglia are pivotal in the pathogenesis of AIDS dementia, as they serve as the major target of HIV infection in the CNS. In addition, activation of microglia correlates best with clinical dementia. Although the beta-chemokine RANTES/CCL5 is important in modulating HIV infection as well as cellular activation, no information is available regarding how its expression is regulated in microglia by HIV-1. Here we report that RANTES/CCL5 expression is induced in microglia by HIV-1, but that this requires infection by HIV-1. This conclusion was supported by (1) the delayed kinetics coinciding with viral replication; (2) the lack of effect of X4 viruses; (3) inhibition by the reverse transcriptase inhibitor AZT, and (4) the lack of effect of cytokine antagonists or antibodies. Interestingly, RANTES/CCL5 production was dependent on the viral accessory protein Vpr, in addition to Nef, demonstrating a novel role for Vpr in chemokine induction in primary macrophage-type cells. Furthermore, the specific p38 MAP kinase inhibitor SB203580 augmented chemokine expression in microglia, indicating a negative role played by p38. These data suggest unique features of RANTES/CCL5 regulation by HIV-1 in human microglial cells.
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MESH Headings
- Animals
- Anti-HIV Agents/pharmacology
- COS Cells
- Cells, Cultured
- Chemokine CCL2/genetics
- Chemokine CCL5/biosynthesis
- Chemokine CCL5/genetics
- Chemokine CXCL10
- Chemokines, CXC/genetics
- Chlorocebus aethiops
- Dose-Response Relationship, Drug
- Gene Expression
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Gene Products, vpr/genetics
- Gene Products, vpr/immunology
- HIV-1/drug effects
- HIV-1/immunology
- HIV-1/isolation & purification
- Humans
- Interferon-beta/immunology
- Interleukin-1/immunology
- Microglia/cytology
- Microglia/immunology
- Microglia/virology
- Mitogen-Activated Protein Kinases/antagonists & inhibitors
- RNA, Messenger
- Reverse Transcriptase Inhibitors/pharmacology
- Time Factors
- Tumor Necrosis Factor-alpha/immunology
- Zidovudine/pharmacology
- nef Gene Products, Human Immunodeficiency Virus
- p38 Mitogen-Activated Protein Kinases
- vpr Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Qiusheng Si
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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