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Ojeda-Juárez D, Kaul M. Transcriptomic and Genetic Profiling of HIV-Associated Neurocognitive Disorders. Front Mol Biosci 2021; 8:721954. [PMID: 34778371 PMCID: PMC8586712 DOI: 10.3389/fmolb.2021.721954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/24/2021] [Indexed: 12/20/2022] Open
Abstract
Early in the HIV pandemic, it became evident that people living with HIV (PLWH) develop a wide range of neurological and neurocognitive complications. Even after the introduction of combination antiretroviral therapy (cART), which dramatically improved survival of PLWH, the overall number of people living with some form of HIV-associated neurocognitive disorders (HAND) seemed to remain unchanged, although the incidence of dementia declined and questions about the incidence and diagnosis of the mildest form of HAND arose. To better understand this complex disease, several transcriptomic analyses have been conducted in autopsy samples, as well as in non-human primates and small animal rodent models. However, genetic studies in the HIV field have mostly focused on the genetic makeup of the immune system. Much less is known about the genetic underpinnings of HAND. Here, we provide a summary of reported transcriptomic and epigenetic changes in HAND, as well as some of the potential genetic underpinnings that have been linked to HAND, and discuss future directions with hurdles to overcome and angles that remain to be explored.
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Affiliation(s)
- Daniel Ojeda-Juárez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Marcus Kaul
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
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Cognitive and Neuronal Link With Inflammation: A Longitudinal Study in People With and Without HIV Infection. J Acquir Immune Defic Syndr 2021; 85:617-625. [PMID: 32932412 DOI: 10.1097/qai.0000000000002484] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Across many settings, lack of virologic control remains common in people with HIV (PWH) because of late presentation and lack of retention in care. This contributes to neuronal damage and neurocognitive impairment, which remains prevalent. More evidence is needed to understand these outcomes in both PWH and people without HIV (PWOH). METHODS We recruited PWH initiating antiretroviral therapy and PWOH at 2 sites in the United States. One hundred eight adults were enrolled (56 PWOH and 52 PWH), most of whom had a second assessment at least 24 weeks later (193 total assessments). Tumor necrosis factor alpha, monocyte chemotactic protein-1 (MCP-1), neopterin, soluble CD14, and neurofilament light chain protein (NFL) were measured in plasma and cerebrospinal fluid (CSF). Using multivariate models including Bayesian model averaging, we analyzed factors associated with global neuropsychological performance (NPT-9) and CSF NFL at baseline and over time. RESULTS At baseline, higher CSF MCP-1 and plasma sCD14 were associated with worse NPT-9 in PWH, while CSF HIV RNA decrease was the only marker associated with improved NPT-9 over time. Among PWH, higher CSF neopterin was most closely associated with higher NFL. Among PWOH, higher CSF MCP-1 was most closely associated with higher NFL. After antiretroviral therapy initiation, decrease in CSF MCP-1 was most closely associated with NFL decrease. CONCLUSION Monocyte-associated CSF biomarkers are highly associated with neuronal damage in both PWH and PWOH. More research is needed to evaluate whether therapies targeting monocyte-associated inflammation may ameliorate HIV-associated neurobehavioral diseases.
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Gomez D, Power C, Fujiwara E. Neurocognitive Impairment and Associated Genetic Aspects in HIV Infection. Curr Top Behav Neurosci 2018; 50:41-76. [PMID: 30523615 DOI: 10.1007/7854_2018_69] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
HIV enters the central nervous system (CNS) early after infection. HIV-associated neurocognitive disorders (HAND) remain a serious complication of HIV infection despite available antiretroviral therapy (ART). Neurocognitive deficits observed in HAND are heterogeneous, suggesting a variability in individuals' susceptibility or resiliency to the detrimental CNS effects of HIV infection. This chapter reviews primary host genomic changes (immune-related genes, genes implicated in cognitive changes in primary neurodegenerative diseases), epigenetic mechanisms, and genetic interactions with ART implicated in HIV progression or HAND/neurocognitive complications of HIV. Limitations of the current findings include diversity of the HAND phenotype and limited replication of findings across cohorts. Strategies to improve the precision of future (epi)genetic studies of neurocognitive consequences of HIV infection are offered.
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Affiliation(s)
- Daniela Gomez
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Christopher Power
- Departments of Psychiatry and Medicine, University of Alberta, Edmonton, AB, Canada
| | - Esther Fujiwara
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada.
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Risk Factors and Pathogenesis of HIV-Associated Neurocognitive Disorder: The Role of Host Genetics. Int J Mol Sci 2018; 19:ijms19113594. [PMID: 30441796 PMCID: PMC6274730 DOI: 10.3390/ijms19113594] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 02/06/2023] Open
Abstract
Neurocognitive impairments associated with human immunodeficiency virus (HIV) infection remain a considerable health issue for almost half the people living with HIV, despite progress in HIV treatment through combination antiretroviral therapy (cART). The pathogenesis and risk factors of HIV-associated neurocognitive disorder (HAND) are still incompletely understood. This is partly due to the complexity of HAND diagnostics, as phenotypes present with high variability and change over time. Our current understanding is that HIV enters the central nervous system (CNS) during infection, persisting and replicating in resident immune and supporting cells, with the subsequent host immune response and inflammation likely adding to the development of HAND. Differences in host (human) genetics determine, in part, the effectiveness of the immune response and other factors that increase the vulnerability to HAND. This review describes findings from studies investigating the role of human host genetics in the pathogenesis of HAND, including potential risk factors for developing HAND. The similarities and differences between HAND and Alzheimer's disease are also discussed. While some specific variations in host genes regulating immune responses and neurotransmission have been associated with protection or risk of HAND development, the effects are generally small and findings poorly replicated. Nevertheless, a few specific gene variants appear to affect the risk for developing HAND and aid our understanding of HAND pathogenesis.
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Abstract
Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain a common end-organ manifestation of viral infection. Subclinical and mild symptoms lead to neurocognitive and behavioral abnormalities. These are associated, in part, with viral penetrance and persistence in the central nervous system. Infections of peripheral blood monocytes, macrophages, and microglia are the primary drivers of neuroinflammation and neuronal impairments. While current antiretroviral therapy (ART) has reduced the incidence of HIV-associated dementia, milder forms of HAND continue. Depression, comorbid conditions such as infectious liver disease, drugs of abuse, antiretroviral drugs themselves, age-related neurodegenerative diseases, gastrointestinal maladies, and concurrent social and economic issues can make accurate diagnosis of HAND challenging. Increased life expectancy as a result of ART clearly creates this variety of comorbid conditions that often blur the link between the virus and disease. With the discovery of novel biomarkers, neuropsychologic testing, and imaging techniques to better diagnose HAND, the emergence of brain-penetrant ART, adjunctive therapies, longer life expectancy, and better understanding of disease pathogenesis, disease elimination is perhaps a realistic possibility. This review focuses on HIV-associated disease pathobiology with an eye towards changing trends in the face of widespread availability of ART.
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Eggers C, Arendt G, Hahn K, Husstedt IW, Maschke M, Neuen-Jacob E, Obermann M, Rosenkranz T, Schielke E, Straube E. HIV-1-associated neurocognitive disorder: epidemiology, pathogenesis, diagnosis, and treatment. J Neurol 2017; 264:1715-1727. [PMID: 28567537 PMCID: PMC5533849 DOI: 10.1007/s00415-017-8503-2] [Citation(s) in RCA: 193] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/30/2017] [Accepted: 05/02/2017] [Indexed: 01/05/2023]
Abstract
The modern antiretroviral treatment of human immunodeficiency virus (HIV-1) infection has considerably lowered the incidence of opportunistic infections. With the exception of the most severe dementia manifestations, the incidence and prevalence of HIV-associated neurocognitive disorders (HAND) have not decreased, and HAND continues to be relevant in daily clinical practice. Now, HAND occurs in earlier stages of HIV infection, and the clinical course differs from that before the widespread use of combination antiretroviral treatment (cART). The predominant clinical feature is a subcortical dementia with deficits in the domains concentration, attention, and memory. Motor signs such as gait disturbance and impaired manual dexterity have become less prominent. Prior to the advent of cART, the cerebral dysfunction could at least partially be explained by the viral load and by virus-associated histopathological findings. In subjects where cART has led to undetectable or at least very low viral load, the pathogenic virus-brain interaction is less direct, and an array of poorly understood immunological and probably toxic phenomena are discussed. This paper gives an overview of the current concepts in the field of HAND and provides suggestions for the diagnostic and therapeutic management.
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Affiliation(s)
- Christian Eggers
- Department of Neurology, Krankenhaus Barmherzige Brüder, Seilerstätte 2, 4021, Linz, Austria.
| | - Gabriele Arendt
- Neurologische Klinik, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Katrin Hahn
- Neurologische Klinik, Charité, Berlin, Germany
| | - Ingo W Husstedt
- Klinik für Neurologie, Universitätsklinikum Münster, Münster, Germany
| | - Matthias Maschke
- Neurologische Abteilung, Brüderkrankenhaus Trier, Trier, Germany
| | - Eva Neuen-Jacob
- Institut für Neuropathologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Mark Obermann
- Direktor des Zentrums für Neurologie, Asklepios Kliniken Schildautal, Seesen, Germany
| | - Thorsten Rosenkranz
- Neurologische Abteilung, Asklepios-Klinik Hamburg-St. Georg, Hamburg, Germany
| | - Eva Schielke
- Praxis für Neurologie Berlin-Mitte, 10117, Berlin, Germany
| | - Elmar Straube
- HIV-Schwerpunktpraxis, 30890, Barsinghausen, Germany
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Venkatachari NJ, Jain S, Walker L, Bivalkar-Mehla S, Chattopadhyay A, Bar-Joseph Z, Rinaldo C, Ragin A, Seaberg E, Levine A, Becker J, Martin E, Sacktor N, Ayyavoo V. Transcriptome analyses identify key cellular factors associated with HIV-1-associated neuropathogenesis in infected men. AIDS 2017; 31:623-633. [PMID: 28005686 PMCID: PMC5389669 DOI: 10.1097/qad.0000000000001379] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE HIV-1 viral proteins and host inflammatory factors have a direct role in neuronal toxicity in vitro; however, the contribution of these factors in vivo in HIV-1-associated neurocognitive disorder (HAND) is not fully understood. We applied novel Systems Biology approaches to identify specific cellular and viral factors and their related pathways that are associated with different stages of HAND. DESIGN A cross-sectional study of individuals enrolled in the Multicenter AIDS Cohort Study including HIV-1-seronegative (N = 36) and HIV-1-seropositive individuals without neurocognitive symptoms (N = 16) or with mild neurocognitive disorder (MND) (N = 8) or HIV-associated dementia (HAD) (N = 16). METHODS A systematic evaluation of global transcriptome of peripheral blood mononuclear cells (PBMCs) obtained from HIV-1-seronegative individuals and from HIV-1-positive men without neurocognitive symptoms, or MND or HAD was performed. RESULTS MND and HAD were associated with specific changes in mRNA transcripts and microRNAs in PBMCs. Comparison of upstream regulators and TimePath analyses identified specific cellular factors associated with MND and HAD, whereas HIV-1 viral proteins played a greater role in HAD. In addition, expression of specific microRNAs - miR-let-7a, miR-124, miR-15a and others - were found to correlate with mRNA gene expression and may have a potential protective role in asymptomatic HIV-1-seropositive individuals by regulating cellular signal transduction pathways downstream of chemokines and cytokines. CONCLUSION These results identify signature transcriptome changes in PBMCs associated with stages of HAND and shed light on the potential contribution of host cellular factors and viral proteins in HAND development.
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Affiliation(s)
- Narasimhan J. Venkatachari
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
| | - Siddhartha Jain
- Computer Science Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, 15217, USA
| | - Leah Walker
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
| | - Shalmali Bivalkar-Mehla
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
| | - Ansuman Chattopadhyay
- Molecular Biology Information Service, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Computational Biology and Machine Learning Department, Carnegie Mellon University, Pittsburgh, PA
| | - Ziv Bar-Joseph
- Computer Science Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, 15217, USA
| | - Charles Rinaldo
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
| | - Ann Ragin
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Suite 1600, 737 N. Michigan Ave, Chicago, IL 60611, USA
| | - Eric Seaberg
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21209, USA
| | - Andrew Levine
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, CA 90095
| | - James Becker
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
| | - Eileen Martin
- Department of Psychiatry, Rush University Medical Center, 1645 W Jackson Blvd, Chicago, IL, 60612, USA
| | - Ned Sacktor
- Department of Neurology, Johns Hopkins Bayview Medical Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21209, USA
| | - Velpandi Ayyavoo
- Department of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261
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Jiang C, Li Z, Chen P, Chen L. Association between the tumor necrosis factor-α-308G/A gene polymorphism and HIV-1 susceptibility: a meta-analysis. AIDS Res Hum Retroviruses 2015; 31:859-65. [PMID: 26077837 DOI: 10.1089/aid.2015.0092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The tumor necrosis factor-α (TNF-α)-308G/A gene polymorphism influences the pathogenesis and evolution of HIV-1 disease. Many studies have evaluated the association between this polymorphism and HIV-1 susceptibility, but the exact relationship between them remains ambiguous and contradictory. Accordingly, the present study evaluates the exact association between TNF-α-308G/A gene polymorphism and HIV-1 susceptibility. A systematic literature search was conducted and the case-control studies that were found assessing the association between TNF-α-308G/A gene polymorphism and HIV-1 susceptibility were analyzed. The pooled odds ratios (ORs) and 95% confidence interval (CI) were calculated by a fixed effect model. Heterogeneity was analyzed by Cochran's Q and the I(2) statistics. Publication bias was assessed using the Begg's funnel plot and Egger's test. A total of 679 cases and 873 controls from five studies were included. Overall, no significant relationship was found between TNF-α-308G/A gene polymorphism and HIV-1 susceptibility in this meta-analysis study (A versus G genotype model: OR=0.89, 95% CI=0.59-1.32, p=0.553; GG versus AA+AG model: OR=1.23, 95% CI=0.75-2.02, p=0.407; GG+AG versus AA model: OR=1.40, 95% CI=0.70-2.82, p=0.345; GG versus AA model: OR=1.39, 95% CI=0.69-2.80, p=0.362; AG versus AA model: OR=1.43, 95% CI=0.70-2.96, p=0.329; GG+AA versus AG model: OR=0.76, 95% CI=0.44-1.29, p=0.304). The meta-analysis found no marked association between TNF-α-308G/A gene polymorphism and HIV-1 susceptibility.
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Affiliation(s)
- CaiXiao Jiang
- Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Changsha, Hunan Province, China
| | - ZhanZhan Li
- Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Changsha, Hunan Province, China
| | - Peng Chen
- Xiangya Medical School, Central South University, Changsha, Hunan Province, China
| | - Lizhang Chen
- Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Changsha, Hunan Province, China
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[HIV 1-associated neurocognitive disorder: current epidemiology, pathogenesis, diagnosis and management]. DER NERVENARZT 2015; 85:1280-90. [PMID: 25292163 DOI: 10.1007/s00115-014-4082-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
By restoring the immunological function the modern antiretroviral treatment of human immunodeficiency virus (HIV-1) infection has considerably lowered the incidence of opportunistic infections. As opposed to the classical manifestations of HIV-induced immunosuppression the incidence and prevalence of HIV-associated neurocognitive disorders (HAND) has not noticeably decreased and HAND continues to be relevant in daily clinical practice. At present, HAND occurs in earlier stages of HIV infection, and the clinical course differs from that before the introduction of combination antiretroviral treatment (cART). The predominant clinical manifestation is a subcortical dementia with deficits in the domains attention, concentration and memory. Signs of central motor pathway lesions have become less frequent and less prominent. Prior to the advent of cART the cerebral dysfunction could at least partially be explained by the viral load and by virus-associated histopathological findings. In patients with at least partially successfully treated infections, this relationship no longer exists, but a plethora of poorly understood immunological and probably toxic phenomena are under discussion.This consensus paper summarizes the progress made in the last 12 years in the field of HAND and provides suggestions for the diagnostic and therapeutic management.
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Polymorphisms in the IFNγ, IL-10, and TGFβ genes may be associated with HIV-1 infection. DISEASE MARKERS 2015; 2015:248571. [PMID: 25802474 PMCID: PMC4354727 DOI: 10.1155/2015/248571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 12/22/2014] [Accepted: 12/22/2014] [Indexed: 01/11/2023]
Abstract
OBJECTIVE This study investigated possible associations between the TNFα-308G/A, IFN+874A/T, IL-6-174C/G, IL-10-1082A/G, and TGFβ-509C/T polymorphisms with HIV-1 infection, in addition to correlation of the polymorphisms with clinical markers of AIDS progression, such as levels of CD4+/CD8+ T lymphocytes and plasma viral load. METHODS A total of 216 individuals who were infected with HIV-1 and on antiretroviral therapy (ART) and 294 individuals from the uninfected control group were analyzed. RESULTS All individuals evaluated were negative for total anti-HBc, anti-HCV, anti-T. pallidum, and anti-HTLV-1/2. The polymorphisms were identified by PCR-RFLP. Individuals presenting the IFN+874A allele as well as the AA genotype were more frequent in the HIV-1 infected group compared to the control group (P < 0.05), in addition to having lower levels of CD4+ T lymphocytes. The CD8+ T lymphocytes count was significantly lower in individuals with the IL-10-1082 GG genotype. The TGFβ-509TT genotype was associated with higher plasma viral load. CONCLUSIONS The results suggest that the presence of the IFN+874A allele confers susceptibility to HIV-1 infection and a decrease in the number of CD4+ T lymphocytes. In addition, the genotype associated with high serum levels of TGFβ may be associated with an increase in plasma viral load.
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Abstract
The success of combination antiretroviral therapy (cART) in transforming the lives of HIV-infected individuals with access to these drugs is tempered by the increasing threat of HIV-associated neurocognitive disorders (HAND) to their overall health and quality of life. Intensive investigations over the past two decades have underscored the role of host immune responses, inflammation, and monocyte-derived macrophages in HAND, but the precise pathogenic mechanisms underlying HAND remain only partially delineated. Complicating research efforts and therapeutic drug development are the sheer complexity of HAND phenotypes, diagnostic imprecision, and the growing intersection of chronic immune activation with aging-related comorbidities. Yet, genetic studies still offer a powerful means of advancing individualized care for HIV-infected individuals at risk. There is an urgent need for 1) longitudinal studies using consistent phenotypic definitions of HAND in HIV-infected subpopulations at very high risk of being adversely impacted, such as children, 2) tissue studies that correlate neuropathological changes in multiple brain regions with genomic markers in affected individuals and with changes at the RNA, epigenomic, and/or protein levels, and 3) genetic association studies using more sensitive subphenotypes of HAND. The NIH Brain Initiative and Human Connectome Project, coupled with rapidly evolving systems biology and machine learning approaches for analyzing high-throughput genetic, transcriptomic and epigenetic data, hold promise for identifying actionable biological processes and gene networks that underlie HAND. This review summarizes the current state of understanding of host genetic factors predisposing to HAND in light of past challenges and suggests some priorities for future research to advance the understanding and clinical management of HAND in the cART era.
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Affiliation(s)
- Asha R Kallianpur
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue/Mail Code NE50, Cleveland, OH, 44195, USA,
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Rao VR, Ruiz AP, Prasad VR. Viral and cellular factors underlying neuropathogenesis in HIV associated neurocognitive disorders (HAND). AIDS Res Ther 2014; 11:13. [PMID: 24894206 PMCID: PMC4043700 DOI: 10.1186/1742-6405-11-13] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/08/2014] [Indexed: 11/11/2022] Open
Abstract
As the HIV-1 epidemic enters its fourth decade, HIV-1 associated neurological disorders (HAND) continue to be a major concern in the infected population, despite the widespread use of anti-retroviral therapy. Advancing age and increased life expectancy of the HIV-1 infected population have been shown to increase the risk of cognitive dysfunction. Over the past 10 years, there has been a significant progress in our understanding of the mechanisms and the risk factors involved in the development of HAND. Key events that lead up to neuronal damage in HIV-1 infected individuals can be categorized based on the interaction of HIV-1 with the various cell types, including but not limited to macrophages, brain endothelial cells, microglia, astrocytes and the neurons. This review attempts to decipher these interactions, beginning with HIV-1 infection of macrophages and ultimately resulting in the release of neurotoxic viral and host products. These include: interaction with endothelial cells, resulting in the impairment of the blood brain barrier; interaction with the astrocytes, leading to metabolic and neurotransmitter imbalance; interactions with resident immune cells in the brain, leading to release of toxic cytokines and chemokines. We also review the mechanisms underlying neuronal damage caused by the factors mentioned above. We have attempted to bring together recent findings in these areas to help appreciate the viral and host factors that bring about neurological dysfunction. In addition, we review host factors and viral genotypic differences that affect phenotypic pathological outcomes, as well as recent advances in treatment options to specifically address the neurotoxic mechanisms in play.
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Genetic, transcriptomic, and epigenetic studies of HIV-associated neurocognitive disorder. J Acquir Immune Defic Syndr 2014; 65:481-503. [PMID: 24583618 DOI: 10.1097/qai.0000000000000069] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The Human Genome Project, coupled with rapidly evolving high-throughput technologies, has opened the possibility of identifying heretofore unknown biological processes underlying human disease. Because of the opaque nature of HIV-associated neurocognitive disorder (HAND) neuropathogenesis, the utility of such methods has gained notice among NeuroAIDS researchers. Furthermore, the merging of genetics with other research areas has also allowed for application of relatively nascent fields, such as neuroimaging genomics, and pharmacogenetics, to the context of HAND. In this review, we detail the development of genetic, transcriptomic, and epigenetic studies of HAND, beginning with early candidate gene association studies and culminating in current "omics" approaches that incorporate methods from systems biology to interpret data from multiple levels of biological functioning. Challenges with this line of investigation are discussed, including the difficulty of defining a valid phenotype for HAND. We propose that leveraging known associations between biology and pathology across multiple levels will lead to a more reliable and valid phenotype. We also discuss the difficulties of interpreting the massive and multitiered mountains of data produced by current high-throughput omics assays and explore the utility of systems biology approaches in this regard.
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14
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The longitudinal and interactive effects of HIV status, stimulant use, and host genotype upon neurocognitive functioning. J Neurovirol 2014; 20:243-57. [PMID: 24737013 DOI: 10.1007/s13365-014-0241-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/29/2014] [Accepted: 02/06/2014] [Indexed: 12/18/2022]
Abstract
Both human immunodeficiency virus (HIV)-1 infection and illicit stimulant use can adversely impact neurocognitive functioning, and these effects can be additive. However, significant variability exists such that as-of-yet unidentified exogenous and endogenous factors affect one's risk for neurocognitive impairment. Literature on both HIV and stimulant use indicates that host genetic variants in immunologic and dopamine-related genes are one such factor. In this study, the individual and interactive effects of HIV status, stimulant use, and genotype upon neurocognitive functioning were examined longitudinally over a 10-year period. Nine hundred fifty-two Caucasian HIV+ and HIV- cases from the Multicenter AIDS Cohort Study were included. All cases had at least two comprehensive neurocognitive evaluations between 1985 and 1995. Pre-highly active antiretroviral therapy (HAART) data were examined in order to avoid the confounding effect of variable drug regimens. Linear mixed models were used, with neurocognitive domain scores as the outcome variables. No four-way interactions were found, indicating that HIV and stimulant use do not interact over time to affect neurocognitive functioning as a function of genotype. Multiple three-way interactions were found that involved genotype and HIV status. All immunologically related genes found to interact with HIV status affected neurocognitive functioning in the expected direction; however, only C-C chemokine ligand 2 (CCL2) and CCL3 affected HIV+ individuals specifically. Dopamine-related genetic variants generally affected HIV-negative individuals only. Neurocognitive functioning among HIV+ individuals who also used stimulants was not significantly different from those who did not use stimulants. The findings support the role of immunologically related genetic differences in CCL2 and CCL3 in neurocognitive functioning among HIV+ individuals; however, their impact is minor. Being consistent with findings from another cohort, dopamine (DA)-related genetic differences do not appear to impact the longitudinal neurocognitive functioning of HIV+ individuals.
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Hauser KF, Knapp PE. Interactions of HIV and drugs of abuse: the importance of glia, neural progenitors, and host genetic factors. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 118:231-313. [PMID: 25175867 PMCID: PMC4304845 DOI: 10.1016/b978-0-12-801284-0.00009-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Considerable insight has been gained into the comorbid, interactive effects of HIV and drug abuse in the brain using experimental models. This review, which considers opiates, methamphetamine, and cocaine, emphasizes the importance of host genetics and glial plasticity in driving the pathogenic neuron remodeling underlying neuro-acquired immunodeficiency syndrome and drug abuse comorbidity. Clinical findings are less concordant than experimental work, and the response of individuals to HIV and to drug abuse can vary tremendously. Host-genetic variability is important in determining viral tropism, neuropathogenesis, drug responses, and addictive behavior. However, genetic differences alone cannot account for individual variability in the brain "connectome." Environment and experience are critical determinants in the evolution of synaptic circuitry throughout life. Neurons and glia both exercise control over determinants of synaptic plasticity that are disrupted by HIV and drug abuse. Perivascular macrophages, microglia, and to a lesser extent astroglia can harbor the infection. Uninfected bystanders, especially astroglia, propagate and amplify inflammatory signals. Drug abuse by itself derails neuronal and glial function, and the outcome of chronic exposure is maladaptive plasticity. The negative consequences of coexposure to HIV and drug abuse are determined by numerous factors including genetics, sex, age, and multidrug exposure. Glia and some neurons are generated throughout life, and their progenitors appear to be targets of HIV and opiates/psychostimulants. The chronic nature of HIV and drug abuse appears to result in sustained alterations in the maturation and fate of neural progenitors, which may affect the balance of glial populations within multiple brain regions.
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Affiliation(s)
- Kurt F Hauser
- Department of Pharmacology & Toxicology, Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia, USA.
| | - Pamela E Knapp
- Department of Pharmacology & Toxicology, Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia, USA; Department of Anatomy & Neurobiology, Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia, USA
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Manji H, Jäger HR, Winston A. HIV, dementia and antiretroviral drugs: 30 years of an epidemic. J Neurol Neurosurg Psychiatry 2013; 84:1126-37. [PMID: 23378642 DOI: 10.1136/jnnp-2012-304022] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurological complications due to the HIV itself became apparent early on in the course of the AIDS epidemic. The most feared were the cognitive and motor complications termed AIDS dementia complex or HIV-associated dementia. With the introduction of combination antiretroviral therapy, the incidence of HIV-associated dementia has been dramatically reduced. However, the prevalence of less severe forms of the disorder remains around 20%. There is controversy about whether some patients may continue with progressive cognitive decline despite adequate suppression of the HIV. The salient issues are those of cerebrospinal fluid (CSF) drug penetration, drug neurotoxicity and persistent immune activation and inflammation. This review will also discuss other newly encountered complications, including the compartmentalisation (or CSF escape) and immune reconstitution inflammatory syndromes.
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Affiliation(s)
- Hadi Manji
- MRC Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, London, USA.
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17
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Detection of anti-tat antibodies in CSF of individuals with HIV-associated neurocognitive disorders. J Neurovirol 2013; 19:82-8. [PMID: 23329164 DOI: 10.1007/s13365-012-0144-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/26/2012] [Accepted: 11/29/2012] [Indexed: 10/27/2022]
Abstract
Despite major advances in the development of antiretroviral therapies, currently available treatments have no effect on the production of HIV-Tat protein once the proviral DNA is formed. Tat is a highly neurotoxic and neuroinflammatory protein, but its effects may be modulated by antibody responses against it. We developed an indirect enzyme-linked immunosorbent assay and measured anti-Tat antibody titers in CSF of a well characterized cohort of 52 HIV-infected and 13 control individuals. We successfully measured anti-Tat antibodies in CSF of HIV-infected individuals with excellent sensitivity and specificity, spanning a broad range of detection from 10,000 to over 100,000 relative light units. We analyzed them for relationship to cognitive function, CD4 cell counts, and HIV viral load. Anti-Tat antibody levels were higher in those without neurocognitive dysfunction than in those with HIV-associated neurocognitive dysfunction (HAND) and in individuals with lower CD4 cell counts and higher viral loads. We provide details of an assay which may have diagnostic, prognostic, or therapeutic implications for patients with HAND. Active viral replication may be needed to drive the immune response against Tat protein, but this robust immune response against the protein may be neuroprotective.
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18
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Levine AJ, Service S, Miller EN, Reynolds SM, Singer EJ, Shapshak P, Martin EM, Sacktor N, Becker JT, Jacobson LP, Thompson P, Freimer N. Genome-wide association study of neurocognitive impairment and dementia in HIV-infected adults. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:669-83. [PMID: 22628157 PMCID: PMC3418456 DOI: 10.1002/ajmg.b.32071] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 05/03/2012] [Indexed: 12/29/2022]
Abstract
The neuropathogenesis of HIV-associated neurocognitive disorders (HAND) is unclear. Candidate gene studies have implicated genetic susceptibility loci within immune-related genes; however, these have not been reliably validated. Here, we employed genome-wide association (GWA) methods to discover novel genetic susceptibility loci associated with HAND, and validate susceptibility loci implicated in prior candidate gene studies. Data from 1,287 participants enrolled in the Multicenter AIDS Cohort Study between 1985 and 2010 were used. Genotyping was conducted with Illumina 1M, 1MDuo, or 550K platform. Linear mixed models determined subject-specific slopes for change over time in processing speed and executive functioning, considering all visits including baseline and the most recent study visit. Covariates modeled as fixed effects included: time since the first visit, depression severity, nadir CD4+ T-cell count, hepatitis C co-infection, substance use, and antiretroviral medication regimen. Prevalence of HIV-associated dementia (HAD) and neurocognitive impairment (NCI) was also examined as neurocognitive phenotypes in a case-control analysis. No genetic susceptibility loci were associated with decline in processing speed or executive functioning among almost 2.5 million single nucleotide polymorphisms (SNPs) directly genotyped or imputed. No association between the SNPs and HAD or NCI were found. Previously reported associations between specific genetic susceptibility loci, HIV-associated NCI, and HAD were not validated. In this first GWAS of HAND, no novel or previously identified genetic susceptibility loci were associated with any of the phenotypes examined. Due to the relatively small sample size, future collaborative efforts that incorporate this dataset may still yield important findings.
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Affiliation(s)
- Andrew J Levine
- National Neurological AIDS Bank, Department of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, CA, USA.
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19
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Bol SM, Booiman T, van Manen D, Bunnik EM, van Sighem AI, Sieberer M, Boeser-Nunnink B, de Wolf F, Schuitemaker H, Portegies P, Kootstra NA, van 't Wout AB. Single nucleotide polymorphism in gene encoding transcription factor Prep1 is associated with HIV-1-associated dementia. PLoS One 2012; 7:e30990. [PMID: 22347417 PMCID: PMC3274517 DOI: 10.1371/journal.pone.0030990] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 12/29/2011] [Indexed: 11/18/2022] Open
Abstract
Background Infection with HIV-1 may result in severe cognitive and motor impairment, referred to as HIV-1-associated dementia (HAD). While its prevalence has dropped significantly in the era of combination antiretroviral therapy, milder neurocognitive disorders persist with a high prevalence. To identify additional therapeutic targets for treating HIV-associated neurocognitive disorders, several candidate gene polymorphisms have been evaluated, but few have been replicated across multiple studies. Methods We here tested 7 candidate gene polymorphisms for association with HAD in a case-control study consisting of 86 HAD cases and 246 non-HAD AIDS patients as controls. Since infected monocytes and macrophages are thought to play an important role in the infection of the brain, 5 recently identified single nucleotide polymorphisms (SNPs) affecting HIV-1 replication in macrophages in vitro were also tested. Results The CCR5 wt/Δ32 genotype was only associated with HAD in individuals who developed AIDS prior to 1991, in agreement with the observed fading effect of this genotype on viral load set point. A significant difference in genotype distribution among all cases and controls irrespective of year of AIDS diagnosis was found only for a SNP in candidate gene PREP1 (p = 1.2×10−5). Prep1 has recently been identified as a transcription factor preferentially binding the −2,518 G allele in the promoter of the gene encoding MCP-1, a protein with a well established role in the etiology of HAD. Conclusion These results support previous findings suggesting an important role for MCP-1 in the onset of HIV-1-associated neurocognitive disorders.
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Affiliation(s)
- Sebastiaan M. Bol
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Thijs Booiman
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Daniëlle van Manen
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Evelien M. Bunnik
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Ard I. van Sighem
- HIV Monitoring Foundation, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Margit Sieberer
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Brigitte Boeser-Nunnink
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Frank de Wolf
- HIV Monitoring Foundation, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
- Department of Infectious Disease Epidemiology, Imperial College, London, United Kingdom
| | - Hanneke Schuitemaker
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Peter Portegies
- Department of Neurology at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
- Department of Neurology at the OLVG Hospital, Amsterdam, The Netherlands
| | - Neeltje A. Kootstra
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Angélique B. van 't Wout
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory and Center for Infection and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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20
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Abstract
Macrophages and CD4+ T cells are natural target cells for HIV-1, and both cell types contribute to the establishment of the viral reservoir that is responsible for continuous residual virus replication during antiretroviral therapy and viral load rebound upon treatment interruption. Scientific findings that support a critical role for the infected monocyte/macrophage in HIV-1-associated diseases, such as neurological disorders and cardiovascular disease, are accumulating. To prevent or treat these HIV-1-related diseases, we need to halt HIV-1 replication in the macrophage reservoir. This article describes our current knowledge of how monocytes and certain macrophage subsets are able to restrict HIV-1 infection, in addition to what makes macrophages respond less well to current antiretroviral drugs as compared with CD4+ T cells. These insights will help to find novel approaches that can be used to meet this challenge.
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Affiliation(s)
- Sebastiaan M Bol
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory, and Center for Infectious Diseases and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Viviana Cobos-Jiménez
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory, and Center for Infectious Diseases and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Neeltje A Kootstra
- Department of Experimental Immunology, Sanquin Research, Landsteiner Laboratory, and Center for Infectious Diseases and Immunity Amsterdam (CINIMA) at the Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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21
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Shapshak P, Kangueane P, Fujimura RK, Commins D, Chiappelli F, Singer E, Levine AJ, Minagar A, Novembre FJ, Somboonwit C, Nath A, Sinnott JT. Editorial neuroAIDS review. AIDS 2011; 25:123-41. [PMID: 21076277 PMCID: PMC4464840 DOI: 10.1097/qad.0b013e328340fd42] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Paul Shapshak
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Department of Psychiatry and Behavioral Medicine, University of South Florida, College of Medicine, Tampa, Florida, USA
| | - Pandjassarame Kangueane
- Biomedical Informatics, 17A lrulan Sundai Annex, Pondicherry, India
- AIMST University, Kedha, Malaysia
| | - Robert K. Fujimura
- Geriatric Research Education and Clinical Centers, Veterans Administration, Puget Sound Healthcare System, Seattle, Washington
| | - Deborah Commins
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles
| | | | - Elyse Singer
- Department of Neurology and National Neurological AIDS Bank, UCLA School of Medicine, Westwood, California
| | - Andrew J. Levine
- Department of Neurology and National Neurological AIDS Bank, UCLA School of Medicine, Westwood, California
| | - Alireza Minagar
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, Louisiana
| | | | - Charurut Somboonwit
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Clinical Research Unit, Hillsborough Health Department, Tampa, Florida
| | - Avindra Nath
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - John T. Sinnott
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, Tampa, Florida, USA
- Clinical Research Unit, Hillsborough Health Department, Tampa, Florida
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22
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Chew CSN, Cherry CL, Imran D, Yunihastuti E, Kamarulzaman A, Varna S, Ismail R, Phipps M, Aghafar Z, Gut I, Price P. Tumour necrosis factor haplotypes associated with sensory neuropathy in Asian and Caucasian human immunodeficiency virus patients. ACTA ACUST UNITED AC 2010; 77:126-30. [PMID: 20887379 DOI: 10.1111/j.1399-0039.2010.01570.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In human immunodeficiency virus (HIV) patients, neuropathy is a common adverse side effect to some antiretroviral treatments, particularly stavudine. As stavudine is cheap, it is widely used in Asia and Africa. We showed that increasing age and height moderately predict the development of neuropathy. This was improved by the inclusion of tumour necrosis factor (TNF)-1031 (rs1799964). To investigate this association, Malay (n = 64), Chinese (n = 74) and Caucasian patients (n = 37) exposed to stavudine were screened for neuropathy. DNA samples were genotyped for polymorphisms in the central major histocompatibility complex (MHC) near TNF, and haplotypes were derived. The haplotype group FVa6,7,8 (incorporating TNF-1031) was found to be associated with neuropathy in Chinese patients in bivariate analyses (P = 0.03), and in Malays and Chinese in a multivariate analysis correcting for age and height (P = 0.02, P = 0.03, respectively). This trend was also confirmed in Caucasians.
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Affiliation(s)
- C S N Chew
- Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Australia
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23
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Veloso S, Olona M, García F, Domingo P, Alonso-Villaverde C, Broch M, Peraire J, Viladés C, Plana M, Pedrol E, López-Dupla M, Aguilar C, Gutiérrez M, Leon A, Tasias M, Gatell JM, Richart C, Vidal F. Effect of TNF-alpha genetic variants and CCR5 Delta 32 on the vulnerability to HIV-1 infection and disease progression in Caucasian Spaniards. BMC MEDICAL GENETICS 2010; 11:63. [PMID: 20420684 PMCID: PMC2877017 DOI: 10.1186/1471-2350-11-63] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 04/26/2010] [Indexed: 02/03/2023]
Abstract
BACKGROUND Tumor necrosis factor alpha (TNF-alpha) is thought to be involved in the various immunogenetic events that influence HIV-1 infection. METHODS We aimed to determine whether carriage of the TNF-alpha-238G>A, -308G>A and -863 C>A gene promoter single nucleotide polymorphisms (SNP) and the CCR5 Delta 32 variant allele influence the risk of HIV-1 infection and disease progression in Caucasian Spaniards. The study group consisted of 423 individuals. Of these, 239 were uninfected (36 heavily exposed but uninfected [EU] and 203 healthy controls [HC]) and 184 were HIV-1-infected (109 typical progressors [TP] and 75 long-term nonprogressors [LTNP] of over 16 years' duration). TNF-alpha SNP and the CCR5 Delta 32 allele were assessed using PCR-RFLP and automatic sequencing analysis methods on white blood cell DNA. Genotype and allele frequencies were compared using the chi 2 test and the Fisher exact test. Haplotypes were compared by logistic regression analysis. RESULTS The distribution of TNF-alpha-238G>A, -308G>A and -863 C>A genetic variants was non-significantly different in HIV-1-infected patients compared with uninfected individuals: -238G>A, p = 0.7 and p = 0.3; -308G>A, p = 0.05 and p = 0.07; -863 C>A, p = 0.7 and p = 0.4, for genotype and allele comparisons, respectively. Haplotype analyses, however, indicated that carriers of the haplotype H3 were significantly more common among uninfected subjects (p = 0.04). Among the infected patients, the distribution of the three TNF-alpha genetic variants assessed was non-significantly different between TP and LTNP: -238G>A, p = 0.35 and p = 0.7; -308G>A, p = 0.7 and p = 0.6: -863 C>A, p = 0.2 and p = 0.2, for genotype and allele comparisons, respectively. Haplotype analyses also indicated non-significant associations. Subanalyses in the LTNP subset indicated that the TNF-alpha-238A variant allele was significantly overrepresented in patients who spontaneously controlled plasma viremia compared with those who had a detectable plasma viral load (genotype comparisons, p = 0.02; allele comparisons, p = 0.03). The CCR5 Delta 32 distribution was non-significantly different in HIV-1-infected patients with respect to the uninfected population (p = 0.15 and p = 0.2 for genotype and allele comparisons, respectively) and in LTNP vs TP (p = 0.4 and p = 0.5 for genotype and allele comparisons, respectively). CONCLUSIONS In our cohort of Caucasian Spaniards, TNF-alpha genetic variants could be involved in the vulnerability to HIV-1 infection. TNF-alpha genetic variants were unrelated to disease progression in infected subjects. The -238G>A SNP may modulate the control of viremia in LTNP. Carriage of the CCR5 Delta 32 variant allele had no effect on the risk of infection and disease progression.
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Affiliation(s)
- Sergi Veloso
- Hospital Universitari de Tarragona Joan XXIII, Tarragona, Spain
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24
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Stellbrink HJ, Baldus S, Behrens G, Bogner JR, Harrer T, Hoffmann C, van Lunzen J, Münch J, Racz P, Scheller C, Stoll M, Tenner-Racz K, Rockstroh J. HIV-induced immune activation: pathogenesis and clinical relevance - summary of a workshop organized by the German AIDS Society (DAIG e.v.) and the ICH Hamburg, Hamburg, Germany, November 22, 2008. Eur J Med Res 2010; 15:1-12. [PMID: 20159665 PMCID: PMC3351841 DOI: 10.1186/2047-783x-15-1-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This manuscript is communicated by the German AIDS Society (DAIG) http://www.daignet.de. It summarizes a series of presentations and discussions during a workshop on immune activation due to HIV infection. The workshop was held on November 22nd 2008 in Hamburg, Germany. It was organized by the ICH Hamburg under the auspices of the German AIDS Society (DAIG e.V.).
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25
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Ellis RJ, Calero P, Stockin MD. HIV infection and the central nervous system: a primer. Neuropsychol Rev 2009; 19:144-51. [PMID: 19415500 PMCID: PMC2690832 DOI: 10.1007/s11065-009-9094-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 04/22/2009] [Indexed: 10/28/2022]
Abstract
The purpose of this brief review is to prepare readers who may be unfamiliar with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) and the rapidly accumulating changes in the epidemic by providing an introduction to HIV disease and its treatment. The general concepts presented here will facilitate understanding of the papers in this issue on HIV-associated neurocognitive disorders (HAND). Toward that end, we briefly review the biology of HIV and how it causes disease in its human host, its epidemiology, and how antiretroviral treatments are targeted to interfere with the molecular biology that allows the virus to reproduce. Finally, we describe what is known about how HIV injures the nervous system, leading to HAND, and discuss potential strategies for preventing or treating the effects of HIV on the nervous system.
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Affiliation(s)
- Ronald J Ellis
- University of California, San Diego, San Diego, CA 92103, USA.
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26
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Jayadev S, Garden GA. Host and viral factors influencing the pathogenesis of HIV-associated neurocognitive disorders. J Neuroimmune Pharmacol 2009; 4:175-89. [PMID: 19373562 DOI: 10.1007/s11481-009-9154-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 03/27/2009] [Indexed: 01/03/2023]
Abstract
The human immunodeficiency virus (HIV) invades the central nervous system early in the course of infection and establishes a protected viral reservoir. However, neurocognitive consequences of HIV infection, known collectively as HIV-associated neurocognitive disorders (HAND), develop in only a small portion of infected patients. The precise mechanisms of pathogenesis involved in HIV-induced central nervous system injury are still not completely understood. In particular, most theories of HAND pathogenesis cannot account for either the selective vulnerability of specific neuronal populations to HIV-induced neurodegeneration or why only a subset of patients develop clinically detectable nervous system disease. Epidemiological and virological studies have identified a variety of host and viral factors that are associated with increased risk of developing HAND. Some host factors that predispose HIV-infected patients to HAND overlap with those associated with Alzheimer's disease (AD), suggesting the possibility that common pathogenic mechanisms may participate in both diseases. Here, we will review reports of host and viral factors associated with HAND and place these studies in the context of the data employed to support current theories regarding the molecular and cellular mechanisms that lead to HIV-induced neurodegeneration with additional focus on mechanisms common to AD pathogenesis.
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Affiliation(s)
- Suman Jayadev
- Department of Neurology and Center for Neurogenetics and Neurotherapeutics, University of Washington, Seattle, WA 98195, USA
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27
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The role of host genetics in the susceptibility for HIV-associated neurocognitive disorders. AIDS Behav 2009; 13:118-32. [PMID: 18264751 DOI: 10.1007/s10461-008-9360-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Accepted: 01/22/2008] [Indexed: 12/23/2022]
Abstract
Despite progress in the treatment of the Human Immunodeficiency virus (HIV), there continues to be a high prevalence of infected individuals who develop neurocognitive deficits and disorders. Our understanding of the potential cause of HIV-associated neurocognitive disorders (HAND) continues to develop on many fronts. Among them is the study of host genetics. Here, we review the most current information regarding the association between host genetics and risk for HIV infection, AIDS, and HAND. We focus on the role of dopamine dysfunction in the etiology of HAND, and propose a number of genetic polymorphisms within genes related to dopaminergic functioning and other neurobiological factors that may confer vulnerability or protection against HAND.
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28
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Boissé L, Gill MJ, Power C. HIV infection of the central nervous system: clinical features and neuropathogenesis. Neurol Clin 2008; 26:799-819, x. [PMID: 18657727 DOI: 10.1016/j.ncl.2008.04.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Almost 65 million people worldwide have been infected with HIV since it was first identified in the early 1980s. Neurologic disorders associated with HIV type 1 affect between 40% and 70% of infected individuals. The most significant of these disorders include HIV-associated neurocognitive disorder, which comprises HIV-associated dementia, mild neurocognitive disorder, and asymptomatic neurocognitive impairment. Despite the availability of combination antiretroviral therapy, HIV-related central nervous system disorders continue to represent a substantial personal, economic, and societal burden. This review summarizes the clinical manifestations, diagnosis, treatment, and pathogenesis of the primary HIV-associated central nervous system disorders.
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Affiliation(s)
- Lysa Boissé
- Division of Neurology, Queen's University, 76 Stuart Street, Kingston, ON K7L 2V7, Canada
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29
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Affandi JS, Price P, Imran D, Yunihastuti E, Djauzi S, Cherry CL. Can we predict neuropathy risk before stavudine prescription in a resource-limited setting? AIDS Res Hum Retroviruses 2008; 24:1281-4. [PMID: 18834321 DOI: 10.1089/aid.2008.0045] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
A toxic sensory neuropathy associated with exposure to inexpensive nucleoside analogue reverse transcriptase inhibitors (NRTIs) [particularly stavudine (d4T)] causes dilemmas in the management of patients with HIV, especially in resource-poor settings. Here patients (n = 96) attending Pokdisus AIDS Clinic at the Cipto Mangunkusumo Hospital, Jakarta who had been treated with d4T were screened for symptomatic neuropathy. Clinical, demographic, and genetic factors were considered as possible neuropathy risk factors. DNA from saliva was used to examine alleles of TNFA-308, BAT1 (intron 10), TNFA-1031, IL1A+4845, and IL12B (3' UTR). The prevalence of neuropathy (symptoms and signs) was 34%. On multivariate analysis, neuropathy following d4T exposure was associated with increasing age, increasing height, and TNFA-1031*2 (model p = 0.0009). Isoniazid exposure (present in 56% of patients) was not associated with neuropathy in this cohort, where all patients had received pyridoxine coadministration. These data suggest that a simple algorithm based on patient age, height, and TNF genotype could be used to predict the individual's risk of symptomatic neuropathy prior to prescription of d4T.
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Affiliation(s)
- Jacquita S. Affandi
- School of Surgery and Pathology, University of Western Australia, Perth, Australia
| | - Patricia Price
- School of Surgery and Pathology, University of Western Australia, Perth, Australia
- Clinical Immunology and Immunogenetics, Royal Perth Hospital, Perth, Australia
| | - Darma Imran
- Pokdisus (Working Group on AIDS) Faculty of Medicine, University of Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Evy Yunihastuti
- Pokdisus (Working Group on AIDS) Faculty of Medicine, University of Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Samsuridjal Djauzi
- Pokdisus (Working Group on AIDS) Faculty of Medicine, University of Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Catherine L. Cherry
- Burnet Institute, Melbourne, Australia
- Infectious Diseases Unit, Alfred Hospital, Melbourne, Australia
- Department of Medicine, Monash University, Melbourne, Australia
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30
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IL-1beta (+3954C/T) polymorphism could protect human immunodeficiency virus (HIV)-infected patients on highly active antiretroviral treatment (HAART) against lipodystrophic syndrome. Genet Med 2008; 10:215-23. [PMID: 18344712 DOI: 10.1097/gim.0b013e3181632713] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To evaluate the impact of acquired and inherited factors on the development of lipodystrophic syndrome in patients on highly active antiretroviral therapy. METHODS Two hundred forty-three human immunodeficiency virus-infected Caucasians on highly active antiretroviral therapy were prospectively followed-up for 3 years. Eleven were naIve and 232 were on antiretrovirals (mean, 93.0 months +/- 43.8 months). Lipodystrophic syndrome was diagnosed clinically with a lipodystrophy severity grading scale. Polymorphisms of cytokines (IL-1beta, IL-6, TNF-alpha), TLR4, and NOS genes were genotyped. RESULTS Ninety (37%) patients developed lipodystrophic syndrome. The polymorphic T allele of the (+3954C/T) polymorphism of IL-1beta was less frequent in patients with lipodystrophic syndrome compared with those without (17.8% vs. 27.0%, P = 0.03). Factors significantly associated with lipodystrophic syndrome were time on stavudine (P < 0.001), use of stavudine (P = 0.001), absence of the T allele of the (+3954C/T) IL-1beta polymorphism (P = 0.02), acquired immune deficiency syndrome diagnosis (P = 0.005), nadir levels of CD4 (P = 0.003), and time on highly active antiretroviral therapy (P = 0.003). Of these factors, only the time on stavudine (hazard ratio [95% confidence intervals] 1.007 [1.001-1.013]), use of stavudine (1.678 [1.048-2.68]), and absence of the T allele of the IL-1beta (+3954C/T) polymorphism (0.569 [0.347-0.931]) were significantly associated with lipodystrophic syndrome by Cox regression. CONCLUSIONS Genotyping of the (+3954C/T) polymorphism of IL-1beta could be useful in patients starting highly active antiretroviral therapy, especially in potential users of stavudine, to predict their risk of developing lipodystrophic syndrome.
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Effect of etanercept, a tumor necrosis factor-alpha inhibitor, on neuropathic pain in the rat chronic constriction injury model. Spine (Phila Pa 1976) 2008; 33:227-34. [PMID: 18303453 DOI: 10.1097/brs.0b013e318162340a] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN The effects of a low, local dose of a tumor necrosis factor-alpha (TNF-alpha) inhibitor on neuropathic pain behaviors in a rat chronic constriction injury model were evaluated. OBJECTIVE To investigate whether a peripherally implanted polymer drug depot can deliver a dose of etanercept sufficient to reduce thermal hyperalgesia and mechanical allodynia in a rat model of neuropathic pain. SUMMARY OF BACKGROUND DATA TNF-alpha inhibitors reduce pain-associated behavior in experimental models of neuropathic pain. Moreover, systemic injections of TNF-alpha inhibitors have suggested some efficacy in treating sciatic pain in limited, off-label clinical studies. Improvements in these results may be obtained by optimal dosing via targeted, sustained delivery at the site of disc-induced inflammation. METHODS Unilateral chronic constriction injury was applied to the sciatic nerve of 56 male, Wistar rats. Four groups of animals (n = 7) received 0.5 mL phosphate-buffered saline every 3 days, 0.3 or 3 mg/kg etanercept every 3 days, or gabapentin (60 mg/kg) 1 hour before each behavioral test all via subcutaneous injection. Two groups of animals received 1.5 or 3.0 microg/h etanercept delivered by poly(lactic-co-glycolic acid) (PLGA) millicylinders (1 mm diameter x 10 mm long) implanted near the injured sciatic nerve. One group received a PLGA millicylinder implanted near the injured sciatic nerve. The final group received 3.0 microg/h etanercept via PLGA millicylinder implanted next to the uninjured, contralateral sciatic nerve. RESULTS A low, local dose of etanercept (approximately 3 microg/h) delivered by a polymer depot significantly reduced (P < 0.05) thermal hyperalgesia for 57 days as compared to polymer depot without drug or an etanercept-loaded depot implanted near the contralateral sciatic nerve, and equivalent to a 10-fold higher dose delivered by repeat subcutaneous injection. CONCLUSION This preclinical study indicates that delivering TNF-alpha inhibitors by means of a locally administered polymeric formulation provides long-lasting analgesia in an inflammatory neuropathic pain model.
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Cherry CL, Rosenow A, Affandi JS, McArthur JC, Wesselingh SL, Price P. Cytokine genotype suggests a role for inflammation in nucleoside analog-associated sensory neuropathy (NRTI-SN) and predicts an individual's NRTI-SN risk. AIDS Res Hum Retroviruses 2008; 24:117-23. [PMID: 18240960 DOI: 10.1089/aid.2007.0168] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Nucleoside analog-associated sensory neuropathy (NRTI-SN) attributed to stavudine, didanosine, or zalcitabine (the dNRTIs) and distal sensory polyneuropathy (DSP) attributed to HIV are clinically indistinguishable. As inflammatory cytokines are involved in DSP, we addressed a role for inflammation in NRTI-SN by determining the alleles of immune-related genes carried by patients with and without NRTI-SN. Demographic details associated with risk of various neuropathies were included in the analysis. Alleles of 14 polymorphisms in 10 genes were determined in Australian HIV patients with definite NRTI-SN (symptom onset <6 months after first dNRTI exposure, n = 16), NRTI-SN-resistant patients (no neuropathy despite >6 months on dNRTIs, n = 20), patients with late onset NRTI-SN (neuropathy onset after >6 months of dNRTIs, n = 19), and HIV-negative controls. Carriage of TNFA-1031*2 was highest in NRTI-SN patients, suggesting potentiation of NRTI-SN. Carriage of IL12B (3' UTR)*2 was higher in NRTI-SN-resistant patients than controls or NRTI-SN patients, suggesting a protective role. BAT1 (intron 10)*2 was more common in NRTI-SN than resistant patients, but neither group differed from controls. This marks the conserved HLA-A1, B8, DR3 haplotype. Of the demographic details considered, increasing height was associated with NRTI-SN risk. A model including cytokine genotype and height predicted NRTI-SN status (p < 0.0001, R(2) = 0.54). Late onset NRTI-SN patients clustered genetically with NRTI-SN-resistant patients, so these patients may be genetically "protected." In addition to patient height, cytokine genotype influenced NRTI-SN risk following dNRTI exposure, suggesting inflammation contributes to NRTI-SN.
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Affiliation(s)
- Catherine L. Cherry
- Burnet Institute, Melbourne, Australia
- Alfred Hospital, Melbourne, Australia
- Monash University, Melbourne, Australia
| | - Ann Rosenow
- University of Western Australia, Perth, Australia
| | | | | | - Steven L. Wesselingh
- Burnet Institute, Melbourne, Australia
- Alfred Hospital, Melbourne, Australia
- Monash University, Melbourne, Australia
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Peterson KE, Chesebro B. Influence of proinflammatory cytokines and chemokines on the neuropathogenesis of oncornavirus and immunosuppressive lentivirus infections. Curr Top Microbiol Immunol 2007; 303:67-95. [PMID: 16570857 DOI: 10.1007/978-3-540-33397-5_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Retroviral infection of the CNS can lead to severe debilitating neurological diseases in humans and other animals. Four general types of pathogenic effects with various retroviruses have been observed including: hemorrhage (TR1.3), spongiform encephalopathy (CasBrE, FrCasE, PVC211, NT40, Mol-ts1), demyelination with inflammatory lesions (HTLV-1, visna, CAEV), and encephalopathy with gliosis and proinflammatory chemokines and cytokines, usually with microglial giant cells and nodules [human immunodeficiencyvirus (HIV), feline immunodeficiencyvirus (FIV), simian immunodeficiency virus (SIV), Fr98]. This review focuses on this fourth group of retroviruses. In this latter group, proinflammatory cytokine and chemokine upregulation accompanies the disease process, and may influence pathogenesis by direct effects on resident CNS cells. The review first discusses the Fr98 murine polytropic virus system with particular reference to the roles of cytokines and chemokines in the pathogenic process. The Fr98 data are then compared and contrasted to the cytokine and chemokine data in the lentivirus systems, HIV, SIV, and FIV. Finally, various mechanisms are presented by which tumor necrosis factor (TNF) and several chemokines may alter the pathogenesis of retrovirus infection of the CNS.
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Affiliation(s)
- K E Peterson
- Dept. of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
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Sriram K, O'Callaghan JP. Divergent roles for tumor necrosis factor-alpha in the brain. J Neuroimmune Pharmacol 2007; 2:140-53. [PMID: 18040839 DOI: 10.1007/s11481-007-9070-6] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 03/01/2007] [Indexed: 01/05/2023]
Abstract
Proinflammatory cytokines and chemokines have been implicated in the pathogenesis of several neurological and neurodegenerative disorders. Prominent among such factors is the pleiotropic cytokine, tumor necrosis factor (TNF)-alpha. Under normal physiological conditions, TNF-alpha orchestrates a diverse array of functions involved in immune surveillance and defense, cellular homeostasis, and protection against certain neurological insults. However, paradoxical effects of this cytokine have been observed. TNF-alpha is elicited in the brain following injury (ischemia, trauma), infection (HIV, meningitis), neurodegeneration (Alzheimer's, Parkinson's), and chemically induced neurotoxicity. The multifarious identity for this cytokine appears to be influenced by several mechanisms. Among the most prominent are the regulation of TNFalpha-induced NF-kappaB activation by adapter proteins such as TRADD and TRAF, and second, the heterogeneity of microglia and their distribution pattern across brain regions. Here, we review the differential role of TNF-alpha in response to brain injury, with emphasis on neurodegeneration, and discuss the possible mechanisms for such diverse and region-specific effects.
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Affiliation(s)
- Krishnan Sriram
- National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, CDC-NIOSH, 1095 Willowdale Road, Morgantown, WV 26505, USA
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Ellis R, Langford D, Masliah E. HIV and antiretroviral therapy in the brain: neuronal injury and repair. Nat Rev Neurosci 2007; 8:33-44. [PMID: 17180161 DOI: 10.1038/nrn2040] [Citation(s) in RCA: 384] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Approximately 40 million people worldwide are infected with human immunodeficiency virus (HIV). Despite HIV's known propensity to infect the CNS and cause neurological disease, HIV neurocognitive disorders remain under-recognized. Although combination antiretroviral therapy has improved the health of millions of those living with HIV, the penetration into the CNS of many such therapies is limited, and patients' quality of life continues to be diminished by milder, residual neurocognitive impairment. Synaptodendritic neuronal injury is emerging as an important mediator of such deficits in HIV. By carefully selecting specific antiretrovirals and supplementing them with neuroprotective agents, physicians might be able to facilitate innate CNS repair, promoting enhanced synaptodendritic plasticity, neural function and clinical neurological status.
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Affiliation(s)
- Ronald Ellis
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
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36
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Konsman JP, Drukarch B, Van Dam AM. (Peri)vascular production and action of pro-inflammatory cytokines in brain pathology. Clin Sci (Lond) 2006; 112:1-25. [PMID: 17132137 DOI: 10.1042/cs20060043] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In response to tissue injury or infection, the peripheral tissue macrophage induces an inflammatory response through the release of IL-1β (interleukin-1β) and TNFα (tumour necrosis factor α). These cytokines stimulate macrophages and endothelial cells to express chemokines and adhesion molecules that attract leucocytes into the peripheral site of injury or infection. The aims of the present review are to (i) discuss the relevance of brain (peri)vascular cells and compartments to bacterial meningitis, HIV-1-associated dementia, multiple sclerosis, ischaemic and traumatic brain injury, and Alzheimer's disease, and (ii) to provide an overview of the production and action of pro-inflammatory cytokines by (peri)vascular cells in these pathologies of the CNS (central nervous system). The brain (peri)vascular compartments are highly relevant to pathologies affecting the CNS, as infections are almost exclusively blood-borne. Insults disrupt blood and energy flow to neurons, and active brain-to-blood transport mechanisms, which are the bottleneck in the clearance of unwanted molecules from the brain. Perivascular macrophages are the most reactive cell type and produce IL-1β and TNFα after infection or injury to the CNS. The main cellular target for IL-1β and TNFα produced in the brain (peri)vascular compartment is the endothelium, where these cytokines induce the expression of adhesion molecules and promote leucocyte infiltration. Whether this and other effects of IL-1 and TNF in the brain (peri)vascular compartments are detrimental or beneficial in neuropathology remains to be shown and requires a clear understanding of the role of these cytokines in both damaging and repair processes in the CNS.
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Affiliation(s)
- Jan P Konsman
- Laboratory of Integrative Neurobiology, CNRS FRE 2723/INRA UR 1244/University Bordeaux2, Institut François Magendie, Bordeaux, France
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Navia BA, Rostasy K. The AIDS dementia complex: clinical and basic neuroscience with implications for novel molecular therapies. Neurotox Res 2005; 8:3-24. [PMID: 16260383 DOI: 10.1007/bf03033817] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The AIDS dementia complex (ADC, also referred to as HIV-associated cognitive impairment) is a common disorder among HIV-infected patients associated with both inflammatory and neurodegenerative processes. This review describes recent advances in the clinical and basic neurosciences of HIV infection and discusses the multivariable nature of what has become a chronic disorder in the context of highly active antiretroviral therapies (HAART). Since its initial description twenty years ago, advances in cell and molecular biology along with those in neuroimaging have furthered our understanding of the underlying pathogenic mechanisms. The clinical and neuropsychological profile of ADC is generally consistent with a "frontal-subcortical" pattern of injury. Neuropathogenesis is largely driven by indirect mechanisms mediated by infected, or more commonly, immune activated macrophages, which secrete viral and host-derived factors. Magnetic resonance spectroscopy (MRS) provides a robust in vivo method to measure the inflammatory and neurotoxic events triggered by these factors and their associated signals. Although the use of combined or highly active antiretroviral therapies (HAART) has significantly improved survival rates, cerebral injury and cognitive impairment remain common events. Factors such as aging and chronic infection will likely impact the course of this disease, its pathogenesis, and treatment. The combined observations presented in this review suggest a number of critical areas for future inquiry.
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Affiliation(s)
- B A Navia
- Department of Community Medicine, Tufts University School of Medicine, Boston MA, USA.
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38
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Abstract
Cognitive disorders, vacuolar myelopathy, and sensory neuropathies associated with HIV are the most common disorders in patients with HIV AIDS, and are the focus of this review. These disorders are treatable and of those associated with HIV AIDS the pathogenic mechanisms are the most understood. Although triggered by productive HIV macrophage infections, aberrant immune activation plays a major role in inducing the CNS disorders. Novel therapies aimed at these inflammatory mechanisms can be effective. The sensory neuropathies associated with HIV infection are a major cause of morbidity; incidence may be increased by the toxic effects of specific antiretroviral drugs within the peripheral nervous system.
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Affiliation(s)
- Justin C McArthur
- HIV Neurosciences Program, Johns Hopkins University, Baltimore, MD, USA.
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Abstract
CONTEXT Wide variability exists in the susceptibility to and outcome from sepsis even within similar intensive care unit populations. Some of this variability in the host may be due to genetic variation in genes coding for components of the innate immune response. OBJECTIVE To review the evidence for a genetic influence on the susceptibility to and outcome from sepsis. DESIGN Literature review. PATIENTS Variety of adult and pediatric patients with various critical illnesses and infections. INTERVENTIONS None. MAIN OUTCOME MEASURES Susceptibility to clinical symptoms of sepsis and outcome as measured by severity of disease and mortality. RESULTS Polymorphisms in genes coding for proteins involved in the recognition of bacterial pathogens (Toll-like receptor 4, CD14, Fc(gamma)RIIa, and mannose-binding lectin) and the response to bacterial pathogens (tumor necrosis factor-alpha, interleukin (IL)-1alpha, IL-1beta, IL-1 receptor agonist, IL-6, IL-10, heat shock proteins, angiotensin I converting enzyme, plasminogen activator inhibitor-1) can influence the amount or function of the protein produced in response to bacterial stimuli. Evidence is discussed suggesting that some of these genetic polymorphisms influence the susceptibility to and outcome from sepsis. CONCLUSION Host genetic variability in the regulatory and coding regions of genes for components of the innate immune system may influence the susceptibility to and/or outcome from sepsis. The disparate results observed in many studies of polymorphisms in sepsis emphasize the need for future studies to be larger, to include the analysis of multiple polymorphisms, and to be better designed with respect to control populations to identify the degree of influence that genetic variability has on sepsis.
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Affiliation(s)
- Mary K Dahmer
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
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40
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van Marle G, Henry S, Todoruk T, Sullivan A, Silva C, Rourke SB, Holden J, McArthur JC, Gill MJ, Power C. Human immunodeficiency virus type 1 Nef protein mediates neural cell death: a neurotoxic role for IP-10. Virology 2005; 329:302-18. [PMID: 15518810 DOI: 10.1016/j.virol.2004.08.024] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Revised: 07/22/2004] [Accepted: 08/12/2004] [Indexed: 02/01/2023]
Abstract
HIV-1 Nef is expressed in astrocytes, but a contribution to neuropathogenesis and the development of HIV-associated dementia (HAD) remains uncertain. To determine the neuropathogenic actions of the HIV-1 Nef protein, the brain-derived (YU-2) and blood-derived (NL4-3) Nef proteins were expressed in neural cells using an alphavirus vector, which resulted in astrocyte death (P < 0.001). Supernatants from Nef-expressing astrocytes also caused neuronal death, suggesting the release of neurotoxic molecules by astrocytes. Analysis of pro-inflammatory gene induction in astrocytes expressing Nef revealed increased IP-10 mRNA expression (4000-fold) that was Nef sequence dependent. Recombinant IP-10 caused selective cell death in neurons (P < 0.001) but not astrocytes, and the cytotoxicity of supernatant from astrocytes expressing Nef YU-2 was blocked by an antibody directed against the chemokine receptor CXCR3 (P < 0.001). SCID/NOD mice implanted with a Nef YU-2-expressing vector displayed abnormal motor behavior (P < 0.05), neuroinflammation, and neuronal loss relative to controls. Analysis of mRNA levels in brains from patients with HAD also revealed increased expression of IP-10 (P < 0.05), which was confirmed by immunoreactivity detected principally in astrocytes. Phylogenetic and protein structure analyses of Nef sequences derived from HIV/AIDS patients with and without HAD suggested viral evolution toward a neurotropic Nef protein. These results indicate that HIV-1 Nef contributes to neuropathogenesis by directly causing astrocyte death together with indirect neuronal death through the cytotoxic actions of IP-10 on neurons. Furthermore, Nef molecular diversity was evident in brain tissue among patients with neurological disease and which may influence IP-10 production by astrocytes.
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MESH Headings
- AIDS Dementia Complex/metabolism
- AIDS Dementia Complex/physiopathology
- Animals
- Animals, Genetically Modified
- Astrocytes/metabolism
- Astrocytes/virology
- Cell Death
- Cells, Cultured
- Chemokine CCL2/biosynthesis
- Chemokine CCL2/genetics
- Chemokine CXCL10
- Chemokines, CXC/biosynthesis
- Chemokines, CXC/pharmacology
- Chemokines, CXC/physiology
- Gene Products, nef/biosynthesis
- Gene Products, nef/genetics
- Genetic Vectors
- HIV-1/genetics
- HIV-1/pathogenicity
- Humans
- Interleukin-1/biosynthesis
- Interleukin-1/genetics
- Interleukin-1beta
- Male
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Molecular Sequence Data
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Neurotoxins/pharmacology
- Peptide Fragments/biosynthesis
- Peptide Fragments/genetics
- RNA, Messenger/analysis
- Recombinant Proteins/pharmacology
- nef Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Guido van Marle
- Department of Clinical Neurosciences, University of Calgary, Calgary AB, Canada
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van Marle G, Power C. Human immunodeficiency virus type 1 genetic diversity in the nervous system: Evolutionary epiphenomenon or disease determinant? J Neurovirol 2005; 11:107-28. [PMID: 16036790 DOI: 10.1080/13550280590922838] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Over the past decade there has been a revolution in the understanding and care of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)-associated disease. Much of this progress stems from a broader recognition of the importance of differences in viral types, including receptor preference(s), replication properties, and reservoirs, as contributing factors to immunosuppresion and disease progression. In contrast, there is limited conceptualizatin of viral diversity and turnover in the brain and circulation in relation to neurocognitive impairments. Herein, the authors review current concepts regarding viral molecular diversity and phenotypes together with features of HIV-1 neuroinvasion, neurotropism, neurovirulence and neurosusceptiblity. Viral genetic and antigenic diversity is reduced within the brain compared to blood or other systemic organs within individuals. Conversely, viral molecular heterogeneity is greater in patients with HIV-associated dementia compared to nondemented patients, depending on the viral gene examined. Individual viral proteins exert multiple neuropathogenic effects, although the neurological consequences of different viral polymorphisms remain uncertain. Nonetheless, host genetic polymorphisms clearly influence neurological disease outcomes and likely dictate both acquired and innate immune responses, which in turn shape viral evolution within the host. Emerging issues include widespread antiretroviral therapy resistance and increasing awareness of viral superinfections together with viral recombination, all of which are likely to impact on both HIV genetic variation and neuropathogenesis. With the persisting prevalence of HIV-induced neurocognitive disabilities, despite marked improvements in managing immunosuppression, it remains imperative to fully define and understand the mechanisms by which viral dynamics and diversity contribute to neurological disease, permitting the development of new therapeutic strategies.
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Affiliation(s)
- Guido van Marle
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
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Peterson KE, Hughes S, Dimcheff DE, Wehrly K, Chesebro B. Separate sequences in a murine retroviral envelope protein mediate neuropathogenesis by complementary mechanisms with differing requirements for tumor necrosis factor alpha. J Virol 2004; 78:13104-12. [PMID: 15542662 PMCID: PMC525006 DOI: 10.1128/jvi.78.23.13104-13112.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The innate immune response, through the induction of proinflammatory cytokines and antiviral factors, plays an important role in protecting the host from pathogens. Several components of the innate response, including tumor necrosis factor alpha (TNF-alpha), monocyte chemoattractant protein 1, interferon-inducible protein 10, and RANTES, are upregulated in the brain following neurovirulent retrovirus infection in humans and in animal models. However, it remains unclear whether this immune response is protective, pathogenic, or both. In the present study, by using TNF-alpha(-/-) mice we analyzed the contribution of TNF-alpha to neurological disease induced by four neurovirulent murine retroviruses, with three of these viruses encoding portions of the same neurovirulent envelope protein. Surprisingly, only one retrovirus (EC) required TNF-alpha for disease induction, and this virus induced less TNF-alpha expression in the brain than did the other retroviruses. Analysis of glial fibrillary acidic protein and F4/80 in EC-infected TNF-alpha(-/-) mice showed normal activation of astrocytes but not of microglia. Thus, TNF-alpha-mediated microglial activation may be important in the pathogenic process initiated by EC infection. In contrast, TNF-alpha was not required for pathogenesis of the closely related BE virus and the BE virus induced disease in TNF-alpha(-/-) mice by a different mechanism that did not require microglial activation. These results provide new insights into the multifactorial mechanisms involved in retrovirus-induced neurodegeneration and may also have analogies to other types of neurodegeneration.
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Affiliation(s)
- Karin E Peterson
- Department of Pathobiological Sciences, School of Veterinary Medicine, Skip Bertman Dr., Louisiana State University, Baton Rouge, LA 70803, USA.
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Saha RN, Pahan K. Tumor necrosis factor-alpha at the crossroads of neuronal life and death during HIV-associated dementia. J Neurochem 2003; 86:1057-71. [PMID: 12911614 PMCID: PMC1955474 DOI: 10.1046/j.1471-4159.2003.01942.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human immunodeficiency type-1 (HIV-1) infection is known to cause disorders of the CNS, including HIV-associated dementia (HAD). It is suspected that tumor necrosis factor-alpha (TNF-alpha) released by infected microglia and macrophages play a role in neuronal injury seen in HAD patients. Accordingly, studies suggest that the level of TNF-alpha mRNA increases with increasing severity of dementia in patients, and that inhibitors of TNF-alpha release reduces neuronal injury in murine model of HAD. However, the exact role of TNF-alpha in relation to neuronal dysfunction is a matter of ongoing debate. One school of thought hails TNF-alpha as the inducer and mediator of neurodegeneration and their evidence suggest that TNF-alpha kill neurons directly by recruiting caspases or may kill indirectly by various means. In sharp contrast to this, another concept theory envisages a role for TNF-alpha in negotiating neuroprotection during HAD. The current compilation examines these contradictory concepts, and evaluates their efficacy in the light of TNF-alpha signaling. It also attempts to elaborate the current consensus outlook of TNF-alpha's role during HAD.
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Affiliation(s)
- Ramendra N Saha
- Department of Oral Biology, University of Nebraska Medical Center, 40th and Holdrege, Lincoln, NE 68583-0740, USA
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Price P, Bolitho P, Jaye A, Glasson M, Yindom LM, Sirugo G, Chase D, McDermid J, Whittle H. A Gambian TNF haplotype matches the European HLA-A1,B8,DR3 and Chinese HLA-A33,B58,DR3 haplotypes. TISSUE ANTIGENS 2003; 62:72-5. [PMID: 12859597 DOI: 10.1034/j.1399-0039.2003.00083.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Caucasians carry TNFA-308*2 in the 8.1 ancestral haplotype (AH) (HLA-A1,B8,DR3). In Gambians, TNFA-308*2 occurs without HLA-B8 or -DR3, suggesting an independent effect of TNFA-308 on disease. Hence we sought a segment of the 8.1 AH in Gambians. BAT1 (intron 10)*2 was selected as a specific marker of the haplotype and was found with TNFA-308*2 in Gambians. Samples homozygous at TNFA-308 and BAT1 (intron 10) demonstrated identity between the African TNFA-308*2 haplotype, the 8.1AH and the Asian diabetogenic 58.1AH (HLA-A33,B58,DR3) across a region spanning BAT1, ATP6G, IKBL, LTA, TNFA, LTB, LST-1 and AIF-1. Conservation of this block in geographically distinct populations suggests a common evolutionary origin and challenges current views of the role of TNFA-308*2 in disease.
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Affiliation(s)
- P Price
- School of Pathology and Surgery, University of Western Australia, Nedlands, Australia.
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van Marle G, Ethier J, Silva C, Mac Vicar BA, Power C. Human immunodeficiency virus type 1 envelope-mediated neuropathogenesis: targeted gene delivery by a Sindbis virus expression vector. Virology 2003; 309:61-74. [PMID: 12726727 DOI: 10.1016/s0042-6822(02)00139-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sindbis virus (SIN) expression vectors offer the opportunity for studying neuropathogenesis because of their distinct neural cell tropism. Here, we demonstrate that a recombinant SIN vector expressing EGFP (SINrep5-EGFP) infected multiple cell types including neural cells from several species relevant to lentivirus pathogenesis with high levels of transgene expression. Infection of human neurons by a recombinant SIN (SINrep5-JRFL) expressing the full-length envelope from a neurovirulent human immunodeficiency virus type 1 (HIV-1) strain (JRFL) caused increased cytotoxicity compared to infection with SINrep5-EGFP (P < 0.001), while no cytotoxicity was observed among infected human astrocytes or monocytoid cells. Both human monocyte-derived macrophages (MDM) (P < 0.01) and astrocytes (P < 0.001) infected with SINrep5-JRFL released soluble neurotoxins in contrast to SINrep5-EGFP or mock-infected cells, although this was most prominent for the astrocytes. Implantation of SINrep5-JRFL into the brains of SCID/NOD mice induced neuroinflammation, neuronal loss, and neurobehavioral changes characteristic of HIV-1 infection, which were not present in SINrep5-EGFP or mock-infected animals. Thus SIN expression vectors represent novel tools for studying in vitro and in vivo HIV-1 neuropathogenesis because of their high levels of transgene expression in specific cell types within the brain.
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Affiliation(s)
- Guido van Marle
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
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McArthur JA, Zhang Q, Quasney MW. Association between the A/A genotype at the lymphotoxin-alpha+250 site and increased mortality in children with positive blood cultures. Pediatr Crit Care Med 2002; 3:341-4. [PMID: 12780951 DOI: 10.1097/00130478-200210000-00002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Tumor necrosis factor-alpha has been implicated in the hemodynamic manifestations of sepsis. Genetic polymorphisms located in the first intron of the lymphotoxin-alpha gene have been associated with increased secretion of tumor necrosis factor-alpha. We hypothesized that bacteremic children with the high secretor genotype, AA, have higher levels of tumor necrosis factor-alpha and a worse outcome. METHODS Genotypic analysis was performed in children with bacteremia using polymerase chain reaction amplification and restriction enzyme digestion. The serum tumor necrosis factor-alpha levels were measured by enzyme-linked immunosorbent assay technique. RESULTS Genotypic frequencies at the lymphotoxin-alpha+250 site were 11 of 34 (0.32) AA, 16 of 34 (0.47) GA, and 7 of 34 (0.21) GG. Serum tumor necrosis factor-alpha levels were 324 +/- 124 pg/mL in bacteremic children with the AA genotype at the lymphotoxin-alpha+250 site compared with 92 +/- 59 pg/mL in bacteremic children with the AG genotype (p < .001) and 92 +/- 21 pg/mL in bacteremic children with the GG genotype (p < .001). Eight of 11 bacteremic children with the AA genotype died compared with 3 of 16 bacteremic children with the GA genotype (p < .001) and zero of seven bacteremic children with the GG genotype (p < .001). CONCLUSION The AA genotype at the lymphotoxin-alpha+250 site is associated with higher serum tumor necrosis factor-alpha levels and a higher mortality in children with bacteremia.
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Van Marle G, Rourke SB, Zhang K, Silva C, Ethier J, Gill MJ, Power C. HIV dementia patients exhibit reduced viral neutralization and increased envelope sequence diversity in blood and brain. AIDS 2002; 16:1905-14. [PMID: 12351950 DOI: 10.1097/00002030-200209270-00007] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To examine the relationship between the humoral immune response and viral envelope diversity among HIV/AIDS patients with or without HIV-associated dementia (HAD). METHODS Whole blood and sera were collected from age- and disease-progression matched AIDS-defined patients with and without neuro-cognitive impairment at two centers. Peripheral blood mononuclear cells were isolated from whole blood and separated into monocyte/macrophage and peripheral blood lymphocyte (PBL) preparations. Genomic DNA, isolated from the PBL population, was used as template to amplify HIV-1 C2V3 envelope sequences in a nested PCR protocol. The resulting fragments were sequenced and subjected to a phylogenetic analysis. RESULTS Sera from non-demented (ND; n = 21) patients neutralized infection of CCR5-dependent, but not CXCR4-dependent viruses, more efficiently than sera from HAD patients (n = 15) (P < 0.05). A recombinant virus containing a brain derived C2V3 sequence was also neutralized less efficiently by sera from HAD patients ( < 0.05). C2V3 envelope sequences amplified from PBL revealed significantly greater diversity within the V3 region from HAD compared with ND patients (P < 0.001). The number of non-synonymous substitutions was positively correlated with the severity of neuro-cognitive impairment of patients (P < 0.005). Similarly, brain derived V3 sequences exhibited significantly increased diversity among HAD patients (P < 0.001). CONCLUSION Our findings imply that HAD patients exhibited impaired serological responses that may lead to the emergence of viral mutants that potentially could infect the brain and mediate neurodegeneration.
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Affiliation(s)
- Guido Van Marle
- Department of Clinical Neurosciences, University of Calgary, Canada
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Abstract
Neuronal damage and death are consistent pathologic findings in the brains of patients with ADC, and multiple cell model systems have demonstrated neurotoxicity through the effects of HIV-1 infection in macrophages and microglia. Brain MRI studies (1H-MRS) indicate that reversible neuronal cell dysfunction occurs early during the course of HIV-1 infection, long before overt symptoms of ADC appear. Epidemiologic studies suggest that a high viral load in the CNS is a major risk factor for ADC and that HAART may significantly reduce, but not eliminate, the risk of developing ADC. Targeted adjunctive therapies administered early are likely necessary to maximize CNS protection against HIV, and rational approaches to such therapy are rapidly evolving through in vitro analysis of the mechanisms of HIV-associated neurotoxicity. Soluble factors released by infected cells may directly or indirectly damage neurons and induce apoptosis at the level of NMDA subtype of glutamate receptors, and NMDA receptor antagonists represent a major therapeutic option currently under intense clinical investigation. Likewise, drugs with antioxidant or free radical scavenging effects offer another rational approach to adjunctive therapy and are also under intense clinical scrutiny. Finally, agents that inhibit neuronal death-signaling pathways (e.g., p38 MAPK inhibitors) and that stimulate cell survival pathways (e.g., Akt/PKB) may represent the next investigational step in designing anti-ADC therapies.
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Affiliation(s)
- Dennis L Kolson
- Department of Neurology, University of Pennsylvania Medical Center, Room 280C, Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104-6140, USA.
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Patrick MK, Johnston JB, Power C. Lentiviral neuropathogenesis: comparative neuroinvasion, neurotropism, neurovirulence, and host neurosusceptibility. J Virol 2002; 76:7923-31. [PMID: 12133996 PMCID: PMC155171 DOI: 10.1128/jvi.76.16.7923-7931.2002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Megan K Patrick
- Department of Clinical Neurosciences, University of Calgary, Alberta, Canada T2N 4N1
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