1
|
Wahl A, Al-Harthi L. HIV infection of non-classical cells in the brain. Retrovirology 2023; 20:1. [PMID: 36639783 PMCID: PMC9840342 DOI: 10.1186/s12977-023-00616-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
HIV-associated neurological disorders (HAND) affect up to 50% of people living with HIV (PLWH), even in the era of combination antiretroviral therapy (cART). HIV-DNA can be detected in the cerebral spinal fluid (CSF) of approximately half of aviremic ART-suppressed PLWH and its presence is associated with poorer neurocognitive performance. HIV DNA + and HIV RNA + cells have also been observed in postmortem brain tissue of individuals with sustained cART suppression. In this review, we provide an overview of how HIV invades the brain and HIV infection of resident brain glial cells (astrocytes and microglia). We also discuss the role of resident glial cells in persistent neuroinflammation and HAND in PLWH and their potential contribution to the HIV reservoir. HIV eradication strategies that target persistently infected glia cells will likely be needed to achieve HIV cure.
Collapse
Affiliation(s)
- Angela Wahl
- grid.10698.360000000122483208International Center for the Advancement of Translational Science, University of North Carolina at Chapel Hill, Chapel Hill, NC USA ,grid.10698.360000000122483208Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC USA ,grid.10698.360000000122483208Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Lena Al-Harthi
- grid.240684.c0000 0001 0705 3621Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL USA
| |
Collapse
|
2
|
Chen K, Phan T, Lin A, Sardo L, Mele AR, Nonnemacher MR, Klase Z. Morphine exposure exacerbates HIV-1 Tat driven changes to neuroinflammatory factors in cultured astrocytes. PLoS One 2020; 15:e0230563. [PMID: 32210470 PMCID: PMC7094849 DOI: 10.1371/journal.pone.0230563] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 03/03/2020] [Indexed: 12/16/2022] Open
Abstract
Despite antiretroviral therapy human immunodeficiency virus type-1 (HIV-1) infection results in neuroinflammation of the central nervous system that can cause HIV-associated neurocognitive disorders (HAND). The molecular mechanisms involved in the development of HAND are unclear, however, they are likely due to both direct and indirect consequences of HIV-1 infection and inflammation of the central nervous system. Additionally, opioid abuse in infected individuals has the potential to exacerbate HIV-comorbidities, such as HAND. Although restricted for productive HIV replication, astrocytes (comprising 40-70% of all brain cells) likely play a significant role in neuropathogenesis in infected individuals due to the production and response of viral proteins. The HIV-1 protein Tat is critical for viral transcription, causes neuroinflammation, and can be secreted from infected cells to affect uninfected bystander cells. The Wnt/β-catenin signaling cascade plays an integral role in restricting HIV-1 infection in part by negatively regulating HIV-1 Tat function. Conversely, Tat can overcome this negative regulation and inhibit β-catenin signaling by sequestering the critical transcription factor TCF-4 from binding to β-catenin. Here, we aimed to explore how opiate exposure affects Tat-mediated suppression of β-catenin in astrocytes and the downstream modulation of neuroinflammatory genes. We observed that morphine can potentiate Tat suppression of β-catenin activity in human astrocytes. In contrast, Tat mutants deficient in secretion, and lacking neurotoxic effects, do not affect β-catenin activity in the presence or absence of morphine. Finally, morphine treatment of astrocytes was sufficient to reduce the expression of genes involved in neuroinflammation. Examining the molecular mechanisms of how HIV-1 infection and opiate exposure exacerbate neuroinflammation may help us inform or predict disease progression prior to HAND development.
Collapse
Affiliation(s)
- Kenneth Chen
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States of America
| | - Thienlong Phan
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States of America
| | - Angel Lin
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States of America
| | - Luca Sardo
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States of America
- Current institution – Department of Infectious Diseases and Vaccines, MRL, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Anthony R. Mele
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael R. Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Zachary Klase
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States of America
| |
Collapse
|
3
|
Banerjee A, Benjamin R, Banerjee S. Impact of viral factors on subcellular distribution and RNA export activity of HIV-1 rev in astrocytes 1321N1. PLoS One 2013; 8:e72905. [PMID: 24023789 PMCID: PMC3762830 DOI: 10.1371/journal.pone.0072905] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/14/2013] [Indexed: 02/05/2023] Open
Abstract
CNS associated cells are permissive to HIV-1 infection, but poor in virus production due to attenuated Rev activity. The temporal and the spatial distribution of Rev in human astrocyte 1321N1 and glioblastoma GO-G-CCM were monitored for explaining the reduced Rev activity and low viral production during HIV-1 infection. Rev remained localized to the nuclei of these cells upon infection, attenuating its export activity, as manifested by low copy number of RRE-containing viral-mRNA in the cytoplasm of these cells. In contrast to infection, when Rev alone was transiently expressed, it localized in the cytoplasm of 1321N1. The localization changed to the nucleus when Rev was expressed in the presence of other viral proteins through pro-viral DNA pNL4-3. This study, for the first time, revealed the impact of other HIV-1 proteins apart from host factors in regulating the subcellular localization of Rev in astrocytes and hence the fate of HIV-1 infection in these cells.
Collapse
Affiliation(s)
- Atoshi Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Ronald Benjamin
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
| | - Sharmistha Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Andhra Pradesh, India
- * E-mail:
| |
Collapse
|
4
|
Human immunodeficiency virus type 1 (HIV-1) transactivator of transcription through its intact core and cysteine-rich domains inhibits Wnt/β-catenin signaling in astrocytes: relevance to HIV neuropathogenesis. J Neurosci 2013; 32:16306-13. [PMID: 23152614 DOI: 10.1523/jneurosci.3145-12.2012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Wnt/β-catenin is a neuroprotective pathway regulating cell fate commitment in the CNS and many vital functions of neurons and glia. Its dysregulation is linked to a number of neurodegenerative diseases. Wnt/β-catenin is also a repressor of HIV transcription in multiple cell types, including astrocytes, which are dysregulated in HIV-associated neurocognitive disorder. Given that HIV proteins can overcome host restriction factors and that perturbations of Wnt/β-catenin signaling can compromise astrocyte function, we evaluated the impact of HIV transactivator of transcription (Tat) on Wnt/β-catenin signaling in astrocytes. HIV clade B Tat, in primary progenitor-derived astrocytes and U87MG cells, inhibited Wnt/β-catenin signaling as demonstrated by its inhibition of active β-catenin, TOPflash reporter activity, and Axin-2 (a downstream target of Wnt/β-catenin signaling). Point mutations in either the core region (K41A) or the cysteine-rich region (C30G) of Tat abrogated its ability to inhibit β-catenin signaling. Clade C Tat, which lacks the dicysteine motif, did not alter β-catenin signaling, confirming that the dicysteine motif is critical for Tat inhibition of β-catenin signaling. Tat coprecipitated with TCF-4 (a transcription factor that partners with β-catenin), suggesting a physical interaction between these two proteins. Furthermore, knockdown of β-catenin or TCF-4 enhanced docking of Tat at the TAR region of the HIV long terminal repeat. These findings highlight a bidirectional interference between Tat and Wnt/β-catenin that negatively impacts their cognate target genes. The consequences of this interaction include alleviation of Wnt/β-catenin-mediated suppression of HIV and possible astrocyte dysregulation contributing to HIV neuropathogenesis.
Collapse
|
5
|
Liu J, Henao-Mejia J, Liu H, Zhao Y, He JJ. Translational regulation of HIV-1 replication by HIV-1 Rev cellular cofactors Sam68, eIF5A, hRIP, and DDX3. J Neuroimmune Pharmacol 2011; 6:308-21. [PMID: 21360055 DOI: 10.1007/s11481-011-9265-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
Abstract
Nuclear export and translation of HIV-1 RNA are two important posttranscriptional events for HIV-1 gene expression and replication. HIV-1 Rev functions to export unspliced and incompletely spliced HIV-1 RNA from the nucleus to the cytoplasm; it requires interaction with several cellular cofactors such as Sam68, eIF5A, hRIP, and DDX3. Meanwhile, some studies have also implicated Rev and some of its cofactors such as Sam68 in HIV-1 RNA translation. Thus, in this study, we aimed to characterize the potential function of all these four Rev cofactors in HIV-1 RNA translation. Ectopic expression, siRNA knockdown, and trans-complementation assays confirmed that all these cofactors were very important for HIV-1 gene expression and production through Rev and, accordingly, Rev-dependent reporter gene expression. Importantly, these studies revealed for the first time that each of these cofactors also regulated Rev-independent reporter gene expression. To directly determine the roles of these cofactors in HIV-1 RNA translation, we designed and synthesized a full-length capped HIV-1 RNA in vitro, transfected it into cells to bypass the RNA nuclear export step, and determined HIV-1 Gag expression from the cytoplasmic RNA in the cells that had ectopically expressed or siRNA knocked down cofactors. Gag expression was found to closely correlate with the expression levels of all these cofactors. Furthermore, we took advantage of a HIV-1 internal ribosomal entry site (IRES)-based bicistronic reporter gene assay and determined the effects of these cofactors on cap-independent IRES-mediated HIV-1 translation. The results showed that DDX3, eIF5A, and hRIP enhanced HIV-1 IRES-mediated translation, whereas Sam68 did not. Taken together, these results show that HIV-1 Rev cofactors Sam68, eIF5A, hRIP, and DDX3 also function in the translation of HIV-1 RNA and suggest that the regulatory mechanisms of HIV-1 RNA translation are likely different among these cofactors.
Collapse
Affiliation(s)
- Jinfeng Liu
- The First Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710061, People's Republic of China
| | | | | | | | | |
Collapse
|
6
|
Henao-Mejia J, He JJ. Sam68 relocalization into stress granules in response to oxidative stress through complexing with TIA-1. Exp Cell Res 2009; 315:3381-95. [PMID: 19615357 PMCID: PMC2783656 DOI: 10.1016/j.yexcr.2009.07.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 06/21/2009] [Accepted: 07/08/2009] [Indexed: 12/25/2022]
Abstract
Sam68 has been implicated in a variety of important cellular processes such as RNA metabolism and intracellular signaling. We have recently shown that Sam68 cytoplasmic mutants induce stress granules (SG) and inhibit HIV-1 nef mRNA translation [J. Henao-Mejia, Y. Liu, I.W. Park, J. Zhang, J. Sanford, J.J. He, Suppression of HIV-1 Nef translation by Sam68 mutant-induced stress granules and nef mRNA sequestration, Mol. Cell 33 (2009) 87-96]. These findings prompted us to investigate the possibility and the underlying mechanisms of the wild-type counterpart Sam68 SG recruitment. Herein, we revealed that Sam68 was significantly recruited into cytoplasmic SG under oxidative stress. We then demonstrated that domain aa269-321 and KH domain were both essential for this recruitment. Nevertheless, Sam68 knockdown had no effects on SG assembly, indicating that Sam68 is not a constitutive component of the SG. Moreover, we showed that Sam68 cytoplasmic mutant-induced SG formation was independent of eIF2alpha phosphorylation. Lastly, we demonstrated that Sam68 was complexed with T-cell intracellular antigen-1 (TIA-1), a core SG component, and that the complex formation was correlated with Sam68 SG recruitment. Taken together, these results provide direct evidence for the first time that Sam68 is recruited into SG through complexing with TIA-1 in response to oxidative stress and suggest that cytoplasmic SG recruitment of Sam68 and ensuing changes in Sam68 physiological functions are part of the host response to external stressful conditions.
Collapse
Affiliation(s)
- Jorge Henao-Mejia
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Johnny J. He
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202
- Center for AIDS Research, Indiana University School of Medicine, Indianapolis, IN 46202
| |
Collapse
|
7
|
Abstract
Productive HIV-1 replication is mainly controlled at the transcriptional level by HIV-1 Tat and at the post-transcriptional level by HIV-1 Rev. A number of host factors have been identified to be involved in these processes. Src-associated protein of 68 kDa in mitosis (Sam68) is a multi-functional RNA-binding protein and has been implicated in several important cellular processes. More evidence has accumulated to support an important regulatory function of Sam68 at two distinct steps of HIV-1 gene expression. Sam68 interacts with HIV-1 Rev protein and directly participates in nuclear exportation of HIV-1 unspliced or singly spliced RNA. In addition, Sam68 functions in the cytoplasmic processes of HIV-1 replication such as the translational regulation of HIV-1 RNA. Elucidation of the precise molecular function of Sam68 in HIV-1 gene expression is clearly warranted and is expected to unambiguously establish Sam68 as an important host factor for HIV-1 replication.
Collapse
Affiliation(s)
- Johnny J He
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | | | | |
Collapse
|
8
|
Abstract
Rev remains a hot topic. In this review, we revisit the insights that have been gained into the control of gene expression by the retroviral protein Rev and speculate on where current research is leading. We outline what is known about the role of Rev in translation and encapsidation and how these are linked to its more traditional role of nuclear export, underlining the multifaceted nature of this small viral protein. We discuss what more is to be learned in these fields and why continuing research on these 116 amino acids and understanding their function is still important in devising methods to combat AIDS.
Collapse
Affiliation(s)
- H C T Groom
- Department of Medicine, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK
| | - E C Anderson
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - A M L Lever
- Department of Medicine, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK
| |
Collapse
|
9
|
Henao-Mejia J, Liu Y, Park IW, Zhang J, Sanford J, He JJ. Suppression of HIV-1 Nef translation by Sam68 mutant-induced stress granules and nef mRNA sequestration. Mol Cell 2009; 33:87-96. [PMID: 19150430 PMCID: PMC2644331 DOI: 10.1016/j.molcel.2008.11.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 09/21/2008] [Accepted: 11/01/2008] [Indexed: 02/01/2023]
Abstract
HIV-1 Nef plays important roles in HIV-1 replication and pathogenesis. It is translated from completely spliced HIV-1 RNA, and its expression is inherently regulated at the levels of viral DNA transcription and RNA splicing. Here we show that Sam68 cytoplasmic mutants potently suppress Nef expression. The suppression requires Sam68 domain aa 269-321 and is correlated with its ability to induce stress granules. In addition, the suppression is specific to Nef, and direct binding to nef mRNA 3'UTR confers the suppression specificity. Furthermore, nef mRNA is targeted to and enriched in these induced stress granules. Importantly, Nef suppression occurs in the context of HIV-1 infection of CD4+ T lymphocytes with little MHC I and CD4 downregulation. Taken together, these results demonstrate that stress granule induction and nef mRNA sequestration account for this translational suppression of Nef expression and offer a strategy for development of anti-HIV therapeutics to buttress our fight against HIV/AIDS.
Collapse
Affiliation(s)
- Jorge Henao-Mejia
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | |
Collapse
|
10
|
Marsh K, Soros V, Cochrane A. Selective translational repression of HIV-1 RNA by Sam68DeltaC occurs by altering PABP1 binding to unspliced viral RNA. Retrovirology 2008; 5:97. [PMID: 18957126 PMCID: PMC2584037 DOI: 10.1186/1742-4690-5-97] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Accepted: 10/28/2008] [Indexed: 12/13/2022] Open
Abstract
HIV-1 structural proteins are translated from incompletely spliced 9 kb and 4 kb mRNAs, which are transported to the cytoplasm by Crm1. It has been assumed that once in the cytoplasm, translation of incompletely spliced HIV-1 mRNAs occurs in the same manner as host mRNAs. Previous analyses have demonstrated that Sam68 and a mutant thereof, Sam68DeltaC, have dramatic effects on HIV gene expression, strongly enhancing and inhibiting viral structural protein synthesis, respectively. While investigating the inhibition of incompletely spliced HIV-1 mRNAs by Sam68DeltaC, we determined that the effect was independent of the perinuclear bundling of the viral RNA. Inhibition was dependent upon the nuclear export pathway used, as translation of viral RNA exported via the Tap/CTE export pathway was not blocked by Sam68DeltaC. We demonstrate that inhibition of HIV expression by Sam68DeltaC is correlated with a loss of PABP1 binding with no attendant change in polyadenosine tail length of the affected RNAs. The capacity of Sam68DeltaC to selectively inhibit translation of HIV-1 RNAs exported by Crm1 suggests that it is able to recognize unique characteristics of these viral RNPs, a property that could lead to new therapeutic approaches to controlling HIV-1 replication.
Collapse
Affiliation(s)
- Kim Marsh
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
| | | | | |
Collapse
|
11
|
Carroll-Anzinger D, Kumar A, Adarichev V, Kashanchi F, Al-Harthi L. Human immunodeficiency virus-restricted replication in astrocytes and the ability of gamma interferon to modulate this restriction are regulated by a downstream effector of the Wnt signaling pathway. J Virol 2007; 81:5864-71. [PMID: 17392368 PMCID: PMC1900315 DOI: 10.1128/jvi.02234-06] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Astrocyte dysregulation correlates with the severity and the rate of human immunodeficiency virus (HIV)-associated dementia (HAD) progression, highlighting a pivotal role for astrocytes in HIV neuropathogenesis. Yet, astrocytes limit HIV, indicating that they possess an intrinsic molecular mechanism to restrict HIV replication. We previously established that this restriction can be partly overcome by priming astrocytes with gamma interferon (IFN-gamma), which is elevated in the cerebral spinal fluid of HAD patients. We evaluated the mechanism of restrictive HIV replication in astrocytes and how IFN-gamma priming modulates this restriction. We demonstrate that the downstream effector of Wnt signaling, T-cell factor 4 (TCF-4), is part of a transcriptional complex that is immunoprecipitated with HIV TAR-containing region in untreated astrocytes but not in IFN-gamma-treated cells. Blocking TCF-4 activity with a dominant-negative mutant enhanced HIV replication by threefold in both the astrocytoma cell line U87MG and primary fetal astrocytes. Using a TCF-4 reporter plasmid, we directly demonstrate that Wnt signaling is active in human astrocytes and is markedly reduced by IFN-gamma treatment. Collectively, these data implicate TCF-4 in repressing HIV replication and the ability of IFN-gamma to regulate this restriction by inhibiting TCF-4. Given that TCF-4 is the downstream effector of Wnt signaling, harnessing Wnt signaling as an intrinsic molecular mechanism to limit HIV replication may emerge as a powerful tool to regulate HIV replication within and outside of the brain.
Collapse
Affiliation(s)
- Deborah Carroll-Anzinger
- Department of Immunology/Microbiology, Rush University Medical Center, 1735 W. Harrison Street, 614 Cohn, Chicago, IL 60612, USA
| | | | | | | | | |
Collapse
|