1
|
Vanegas-Torres CA, Schindler M. HIV-1 Vpr Functions in Primary CD4 + T Cells. Viruses 2024; 16:420. [PMID: 38543785 PMCID: PMC10975730 DOI: 10.3390/v16030420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 05/23/2024] Open
Abstract
HIV-1 encodes four accesory proteins in addition to its structural and regulatory genes. Uniquely amongst them, Vpr is abundantly present within virions, meaning it is poised to exert various biological effects on the host cell upon delivery. In this way, Vpr contributes towards the establishment of a successful infection, as evidenced by the extent to which HIV-1 depends on this factor to achieve full pathogenicity in vivo. Although HIV infects various cell types in the host organism, CD4+ T cells are preferentially targeted since they are highly permissive towards productive infection, concomitantly bringing about the hallmark immune dysfunction that accompanies HIV-1 spread. The last several decades have seen unprecedented progress in unraveling the activities Vpr possesses in the host cell at the molecular scale, increasingly underscoring the importance of this viral component. Nevertheless, it remains controversial whether some of these advances bear in vivo relevance, since commonly employed cellular models significantly differ from primary T lymphocytes. One prominent example is the "established" ability of Vpr to induce G2 cell cycle arrest, with enigmatic physiological relevance in infected primary T lymphocytes. The objective of this review is to present these discoveries in their biological context to illustrate the mechanisms whereby Vpr supports HIV-1 infection in CD4+ T cells, whilst identifying findings that require validation in physiologically relevant models.
Collapse
Affiliation(s)
| | - Michael Schindler
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tuebingen, 72076 Tuebingen, Germany;
| |
Collapse
|
2
|
Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [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: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
Collapse
Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| |
Collapse
|
3
|
Li M, Budai MM, Chen M, Wang J. Targeting HIV-1 reservoirs in T cell subsets. Front Immunol 2023; 14:1087923. [PMID: 36742330 PMCID: PMC9895780 DOI: 10.3389/fimmu.2023.1087923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/09/2023] [Indexed: 01/22/2023] Open
Abstract
The HIV-1 reservoirs harbor the latent proviruses that are integrated into the host genome. It is a challenging task to eradicate the proviruses in order to achieve an HIV cure. We have described a strategy for the clearance of HIV-1 infection through selective elimination of host cells harboring replication-competent HIV (SECH), by inhibition of autophagy and promotion of apoptosis during viral re-activation. HIV-1 can infect various CD4+ T cell subsets, but it is not known whether the SECH approach is equally effective in targeting HIV-1 reservoirs in these different subsets in vivo. In a humanized mouse model, we found that treatments of HIV-1 infection by suppressive antiretroviral therapy (ART) led to the establishment of latent HIV reservoirs in naïve, central memory and effector memory T cells. Moreover, SECH treatments could clear latent HIV-1 reservoirs in these different T cell subsets of humanized mice. Co-culture studies showed that T cell subsets latently infected by HIV-1, but not uninfected bystander cells, were susceptible to cell death induced by SECH treatments. Our study suggests that the SECH strategy is effective for specific targeting of latent HIV-1 reservoirs in different T cell subsets.
Collapse
Affiliation(s)
- Min Li
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, United States
| | - Marietta M. Budai
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, United States
| | - Min Chen
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, United States
| | - Jin Wang
- Immunobiology and Transplant Science Center, Houston Methodist Research Institute, Houston, TX, United States
- Department of Surgery, Weill Cornell Medical College, Cornell University, New York, NY, United States
| |
Collapse
|
4
|
Udayantha HMV, Samaraweera AV, Liyanage DS, Sandamalika WMG, Lim C, Yang H, Lee JH, Lee S, Lee J. Molecular characterization, antiviral activity, and UV-B damage responses of Caspase-9 from Amphiprion clarkii. FISH & SHELLFISH IMMUNOLOGY 2022; 125:247-257. [PMID: 35588907 DOI: 10.1016/j.fsi.2022.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 04/18/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Apoptosis plays a vital role in maintaining cellular homeostasis in multicellular organisms. Caspase-9 (casp-9) is one of the major initiator caspases that induces apoptosis by activating downstream intrinsic apoptosis pathway genes. Here, we isolated the cDNA sequence (1992 bp) of caspase-9 from Amphiprion clarkii (Accasp-9) that consists of a 1305 bp coding region and encodes a 434 aa protein. In silico analysis showed that Accasp-9 has a theoretical isoelectric point of 5.81 and a molecular weight of 48.45 kDa. Multiple sequence alignment revealed that the CARD domain is located at the N-terminus, whereas the large P-20 and small P-10 domains are located at the C-terminus. Moreover, a highly conserved pentapeptide active site (296QACGG301), as well as histidine and cysteine active sites, are also retained at the C-terminus. In phylogenetic analysis, Accasp-9 formed a clade with casp-9 from different species, distinct from other caspases. Accasp-9 was highly expressed in the gill and intestine compared with other tissues analyzed in healthy A. clarkii. Accasp-9 expression was significantly elevated in the blood after stimulation with Vibrio harveyi and polyinosinic:polycytidylic acid (poly I:C; 12-48 h), but not with lipopolysaccharide. The nucleoprotein expression of the viral hemorrhagic septicemia virus was significantly reduced in Accasp-9 overexpressed fathead minnow (FHM) cells compared with that in the control. In addition, other in vitro assays revealed that cell apoptosis was significantly elevated in poly I:C and UV-B-treated Accasp-9 transfected FHM cells. However, H248P or C298S mutated Accasp-9 significantly reduced apoptosis in UV-B irradiated cells. Collectively, our results show that Accasp-9 might play a defensive role against invading pathogens and UV-B radiation and H248 and C298 active residues are significantly involved in apoptosis in teleosts.
Collapse
Affiliation(s)
- H M V Udayantha
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Anushka Vidurangi Samaraweera
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - D S Liyanage
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - W M Gayashani Sandamalika
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Chaehyeon Lim
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Hyerim Yang
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Ji Hun Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Sukkyoung Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju, 63333, Republic of Korea
| | - Jehee Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju, 63333, Republic of Korea.
| |
Collapse
|
5
|
Romero-Cordero S, Noguera-Julian A, Cardellach F, Fortuny C, Morén C. Mitochondrial changes associated with viral infectious diseases in the paediatric population. Rev Med Virol 2021; 31:e2232. [PMID: 33792105 PMCID: PMC9286481 DOI: 10.1002/rmv.2232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 12/24/2022]
Abstract
Infectious diseases occur worldwide with great frequency in both adults and children, causing 350,000 deaths in 2017, according to the latest World Health Organization reports. Both infections and their treatments trigger mitochondrial interactions at multiple levels: (i) incorporation of damaged or mutated proteins into the complexes of the electron transport chain; (ii) impact on mitochondrial genome (depletion, deletions and point mutations) and mitochondrial dynamics (fusion and fission); (iii) membrane potential impairment; (iv) apoptotic regulation; and (v) generation of reactive oxygen species, among others. Such alterations may result in serious adverse clinical events with considerable impact on the quality of life of the children and could even cause death. Herein, we use a systematic review to explore the association between mitochondrial alterations in paediatric infections including human immunodeficiency virus, cytomegalovirus, herpes viruses, various forms of hepatitis, adenovirus, T-cell lymphotropic virus and influenza. We analyse how these paediatric viral infectious processes may cause mitochondrial deterioration in this especially vulnerable population, with consideration for the principal aspects of research and diagnosis leading to improved disease understanding, management and surveillance.
Collapse
Affiliation(s)
- Sonia Romero-Cordero
- Faculty of Medicine, Pompeu Fabra University, Barcelona, Spain.,Faculty of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Antoni Noguera-Julian
- Malalties Infeccioses i Resposta Inflamatòria Sistèmica en Pediatria, Unitat d´Infeccions, Servei de Pediatria, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain.,Departament de Pediatria, Universitat de Barcelona, Barcelona, Spain.,CIBER de Epidemiología y Salud Pública, CIBERESP (ISCIII), Madrid, Spain.,Red de Investigación Translacional en Infectología Pediátrica, RITIP, Madrid, Spain
| | - Francesc Cardellach
- Faculty of Medicine and Health Sciences, Muscle Research and Mitochondrial Function Laboratory, Cellex-IDIBAPS, University of Barcelona, Barcelona, Spain.,CIBER de Enfermedades Raras, CIBERER (ISCIII), Madrid, Spain.,Internal Medicine Department, Hospital Clínic of Barcelona (HCB), Barcelona, Spain
| | - Clàudia Fortuny
- Malalties Infeccioses i Resposta Inflamatòria Sistèmica en Pediatria, Unitat d´Infeccions, Servei de Pediatria, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain.,Departament de Pediatria, Universitat de Barcelona, Barcelona, Spain.,CIBER de Epidemiología y Salud Pública, CIBERESP (ISCIII), Madrid, Spain.,Red de Investigación Translacional en Infectología Pediátrica, RITIP, Madrid, Spain
| | - Constanza Morén
- Faculty of Medicine and Health Sciences, Muscle Research and Mitochondrial Function Laboratory, Cellex-IDIBAPS, University of Barcelona, Barcelona, Spain.,CIBER de Enfermedades Raras, CIBERER (ISCIII), Madrid, Spain.,Internal Medicine Department, Hospital Clínic of Barcelona (HCB), Barcelona, Spain
| |
Collapse
|
6
|
Gomes STM, da Silva Graça Amoras E, Gomes ÉR, Queiroz MAF, Júnior ECS, de Vasconcelos Massafra JM, da Silva Lemos P, Júnior JLV, Ishak R, Vallinoto ACR. Immune escape mutations in HIV-1 controllers in the Brazilian Amazon region. BMC Infect Dis 2020; 20:546. [PMID: 32711474 PMCID: PMC7382849 DOI: 10.1186/s12879-020-05268-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV-1) infection is characterized by high viral replication and a decrease in CD4+ T cells (CD4+TC), resulting in AIDS, which can lead to death. In elite controllers and viremia controllers, viral replication is naturally controlled, with maintenance of CD4+TC levels without the use of antiretroviral therapy (ART). METHODS The aim of the present study was to describe virological and immunological risk factors among HIV-1-infected individuals according to characteristics of progression to AIDS. The sample included 30 treatment-naive patients classified into three groups based on infection duration (> 6 years), CD4+TC count and viral load: (i) 2 elite controllers (ECs), (ii) 7 viremia controllers (VCs) and (iii) 21 nonviremia controllers (NVCs). Nested PCR was employed to amplify the virus genome, which was later sequenced using the Ion PGM platform for subtyping and analysis of immune escape mutations. RESULTS Viral samples were classified as HIV-1 subtypes B and F. Greater selection pressure on mutations was observed in the group of viremia controllers, with a higher frequency of immunological escape mutations in the genes investigated, including two new mutations in gag. The viral sequences of viremia controllers and nonviremia controllers did not differ significantly regarding the presence of immune escape mutations. CONCLUSION The results suggest that progression to AIDS is not dependent on a single variable but rather on a set of characteristics and pressures exerted by virus biology and interactions with immunogenetic host factors.
Collapse
Affiliation(s)
- Samara Tatielle Monteiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
- Graduate Program in Biology of Infectious and Parasitic Agents, Biological Science Institute, Federal University of Pará, Ananindeua, Brazil
| | | | - Érica Ribeiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Maria Alice Freitas Queiroz
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Edivaldo Costa Sousa Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | | | - Poliana da Silva Lemos
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - João Lídio Vianez Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - Ricardo Ishak
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | | |
Collapse
|
7
|
Wan Q, Song D, Li H, He ML. Stress proteins: the biological functions in virus infection, present and challenges for target-based antiviral drug development. Signal Transduct Target Ther 2020; 5:125. [PMID: 32661235 PMCID: PMC7356129 DOI: 10.1038/s41392-020-00233-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/26/2020] [Accepted: 06/13/2020] [Indexed: 02/06/2023] Open
Abstract
Stress proteins (SPs) including heat-shock proteins (HSPs), RNA chaperones, and ER associated stress proteins are molecular chaperones essential for cellular homeostasis. The major functions of HSPs include chaperoning misfolded or unfolded polypeptides, protecting cells from toxic stress, and presenting immune and inflammatory cytokines. Regarded as a double-edged sword, HSPs also cooperate with numerous viruses and cancer cells to promote their survival. RNA chaperones are a group of heterogeneous nuclear ribonucleoproteins (hnRNPs), which are essential factors for manipulating both the functions and metabolisms of pre-mRNAs/hnRNAs transcribed by RNA polymerase II. hnRNPs involve in a large number of cellular processes, including chromatin remodelling, transcription regulation, RNP assembly and stabilization, RNA export, virus replication, histone-like nucleoid structuring, and even intracellular immunity. Dysregulation of stress proteins is associated with many human diseases including human cancer, cardiovascular diseases, neurodegenerative diseases (e.g., Parkinson’s diseases, Alzheimer disease), stroke and infectious diseases. In this review, we summarized the biologic function of stress proteins, and current progress on their mechanisms related to virus reproduction and diseases caused by virus infections. As SPs also attract a great interest as potential antiviral targets (e.g., COVID-19), we also discuss the present progress and challenges in this area of HSP-based drug development, as well as with compounds already under clinical evaluation.
Collapse
Affiliation(s)
- Qianya Wan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Dan Song
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Huangcan Li
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Ming-Liang He
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China. .,CityU Shenzhen Research Institute, Shenzhen, China.
| |
Collapse
|
8
|
Cellular Determinants of HIV Persistence on Antiretroviral Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1075:213-239. [PMID: 30030795 DOI: 10.1007/978-981-13-0484-2_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The era of antiretroviral therapy has made HIV-1 infection a manageable chronic disease for those with access to treatment. Despite treatment, virus persists in tissue reservoirs seeded with long-lived infected cells that are resistant to cell death and immune recognition. Which cells contribute to this reservoir and which factors determine their persistence are central questions that need to be answered to achieve viral eradication. In this chapter, we describe how cell susceptibility to infection, resistance to cell death, and immune-mediated killing as well as natural cell life span and turnover potential are central components that allow persistence of different lymphoid and myeloid cell subsets that were recently identified as key players in harboring latent and actively replicating virus. The relative contribution of these subsets to persistence of viral reservoir is described, and the open questions are highlighted.
Collapse
|
9
|
Canonical and Non-Canonical Autophagy in HIV-1 Replication Cycle. Viruses 2017; 9:v9100270. [PMID: 28946621 PMCID: PMC5691622 DOI: 10.3390/v9100270] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 12/11/2022] Open
Abstract
Autophagy is a lysosomal-dependent degradative process essential for maintaining cellular homeostasis, and is a key player in innate and adaptive immune responses to intracellular pathogens such as human immunodeficiency virus type 1 (HIV-1). In HIV-1 target cells, autophagy mechanisms can (i) selectively direct viral proteins and viruses for degradation; (ii) participate in the processing and presentation of viral-derived antigens through major histocompatibility complexes; and (iii) contribute to interferon production in response to HIV-1 infection. As a consequence, HIV-1 has evolved different strategies to finely regulate the autophagy pathway to favor its replication and dissemination. HIV-1 notably encodes accessory genes encoding Tat, Nef and Vpu proteins, which are able to perturb and hijack canonical and non-canonical autophagy mechanisms. This review outlines the current knowledge on the complex interplay between autophagy and HIV-1 replication cycle, providing an overview of the autophagy-mediated molecular processes deployed both by infected cells to combat the virus and by HIV-1 to evade antiviral response.
Collapse
|
10
|
Insulin Treatment Prevents Neuroinflammation and Neuronal Injury with Restored Neurobehavioral Function in Models of HIV/AIDS Neurodegeneration. J Neurosci 2017; 36:10683-10695. [PMID: 27733618 DOI: 10.1523/jneurosci.1287-16.2016] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/26/2016] [Indexed: 12/17/2022] Open
Abstract
HIV-1 infection of the brain causes the neurodegenerative syndrome HIV-associated neurocognitive disorders (HAND), for which there is no specific treatment. Herein, we investigated the actions of insulin using ex vivo and in vivo models of HAND. Increased neuroinflammatory gene expression was observed in brains from patients with HIV/AIDS. The insulin receptor was detected on both neurons and glia, but its expression was unaffected by HIV-1 infection. Insulin treatment of HIV-infected primary human microglia suppressed supernatant HIV-1 p24 levels, reduced CXCL10 and IL-6 transcript levels, and induced peroxisome proliferator-activated receptor gamma (PPAR-γ) expression. Insulin treatment of primary human neurons prevented HIV-1 Vpr-mediated cell process retraction and death. In feline immunodeficiency virus (FIV) infected cats, daily intranasal insulin treatment (20.0 IU/200 μl for 6 weeks) reduced CXCL10, IL-6, and FIV RNA detection in brain, although PPAR-γ in glia was increased compared with PBS-treated FIV+ control animals. These molecular changes were accompanied by diminished glial activation in cerebral cortex and white matter of insulin-treated FIV+ animals, with associated preservation of cortical neurons. Neuronal counts in parietal cortex, striatum, and hippocampus were higher in the FIV+/insulin-treated group compared with the FIV+/PBS-treated group. Moreover, intranasal insulin treatment improved neurobehavioral performance, including both memory and motor functions, in FIV+ animals. Therefore, insulin exerted ex vivo and in vivo antiviral, anti-inflammatory, and neuroprotective effects in models of HAND, representing a new therapeutic option for patients with inflammatory or infectious neurodegenerative disorders including HAND. SIGNIFICANCE STATEMENT HIV-associated neurocognitive disorders (HAND) represent a spectrum disorder of neurocognitive dysfunctions resulting from HIV-1 infection. Although the exact mechanisms causing HAND are unknown, productive HIV-1 infection in the brain with associated neuroinflammation is a potential pathogenic mechanism resulting in neuronal damage and death. We report that, in HIV-infected microglia cultures, insulin treatment led to reduced viral replication and inflammatory gene expression. In addition, intranasal insulin treatment of experimentally feline immunodeficiency virus-infected animals resulted in improved motor and memory performances. We show that insulin restored expression of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ), which is suppressed by HIV-1 replication. Our findings indicate a unique function for insulin in improving neurological outcomes in lentiviral infections, implicating insulin as a therapeutic intervention for HAND.
Collapse
|
11
|
González ME. The HIV-1 Vpr Protein: A Multifaceted Target for Therapeutic Intervention. Int J Mol Sci 2017; 18:ijms18010126. [PMID: 28075409 PMCID: PMC5297760 DOI: 10.3390/ijms18010126] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 12/16/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) Vpr protein is an attractive target for antiretroviral drug development. The conservation both of the structure along virus evolution and the amino acid sequence in viral isolates from patients underlines the importance of Vpr for the establishment and progression of HIV-1 disease. While its contribution to virus replication in dividing and non-dividing cells and to the pathogenesis of HIV-1 in many different cell types, both extracellular and intracellular forms, have been extensively studied, its precise mechanism of action nevertheless remains enigmatic. The present review discusses how the apparently multifaceted interplay between Vpr and host cells may be due to the impairment of basic metabolic pathways. Vpr protein modifies host cell energy metabolism, oxidative status, and proteasome function, all of which are likely conditioned by the concentration and multimerization of the protein. The characterization of Vpr domains along with new laboratory tools for the assessment of their function has become increasingly relevant in recent years. With these advances, it is conceivable that drug discovery efforts involving Vpr-targeted antiretrovirals will experience substantial growth in the coming years.
Collapse
Affiliation(s)
- María Eugenia González
- Unidad de Expresión Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo Km 2, Majadahonda, 28220 Madrid, Spain.
| |
Collapse
|
12
|
Zhou HY, Zheng YH, He Y, Chen Z, He B. The role of autophagy in THP-1 macrophages resistance to HIV- vpr-induced apoptosis. Exp Cell Res 2017; 351:68-73. [PMID: 28057470 DOI: 10.1016/j.yexcr.2016.12.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/14/2016] [Accepted: 12/28/2016] [Indexed: 11/17/2022]
Abstract
Macrophages are resistant to cell death and are one of HIV reservoirs. HIV viral protein Vpr has the potential to promote infection of and survival of macrophages, which could be a highly significant factor in the development and/or maintenance of macrophage viral reservoirs. However, the impact of vpr on macrophages resistance to apoptosis is yet to be comprehended. Autophagy is a cell survival mechanism under stress state. In this study, we investigated whether autophagy is involved in macrophages resistant to vpr-induced apoptosis. Using the THP1 macrophages, we studied the interconnection between macrophages resistance to apoptosis and autophagy. We found that vpr is able to trigger autophagy in transfected THP-1 macrophages confirmed by electron microscopy (EM) and western blot analysis, and inhibition of autophagy with 3MA increased vpr-induced apoptosis. The results indicate that autophagy may be responsible for maintenance of macrophage HIV reservoirs.
Collapse
Affiliation(s)
- Hua-Ying Zhou
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China.
| | - Yu-Huang Zheng
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Yan He
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Zi Chen
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Bo He
- Department of Infectious Diseases, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| |
Collapse
|
13
|
HIV-1 Vpr increases HCV replication through VprBP in cell culture. Virus Res 2016; 223:153-60. [DOI: 10.1016/j.virusres.2016.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 07/15/2016] [Accepted: 07/18/2016] [Indexed: 12/16/2022]
|
14
|
Zhou X, DeLucia M, Ahn J. SLX4-SLX1 Protein-independent Down-regulation of MUS81-EME1 Protein by HIV-1 Viral Protein R (Vpr). J Biol Chem 2016; 291:16936-16947. [PMID: 27354282 DOI: 10.1074/jbc.m116.721183] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Indexed: 12/22/2022] Open
Abstract
Evolutionarily conserved structure-selective endonuclease MUS81 forms a complex with EME1 and further associates with another endonuclease SLX4-SLX1 to form a four-subunit complex of MUS81-EME1-SLX4-SLX1, coordinating distinctive biochemical activities of both endonucleases in DNA repair. Viral protein R (Vpr), a highly conserved accessory protein in primate lentiviruses, was previously reported to bind SLX4 to mediate down-regulation of MUS81. However, the detailed mechanism underlying MUS81 down-regulation is unclear. Here, we report that HIV-1 Vpr down-regulates both MUS81 and its cofactor EME1 by hijacking the host CRL4-DCAF1 E3 ubiquitin ligase. Multiple Vpr variants, from HIV-1 and SIV, down-regulate both MUS81 and EME1. Furthermore, a C-terminally truncated Vpr mutant and point mutants R80A and Q65R, all of which lack G2 arrest activity, are able to down-regulate MUS81-EME1, suggesting that Vpr-induced G2 arrest is not correlated with MUS81-EME1 down-regulation. We also show that neither the interaction of MUS81-EME1 with Vpr nor their down-regulation is dependent on SLX4-SLX1. Together, these data provide new insight on a conserved function of Vpr in a host endonuclease down-regulation.
Collapse
Affiliation(s)
- Xiaohong Zhou
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Maria DeLucia
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Jinwoo Ahn
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| |
Collapse
|
15
|
Saxena M, Busca A, Holcik M, Kumar A. Bacterial DNA Protects Monocytic Cells against HIV-Vpr-Induced Mitochondrial Membrane Depolarization. THE JOURNAL OF IMMUNOLOGY 2016; 196:3754-67. [PMID: 26969755 DOI: 10.4049/jimmunol.1402379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/19/2016] [Indexed: 12/26/2022]
Abstract
Monocytes and macrophages are important HIV reservoirs, as they exhibit marked resistance to apoptosis upon infection. However, the mechanism underlying resistance to apoptosis in these cells is poorly understood. Using HIV-viral protein R-52-96 aa peptide (Vpr), we show that primary monocytes and THP-1 cells treated with Vpr are highly susceptible to mitochondrial depolarization, but develop resistance following stimulation with bacterial DNA or CpG oligodeoxynucleotide. We have shown that Vpr-induced mitochondrial depolarization is mediated by TNFR-associated factor-1 (TRAF-1) and TRAF-2 degradation and subsequent activation of caspase-8, Bid, and Bax. To provide the mechanism governing such resistance to mitochondrial depolarization, our results show that prior stimulation with CpG oligodeoxynucleotide or Escherichia coli DNA prevented: 1) TRAF-1/2 downregulation; 2) activation of caspase-8, Bid, and Bax; and 3) subsequent mitochondrial depolarization and release of apoptosis-inducing factor and cytochrome c Furthermore, this protection was mediated by upregulation of antiapoptotic protein (c-IAP-2) through calmodulin-dependent kinase-II activation. Thus, c-IAP-2 may prevent Vpr-mediated mitochondrial depolarization through stabilizing TRAF-1/2 expression and sequential inhibition of caspase-8, Bid, and Bax.
Collapse
Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Martin Holcik
- Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and
| | - Ashok Kumar
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| |
Collapse
|
16
|
Monroy N, Herrero L, Carrasco L, González ME. Influence of glutathione availability on cell damage induced by human immunodeficiency virus type 1 viral protein R. Virus Res 2015; 213:116-123. [PMID: 26597719 DOI: 10.1016/j.virusres.2015.11.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 01/23/2023]
Abstract
The human immunodeficiency virus type 1 (HIV-1) encodes for accessory viral protein R (Vpr), which arrests the cell cycle of host cells at G2 and causes mitochondrial dysfunction and alterations in glycolysis. High-level expression of Vpr protein correlates with increased viral production and disease progression. Vpr causes structural and functional injury in many types of eukaryotic cells, whether or not they are permissive for viral replication; among them is the budding yeast Saccharomyces cerevisiae. We hypothesized that the dramatic Vpr-induced injuries in yeast could be prevented by strengthening their redox response capacity. We show that exogenous addition of glutathione (GSH) or its prodrug, N-acetylcysteine (NAC), protected budding yeasts from Vpr-induced cytopathic effects. Moreover, addition of adenosine triphosphate (ATP) to growing cultures of Vpr-producing yeast returned cellular growth to control levels, whereas the addition dehydroascorbic acid (DHA) had only a minor protective effect. The diminished protein levels of Cox2p and Cox4p in wild typeVpr-producing yeasts together with the acute sensitivity of petite yeasts to Vpr activity may have been caused by low intracellular ATP levels. As a consequence of this energy deficit, eukaryotic cells would be unable to synthetize adequate supplies of GSH or to signal the mitochondrial retrograde response. Our findings strongly suggest that the cytopathogenic effect of Vpr protein in eukaryotic cells can be prevented by increasing intracellular antioxidant stores or, alternatively, supplying external ATP. Furthermore, these results support a potentially promising future for S. cerevisiae expression as a modality to search for Vpr-targeted inhibitors.
Collapse
Affiliation(s)
- Noemí Monroy
- Unidad de Expresión Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo Km 2, 28220 Majadahonda, Madrid, Spain
| | - Laura Herrero
- Unidad de Expresión Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo Km 2, 28220 Majadahonda, Madrid, Spain
| | - Luis Carrasco
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
| | - María Eugenia González
- Unidad de Expresión Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo Km 2, 28220 Majadahonda, Madrid, Spain.
| |
Collapse
|
17
|
HIV-1 Vpr- and Reverse Transcription-Induced Apoptosis in Resting Peripheral Blood CD4 T Cells and Protection by Common Gamma-Chain Cytokines. J Virol 2015; 90:904-16. [PMID: 26537673 DOI: 10.1128/jvi.01770-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/26/2015] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED HIV-1 infection leads to the progressive depletion of the CD4 T cell compartment by various known and unknown mechanisms. In vivo, HIV-1 infects both activated and resting CD4 T cells, but in vitro, in the absence of any stimuli, resting CD4 T cells from peripheral blood are resistant to infection. This resistance is generally attributed to an intracellular environment that does not efficiently support processes such as reverse transcription (RT), resulting in abortive infection. Here, we show that in vitro HIV-1 infection of resting CD4 T cells induces substantial cell death, leading to abortive infection. In vivo, however, various microenvironmental stimuli in lymphoid and mucosal tissues provide support for HIV-1 replication. For example, common gamma-chain cytokines (CGCC), such as interleukin-7 (IL-7), render resting CD4 T cells permissible to HIV-1 infection without inducing T cell activation. Here, we find that CGCC primarily allow productive infection by preventing HIV-1 triggering of apoptosis, as evidenced by early release of cytochrome c and caspase 3/7 activation. Cell death is triggered both by products of reverse transcription and by virion-borne Vpr protein, and CGCC block both mechanisms. When HIV-1 RT efficiency was enhanced by SIVmac239 Vpx protein, cell death was still observed, indicating that the speed of reverse transcription and the efficiency of its completion contributed little to HIV-1-induced cell death in this system. These results show that a major restriction on HIV-1 infection in resting CD4 T cells resides in the capacity of these cells to survive the early steps of HIV-1 infection. IMPORTANCE A major consequence of HIV-1 infection is the destruction of CD4 T cells. Here, we show that delivery of virion-associated Vpr protein and the process of reverse transcription are each sufficient to trigger apoptosis of resting CD4 T cells isolated from peripheral blood. While these 2 mechanisms have been previously described in various cell types, we show for the first time their concerted effect in inducing resting CD4 T cell depletion. Importantly, we found that cytokines such as IL-7 and IL-4, which are particularly active in sites of HIV-1 replication, protect resting CD4 T cells from these cytopathic effects and, primarily through this protection, rather than through enhancement of specific replicative steps, they promote productive infection. This study provides important new insights for the understanding of the early steps of HIV-1 infection and T cell depletion.
Collapse
|
18
|
Vpr Enhances Tumor Necrosis Factor Production by HIV-1-Infected T Cells. J Virol 2015; 89:12118-30. [PMID: 26401039 DOI: 10.1128/jvi.02098-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 09/16/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED The HIV-1 accessory protein Vpr displays different activities potentially impacting viral replication, including the arrest of the cell cycle in the G2 phase and the stimulation of apoptosis and DNA damage response pathways. Vpr also modulates cytokine production by infected cells, but this property remains partly characterized. Here, we investigated the effect of Vpr on the production of the proinflammatory cytokine tumor necrosis factor (TNF). We report that Vpr significantly increases TNF secretion by infected lymphocytes. De novo production of Vpr is required for this effect. Vpr mutants known to be defective for G2 cell cycle arrest induce lower levels of TNF secretion, suggesting a link between these two functions. Silencing experiments and the use of chemical inhibitors further implicated the cellular proteins DDB1 and TAK1 in this activity of Vpr. TNF secreted by HIV-1-infected cells triggers NF-κB activity in bystander cells and allows viral reactivation in a model of latently infected cells. Thus, the stimulation of the proinflammatory pathway by Vpr may impact HIV-1 replication in vivo. IMPORTANCE The role of the HIV-1 accessory protein Vpr remains only partially characterized. This protein is important for viral pathogenesis in infected individuals but is dispensable for viral replication in most cell culture systems. Some of the functions described for Vpr remain controversial. In particular, it remains unclear whether Vpr promotes or instead prevents proinflammatory and antiviral immune responses. In this report, we show that Vpr promotes the release of TNF, a proinflammatory cytokine associated with rapid disease progression. Using Vpr mutants or inhibiting selected cellular genes, we show that the cellular proteins DDB1 and TAK1 are involved in the release of TNF by HIV-infected cells. This report provides novel insights into how Vpr manipulates TNF production and helps clarify the role of Vpr in innate immune responses and inflammation.
Collapse
|
19
|
Le Noury DA, Mosebi S, Papathanasopoulos MA, Hewer R. Functional roles of HIV-1 Vpu and CD74: Details and implications of the Vpu-CD74 interaction. Cell Immunol 2015; 298:25-32. [PMID: 26321123 DOI: 10.1016/j.cellimm.2015.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/22/2015] [Indexed: 01/24/2023]
Abstract
HIV-1 Vpu has a variety of functions, including CD4 degradation and the downregulation of MHCII. Downregulation of the MHCII occurs through Vpu binding to the cytoplasmic domain of CD74, the chaperone for antigen presentation. The CD74 cytoplasmic domain also plays a vital role in cell signaling through the activation of an NF-κB signal cascade for the maturation, proliferation and survival of B cells as well as by binding the macrophage inhibitory factor. In view of these functions, it follows that the Vpu-CD74 interaction has multiple downstream consequences for the immune system as it not only impairs foreign antigen presentation but may also have an effect on signal transduction cascades. It is thought that Vpu specifically targets intracellular CD74 while other HIV-1 proteins cannot. Therefore, this protein-protein interaction would be a potential drug target in order to reduce viral persistence. We review the functional importance and specific binding site of Vpu and CD74.
Collapse
Affiliation(s)
- Denise A Le Noury
- Centre for Metal-based Drug Discovery, Mintek, Private Bag X3015, Randburg 2125, South Africa; Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand Medical School, Private Bag 3, WITS, 2050, South Africa.
| | - Salerwe Mosebi
- Centre for Metal-based Drug Discovery, Mintek, Private Bag X3015, Randburg 2125, South Africa.
| | - Maria A Papathanasopoulos
- Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand Medical School, Private Bag 3, WITS, 2050, South Africa.
| | - Raymond Hewer
- Centre for Metal-based Drug Discovery, Mintek, Private Bag X3015, Randburg 2125, South Africa.
| |
Collapse
|
20
|
How do viruses control mitochondria-mediated apoptosis? Virus Res 2015; 209:45-55. [PMID: 25736565 PMCID: PMC7114537 DOI: 10.1016/j.virusres.2015.02.026] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 12/16/2022]
Abstract
There is no doubt that viruses require cells to successfully reproduce and effectively infect the next host. The question is what is the fate of the infected cells? All eukaryotic cells can "sense" viral infections and exhibit defence strategies to oppose viral replication and spread. This often leads to the elimination of the infected cells by programmed cell death or apoptosis. This "sacrifice" of infected cells represents the most primordial response of multicellular organisms to viruses. Subverting host cell apoptosis, at least for some time, is therefore a crucial strategy of viruses to ensure their replication, the production of essential viral proteins, virus assembly and the spreading to new hosts. For that reason many viruses harbor apoptosis inhibitory genes, which once inside infected cells are expressed to circumvent apoptosis induction during the virus reproduction phase. On the other hand, viruses can take advantage of stimulating apoptosis to (i) facilitate shedding and hence dissemination, (ii) to prevent infected cells from presenting viral antigens to the immune system or (iii) to kill non-infected bystander and immune cells which would limit viral propagation. Hence the decision whether an infected host cell undergoes apoptosis or not depends on virus type and pathogenicity, its capacity to oppose antiviral responses of the infected cells and/or to evade any attack from immune cells. Viral genomes have therefore been adapted throughout evolution to satisfy the need of a particular virus to induce or inhibit apoptosis during its life cycle. Here we review the different strategies used by viruses to interfere with the two major apoptosis as well as with the innate immune signaling pathways in mammalian cells. We will focus on the intrinsic mitochondrial pathway and discuss new ideas about how particular viruses could activately engage mitochondria to induce apoptosis of their host.
Collapse
|
21
|
Mbita Z, Hull R, Dlamini Z. Human immunodeficiency virus-1 (HIV-1)-mediated apoptosis: new therapeutic targets. Viruses 2014; 6:3181-227. [PMID: 25196285 PMCID: PMC4147692 DOI: 10.3390/v6083181] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/12/2014] [Accepted: 07/08/2014] [Indexed: 12/18/2022] Open
Abstract
HIV has posed a significant challenge due to the ability of the virus to both impair and evade the host’s immune system. One of the most important mechanisms it has employed to do so is the modulation of the host’s native apoptotic pathways and mechanisms. Viral proteins alter normal apoptotic signaling resulting in increased viral load and the formation of viral reservoirs which ultimately increase infectivity. Both the host’s pro- and anti-apoptotic responses are regulated by the interactions of viral proteins with cell surface receptors or apoptotic pathway components. This dynamic has led to the development of therapies aimed at altering the ability of the virus to modulate apoptotic pathways. These therapies are aimed at preventing or inhibiting viral infection, or treating viral associated pathologies. These drugs target both the viral proteins and the apoptotic pathways of the host. This review will examine the cell types targeted by HIV, the surface receptors exploited by the virus and the mechanisms whereby HIV encoded proteins influence the apoptotic pathways. The viral manipulation of the hosts’ cell type to evade the immune system, establish viral reservoirs and enhance viral proliferation will be reviewed. The pathologies associated with the ability of HIV to alter apoptotic signaling and the drugs and therapies currently under development that target the ability of apoptotic signaling within HIV infection will also be discussed.
Collapse
Affiliation(s)
- Zukile Mbita
- College of Agriculture and Environmental Sciences, University of South Africa, Florida Science Campus, C/o Christiaan de Wet and Pioneer Avenue P/Bag X6, Johannesburg 1710, South Africa.
| | - Rodney Hull
- College of Agriculture and Environmental Sciences, University of South Africa, Florida Science Campus, C/o Christiaan de Wet and Pioneer Avenue P/Bag X6, Johannesburg 1710, South Africa.
| | - Zodwa Dlamini
- College of Agriculture and Environmental Sciences, University of South Africa, Florida Science Campus, C/o Christiaan de Wet and Pioneer Avenue P/Bag X6, Johannesburg 1710, South Africa.
| |
Collapse
|
22
|
Agarwal N, Iyer D, Patel SG, Sekhar RV, Phillips TM, Schubert U, Oplt T, Buras ED, Samson SL, Couturier J, Lewis DE, Rodriguez-Barradas MC, Jahoor F, Kino T, Kopp JB, Balasubramanyam A. HIV-1 Vpr induces adipose dysfunction in vivo through reciprocal effects on PPAR/GR co-regulation. Sci Transl Med 2014; 5:213ra164. [PMID: 24285483 DOI: 10.1126/scitranslmed.3007148] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Viral infections, such as HIV, have been linked to obesity, but mechanistic evidence that they cause adipose dysfunction in vivo is lacking. We investigated a pathogenic role for the HIV-1 accessory protein viral protein R (Vpr), which can coactivate the glucocorticoid receptor (GR) and co-repress peroxisome proliferator-activated receptor γ (PPARγ) in vitro, in HIV-associated adipose dysfunction. Vpr circulated in the blood of most HIV-infected patients tested, including those on antiretroviral therapy (ART) with undetectable viral load. Vpr-mediated mechanisms were dissected in vivo using mouse models expressing the Vpr transgene in adipose tissues and liver (Vpr-Tg) or infused with synthetic Vpr. Both models demonstrated accelerated whole-body lipolysis, hyperglycemia and hypertriglyceridemia, and tissue-specific findings. Fat depots in these mice had diminished mass, macrophage infiltration, and blunted PPARγ target gene expression but increased GR target gene expression. In liver, we observed blunted PPARα target gene expression, steatosis with decreased adenosine monophosphate-activated protein kinase activity, and insulin resistance. Similar to human HIV-infected patients, Vpr circulated in the serum of Vpr-Tg mice. Vpr blocked differentiation in preadipocytes through cell cycle arrest, whereas in mature adipocytes, it increased lipolysis with reciprocally altered association of PPARγ and GR with their target promoters. These results delineate a distinct pathogenic sequence: Vpr, released from HIV-1 in tissue reservoirs after ART, can disrupt PPAR/GR co-regulation and cell cycle control to produce adipose dysfunction and hepatosteatosis. Confirmation of these mechanisms in HIV patients could lead to targeted treatment of the metabolic complications with Vpr inhibitors, GR antagonists, or PPARγ/PPARα agonists.
Collapse
Affiliation(s)
- Neeti Agarwal
- Translational Metabolism Unit, Diabetes Research Center, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
UNLABELLED HIV-1 modulates key host cellular pathways for successful replication and pathogenesis through viral proteins. By evaluating the hijacking of the host ubiquitination pathway by HIV-1 at the whole-cell level, we now show major perturbations in the ubiquitinated pool of the host proteins post-HIV-1 infection. Our overexpression- and infection-based studies of T cells with wild-type and mutant HIV-1 proviral constructs showed that Vpr is necessary and sufficient for reducing whole-cell ubiquitination. Mutagenic analysis revealed that the three leucine-rich helical regions of Vpr are critical for this novel function of Vpr, which was independent of its other known cellular functions. We also validated that this effect of Vpr was conserved among different subtypes (subtypes B and C) and circulating recombinants from Northern India. Finally, we establish that this phenomenon is involved in HIV-1-mediated diversion of host ubiquitination machinery specifically toward the degradation of various restriction factors during viral pathogenesis. IMPORTANCE HIV-1 is known to rely heavily on modulation of the host ubiquitin pathway, particularly for counteraction of antiretroviral restriction factors, i.e., APOBEC3G, UNG2, and BST-2, etc.; viral assembly; and release. Reports to date have focused on the molecular hijacking of the ubiquitin machinery by HIV-1 at the level of E3 ligases. Interaction of a viral protein with an E3 ligase alters its specificity to bring about selective protein ubiquitination. However, in the case of infection, multiple viral proteins can interact with this multienzyme pathway at various levels, making it much more complicated. Here, we have addressed the manipulation of ubiquitination at the whole-cell level post-HIV-1 infection. Our results show that HIV-1 Vpr is necessary and sufficient to bring about the redirection of the host ubiquitin pathway toward HIV-1-specific outcomes. We also show that the three leucine-rich helical regions of Vpr are critical for this effect and that this ability of Vpr is conserved across circulating recombinants. Our work, the first of its kind, provides novel insight into the regulation of the ubiquitin system at the whole-cell level by HIV-1.
Collapse
|
24
|
Gangwani MR, Noel RJ, Shah A, Rivera-Amill V, Kumar A. Human immunodeficiency virus type 1 viral protein R (Vpr) induces CCL5 expression in astrocytes via PI3K and MAPK signaling pathways. J Neuroinflammation 2013; 10:136. [PMID: 24225433 PMCID: PMC3831867 DOI: 10.1186/1742-2094-10-136] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 10/28/2013] [Indexed: 12/18/2022] Open
Abstract
Background Neurocognitive impairments remain prevalent in HIV-1 infected individuals despite current antiretroviral therapies. It is increasingly becoming evident that astrocytes play a critical role in HIV-1 neuropathogenesis through the production of proinflammatory cytokines/chemokines. HIV-1 viral protein R (Vpr) plays an important role in neuronal dysfunction; however, its role in neuroinflammation is not well characterized. The major objective of this study was to determine the effect of Vpr in induction of proinflammatory chemokine CCL5 in astrocytes and to define the underlying mechanism(s). Methods SVGA astrocytes were either mock transfected or were transfected with a plasmid encoding HIV-1 Vpr, and the cells were harvested at different time intervals. The mRNA level of CCL5 expression was quantified using real-time RT-PCR, and cell culture supernatants were assayed for CCL5 protein concentration. Immunocytochemistry was performed on HIV-1 Vpr transfected astrocytes to check CCL5 expression. Various signaling mechanisms such as p38 MAPK, PI3K/Akt, NF-κB and AP-1 were explored using specific chemical inhibitors and siRNAs. Results HIV-1 Vpr transfected astrocytes exhibited time-dependent induction of CCL5 as compared to mock-transfected astrocytes at both the mRNA and protein level. Immunostained images of astrocytes transfected with HIV-1 Vpr also showed much higher accumulation of CCL5 in comparison to untransfected and mock-transfected astrocytes. Pre-treatment with NF-κB (SC514) and PI3K/Akt (LY294002) inhibitor partially abrogated CCL5 mRNA and protein expression levels as opposed to untreated controls after HIV-1 Vpr transfection. Specific siRNAs against p50 and p65 subunits of NF-κB, p38δ MAPK, Akt-2 and Akt-3, and AP-1 transcription factor substantially inhibited the production of CCL5 in HIV-1 Vpr transfected astrocytes. Conclusion These results demonstrate the ability of HIV-1 Vpr to induce CCL5 in astrocytes in a time-dependent manner. Furthermore, this effect was observed to be mediated by transcription factors NF-κB and AP-1 and involved the p38-MAPK and PI3K/Akt pathway.
Collapse
Affiliation(s)
| | | | | | | | - Anil Kumar
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri, Kansas City, MO 64108, USA.
| |
Collapse
|
25
|
Hanauske-Abel HM, Saxena D, Palumbo PE, Hanauske AR, Luchessi AD, Cambiaghi TD, Hoque M, Spino M, Gandolfi DD, Heller DS, Singh S, Park MH, Cracchiolo BM, Tricta F, Connelly J, Popowicz AM, Cone RA, Holland B, Pe’ery T, Mathews MB. Drug-induced reactivation of apoptosis abrogates HIV-1 infection. PLoS One 2013; 8:e74414. [PMID: 24086341 PMCID: PMC3781084 DOI: 10.1371/journal.pone.0074414] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 08/01/2013] [Indexed: 12/11/2022] Open
Abstract
HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose) polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP) in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of selectively cytocidal antivirals that eliminate viral infection by destroying infected cells. A drug-based drug discovery program, based on these compounds, is warranted to determine the potential of such agents in clinical trials of HIV-infected patients.
Collapse
Affiliation(s)
- Hartmut M. Hanauske-Abel
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
- Department of Pediatrics, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
- Department of Obstetrics, Gynecology & Women’s Health, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Deepti Saxena
- Department of Pediatrics, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Paul E. Palumbo
- Department of Pediatrics, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Axel-Rainer Hanauske
- Oncology Center and Medical Clinic III, Asklepios Clinic St. George, Hamburg, Germany
| | - Augusto D. Luchessi
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Tavane D. Cambiaghi
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Mainul Hoque
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Michael Spino
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
- ApoPharma Inc., Toronto, Ontario, Canada
| | | | - Debra S. Heller
- Department of Pathology & Laboratory Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Sukhwinder Singh
- Department of Pathology & Laboratory Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Myung Hee Park
- Oral and Pharyngeal Cancer Branch, National Institute for Dental and Craniofacial Research, Bethesda, Maryland, United States of America
| | - Bernadette M. Cracchiolo
- Department of Obstetrics, Gynecology & Women’s Health, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | | | | | - Anthony M. Popowicz
- Department of Information Technology, Rockefeller University, New York, New York, United States of America
| | - Richard A. Cone
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Bart Holland
- Department of Preventive Medicine & Community Health, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Tsafi Pe’ery
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
- Department of Medicine, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Michael B. Mathews
- Department of Biochemistry & Molecular Biology, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| |
Collapse
|
26
|
Barrero CA, Datta PK, Sen S, Deshmane S, Amini S, Khalili K, Merali S. HIV-1 Vpr modulates macrophage metabolic pathways: a SILAC-based quantitative analysis. PLoS One 2013; 8:e68376. [PMID: 23874603 PMCID: PMC3709966 DOI: 10.1371/journal.pone.0068376] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 05/29/2013] [Indexed: 01/09/2023] Open
Abstract
Human immunodeficiency virus type 1 encoded viral protein Vpr is essential for infection of macrophages by HIV-1. Furthermore, these macrophages are resistant to cell death and are viral reservoir. However, the impact of Vpr on the macrophage proteome is yet to be comprehended. The goal of the present study was to use a stable-isotope labeling by amino acids in cell culture (SILAC) coupled with mass spectrometry-based proteomics approach to characterize the Vpr response in macrophages. Cultured human monocytic cells, U937, were differentiated into macrophages and transduced with adenovirus construct harboring the Vpr gene. More than 600 proteins were quantified in SILAC coupled with LC-MS/MS approach, among which 136 were significantly altered upon Vpr overexpression in macrophages. Quantified proteins were selected and clustered by biological functions, pathway and network analysis using Ingenuity computational pathway analysis. The proteomic data illustrating increase in abundance of enzymes in the glycolytic pathway (pentose phosphate and pyruvate metabolism) was further validated by western blot analysis. In addition, the proteomic data demonstrate down regulation of some key mitochondrial enzymes such as glutamate dehydrogenase 2 (GLUD2), adenylate kinase 2 (AK2) and transketolase (TKT). Based on these observations we postulate that HIV-1 hijacks the macrophage glucose metabolism pathway via the Vpr-hypoxia inducible factor 1 alpha (HIF-1 alpha) axis to induce expression of hexokinase (HK), glucose-6-phosphate dehyrogenase (G6PD) and pyruvate kinase muscle type 2 (PKM2) that facilitates viral replication and biogenesis, and long-term survival of macrophages. Furthermore, dysregulation of mitochondrial glutamate metabolism in macrophages can contribute to neurodegeneration via neuroexcitotoxic mechanisms in the context of NeuroAIDS.
Collapse
Affiliation(s)
- Carlos A. Barrero
- Department of Biochemistry, Temple University School of Medicine, Fels Institute, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Prasun K. Datta
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| | - Satarupa Sen
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Satish Deshmane
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Shohreh Amini
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Kamel Khalili
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Salim Merali
- Department of Biochemistry, Temple University School of Medicine, Fels Institute, Philadelphia, Pennsylvania, United States of America
- Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| |
Collapse
|
27
|
Zhang S, Zhang B, Xu X, Wang L, Feng X, Wang Q, Huang H, Wu J, Li P, Wang J. HIV-1 viral protein R downregulates Ebp1 and stabilizes p53 in glioblastoma U87MG cells. Clin Transl Oncol 2013; 16:293-300. [PMID: 23828502 DOI: 10.1007/s12094-013-1072-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 06/20/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE HIV-1 viral protein R (Vpr) inhibits cell growth and induces apoptosis in a wide range of cancers. However, the mechanism by which Vpr induces cell cycle arrest and apoptosis in GBM cell lines is unclear. The present work was taken to detect the proteins interacted with Vpr in U87MG cells. METHODS We analyzed the differential expression of proteins between glioblastoma cell U87MG treated with Ad-Vpr and untreated by 2-DE. We used antibody array analysis to analyze the common molecules in the apoptosis of U87MG induced by Vpr. RESULTS We analyzed the differential expression of proteins between U87MG cell treated with Ad-Vpr and untreated, and found that proteins related to DNA damage repair or different apoptosis pathways were involved in the G2 arrest and apoptosis mediated by Vpr. In addition, proliferation-associated protein 2G4 (PA2G4), also known as Ebp1, was down-regulated and p53 was up-regulated in U87MG cells treated with Ad-Vpr. CONCLUSIONS Our data suggest that Vpr may inhibit Ebp1 to stabilize p53, which in turn leads to G2 arrest and apoptosis in U87MG cells.
Collapse
Affiliation(s)
- S Zhang
- Tianjin Neurosurgical Institute, Tianjin Huanhu Hospital, Tianjin, 300060, People's Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Tomasicchio M, Avenant C, Du Toit A, Ray RM, Hapgood JP. The progestin-only contraceptive medroxyprogesterone acetate, but not norethisterone acetate, enhances HIV-1 Vpr-mediated apoptosis in human CD4+ T cells through the glucocorticoid receptor. PLoS One 2013; 8:e62895. [PMID: 23658782 PMCID: PMC3643923 DOI: 10.1371/journal.pone.0062895] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/26/2013] [Indexed: 12/25/2022] Open
Abstract
The glucocorticoid receptor (GR) regulates several physiological functions, including immune function and apoptosis. The HIV-1 virus accessory protein, viral protein R (Vpr), can modulate the transcriptional response of the GR. Glucocorticoids (GCs) and Vpr have been reported to induce apoptosis in various cells, including T-cells. We have previously shown that the injectable contraceptive, medroxyprogesterone acetate (MPA) is a partial to full agonist for the GR, unlike norethisterone acetate (NET-A). We investigated the functional cross talk between the GR and Vpr in inducing apoptosis in CD4(+) T-cells, in the absence and presence of GCs and these progestins, as well as progesterone. By using flow cytometry, we show that, in contrast to NET-A and progesterone, the synthetic GR ligand dexamethasone (Dex), cortisol and MPA induce apoptosis in primary CD4(+) T-cells. Furthermore, the C-terminal part of the Vpr peptide, or HIV-1 pseudovirus, together with Dex or MPA further increased the apoptotic phenotype, unlike NET-A and progesterone. By a combination of Western blotting, PCR and the use of receptor- selective agonists, we provide evidence that the GR and the estrogen receptor are the only steroid receptors expressed in peripheral blood mononuclear cells. These results, together with the findings that RU486, a GR antagonist, prevents Dex-, MPA- and Vpr-mediated apoptosis, provide evidence for the first time that GR agonists or partial agonists increase apoptosis in primary CD4(+) T-cells via the GR. We show that apoptotic induction involves differential expression of key apoptotic genes by both Vpr and GCs/MPA. This work suggests that contraceptive doses of MPA but not NET-A or physiological doses of progesterone could potentially accelerate depletion of CD4(+) T-cells in a GR-dependent fashion in HIV-1 positive women, thereby contributing to immunodeficiency. The results imply that choice of progestin used in contraception may be critical to susceptibility and progression of diseases such as HIV-1.
Collapse
Affiliation(s)
- Michele Tomasicchio
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Chanel Avenant
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Andrea Du Toit
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Roslyn M. Ray
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Janet P. Hapgood
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| |
Collapse
|
29
|
Walker TN, Cimakasky LM, Coleman EM, Madison MN, Hildreth JE. Antibody against integrin lymphocyte function-associated antigen 1 inhibits HIV type 1 infection in primary cells through caspase-8-mediated apoptosis. AIDS Res Hum Retroviruses 2013; 29:371-83. [PMID: 22697794 DOI: 10.1089/aid.2011.0395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
HIV-1 infection induces formation of a virological synapse wherein CD4, chemokine receptors, and cell-adhesion molecules such as lymphocyte function-associated antigen 1 (LFA-1) form localized domains on the cell surface. Studies show that LFA-1 on the surface of HIV-1 particles retains its adhesion function and enhances virus attachment to susceptible cells by binding its counterreceptor intercellular adhesion molecule 1 (ICAM-1). This virus-cell interaction augments virus infectivity by facilitating binding and entry events. In this study, we demonstrate that inhibition of the LFA-1/ICAM-1 interaction by a monoclonal antibody leads to decreased virus production and spread in association with increased apoptosis of HIV-infected primary T cells. The data indicate that the LFA-1/ICAM-1 interaction may limit apoptosis in HIV-1-infected T cells. This phenomenon appears similar to anoikis wherein epithelial cells are protected from apoptosis conferred by ligand-bound integrins. These results have implications for further understanding HIV pathogenesis and replication in peripheral compartments and lymphoid organs.
Collapse
Affiliation(s)
- Tiffany N. Walker
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee
| | | | - Ebony M. Coleman
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, California
| | - M. Nia Madison
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee
| | - James E.K. Hildreth
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, California
| |
Collapse
|
30
|
Zhao C, Zhang X, Li F, Huan P, Xiang J. Functional analysis of the promoter of the heat shock cognate 70 gene of the Pacific white shrimp, Litopenaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2013; 34:397-401. [PMID: 23032439 DOI: 10.1016/j.fsi.2012.09.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 09/23/2012] [Accepted: 09/24/2012] [Indexed: 06/01/2023]
Abstract
Current knowledge on cis-regulatory elements of immune genes of the Pacific white shrimp (Litopenaeus vannamei) is poor. In this study, we identified the promoter of the heat shock cognate protein 70 (HSC70) gene of L. vannamei (lvhsc70). The promoter activity of lvhsc70 promoter was analyzed in insect sf9 cell lines. First, the putative promoter sequence was proved to be able to drive the expression of reporter EGFP gene successfully. Then serial deletion experiments were conducted to investigate functional transcription elements in the promoter region. The results revealed that both positive and negative transcription elements existed in this region. These results are quite different from the previous report on the promoter of HSC70 gene in Penaeus monodon (pmhsc70), where only positive transcription elements were indicated. The sequences that are not conserved between the promoters of lvhsc70 and pmhsc70 might contribute to the differences. Finally, we tested the effect of a putative "NF-κb binding site" in the promoter and, surprisingly, found that deletion of this site would result in a significantly enhancement of the expression of reporter genes, while the underlying mechanisms remain unrevealed. Our results would provide supports for future studies to identify the functional transcription elements in the lvhsc70 promoter and to expand our knowledge on regulation of innate immune genes in penaeid shrimp.
Collapse
Affiliation(s)
- Cui Zhao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | | | | | | | | |
Collapse
|
31
|
Busca A, Saxena M, Kumar A. Critical role for antiapoptotic Bcl-xL and Mcl-1 in human macrophage survival and cellular IAP1/2 (cIAP1/2) in resistance to HIV-Vpr-induced apoptosis. J Biol Chem 2012; 287:15118-33. [PMID: 22403404 DOI: 10.1074/jbc.m111.312660] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Macrophages are resistant to HIV cytopathic effects, which contributes to viral persistence and reservoir formation. HIV viral protein R (Vpr) is a potent apoptosis-inducing agent for primary monocytes. Because the biologically active Vpr is found in serum and cerebrospinal fluid of HIV-infected patients, we investigated the apoptotic effect of Vpr on monocyte-derived macrophages and phorbol 12-myristate 13-acetate-activated THP1 macrophages. Our results show that primary monocytes and THP1 cells develop resistance to Vpr-induced apoptosis following differentiation into macrophages. To determine the effect of Vpr on the expression of antiapoptotic proteins, we show that in contrast to the undifferentiated cells, Vpr did not down-regulate the expression of antiapoptotic inhibitors of apoptosis (IAPs) and Bcl2 family members in macrophages, suggesting their involvement in resistance to Vpr-induced apoptosis. However, knocking down Bcl-xL and Mcl-1 proteins induced spontaneous apoptosis with no impact on susceptibility to Vpr-induced apoptosis. In contrast, down-regulation of cellular IAP1 (cIAP1) and cIAP2 by using siRNAs and SMAC (second mitochondria-derived activator of caspases) mimetic sensitized macrophages to Vpr-induced apoptosis. Overall, our results suggest that resistance to Vpr-induced apoptosis is specifically mediated by cIAP1/2 genes independent of Bcl-xL and Mcl-1, which play a key role in maintaining cell viability. Moreover, IAP modulation may be a potential strategy to eliminate HIV persistence in macrophages.
Collapse
Affiliation(s)
- Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | | | | |
Collapse
|
32
|
|
33
|
Saxena M, Busca A, Pandey S, Kryworuchko M, Kumar A. CpG protects human monocytic cells against HIV-Vpr-induced apoptosis by cellular inhibitor of apoptosis-2 through the calcium-activated JNK pathway in a TLR9-independent manner. THE JOURNAL OF IMMUNOLOGY 2011; 187:5865-78. [PMID: 22068233 DOI: 10.4049/jimmunol.1100115] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Monocytic cells survive HIV replication and consequent cytopathic effects because of their decreased sensitivity to HIV-induced apoptosis. However, the mechanism underlying this resistance to apoptosis remains poorly understood. Lymphocytic cells are exposed to microbial products because of their translocation from the gut in persons with chronic HIV infections or following coinfections. We hypothesized that activation of monocytic cells by such microbial products through interaction with corresponding TLRs may confer antiapoptotic signals. Using HIV-viral protein R (Vpr)(52-96) peptide as a model apoptosis-inducing agent, we demonstrated that unlike monocyte-derived macrophages, undifferentiated primary human monocytes and promonocytic THP-1 cells are highly susceptible to Vpr(52-96)-induced apoptosis. Interestingly, monocytes and THP-1 cells stimulated with TLR9 agonist CpG induced almost complete resistance to Vpr(52-96)-induced apoptosis, albeit through a TLR9-independent signaling pathway. Moreover, CpG selectively induced the antiapoptotic cellular inhibitor of apoptosis (c-IAP)-2 protein and inhibition of the c-IAP-2 gene by either specific small interfering RNA or synthetic second mitochondrial activator of caspases mimetic reversed CpG-induced resistance against Vpr(52-96)-mediated apoptosis. We demonstrated that c-IAP-2 is regulated by the JNK and calcium signaling pathway, in particular calmodulin-dependent protein kinase-II. Furthermore, inhibition of JNK and the calcium signaling including the calmodulin-dependent protein kinase-II by either pharmacological inhibitors or their specific small interfering RNAs reversed CpG-induced protection against Vpr(52-96)-mediated apoptosis. We also show that CpG induced JNK phosphorylation through activation of the calcium signaling pathway. Taken together, our results suggest that CpG-induced protection may be mediated by c-IAP-2 through the calcium-activated JNK pathway via what appeared to be TLR9-independent signaling pathways.
Collapse
Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | | | | | | | | |
Collapse
|
34
|
Busca A, Saxena M, Kryworuchko M, Kumar A. Anti-apoptotic genes in the survival of monocytic cells during infection. Curr Genomics 2011; 10:306-17. [PMID: 20119528 PMCID: PMC2729995 DOI: 10.2174/138920209788920967] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 05/06/2009] [Accepted: 06/08/2009] [Indexed: 01/28/2023] Open
Abstract
Macrophages are cells of the immune system that protect organisms against invading pathogens by fulfilling critical roles in innate and adaptive immunity and inflammation. They originate from circulating monocytes and show a high degree of heterogeneity, which reflects the specialization of function given by different anatomical locations. Differentiation of monocytes towards a macrophage phenotype is also accompanied by an increase of resistance against various apoptotic stimuli, a required characteristic that allows macrophages to accomplish their function in a stressful environment. Apoptosis, a form of programmed cell death, is a tightly regulated process, needed to maintain homeostasis by balancing proliferation with cellular demise. Caspases, a family of cysteine proteases that are highly conserved in multicellular organisms, function as central regulators of apoptosis. FLIP (FLICE-inhibitory protein), anti-apoptotic members of the Bcl2 family and inhibitors of apoptosis (IAP) are the main three groups of anti-apoptotic genes that counteract caspase activation through both the extrinsic and intrinsic apoptotic pathways. Modulation of the apoptotic machinery during viral and bacterial infections, as well as in various malignancies, is a wellestablished mechanism that promotes the survival of affected cells. The involvement of anti-apoptotic genes in the survival of monocytes/macrophages, either physiological or pathological, will be described in this review. How viral and bacterial infections that target cells of the monocytic lineage affect the expression of anti-apoptotic genes is important in understanding the pathological mechanisms that lead to manifested disease. The latest therapeutic approaches that target anti-apoptotic genes will also be discussed.
Collapse
Affiliation(s)
- Aurelia Busca
- Infectious Disease and Vaccine Research Centre, Children's Hospital of Eastern Ontario, Research Institute, Division of Virology
| | | | | | | |
Collapse
|
35
|
Zhao RY, Li G, Bukrinsky MI. Vpr-host interactions during HIV-1 viral life cycle. J Neuroimmune Pharmacol 2011; 6:216-29. [PMID: 21318276 PMCID: PMC5482210 DOI: 10.1007/s11481-011-9261-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 01/23/2011] [Indexed: 12/21/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is a multifunctional viral protein that plays important role at multiple stages of the HIV-1 viral life cycle. Although the molecular mechanisms underlying these activities are subject of ongoing investigations, overall, these activities have been linked to promotion of viral replication and impairment of anti-HIV immunity. Importantly, functional defects of Vpr have been correlated with slow disease progression of HIV-infected patients. Vpr is required for efficient viral replication in non-dividing cells such as macrophages, and it promotes, to some extent, viral replication in proliferating CD4+ T cells. The specific activities of Vpr include modulation of fidelity of viral reverse transcription, nuclear import of the HIV-1 pre-integration complex, transactivation of the HIV-1 LTR promoter, induction of cell cycle G2 arrest and cell death via apoptosis. In this review, we focus on description of the cellular proteins that specifically interact with Vpr and discuss their significance with regard to the known Vpr activities at each step of the viral life cycle in proliferating and non-proliferating cells.
Collapse
Affiliation(s)
- Richard Y Zhao
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | | | | |
Collapse
|
36
|
Février M, Dorgham K, Rebollo A. CD4+ T cell depletion in human immunodeficiency virus (HIV) infection: role of apoptosis. Viruses 2011; 3:586-612. [PMID: 21994747 PMCID: PMC3185763 DOI: 10.3390/v3050586] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/03/2011] [Accepted: 05/04/2011] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infection is principally a mucosal disease and the gastrointestinal (GI) tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT) might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis.
Collapse
Affiliation(s)
- Michèle Février
- Unité Génomique Virale et Vaccination, CNRS URA3015, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France.
| | | | | |
Collapse
|
37
|
Zhang B, Feng X, Wang J, Xu X, Lin N, Liu H. Combined Antitumor Effect of Ad-bFGF-siRNA and Ad-Vpr on the Growth of Xenograft Glioma in Nude Mouse Model. Pathol Oncol Res 2010; 17:237-42. [DOI: 10.1007/s12253-010-9303-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 08/19/2010] [Indexed: 10/19/2022]
|
38
|
Fritz JV, Briant L, Mély Y, Bouaziz S, de Rocquigny H. HIV-1 viral protein r: from structure to function. Future Virol 2010. [DOI: 10.2217/fvl.10.47] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The viral protein r (Vpr) of HIV-1 binds several host proteins leading to pleiotropic functions, such as G2/M cell cycle arrest, apoptosis induction and gene transactivation. Vpr is encapsidated through the Gag C-terminus into the nascent viral particles, suggesting that Vpr plays several important functions in the early stages of the viral lifecycle. In this regard, Vpr interacts with nucleic acids and membranes to facilitate the preintegration complex migration and incorporation into the nucleus of nondividing cells. Thus, Vpr has to recruit several host and viral factors to promote its functions during HIV-1 pathogenesis. This article focuses on its interacting partners by giving an overview of the functional outcome of the different Vpr complexes, as well as the structural determinants of Vpr required for its binding properties.
Collapse
Affiliation(s)
- Joëlle V Fritz
- Department of Infectious Diseases, Virology, Universitätsklinikum, Im Neuenheimer Feld, 324, D-69120, Heidelberg, Germany
| | - Laurence Briant
- Université Montpellier 1, Centre d’études d’agents Pathogènes et Biotechnologies pour la Santé, CNRS, UMR 5236, CPBS, F-34965 Montpellier, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
| | - Serge Bouaziz
- Laboratoire de Cristallographie et RMN Biologiques, CNRS UMR8015 UFR des Sciences Pharmaceutiques et Biologiques 4, Avenue de L’observatoire, 75006 Paris, France: Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
| | | |
Collapse
|
39
|
|
40
|
Planelles V, Barker E. Roles of Vpr and Vpx in modulating the virus-host cell relationship. Mol Aspects Med 2010; 31:398-406. [PMID: 20558198 DOI: 10.1016/j.mam.2010.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 05/26/2010] [Indexed: 01/02/2023]
Abstract
The human and simian immunodeficiency viruses contain small open reading frames known as vpr and vpx. These genes encode proteins that are highly related both at the amino acid level and functionally, although key differences do exist. This review describes the main functions ascribed to Vpr and Vpx in the context of both viral replication and modulation of host cell biology.
Collapse
Affiliation(s)
- Vicente Planelles
- Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, #2100 - Room 2520, Salt Lake City, UT 84112, USA.
| | | |
Collapse
|
41
|
HIV-1 viral protein r induces ERK and caspase-8-dependent apoptosis in renal tubular epithelial cells. AIDS 2010; 24:1107-19. [PMID: 20404718 DOI: 10.1097/qad.0b013e328337b0ab] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE HIV-associated nephropathy (HIVAN) is the most common cause of end-stage renal disease in persons with HIV/AIDS and is characterized by focal glomerulosclerosis and dysregulated renal tubular epithelial cell (RTEC) proliferation and apoptosis. HIV-1 viral protein r (Vpr) has been implicated in HIV-induced RTEC apoptosis but the mechanisms of Vpr-induced RTEC apoptosis are unknown. The aim of this study was therefore to determine the mechanisms of Vpr-induced apoptosis in RTEC. METHODS Apoptosis and caspase activation were analyzed in human RTEC (HK2) after transduction with Vpr-expressing and control lentiviral vectors. Bax and BID were inhibited with lentiviral shRNA, and ERK activation was blocked with the MEK1,2 inhibitor, U0126. RESULTS Vpr induced apoptosis as indicated by caspase 3/7 activation, PARP-1 cleavage and mitochondrial injury. Vpr activated both caspases-8 and 9. Inhibition of Bax reduced Vpr-induced apoptosis, as reported in other cell types. Additionally, Vpr-induced cleavage of BID to tBID and suppression of BID expression prevented Vpr-induced apoptosis. Since sustained ERK activation can activate caspase-8 in some cell types, we studied the role of ERK in Vpr-induced caspase-8 activation. Vpr induced sustained ERK activation in HK2 cells and incubation with U0126 reduced Vpr-induced caspase-8 activation, BID cleavage and apoptosis. We detected phosphorylated ERK in RTEC in HIVAN biopsy specimens by immunohistochemistry. CONCLUSIONS These studies delineate a novel pathway of Vpr-induced apoptosis in RTEC, which is mediated by sustained ERK activation, resulting in caspase 8-mediated cleavage of BID to tBID, thereby facilitating Bax-mediated mitochondrial injury and apoptosis.
Collapse
|
42
|
Yan F, Xia D, Hu J, Yuan H, Zou T, Zhou Q, Liang L, Qi Y, Xu H. Heat shock cognate protein 70 gene is required for prevention of apoptosis induced by WSSV infection. Arch Virol 2010; 155:1077-83. [PMID: 20458509 DOI: 10.1007/s00705-010-0686-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 04/29/2010] [Indexed: 12/01/2022]
Abstract
Here, we show that heat shock cognate protein 70 (Hsc70) in shrimp cells can inhibit apoptosis induced by white spot syndrome virus (WSSV) infection. Caspase-3 protease activity of hemocytes increased significantly, correlating with a reduction in endogenous Hsc70 late in WSSV infection. Hsc70 dsRNA caused a significant increase in caspase-3 activity in the hemocytes of non-infected shrimp and WSSV-infected shrimp. We propose that upregulation of Hsc70 expression early in WSSV infection may also be used to prevent premature apoptotic cell death, and the precipitous downregulation of Hsc70 late in WSSV infection may lead to the timed induction of apoptosis.
Collapse
Affiliation(s)
- Feng Yan
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
Like most viral regulatory proteins, HIV-1 Vpr and homologous proteins from primate lentiviruses are small and multifunctional. They are associated with a plethora of effects and functions, including induction of cell cycle arrest in the G(2) phase, induction of apoptosis, transactivation, enhancement of the fidelity of reverse transcription, and nuclear import of viral DNA in macrophages and other nondividing cells. This review focuses on the cellular proteins that have been reported to interact with Vpr and their significance with respect to the known functions and effects of Vpr on cells and on viral replication.
Collapse
Affiliation(s)
- Vicente Planelles
- Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East #2100-Room 2520, Salt Lake City, Utah 84112, USA.
| | | |
Collapse
|
44
|
Matrix protein 2 of influenza A virus blocks autophagosome fusion with lysosomes. Cell Host Microbe 2009; 6:367-80. [PMID: 19837376 DOI: 10.1016/j.chom.2009.09.005] [Citation(s) in RCA: 422] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 06/29/2009] [Accepted: 09/14/2009] [Indexed: 02/02/2023]
Abstract
Influenza A virus is an important human pathogen causing significant morbidity and mortality every year and threatening the human population with epidemics and pandemics. Therefore, it is important to understand the biology of this virus to develop strategies to control its pathogenicity. Here, we demonstrate that influenza A virus inhibits macroautophagy, a cellular process known to be manipulated by diverse pathogens. Influenza A virus infection causes accumulation of autophagosomes by blocking their fusion with lysosomes, and one viral protein, matrix protein 2, is necessary and sufficient for this inhibition of autophagosome degradation. Macroautophagy inhibition by matrix protein 2 compromises survival of influenza virus-infected cells but does not influence viral replication. We propose that influenza A virus, which also encodes proapoptotic proteins, is able to determine the death of its host cell by inducing apoptosis and also by blocking macroautophagy.
Collapse
|
45
|
Mitzner D, Dudek SE, Studtrucker N, Anhlan D, Mazur I, Wissing J, Jänsch L, Wixler L, Bruns K, Sharma A, Wray V, Henklein P, Ludwig S, Schubert U. Phosphorylation of the influenza A virus protein PB1-F2 by PKC is crucial for apoptosis promoting functions in monocytes. Cell Microbiol 2009; 11:1502-16. [DOI: 10.1111/j.1462-5822.2009.01343.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
46
|
Postigo A, Ferrer PE. Viral inhibitors reveal overlapping themes in regulation of cell death and innate immunity. Microbes Infect 2009; 11:1071-8. [PMID: 19733680 PMCID: PMC7110534 DOI: 10.1016/j.micinf.2009.08.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many viruses regulate a crucial point in the apoptotic pathway by expressing viral Bcl-2 homologues, which have become useful tools to investigate the mechanisms behind the control of the mitochondrial checkpoint of apoptosis. Concurrently, a number of viral inhibitors of innate immune signalling have been instrumental tools in the discovery of key host pathways. Here we discuss how viral inhibitors of the apoptotic and innate signalling pathways have further enhanced the understanding of both research fields and are beginning to shed light on how these two pathways converge.
Collapse
Affiliation(s)
- Antonio Postigo
- Cell Motility Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
| | | |
Collapse
|
47
|
Virion-associated Vpr of human immunodeficiency virus type 1 triggers activation of apoptotic events and enhances fas-induced apoptosis in human T cells. J Virol 2009; 83:11283-97. [PMID: 19692467 DOI: 10.1128/jvi.00756-09] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vpr protein exists in three different forms: soluble, intracellular, and virion associated. Previous studies showed that virion-associated Vpr induces apoptosis in activated peripheral blood mononuclear cells (PBMCs) and Jurkat T cells, but these studies were conducted in the presence of other de novo-expressed HIV proteins that may have had additive proapoptotic effects. In this report, we show that virion-associated Vpr triggers apoptosis through caspases 3/7 and 9 in human T cells independently of other HIV de novo-expressed proteins. In contrast to a previous study, we also detected the activation of caspase 8, the initiator caspase of the death receptor pathway. However, activation of all caspases by virion-associated Vpr was independent of the Fas death receptor pathway. Further analyses showed that virion-associated Vpr enhanced caspase activation in Fas-mediated apoptosis in Jurkat T cells and human activated PBMCs. Thus, our results indicate for the first time that viral particles that contain virion-associated Vpr can cause apoptosis in the absence of other de novo-expressed viral factors and can act in synergy with the Fas receptor pathway, thereby enhancing the apoptotic process in T cells. These findings suggest that virion-associated Vpr can contribute to the depletion of CD4(+) lymphocytes either directly or by enhancing Fas-mediated apoptosis during acute HIV-1 infection and in AIDS.
Collapse
|
48
|
Romani B, Engelbrecht S. Human immunodeficiency virus type 1 Vpr: functions and molecular interactions. J Gen Virol 2009; 90:1795-1805. [PMID: 19458171 DOI: 10.1099/vir.0.011726-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is an accessory protein that interacts with a number of cellular and viral proteins. The functions of many of these interactions in the pathogenesis of HIV-1 have been identified. Deletion of the vpr gene reduces the virulence of HIV-1 dramatically, indicating the importance of this protein for the virus. This review describes the current findings on several established functions of HIV-1 Vpr and some possible roles proposed for this protein. Because Vpr exploits cellular proteins and pathways to influence the biology of HIV-1, understanding the functions of Vpr usually involves the study of cellular pathways. Several functions of Vpr are attributed to the virion-incorporated protein, but some of them are attributed to the expression of Vpr in HIV-1-infected cells. The structure of Vpr may be key to understanding the variety of its interactions. Due to the critical role of Vpr in HIV-1 pathogenicity, study of the interactions between Vpr and cellular proteins may help us to understand the mechanism(s) of HIV-1 pathogenicity.
Collapse
Affiliation(s)
- Bizhan Romani
- Department of Pathology, Division of Medical Virology, University of Stellenbosch, Tygerberg 7505, South Africa
| | - Susan Engelbrecht
- National Health Laboratory Services, Tygerberg 7505, South Africa.,Department of Pathology, Division of Medical Virology, University of Stellenbosch, Tygerberg 7505, South Africa
| |
Collapse
|
49
|
Huard S, Chen M, Burdette KE, Fenyvuesvolgyi C, Yu M, Elder RT, Zhao RY. HIV-1 Vpr-induced cell death in Schizosaccharomyces pombe is reminiscent of apoptosis. Cell Res 2008; 18:961-73. [DOI: 10.1038/cr.2008.272] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
50
|
HIV-1 viral genes and mitochondrial apoptosis. Apoptosis 2008; 13:1088-99. [PMID: 18622704 DOI: 10.1007/s10495-008-0239-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 06/27/2008] [Indexed: 02/07/2023]
Abstract
The mitochondrion is an organelle that regulates various cellular functions including the production of energy and programmed cell death. Aberrant mitochondrial function is often concomitant with various cytopathies and medical disorders. The mitochondrial membrane plays a key role in the induction of cellular apoptosis, and its destabilization, as triggered by both intracellular and extracellular stimuli, results in the release of proapoptotic factors into the cytosol. Not surprisingly, proteins from the human immunodeficiency virus type 1 (HIV) have been implicated in exploiting this organelle to promote the targeted depletion of key immune cells, which assists in viral evasion of the immune system and contributes to the characteristic global immunodeficiency observed during progression of disease. Here we review the mechanisms by which HIV affects the mitochondrion, and suggest that various viral-associated genes may directly regulate apoptotic cell death.
Collapse
|