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Sanami S, Shamsabadi S, Dayhimi A, Pirhayati M, Ahmad S, Pirhayati A, Ajami M, Hemati S, Shirvani M, Alagha A, Abbarin D, Alizadeh A, Pazoki-Toroudi H. Association between cytomegalovirus infection and neurological disorders: A systematic review. Rev Med Virol 2024; 34:e2532. [PMID: 38549138 DOI: 10.1002/rmv.2532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 04/02/2024]
Abstract
Cytomegalovirus (CMV) belongs to the Herpesviridae family and is also known as human herpesvirus type 5. It is a common virus that usually doesn't cause any symptoms in healthy individuals. However, once infected, the virus remains in the host's body for life and can reactivate when the host's immune system weakens. This virus has been linked to several neurological disorders, including Alzheimer's disease, Parkinson's disease, Autism spectrum disorder, Huntington's disease (HD), ataxia, Bell's palsy (BP), and brain tumours, which can cause a wide range of symptoms and challenges for those affected. CMV may influence inflammation, contribute to brain tissue damage, and elevate the risk of moderate-to-severe dementia. Multiple studies suggest a potential association between CMV and ataxia in various conditions, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, acute cerebellitis, etc. On the other hand, the evidence regarding CMV involvement in BP is conflicting, and also early indications of a link between CMV and HD were challenged by subsequent research disproving CMV's presence. This systematic review aims to comprehensively investigate any link between the pathogenesis of CMV and its potential role in neurological disorders and follows the preferred reporting items for systematic review and meta-analysis checklist. Despite significant research into the potential links between CMV infection and various neurological disorders, the direct cause-effect relationship is not fully understood and several gaps in knowledge persist. Therefore, continued research is necessary to gain a better understanding of the role of CMV in neurological disorders and potential treatment avenues.
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Affiliation(s)
- Samira Sanami
- Abnormal Uterine Bleeding Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Shahnam Shamsabadi
- Department of Physiology, Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Dayhimi
- Department of Physiology, Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Pirhayati
- Psychiatric Department, Rasool Akram Hospital, Iran University of Medical Science, Tehran, Iran
| | - Sajjad Ahmad
- Department of Health and Biological Sciences, Abasyn University, Peshawar, Pakistan
- Department of Computer Sciences, Virginia Tech, Blacksburg, Virginia, USA
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon
| | | | - Marjan Ajami
- National Nutrition and Food Technology Research Institute, School of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sara Hemati
- Department of Environmental Health Engineering, School of Health, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Masoud Shirvani
- Department of Neurosurgery, Salamat-Farda Hospital, Tehran, Iran
| | - Ahmad Alagha
- Department of Neurosurgery, Salamat-Farda Hospital, Tehran, Iran
| | - Davood Abbarin
- Department of Neurosurgery, Salamat-Farda Hospital, Tehran, Iran
| | - Akram Alizadeh
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Hamidreza Pazoki-Toroudi
- Department of Physiology, Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Wu F, Zhang J, Wang Q, Liu W, Zhang X, Ning F, Cui M, Qin L, Zhao G, Liu D, Lv S, Xu Y. Identification of immune-associated genes in vascular dementia by integrated bioinformatics and inflammatory infiltrates. Heliyon 2024; 10:e26304. [PMID: 38384571 PMCID: PMC10879030 DOI: 10.1016/j.heliyon.2024.e26304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/04/2024] [Accepted: 02/09/2024] [Indexed: 02/23/2024] Open
Abstract
Objective Dysregulation of the immune system plays a vital role in the pathological process of vascular dementia, and this study aims to spot critical biomarkers and immune infiltrations in vascular dementia employing a bioinformatics approach. Methods We acquired gene expression profiles from the Gene Expression Database. The gene expression data were analyzed using the bioinformatics method to identify candidate immune-related central genes for the diagnosis of vascular dementia. and the diagnostic value of nomograms and Receiver Operating Characteristic (ROC) curves were evaluated. We also examined the role of the VaD hub genes. Using the database and potential therapeutic drugs, we predicted the miRNA and lncRNA controlling the Hub genes. Immune cell infiltration was initiated to examine immune cell dysregulation in vascular dementia. Results 1321 immune genes were included in the combined immune dataset, and 2816 DEGs were examined in GSE122063. Twenty potential genes were found using differential gene analysis and co-expression network analysis. PPI network design and functional enrichment analysis were also done using the immune system as the main subject. To create the nomogram for evaluating the diagnostic value, four potential core genes were chosen by machine learning. All four putative center genes and nomograms have a solid diagnostic value (AUC ranged from 0.81 to 0.92). Their high confidence level became unquestionable by validating each of the four biomarkers using a different dataset. According to GeneMANIA and GSEA enrichment investigations, the pathophysiology of VaD is strongly related to inflammatory responses, drug reactions, and central nervous system degeneration. The data and Hub genes were used to construct a ceRNA network that includes three miRNAs, 90 lncRNA, and potential VaD therapeutics. Immune cells with varying dysregulation were also found. Conclusion Using bioinformatic techniques, our research identified four immune-related candidate core genes (HMOX1, EBI3, CYBB, and CCR5). Our study confirms the role of these Hub genes in the onset and progression of VaD at the level of immune infiltration. It predicts potential RNA regulatory pathways control VaD progression, which may provide ideas for treating clinical disease.
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Affiliation(s)
- Fangchao Wu
- Department of Rehabilitation Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China
| | - Junling Zhang
- Shandong Medicine Technician College, Taian 271000, China
| | - Qian Wang
- Department of Central Laboratory, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, China
| | - Wenxin Liu
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Xinlei Zhang
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Fangli Ning
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Mengmeng Cui
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Lei Qin
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Guohua Zhao
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Di Liu
- Department of Neurology, Dongping County People's Hospital, Taian, 271000, China
| | - Shi Lv
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
| | - Yuzhen Xu
- Department of Rehabilitation, The Second Affiliated Hospital of Shandong First Medical University, Taian, 271000, China
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3
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Nemergut M, Batkova T, Vigasova D, Bartos M, Hlozankova M, Schenkmayerova A, Liskova B, Sheardova K, Vyhnalek M, Hort J, Laczó J, Kovacova I, Sitina M, Matej R, Jancalek R, Marek M, Damborsky J. Increased occurrence of Treponema spp. and double-species infections in patients with Alzheimer's disease. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 844:157114. [PMID: 35787909 DOI: 10.1016/j.scitotenv.2022.157114] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 06/25/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Although the link between microbial infections and Alzheimer's disease (AD) has been demonstrated in multiple studies, the involvement of pathogens in the development of AD remains unclear. Here, we investigated the frequency of the 10 most commonly cited viral (HSV-1, EBV, HHV-6, HHV-7, and CMV) and bacterial (Chlamydia pneumoniae, Helicobacter pylori, Borrelia burgdorferi, Porphyromonas gingivalis, and Treponema spp.) pathogens in serum, cerebrospinal fluid (CSF) and brain tissues of AD patients. We have used an in-house multiplex PCR kit for simultaneous detection of five bacterial and five viral pathogens in serum and CSF samples from 50 AD patients and 53 healthy controls (CTRL). We observed a significantly higher frequency rate of AD patients who tested positive for Treponema spp. compared to controls (AD: 62.2 %; CTRL: 30.3 %; p-value = 0.007). Furthermore, we confirmed a significantly higher occurrence of cases with two or more simultaneous infections in AD patients compared to controls (AD: 24 %; CTRL 7.5 %; p-value = 0.029). The studied pathogens were detected with comparable frequency in serum and CSF. In contrast, Borrelia burgdorferi, human herpesvirus 7, and human cytomegalovirus were not detected in any of the studied samples. This study provides further evidence of the association between microbial infections and AD and shows that paralleled analysis of multiple sample specimens provides complementary information and is advisable for future studies.
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Affiliation(s)
- Michal Nemergut
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | - Tereza Batkova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Department of Neurology, Masaryk University, St. Anne's University Hospital Brno, Brno, Czech Republic; BioVendor R&D, Brno, Czech Republic
| | - Dana Vigasova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | | | | | - Andrea Schenkmayerova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | - Barbora Liskova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | - Katerina Sheardova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Department of Neurology, Masaryk University, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Martin Vyhnalek
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Department of Neurology, Charles University, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Jakub Hort
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Department of Neurology, Charles University, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Jan Laczó
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Department of Neurology, Charles University, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Ingrid Kovacova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Michal Sitina
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Radoslav Matej
- Department of Pathology and Molecular Medicine, Third Faculty of Medicine, Charles University and Thomayer University Hospital, Prague, Czech Republic
| | - Radim Jancalek
- Department of Neurosurgery, St. Anne's University Hospital Brno, Brno, Czech Republic and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Martin Marek
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | - Jiri Damborsky
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic; Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.
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Yong SJ, Yong MH, Teoh SL, Soga T, Parhar I, Chew J, Lim WL. The Hippocampal Vulnerability to Herpes Simplex Virus Type I Infection: Relevance to Alzheimer's Disease and Memory Impairment. Front Cell Neurosci 2021; 15:695738. [PMID: 34483839 PMCID: PMC8414573 DOI: 10.3389/fncel.2021.695738] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/20/2021] [Indexed: 12/24/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) as a possible infectious etiology in Alzheimer’s disease (AD) has been proposed since the 1980s. The accumulating research thus far continues to support the association and a possible causal role of HSV-1 in the development of AD. HSV-1 has been shown to induce neuropathological and behavioral changes of AD, such as amyloid-beta accumulation, tau hyperphosphorylation, as well as memory and learning impairments in experimental settings. However, a neuroanatomical standpoint of HSV-1 tropism in the brain has not been emphasized in detail. In this review, we propose that the hippocampal vulnerability to HSV-1 infection plays a part in the development of AD and amnestic mild cognitive impairment (aMCI). Henceforth, this review draws on human studies to bridge HSV-1 to hippocampal-related brain disorders, namely AD and aMCI/MCI. Next, experimental models and clinical observations supporting the neurotropism or predilection of HSV-1 to infect the hippocampus are examined. Following this, factors and mechanisms predisposing the hippocampus to HSV-1 infection are discussed. In brief, the hippocampus has high levels of viral cellular receptors, neural stem or progenitor cells (NSCs/NPCs), glucocorticoid receptors (GRs) and amyloid precursor protein (APP) that support HSV-1 infectivity, as well as inadequate antiviral immunity against HSV-1. Currently, the established diseases HSV-1 causes are mucocutaneous lesions and encephalitis; however, this review revises that HSV-1 may also induce and/or contribute to hippocampal-related brain disorders, especially AD and aMCI/MCI.
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Affiliation(s)
- Shin Jie Yong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Min Hooi Yong
- Department of Psychology, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia.,Aging Health and Well-being Research Centre, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Seong Lin Teoh
- Department of Anatomy, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia
| | - Tomoko Soga
- Jeffrey Cheah School of Medicine and Health Sciences, Brain Research Institute Monash Sunway, Monash University Malaysia, Subang Jaya, Malaysia
| | - Ishwar Parhar
- Jeffrey Cheah School of Medicine and Health Sciences, Brain Research Institute Monash Sunway, Monash University Malaysia, Subang Jaya, Malaysia
| | - Jactty Chew
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Wei Ling Lim
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia.,Aging Health and Well-being Research Centre, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
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Zhang X, Xi T, Zhang L, Bi Y, Huang Y, Lu Y, Liu X, Fang F. The role of autophagy in human cytomegalovirus IE2 expression. J Med Virol 2021; 93:3795-3803. [PMID: 32710640 DOI: 10.1002/jmv.26357] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/10/2020] [Accepted: 07/20/2020] [Indexed: 01/01/2023]
Abstract
The purpose of this study was to determine whether autophagy regulates the expression of human cytomegalovirus (HCMV) immediately early two viral protein (IE2). Rapamycin and 3-methyladenine (3-MA) were used to stimulate or suppress autophagy during HCMV infection. UL122 recombinant plasmid was transfected to overexpress IE2 and small interference RNA against autophagy-related protein 3 (ATG3) was used to knockdown ATG3. Western blot was performed to measure the expression of viral proteins and autophagy levels. Immunofluorescence was used to detect the immediately early 1 viral protein (IE1) expression. In human embryonic lung fibroblasts, infection of HCMV promotes the lipidation of light chain 3 (LC3) at 6 and 24 hours post infection (hpi), which was accompanied by the increased expression of viral protein IE2. When only IE2 was overexpressed via UL122 recombinant plasmid transfection without HCMV infection, the autophagy hallmarks LC3II and ATG3 were upregulated. Furthermore, viral protein IE2 expression was reduced at 24 and 48 hpi either by the treatment of autophagy inducer rapamycin or by the inhibitor 3-MA before HCMV infection. At the same time, small interference ATG3 transient transfection, used to suppress autophagy, significantly inhibited IE2 expression. However, when 3-MA was used to regulate autophagy levels after HCMV infection, expression of IE2 and IE1 were both decreased, while autophagy inducer rapamycin treatment after HCMV infection increased IE2 expression slightly. IE2 was involved in autophagy induced by HCMV infection and blocking autophagy could inhibit the expression of HCMV viral protein IE2, which might be one way for autophagy to restrict HCMV replication.
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Affiliation(s)
- Xinyan Zhang
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ting Xi
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Linlin Zhang
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yidan Bi
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yuan Huang
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yuanyuan Lu
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xinglou Liu
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Feng Fang
- Department of Pediatrics, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
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Cytomegalovirus-Specific CD4+ T-cell Responses and CMV-IgG Levels Are Associated With Neurocognitive Impairment in People Living With HIV. J Acquir Immune Defic Syndr 2019; 79:117-125. [PMID: 29781883 DOI: 10.1097/qai.0000000000001753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mechanisms leading to neurocognitive impairment (NCI) in people living with HIV (PLWHIV) on stable combination antiretroviral therapy (cART) remain unknown. We investigated the association between immunity against cytomegalovirus (CMV), HIV-specific variables, and NCI in PLWHIV on stable cART and with low comorbidity. METHODS Fifty-two PLWHIV on stable cART and 31 HIV-uninfected controls matched on age, sex, education, and comorbidity were tested with a neurocognitive test battery, and CMV-immunoglobulin G (CMV-IgG) levels were measured. In PLWHIV, CMV-specific (CMV-pp65 and CMV-gB) CD4 and CD8 T-cell responses were measured using intracellular cytokine staining and flow cytometry. NCI was defined as a global deficit scale score (GDS score) ≥0.5. GDS scores and domain-specific scores defined severity of NCI. Logistic and linear multivariable regression analyses were used. RESULTS NCI was detected in 30.8% of PLWHIV, and HIV was associated with an adjusted odds ratio (aOR) of 5.18 [95% confidence interval (CI): 1.15 to 23.41, P = 0.033] for NCI. In PLWHIV, higher CMV-specific CD4 T-cell responses increased the probability of NCI with an aOR of 1.68 (95% CI: 1.10 to 2.57) for CMV-pp65 or an aOR of 3.73 (95% CI: 1.61 to 16.98) for CMV-gB, respectively. Similar associations were not found with CMV-IgG or CMV-specific CD8 T cells, but when assessing severity of NCI, higher CMV-IgG (per 100 U/mL) was associated with worse GDS scores (β = 0.08) (0.01-0.16), P = 0.044), specifically in the domain of speed of information processing (β = 0.20 (0.04-0.36, P = 0.019). CONCLUSIONS PLWHIV had increased risk of NCI. Excess risk may be associated with CMV-specific CD4 T-cell responses and CMV-IgG. Larger longitudinal studies investigating the impact of immunity against CMV on risk of NCI are warranted.
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Clement M, Humphreys IR. Cytokine-Mediated Induction and Regulation of Tissue Damage During Cytomegalovirus Infection. Front Immunol 2019; 10:78. [PMID: 30761144 PMCID: PMC6362858 DOI: 10.3389/fimmu.2019.00078] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Human cytomegalovirus (HCMV) is a β-herpesvirus with high sero-prevalence within the human population. Primary HCMV infection and life-long carriage are typically asymptomatic. However, HCMV is implicated in exacerbation of chronic conditions and associated damage in individuals with intact immune systems. Furthermore, HCMV is a significant cause of morbidity and mortality in the immunologically immature and immune-compromised where disease is associated with tissue damage. Infection-induced inflammation, including robust cytokine responses, is a key component of pathologies associated with many viruses. Despite encoding a large number of immune-evasion genes, HCMV also triggers the induction of inflammatory cytokine responses during infection. Thus, understanding how cytokines contribute to CMV-induced pathologies and the mechanisms through which they are regulated may inform clinical management of disease. Herein, we discuss our current understanding based on clinical observation and in vivo modeling of disease of the role that cytokines play in CMV pathogenesis. Specifically, in the context of the different tissues and organs in which CMV replicates, we give a broad overview of the beneficial and adverse effects that cytokines have during infection and describe how cytokine-mediated tissue damage is regulated. We discuss the implications of findings derived from mice and humans for therapeutic intervention strategies and our understanding of how host genetics may influence the outcome of CMV infections.
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Affiliation(s)
- Mathew Clement
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff, United Kingdom
| | - Ian R Humphreys
- Division of Infection and Immunity/Systems Immunity University Research Institute, Cardiff, United Kingdom
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8
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Pretorius E, Bester J, Kell DB. A Bacterial Component to Alzheimer's-Type Dementia Seen via a Systems Biology Approach that Links Iron Dysregulation and Inflammagen Shedding to Disease. J Alzheimers Dis 2018; 53:1237-56. [PMID: 27340854 PMCID: PMC5325058 DOI: 10.3233/jad-160318] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The progression of Alzheimer's disease (AD) is accompanied by a great many observable changes, both molecular and physiological. These include oxidative stress, neuroinflammation, and (more proximal to cognitive decline) the death of neuronal and other cells. A systems biology approach seeks to organize these observed variables into pathways that discriminate those that are highly involved (i.e., causative) from those that are more usefully recognized as bystander effects. We review the evidence that iron dysregulation is one of the central causative pathway elements here, as this can cause each of the above effects. In addition, we review the evidence that dormant, non-growing bacteria are a crucial feature of AD, that their growth in vivo is normally limited by a lack of free iron, and that it is this iron dysregulation that is an important factor in their resuscitation. Indeed, bacterial cells can be observed by ultrastructural microscopy in the blood of AD patients. A consequence of this is that the growing cells can shed highly inflammatory components such as lipopolysaccharides (LPS). These too are known to be able to induce (apoptotic and pyroptotic) neuronal cell death. There is also evidence that these systems interact with elements of vitamin D metabolism. This integrative systems approach has strong predictive power, indicating (as has indeed been shown) that both natural and pharmaceutical iron chelators might have useful protective roles in arresting cognitive decline, and that a further assessment of the role of microbes in AD development is more than highly warranted.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Douglas B Kell
- School of Chemistry, The University of Manchester, Manchester, Lancs, UK.,The Manchester Institute of Biotechnology, The University of Manchester, Manchester, Lancs, UK.,Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, Lancs, UK
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9
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Itzhaki RF. Herpes and Alzheimer's Disease: Subversion in the Central Nervous System and How It Might Be Halted. J Alzheimers Dis 2018; 54:1273-1281. [PMID: 27497484 DOI: 10.3233/jad-160607] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The last 8 or so years have seen a large increase in the number of studies supporting the concept of a major role for herpes simplex virus type 1 (HSV1) in Alzheimer's disease (AD). The main advances have been made through studies in humans and in mice, investigating the likelihood of reactivation of the latent virus in brain. Others have aimed to explain the mechanisms in cells whereby the increase in amyloid-beta (Aβ) production on HSV1 infection of cells and mouse brains occurs, and the reason that infected cells make this increase. The possibility that other herpesviruses are involved in the development of AD has been explored, and human herpesvirus type 6, Epstein-Barr virus, and cytomegalovirus, in particular, have been implicated. Epidemiological studies have further supported the role specifically of HSV1 and its reactivation in the disease. Antiviral studies have continued, comparing those acting by different mechanisms, such as restricting viral replication, or blocking viral entry into cells, to treat HSV1-infected cell cultures, and then examining the extent to which the virus-induced increases in Aβ and AD-like tau are reduced. All the studies support the usage of antiviral treatment to slow or halt the progression of AD.
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Lövheim H, Olsson J, Weidung B, Johansson A, Eriksson S, Hallmans G, Elgh F. Interaction between Cytomegalovirus and Herpes Simplex Virus Type 1 Associated with the Risk of Alzheimer’s Disease Development. J Alzheimers Dis 2018; 61:939-945. [DOI: 10.3233/jad-161305] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Hugo Lövheim
- Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden
- Department of Public Health and Caring Sciences, Geriatric Medicine, Uppsala University, Uppsala, Sweden
| | - Jan Olsson
- Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden
| | - Bodil Weidung
- Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden
- Department of Public Health and Caring Sciences, Geriatric Medicine, Uppsala University, Uppsala, Sweden
| | - Anders Johansson
- Department of Odontology, Umeå University, Umeå, Sweden
- Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden
| | - Sture Eriksson
- Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden
- Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden
| | - Göran Hallmans
- Department of Public Health and Clinical Medicine, Nutritional Research, Umeå University, Umeå, Sweden
| | - Fredrik Elgh
- Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden
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Abstract
Human immunodeficiency virus (HIV)-infected adults who take stable antiretroviral therapy (ART) are at risk for early onset of age-related diseases. This is likely due to a complex interaction between traditional risk factors, HIV infection itself, and other factors, such as underlying immune dysfunction and persistent inflammation. HIV disrupts the balance between the host and coinfecting microbes, worsening control of these potential pathogens. For example, HIV-infected adults are more likely than the general population to have subclinical bursts of cytomegalovirus (CMV) replication at mucosal sites. Production of antigens can activate the immune system and stimulate HIV replication, and it could contribute to the pathogenesis of adverse outcomes of aging, like cardiovascular disease and neurocognitive impairment. Further investigation of the relationships between CMV, immune dysfunction, and unsuccessful aging during chronic HIV infection is warranted.
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Affiliation(s)
- Sara Gianella
- Department of Medicine, Division of Infectious Disease, University of California-San Diego, La Jolla
| | - Scott Letendre
- Department of Medicine, Division of Infectious Disease, University of California-San Diego, La Jolla
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12
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Bourgade K, Dupuis G, Frost EH, Fülöp T. Anti-Viral Properties of Amyloid-β Peptides. J Alzheimers Dis 2016; 54:859-878. [DOI: 10.3233/jad-160517] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Karine Bourgade
- Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Gilles Dupuis
- Department of Biochemistry, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Eric H. Frost
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tamàs Fülöp
- Department of Medicine, Research Center on Aging, Graduate Program in Immunology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
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13
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Licastro F, Porcellini E. Persistent infections, immune-senescence and Alzheimer's disease. Oncoscience 2016; 3:135-42. [PMID: 27489858 PMCID: PMC4965253 DOI: 10.18632/oncoscience.309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/15/2016] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia. Classical hallmarks of AD such as amyloid deposition and neurofibrillary tangles do not completely explain AD pathogenesis. Recent investigations proposed Aβ peptide as an anti-microbial factor. Our previous works suggested that the concomitant presence of single nucleotide polymorphisms (SNPs) from AD genetic studies might impair antiviral defenses and increase the individual susceptibility to herpes virus infection. Viruses of herpes family by inducing frequent cycles of reactivation and latency constantly challenge the immune response and drive the accumulation of memory T cells. However, the immune system is not able to completely eradicate these viruses. The continuous antigen stimulation activates chronic inflammatory responses that may progressively induce neurodegenerative mechanisms in genetically susceptible elderly. The aim of this paper is to suggest new perspectives in clinical pathogenesis of AD with potential prevention and new medical treatment of the age associated cognitive decline.
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Affiliation(s)
- Federico Licastro
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna 40126, Italy
| | - Elisa Porcellini
- Department of Experimental, Diagnostic and Specialty Medicine, School of Medicine, University of Bologna, Bologna 40126, Italy
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14
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Harris SA, Harris EA. Herpes Simplex Virus Type 1 and Other Pathogens are Key Causative Factors in Sporadic Alzheimer's Disease. J Alzheimers Dis 2016; 48:319-53. [PMID: 26401998 PMCID: PMC4923765 DOI: 10.3233/jad-142853] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review focuses on research in epidemiology, neuropathology, molecular biology, and genetics regarding the hypothesis that pathogens interact with susceptibility genes and are causative in sporadic Alzheimer's disease (AD). Sporadic AD is a complex multifactorial neurodegenerative disease with evidence indicating coexisting multi-pathogen and inflammatory etiologies. There are significant associations between AD and various pathogens, including Herpes simplex virus type 1 (HSV-1), Cytomegalovirus, and other Herpesviridae, Chlamydophila pneumoniae, spirochetes, Helicobacter pylori, and various periodontal pathogens. These pathogens are able to evade destruction by the host immune system, leading to persistent infection. Bacterial and viral DNA and RNA and bacterial ligands increase the expression of pro-inflammatory molecules and activate the innate and adaptive immune systems. Evidence demonstrates that pathogens directly and indirectly induce AD pathology, including amyloid-β (Aβ) accumulation, phosphorylation of tau protein, neuronal injury, and apoptosis. Chronic brain infection with HSV-1, Chlamydophila pneumoniae, and spirochetes results in complex processes that interact to cause a vicious cycle of uncontrolled neuroinflammation and neurodegeneration. Infections such as Cytomegalovirus, Helicobacter pylori, and periodontal pathogens induce production of systemic pro-inflammatory cytokines that may cross the blood-brain barrier to promote neurodegeneration. Pathogen-induced inflammation and central nervous system accumulation of Aβ damages the blood-brain barrier, which contributes to the pathophysiology of AD. Apolipoprotein E4 (ApoE4) enhances brain infiltration by pathogens including HSV-1 and Chlamydophila pneumoniae. ApoE4 is also associated with an increased pro-inflammatory response by the immune system. Potential antimicrobial treatments for AD are discussed, including the rationale for antiviral and antibiotic clinical trials.
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Affiliation(s)
- Steven A Harris
- St. Vincent Medical Group, Northside Internal Medicine, Indianapolis, IN, USA
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15
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Lueg G, Gross CC, Lohmann H, Johnen A, Kemmling A, Deppe M, Groger J, Minnerup J, Wiendl H, Meuth SG, Duning T. Clinical relevance of specific T-cell activation in the blood and cerebrospinal fluid of patients with mild Alzheimer's disease. Neurobiol Aging 2015; 36:81-9. [DOI: 10.1016/j.neurobiolaging.2014.08.008] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/23/2014] [Accepted: 08/07/2014] [Indexed: 11/26/2022]
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16
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Monastero R, Caruso C, Vasto S. Alzheimer's disease and infections, where we stand and where we go. IMMUNITY & AGEING 2014; 11:26. [PMID: 25535510 PMCID: PMC4273443 DOI: 10.1186/s12979-014-0026-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 12/08/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Roberto Monastero
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy
| | - Calogero Caruso
- Department of Pathobiology and Medical and Forensic Biotechnologies, University of Palermo, Palermo, Italy
| | - Sonya Vasto
- National Center for Research, Institute of Biomedicine and Molecular Immunology, Palermo, Italy ; Department of Science and Biological, Chemical and Pharmaceutical Technologies, Institute of Biomedicine and Molecular Immunology, Palermo, Italy
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17
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Itzhaki RF. Herpes simplex virus type 1 and Alzheimer's disease: increasing evidence for a major role of the virus. Front Aging Neurosci 2014; 6:202. [PMID: 25157230 PMCID: PMC4128394 DOI: 10.3389/fnagi.2014.00202] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/23/2014] [Indexed: 12/15/2022] Open
Abstract
Herpes simplex virus type 1 (HSV1), when present in brain of carriers of the type 4 allele of the apolipoprotein E gene (APOE), has been implicated as a major factor in Alzheimer's disease (AD). It is proposed that virus is normally latent in many elderly brains but reactivates periodically (as in the peripheral nervous system) under certain conditions, for example stress, immunosuppression, and peripheral infection, causing cumulative damage and eventually development of AD. Diverse approaches have provided data that explicitly support, directly or indirectly, these concepts. Several have confirmed HSV1 DNA presence in human brains, and the HSV1-APOE-ε4 association in AD. Further, studies on HSV1-infected APOE-transgenic mice have shown that APOE-e4 animals display a greater potential for viral damage. Reactivated HSV1 can cause direct and inflammatory damage, probably involving increased formation of beta amyloid (Aβ) and of AD-like tau (P-tau)-changes found to occur in HSV1-infected cell cultures. Implicating HSV1 further in AD is the discovery that HSV1 DNA is specifically localized in amyloid plaques in AD. Other relevant, harmful effects of infection include the following: dynamic interactions between HSV1 and amyloid precursor protein (APP), which would affect both viral and APP transport; induction of toll-like receptors (TLRs) in HSV1-infected astrocyte cultures, which has been linked to the likely effects of reactivation of the virus in brain. Several epidemiological studies have shown, using serological data, an association between systemic infections and cognitive decline, with HSV1 particularly implicated. Genetic studies too have linked various pathways in AD with those occurring on HSV1 infection. In relation to the potential usage of antivirals to treat AD patients, acyclovir (ACV) is effective in reducing HSV1-induced AD-like changes in cell cultures, and valacyclovir, the bioactive form of ACV, might be most effective if combined with an antiviral that acts by a different mechanism, such as intravenous immunoglobulin (IVIG).
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Affiliation(s)
- Ruth F. Itzhaki
- Faculty of Life Sciences, University of ManchesterManchester, Lancs, UK
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