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Wang D, Jiang Y, Song Y, Zeng Y, Li C, Wang X, Liu Y, Xiao J, Kong Y, Zhao H. Altered T-Cell Subsets are Associated with Dysregulated Cytokine Secretion of CD4 + T Cells During HIV Infection. J Inflamm Res 2021; 14:5149-5163. [PMID: 34675594 PMCID: PMC8504938 DOI: 10.2147/jir.s333902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/27/2021] [Indexed: 11/23/2022] Open
Abstract
Background CD4+ T cells play a critical role in the regulation of immunopathogenesis in HIV infection. Previous studies have shown contradictory results of the CD4+ T-cell responses in people living with HIV (PLHIV). Methods A cross-sectional study was performed on 40 healthy controls, 134 ART-naïve PLHIV, and 34 individuals who experienced 3-year ART with low baseline CD4 count from 4 August 2016 to 23 January 2019. We determined the frequencies of CD4+ T-cell subsets and described the cytokine secretion pattern of total and subsets of CD4+ T cells in these individuals. Results We found that CD4+ T cells in PLHIV displayed enhanced secretion of pro-inflammation cytokines and polyfunctionality due to HIV disease progression (r = -0.282, P = 0.0035 for IFN-γ; r = -0.412, P = 0.0002 for TNF-α; r = -0.243, P < 0.0001 for GM-CSF; r = -0.252, P = 0.0093 for IFN-γ+ TNF-α+ cells). However, the altered T-cell subsets, as presented by the loss of naïve cells and expansion of memory/effector population in PLHIV, were associated with discordant results in total and subsets of CD4+ T cells. As major cytokine-producing T subsets, effector/memory CD4 subsets showed impaired cytokine production (P < 0.05). We further demonstrated that 3-year ART treatment could improve CD4 counts by increasing the pool of naïve T cells but could not restore cytokine secretion in CD4+ T-cell subsets (P < 0.05). Conclusion These data identified the impaired capacity of cytokine secretion in CD4+ T-cell subsets due to HIV disease progression, and the altered T-cell subsets were associated with pseudo-elevation of cytokine production in total CD4+ T cells. This study collectively suggested the importance of therapies that can preserve and/or enhance the function of CD4+ T cells in strategies of HIV remission.
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Affiliation(s)
- Di Wang
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China.,Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Yu Jiang
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Yangzi Song
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China.,Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Yongqin Zeng
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Cuilin Li
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Xinyue Wang
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Ying Liu
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China.,Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Jiang Xiao
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Yaxian Kong
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Hongxin Zhao
- Clinical and Research Center of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People's Republic of China
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Wu T, Ma F, Ma X, Jia W, Pan E, Cheng G, Chen L, Sun C. Regulating Innate and Adaptive Immunity for Controlling SIV Infection by 25-Hydroxycholesterol. Front Immunol 2018; 9:2686. [PMID: 30524435 PMCID: PMC6262225 DOI: 10.3389/fimmu.2018.02686] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/31/2018] [Indexed: 11/13/2022] Open
Abstract
Persistent inflammation and extensive immune activation have been associated with HIV-1/SIV pathogenesis. Previously, we reported that cholesterol-25-hydroxylase (CH25H) and its metabolite 25-hydroxycholesterol (25-HC) had a broad antiviral activity in inhibiting Zika, Ebola, and HIV-1 infection. However, the underlying immunological mechanism of CH25H and 25-HC in inhibiting viral infection remains poorly understood. We report here that 25-HC effectively regulates immune responses for controlling viral infection. CH25H expression was interferon-dependent and induced by SIV infection in monkey-derived macrophages and PBMC cells, and 25-HC inhibited SIV infection both in permissive cell lines and primary monkey lymphocytes. 25-HC also strongly inhibited bacterial lipopolysaccharide (LPS)-stimulated inflammation and restricted mitogen-stimulated proliferation in primary monkey lymphocytes. Strikingly, 25-HC promoted SIV-specific IFN-γ-producing cellular responses, but selectively suppressed proinflammatory CD4+ T lymphocytes secreting IL-2 and TNF-α cytokines in vaccinated mice. In addition, 25-HC had no significant immunosuppressive effects on cytotoxic CD8+ T lymphocytes or antibody-producing B lymphocytes. Collectively, 25-HC modulated both innate and adaptive immune responses toward inhibiting HIV/SIV infection. This study provides insights into improving vaccination and immunotherapy regimes against HIV-1 infection.
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Affiliation(s)
- Tongjin Wu
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, China.,State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,School of Life Sciences, Anhui University, Hefei, China
| | - Feng Ma
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Suzhou Institute of Systems Medicine, Suzhou, China
| | - Xiuchang Ma
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Weizhe Jia
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, China.,College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang, China
| | - Enxiang Pan
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Genhong Cheng
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Suzhou Institute of Systems Medicine, Suzhou, China.,Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, United States
| | - Ling Chen
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Caijun Sun
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, China.,State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
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3
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Shete A, Suryawanshi P, Godbole S, Pawar J, Paranjape R, Thakar M. HIV-infected CD4+ T Cells Use T-bet-dependent Pathway for Production of IL-10 Upon Antigen Recognition. Scand J Immunol 2016; 83:288-96. [PMID: 27028319 DOI: 10.1111/sji.12422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/15/2016] [Indexed: 01/11/2023]
Abstract
Interleukin (IL)-10 has been implicated in persistence of pathogens in a number of chronic infections. Infected CD4+ cells upon reactivation with HIV antigens were also shown to produce IL-10, which might contribute to their persistence. Hence, it is crucial to determine mechanisms regulating IL-10 production after activation with HIV antigens for devising effective blocking strategies. In this study, ERK-, T-bet- and FoxP3-dependent pathways were evaluated for their possible roles in IL-10 production by infected CD4+ cells after reactivation with HIV Env. Intracellular and secreted IL-10 levels were determined by flow cytometry and Bioplex assay after treating PBMCs with PD98059, tipifarnib and cyclosporin A for blocking of ERK-, T-bet-and FoxP3-dependent pathways, respectively. Baseline levels of T-bet, pERK were higher in P24+ CD4+ cells as compared to uninfected CD4+ cells, which increased further after activation with Env. Inhibition of T-bet resulted in 2.3-fold reduction of IL-10 expression whereas ERK and FoxP3 inhibition failed to cause suppression of IL-10 expression. Conversely, IL-10 secreted by PBMCs was inhibited maximally after ERK inhibition suggesting its role in regulation of cytokine secretory pathway. IFN-γ was found to be suppressed after treatment with inhibitors of all these pathways. Thus, the study highlighted need for IL-10 blockade along with the use of antigens for therapeutic vaccinations or latency reversal and identified the T-bet-dependent pathway as an important pathway regulating IL-10 production by infected CD4+ cells. However, simultaneous blockade of IFN-γ precludes use of inhibitor of this pathway as an IL-10 blocking strategy.
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Affiliation(s)
- A Shete
- National AIDS Research Institute, Pune, India
| | | | - S Godbole
- National AIDS Research Institute, Pune, India
| | - J Pawar
- National AIDS Research Institute, Pune, India
| | - R Paranjape
- National AIDS Research Institute, Pune, India
| | - M Thakar
- National AIDS Research Institute, Pune, India
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4
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Couturier J, Agarwal N, Nehete PN, Baze WB, Barry MA, Jagannadha Sastry K, Balasubramanyam A, Lewis DE. Infectious SIV resides in adipose tissue and induces metabolic defects in chronically infected rhesus macaques. Retrovirology 2016; 13:30. [PMID: 27117277 PMCID: PMC4847269 DOI: 10.1186/s12977-016-0260-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/07/2016] [Indexed: 12/20/2022] Open
Abstract
Background HIV reservoirs pose major challenges to viral eradication. The main cellular reservoirs include CD4 T cells and macrophages, whereas anatomic reservoirs are thought to be primarily lymphoid tissues. Adipose tissue represents a potentially important non-lymphoid location for HIV replication and persistence because the stromal-vascular-fraction (AT-SVF) contains activated innate and adaptive immune cells that increase in number during infections, obesity, and chronic inflammation. Results Adipose tissue from two groups of SHIV-SF162p3-infected (~4 weeks acute infection) or SIVmac251-infected (~38 weeks chronic infection) rhesus macaques (N = 8 for each group) were studied for immune cell content, viral infectiousness, and metabolic health. The AT-SVF cells from SHIV-infected monkeys contained abundant memory CD4 and CD8 T cells, with fewer NKT cells and macrophages, and no B cells. Proviral DNA (Gag and Env) was readily detectable by nested PCR in AT-SVF cells from multiple adipose depots (subcutaneous and visceral) of acutely infected monkeys, but mostly from visceral fat. More importantly, viral outgrowth assays using input CD4 T cells derived from AT-SVF cells or peripheral blood of chronically infected monkeys resulted in robust replication of infectious virus from both AT-SVF and peripheral blood CD4 T cells. Chronically infected monkeys also experienced adipocyte dysfunction (suppression of major adipogenic genes) and systemic dyslipidemia (decreased serum total cholesterol and free fatty acids, and increased triglycerides), similar to metabolic abnormalities of HIV patients. Conclusions Adipose tissues of SIV-infected rhesus macaques become major compartments for infected immune cells, which in turn induce defects in adipose tissue metabolism. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0260-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jacob Couturier
- Division of Infectious Diseases, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.,Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Neeti Agarwal
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Diabetes Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Pramod N Nehete
- Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA
| | - Wallace B Baze
- Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA
| | - Michael A Barry
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA
| | - K Jagannadha Sastry
- Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA.,Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA.,Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ashok Balasubramanyam
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Diabetes Research Center, Baylor College of Medicine, Houston, TX, USA.,Endocrine Service, Ben Taub General Hospital, Houston, TX, USA
| | - Dorothy E Lewis
- Division of Infectious Diseases, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA. .,Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA.
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5
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Hegedus A, Kavanagh Williamson M, Huthoff H. HIV-1 pathogenicity and virion production are dependent on the metabolic phenotype of activated CD4+ T cells. Retrovirology 2014; 11:98. [PMID: 25421745 PMCID: PMC4252996 DOI: 10.1186/s12977-014-0098-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 10/24/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND HIV-1, like all viruses, is entirely dependent on the host cell for providing the metabolic resources for completion of the viral replication cycle and the production of virions. It is well established that HIV-1 replicates efficiently in activated CD4+ T cells, whereas resting CD4+ T cells are refractory to infection with HIV-1. A hallmark of T cell activation is the upregulation of glycolysis to meet the biosynthetic and bioenergetic needs of cell proliferation and the execution of effector functions by the secretion of cytokines. To date, it has remained unknown if HIV-1 requires the high glycolytic activity of activated T cells to support its replication. RESULTS We report that in primary CD4+ T cells, the flux through the glycolytic pathway is increased upon infection with HIV-1. This increase in glycolytic activity does not occur in T cell lines when infected with HIV-1. By providing cells with galactose instead of glucose, the former being a poor substrate for glycolysis, we monitored the effect of preventing glycolysis in CD4+ T cells on virus replication cycle and cell fate. We observed that HIV-1 infected primary CD4+ T cells cultured in galactose have a survival advantage over those cultured in glucose and this coincides with reduced caspase 3 activation and apoptosis in cultures with galactose. T cell lines do not recapitulate this difference in cell death. Finally, we demonstrate that virion production is dependent on glycolysis as cultures containing galactose yield reduced amounts of HIV-1 virions compared with cultures containing glucose. CONCLUSIONS The replication of HIV-1 in primary CD4+ T cells causes an increase in glycolytic flux of the cell. Glycolysis is particularly required for virion production and additionally increases the sensitivity of the infected cell to virus-induced cell death.
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Affiliation(s)
- Andrea Hegedus
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
| | - Maia Kavanagh Williamson
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
| | - Hendrik Huthoff
- Department of Infectious Diseases, King's College London, 2nd Floor Borough Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK.
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6
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Pandit H, Gopal S, Sonawani A, Yadav AK, Qaseem AS, Warke H, Patil A, Gajbhiye R, Kulkarni V, Al-Mozaini MA, Idicula-Thomas S, Kishore U, Madan T. Surfactant protein D inhibits HIV-1 infection of target cells via interference with gp120-CD4 interaction and modulates pro-inflammatory cytokine production. PLoS One 2014; 9:e102395. [PMID: 25036364 PMCID: PMC4103819 DOI: 10.1371/journal.pone.0102395] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/17/2014] [Indexed: 01/12/2023] Open
Abstract
Surfactant Protein SP-D, a member of the collectin family, is a pattern recognition protein, secreted by mucosal epithelial cells and has an important role in innate immunity against various pathogens. In this study, we confirm that native human SP-D and a recombinant fragment of human SP-D (rhSP-D) bind to gp120 of HIV-1 and significantly inhibit viral replication in vitro in a calcium and dose-dependent manner. We show, for the first time, that SP-D and rhSP-D act as potent inhibitors of HIV-1 entry in to target cells and block the interaction between CD4 and gp120 in a dose-dependent manner. The rhSP-D-mediated inhibition of viral replication was examined using three clinical isolates of HIV-1 and three target cells: Jurkat T cells, U937 monocytic cells and PBMCs. HIV-1 induced cytokine storm in the three target cells was significantly suppressed by rhSP-D. Phosphorylation of key kinases p38, Erk1/2 and AKT, which contribute to HIV-1 induced immune activation, was significantly reduced in vitro in the presence of rhSP-D. Notably, anti-HIV-1 activity of rhSP-D was retained in the presence of biological fluids such as cervico-vaginal lavage and seminal plasma. Our study illustrates the multi-faceted role of human SP-D against HIV-1 and potential of rhSP-D for immunotherapy to inhibit viral entry and immune activation in acute HIV infection.
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Affiliation(s)
- Hrishikesh Pandit
- Department of Innate Immunity, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Sandhya Gopal
- Department of Innate Immunity, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Archana Sonawani
- Biomedical Informatics Centre, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Ajit Kumar Yadav
- Department of Innate Immunity, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Asif S. Qaseem
- Centre for Infection, Immunity and Disease Mechanisms, Brunel University, London, United Kingdom
| | - Himangi Warke
- Department of Obstetrics and Gynecology, Seth G S Medical College and K E M Hospital, Mumbai, Maharashtra, India
| | - Anushree Patil
- Department of Clinical Research, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Rahul Gajbhiye
- Department of Clinical Research, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Vijay Kulkarni
- Department of Clinical Research, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Maha Ahmed Al-Mozaini
- Immunocompromised Host Research Section, Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Susan Idicula-Thomas
- Biomedical Informatics Centre, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
| | - Uday Kishore
- Centre for Infection, Immunity and Disease Mechanisms, Brunel University, London, United Kingdom
| | - Taruna Madan
- Department of Innate Immunity, National Institute for Research in Reproductive Health (ICMR), Mumbai, Maharashtra, India
- * E-mail:
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7
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Tan X, Li D, Wang X, Zeng Y, Yan Y, Yang L. Claudin-2 downregulation by KSHV infection is involved in the regulation of endothelial barrier function. J Cutan Pathol 2014; 41:630-9. [PMID: 24995964 DOI: 10.1111/cup.12332] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/01/2014] [Accepted: 02/17/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND Kaposi sarcoma (KS), caused by the infection of Kaposi sarcoma-associated herpesvirus (KSHV), is a disease manifested mainly by dark purple skin and mouth nodules. Cancer care studies showed that co-infection of KSHV and human immunodeficiency virus (HIV) was able to increase the patients' survival, but the underlying mechanisms are still elusive. METHODS To understand the mechanism underlying the prolonged survival in KSHV-HIV co-infected patients, we performed microarray analysis on RNA extracted from biopsies from KS tumors and adjacent healthy tissues in four KS patients. Subsequently, we performed hierarchical clustering, gene ontology (GO) and ingenuity pathway analysis. We then characterized the roles of tight junction protein claudin-2 in the endothelial barrier function. RESULTS Three hundred and forty-three differentially expressed genes were identified, of which 246 genes exhibited significantly increased expression in the tumor compared to the adjacent healthy tissue and 97 genes showed downregulated expression, including claudin-2. Knockdown of claudin-2 in cultured endothelial cells enhances barrier function by altering the charge selectivity, but not the size selectivity. CONCLUSION Claudin-2 expression is decreased in KS tumors from patients co-infected with KSHV and HIV. Decreased claudin-2 enhances endothelial barrier function and may play a role in the prolonged survival of patients with KSHV and HIV co-infection.
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Affiliation(s)
- Xiaohua Tan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
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8
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Abstract
Recent advances in the immunology, pathogenesis, and prevention of human immunodeficiency virus (HIV) infection continue to reveal clues to the mechanisms involved in the progressive immunodeficiency attributed to infection, but more importantly have shed light on the correlates of immunity to infection and disease progression. HIV selectively infects, eliminates, and/or dysregulates several key cells of the human immune system, thwarting multiple arms of the host immune response, and inflicting severe damage to mucosal barriers, resulting in tissue infiltration of 'symbiotic' intestinal bacteria and viruses that essentially become opportunistic infections promoting systemic immune activation. This leads to activation and recruitment or more target cells for perpetuating HIV infection, resulting in persistent, high-level viral replication in lymphoid tissues, rapid evolution of resistant strains, and continued evasion of immune responses. However, vaccine studies and studies of spontaneous controllers are finally providing correlates of immunity from protection and disease progression, including virus-specific CD4(+) T-cell responses, binding anti-bodies, innate immune responses, and generation of antibodies with potent antibody-dependent cell-mediated cytotoxicity activity. Emerging correlates of immunity indicate that prevention of HIV infection may be possible through effective vaccine strategies that protect and stimulate key regulatory cells and immune responses in susceptible hosts. Furthermore, immune therapies specifically directed toward boosting specific aspects of the immune system may eventually lead to a cure for HIV-infected patients.
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Affiliation(s)
- Huanbin Xu
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, LA 70433, USA
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9
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The impact of pregnancy on the HIV-1-specific T cell function in infected pregnant women. Clin Immunol 2012; 145:177-88. [PMID: 23103487 DOI: 10.1016/j.clim.2012.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/28/2012] [Accepted: 10/02/2012] [Indexed: 11/22/2022]
Abstract
Evidences indicate that pregnancy can alter the Ag-specific T-cell responses. This work aims to evaluate the impact of pregnancy on the in vitro HIV-1-specific immune response. As compared with non-pregnant patients, lower T-cell proliferation and higher IL-10 production were observed in T-cell cultures from pregnant patients following addition of either mitogens or HIV-1 antigens. In our system, the main T lymphocyte subset involved in producing IL-10 was CD4(+)FoxP3(-). Depletion of CD4(+) cells elevated TNF-α and IFN-γ production. Interestingly, the in vitro HIV-1 replication was lower in cell cultures from pregnant patients, and it was inversely related to IL-10 production. In these cultures, the neutralization of IL-10 by anti-IL-10 mAb elevated TNF-α release and HIV-1 replication. In conclusion, our results reveal that pregnancy-related events should favor the expansion of HIV-1-specific IL-10-secreting CD4(+) T-cells in HIV-1-infected women, which should, in the scenario of pregnancy, help to reduce the risk of vertical HIV-1 transmission.
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10
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Li Y, Ling W, Xu H, Wang M, Wu C. The activation and dynamics of cytokine expression by CD4+ T cells and AIDS progression in HIV-1-infected Chinese individuals. Microb Pathog 2012; 53:189-97. [PMID: 22892467 DOI: 10.1016/j.micpath.2012.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 06/28/2012] [Accepted: 07/25/2012] [Indexed: 11/17/2022]
Abstract
CD4(+) T cells are the main targets of HIV-1 and play a central role during the progression of AIDS, but the mechanism has not been clearly elucidated. In the present study, blood samples were collected from HIV-1-infected Chinese individuals, including typical progressors (TPs) and long-term nonprogressors (LTNPs). More HIV-1 productively infected CD4(+) T cells were obtained through co-cultures and the infected CD4(+) T cells were discriminated from bystander cells by intracellular p24 staining. The activation level and dynamics of cytokine expression of CD4(+) T cells were analyzed. After stimulating the freshly isolated PBMCs with PHA, the frequencies of CD69(+)CD4(+) T cells/CD25(+)CD4(+) T cells were higher in TP than in LTNP group and were positively correlated with viral load and negatively correlated with CD4(+) T cell counts. The activation level of CD4(+) T cells in the co-cultured PBMCs was higher in TP than in LTNP group, and HIV-1 productively infected CD4(+) T cells were more activated than bystander CD4(+) T cells. The expression of Th1 cytokines (IL-2 and IFN-γ) and the frequency of Th1 cells in co-cultured PBMCs were lower in TP than in LTNP group. HIV-1 productively infected CD4(+) T cells expressed higher level of Th1/Th2 cytokines than bystander cells. More productive HIV-1 infection occurred in Th1 than in Th2 cells, followed by Th0 cells. The present results suggest that the excessive activation level of CD4(+) T cells and the preferential replication of HIV-1 in Th1 cells that lead to the shift of Th1 to Th2 are likely crucial to AIDS progression in HIV-1-infected Chinese individuals.
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Affiliation(s)
- Yan Li
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, PR China
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11
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Shete A, Thakar M, Singh DP, Gangakhedkar R, Gaikwad A, Pawar J, Paranjape R. Short communication: HIV antigen-specific reactivation of HIV infection from cellular reservoirs: implications in the settings of therapeutic vaccinations. AIDS Res Hum Retroviruses 2012; 28:835-43. [PMID: 21936714 DOI: 10.1089/aid.2010.0363] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Therapeutic vaccinations using human immunodeficiency virus (HIV) antigens in HIV-infected patients on antiretroviral therapy (ART) have so far been attempted with the purpose of inducing CTL response. However, they can also be useful as a strategy for activation of latent HIV reservoir, which is thought to be mainly comprised of latently infected HIV-specific memory CD4 cells, eventually leading to elimination of the virus. The present study was carried out to explore the ability of different HIV antigens to activate HIV replication as assessed by intracellular P24 detection as well as to induce T cell responses in terms of cytokine expression by flow cytometry after stimulation of PBMCs from HIV-infected patients. HIV antigens were found to be able to activate most of the CD4 T cells harboring proviral DNA. HIV-1 Pol and Env were responsible for induction of higher HIV replication in terms of both magnitude and frequency followed by Gag and Nef. As opposed to this, Pol and Env contributed to fewer numbers of polyfunctional CD8 cells desirable for elimination of HIV-infected cells in comparison to Gag and Nef. Thus, HIV antigens may provide a strategy for the activation of a latent reservoir. It was observed that HIV replication started as early as half an hour after in vitro activation indicating a stringent need for maintaining effective concentrations of antiretroviral drugs to prevent further spread of HIV during this process. HIV-infected cells were found to be responsible for higher IL-10 secretion after activation, which could also serve as one of the reasons for suppressed CD8 responses to Pol and Env as more HIV-infected CD4 cells would be secreting IL-10 in response to these antigens. Since IL-10 blockade helped to improve immune responses in terms of cytokine secretion, it should be considered in settings of therapeutic vaccination to improve CTL responses, which will ultimately limit the persistence of the viral reservoir.
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Affiliation(s)
| | | | | | | | | | - Jyoti Pawar
- National AIDS Research Institute, Pune, India
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Miller Sanders C, Cruse JM, Lewis RE. Toll-like receptor and chemokine receptor expression in HIV-infected T lymphocyte subsets. Exp Mol Pathol 2009; 88:26-31. [PMID: 19769961 DOI: 10.1016/j.yexmp.2009.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 09/13/2009] [Indexed: 11/30/2022]
Abstract
In the present investigation, flow cytometric techniques were utilized to evaluate 100 cases of HIV and 20 normal controls for CXCR4, CCR5, and TLR4 expression in CD4-positive T cells, CD8-positive T cells, regulatory T cells, and Th17 cells, and fluorescence intensity values were determined. TLR4 was expressed by CD4+ T cells and CD8+ T cells in 97 cases, by regulatory T cells in 88 of 95 cases, and by Th17 cells in 93 of 95 cases, while it remained negative in all 20 normal controls. These data indicate that TLR4 upregulation is not limited to gram-negative bacterial infection nor is expression limited to myeloid cells. Upregulation of TLR4 in HIV patients may either be directly or indirectly related to the presence of the virus. CXCR4 was positively expressed by CD4+ T cells in 96 HIV cases, CD8+ T cells in 95, regulatory T cells in 89 of 95 cases evaluated, and Th17 cells in all 92 cases evaluated, while expression remained negative in the majority of normal controls. CCR5 was positively expressed by CD4+ and CD8+ T cells in all 100 HIV cases and by regulatory T cells in 89 of 95 cases evaluated, while expression was negative in most CD4+ and regulatory T cells of normal controls. Statistically significant differences were detected when TLR4 expression by CD4+ and CD8+ T cells was compared to stage of disease. TLR4 expression decreased as infection progressed from acute phase to AIDS. In addition, expression of TLR4 by all T cell subsets was slightly decreased in patients receiving HAART therapy. Results also reveal a positive correlation between CXCR4, CCR5, and TLR4 expression indicating that TLR4 expression and chemokine expression pathways are linked.
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IL-10-secreting T cells from HIV-infected pregnant women downregulate HIV-1 replication: effect enhanced by antiretroviral treatment. AIDS 2009; 23:9-18. [PMID: 19050381 DOI: 10.1097/qad.0b013e328317461e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE This study aimed to evaluate the impact of pregnancy-related immune events on the HIV-1 replication and to analyze their relationship with the risk of vertical transmission. METHODS The peripheral blood from HIV-1-infected pregnant women who controlled (G1) or not controlled (G2) their plasma viral load was drawn, and the plasma and the T cells were obtained. The T-cell cultures were activated in vitro with anti-CD3 and anti-CD28, and the proliferation and cytokine production profile were evaluated after 3 days of incubation. The in-vitro HIV-1 replication was measured in culture supernatants in the seventh day following stimulation. The cytokines were also analyzed in the plasma. RESULTS Our results demonstrated a lower T-cell proliferation and a lower interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma production in polyclonally activated T-cell cultures from G1 patients, when compared with G2. Furthermore, high levels of interleukin-10 were produced both systemically and by activated T-cell cultures from G1 patients. Interestingly, the neutralization of endogenous interleukin-10 by anti-interleukin-10 monoclonal antibody elevated both the inflammatory cytokines' release and the HIV-1 replication in the polyclonally activated T-cell cultures from G1 patients. Additionally, the maternal antiretroviral treatment significantly enhanced the systemic interleukin-10 production. Finally, the higher systemic interleukin-10 levels were inversely correlated with vertical virus transmission risk. CONCLUSION These results indicate that a high tendency of pregnant women to produce interleukin-10 can help them control the HIV-1 replication, and this can reduce the risk of vertical transmission. Furthermore, our data suggest a role for maternal antiretroviral treatment in enhancing this phenomenon.
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Lysis of endogenously infected CD4+ T cell blasts by rIL-2 activated autologous natural killer cells from HIV-infected viremic individuals. PLoS Pathog 2008; 4:e1000101. [PMID: 18617991 PMCID: PMC2438610 DOI: 10.1371/journal.ppat.1000101] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 06/11/2008] [Indexed: 01/08/2023] Open
Abstract
Understanding the cellular mechanisms that ensure an appropriate innate immune response against viral pathogens is an important challenge of biomedical research. In vitro studies have shown that natural killer (NK) cells purified from healthy donors can kill heterologous cell lines or autologous CD4+ T cell blasts exogenously infected with several strains of HIV-1. However, it is not known whether the deleterious effects of high HIV-1 viremia interferes with the NK cell-mediated cytolysis of autologous, endogenously HIV-1-infected CD4+ T cells. Here, we stimulate primary CD4+ T cells, purified ex vivo from HIV-1-infected viremic patients, with PHA and rIL2 (with or without rIL-7). This experimental procedure allows for the significant expansion and isolation of endogenously infected CD4+ T cell blasts detected by intracellular staining of p24 HIV-1 core antigen. We show that, subsequent to the selective down-modulation of MHC class-I (MHC-I) molecules, HIV-1-infected p24pos blasts become partially susceptible to lysis by rIL-2-activated NK cells, while uninfected p24neg blasts are spared from killing. This NK cell-mediated killing occurs mainly through the NKG2D activation pathway. However, the degree of NK cell cytolytic activity against autologous, endogenously HIV-1-infected CD4+ T cell blasts that down-modulate HLA-A and –B alleles and against heterologous MHC-Ineg cell lines is particularly low. This phenomenon is associated with the defective surface expression and engagement of natural cytotoxicity receptors (NCRs) and with the high frequency of the anergic CD56neg/CD16pos subsets of highly dysfunctional NK cells from HIV-1-infected viremic patients. Collectively, our data demonstrate that the chronic viral replication of HIV-1 in infected individuals results in several phenotypic and functional aberrancies that interfere with the NK cell-mediated killing of autologous p24pos blasts derived from primary T cells. Natural killer (NK) cells represent an important line of defense against viral infections. In vitro studies with exogenously infected CD4+ T cell blasts from healthy donors have demonstrated that NK cells can kill autologous HIV-1-infected target cells. However, the ability of NK cells from HIV-1-infected viremic patients to kill autologous, endogenously infected CD4+ T cells had never been examined and remains uncertain. Given the reported abnormalities in phenotype and functions of NK cells from HIV-infected viremic individuals, we determined the function of NK cells in killing HIV-1-infected target cells under conditions that more closely mimic the in vivo environment in HIV-infected individuals. We show that NK cells from HIV-1-infected viremic patients display a variable although generally low ability to selectively eliminate autologous and endogenously HIV-1-infected CD4+ T cell blasts expanded ex vivo from peripheral blood. Various factors, including the markedly defective engagement of important NK cell activation pathways and high frequencies of the pathologic CD56neg/CD16pos NK cell subset in HIV-1-infected viremic patients, influenced NK cell–mediated cytolysis of endogenously infected CD4+ T cell blasts.
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Venkatachari NJ, Buchanan WG, Ayyavoo V. Human immunodeficiency virus (HIV-1) infection selectively downregulates PD-1 expression in infected cells and protects the cells from early apoptosis in vitro and in vivo. Virology 2008; 376:140-53. [PMID: 18440040 DOI: 10.1016/j.virol.2008.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 02/11/2008] [Accepted: 03/18/2008] [Indexed: 12/18/2022]
Abstract
Programmed Death-1 (PD-1), a member of T cell costimulatory molecules is expressed in high levels on antigen specific T cells during chronic viral infection, whereas PD-1 expression in the context of HIV-1 infected CD4+ T cells is not known. Here we report that productively infected CD4+ T cells lose PD-1, whereas bystander cells were unaffected. Additionally, p24+/PD-1 negative cells are less susceptible to apoptosis compared to bystander cells in the same infected milieu. Similar results were observed in vivo, as infected T cells isolated from HIV-1+ individuals have significantly low level of PD-1 and the observed loss of PD-1 in vivo is independent of viral load, CD4 count, and/or antiviral treatment. Together these results indicate that productively infected cells are resistant to early apoptosis by downregulating PD-1, whereas PD-1 enhances the susceptibility of effector T cells to apoptosis suggesting a dual role for PD-1 during HIV-1 infection.
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Affiliation(s)
- Narasimhan J Venkatachari
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Graduate School of Public Health, Pittsburgh, PA 15261, USA
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Valiathan RR, Resh MD. Differential control of CXCR4 and CD4 downregulation by HIV-1 Gag. Virol J 2008; 5:23. [PMID: 18267010 PMCID: PMC2262066 DOI: 10.1186/1743-422x-5-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 02/11/2008] [Indexed: 11/10/2022] Open
Abstract
Background The ESCRT (endosomal sorting complex required for transport) machinery functions to sort cellular receptors into the lumen of the multivesicular body (MVB) prior to lysosomal degradation. ESCRT components can also be recruited by enveloped viruses to sites of viral assembly where they have been proposed to mediate viral egress. For example, HIV-1 budding is dependent on Gag-mediated recruitment of the cellular ESCRTs-I, -III, AIP1/Alix and Vps4 proteins. Viral recruitment of ESCRT proteins could therefore impact on host cell processes such as receptor downregulation. Results Here we show that downregulation of the HIV-1 co-receptor, CXCR4, by its ligand SDF-1, is ESCRT-I dependent. Expression of HIV-1 Gag attenuated downregulation of CXCR4, resulting in accumulation of undegraded receptors within intracellular compartments. The effect of Gag was dependent on an ESCRT-I interacting motif within the C-terminal p6 region of Gag. In contrast, PMA-induced downregulation of the HIV-1 receptor CD4 was independent of ESCRT-I and Vps4; HIV-1 Gag had no effect on this process. Conclusion These results establish that the HIV-1 receptor, CD4, and co-receptor, CXCR4 are differentially regulated by ESCRT proteins. HIV-1 Gag selectively modulates protein sorting at the MVB, interfering with ESCRT-I dependent but not ESCRT-I independent processes.
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Al-Harthi L, MaWhinney S, Connick E, Schooley RT, Forster JE, Benson C, Thompson M, Judson F, Palella F, Landay A. Immunophenotypic alterations in acute and early HIV infection. Clin Immunol 2007; 125:299-308. [PMID: 17916441 DOI: 10.1016/j.clim.2007.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Revised: 07/31/2007] [Accepted: 08/03/2007] [Indexed: 10/22/2022]
Abstract
To understand the extent of immune dysregulation in primary HIV infection (PHI) and the impact of antiretroviral therapy (ART) on restoring these abnormalities, we longitudinally evaluated 52 subjects (Acute-Treated (AT); Early-Treated (ET); Early Untreated (EU)) for markers of activation, proliferation, and function on T cells. ET and AT patients differed by 0.54 log viral load (VL) at baseline but did not differ thereafter by more than 0.34 log10 VL. AT subjects had higher CD8(+) T cell counts and expression of markers indicative of CD8(+) T cell activation (CD38), and proliferation (Ki67), at baseline, than ET subjects but were not different 48 weeks post-ART. Although acute PHI is marked by higher level of immune activation than early PHI, virologic and immunologic responses were similar post-ART, suggesting that the extent of immunologic recovery is not negatively impacted by a delay of treatment beyond the acute stage of disease.
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Affiliation(s)
- Lena Al-Harthi
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA.
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Li Y, Chan EY, Katze MG. Functional genomics analyses of differential macaque peripheral blood mononuclear cell infections by human immunodeficiency virus-1 and simian immunodeficiency virus. Virology 2007; 366:137-49. [PMID: 17507074 PMCID: PMC2082051 DOI: 10.1016/j.virol.2007.04.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 03/23/2007] [Accepted: 04/05/2007] [Indexed: 11/28/2022]
Abstract
The pathogenicity of the primate lentiviruses, human, and simian immunodeficiency viruses, is host-specific. Previous studies indicated that the highly pathogenic human lentivirus HIV-1 has markedly reduced pathogenicity compared to the pathogenic simian lentivirus SIV in pigtail macaques (Macaca nemestrina). We therefore hypothesized that the pigtail macaque peripheral blood mononuclear cells (mPBMCs) would respond differently to infections of HIV-1 and pathogenic SIV. To elucidate the cellular responses to the infections of HIV-1 and SIV, we infected mPBMC with these two viruses. Like infections in vivo, HIV-1 and SIV demonstrated distinct replication kinetics in mPBMCs, with HIV-1 replicating at significantly lower levels. Similarly, gene expression profiling facilitated by macaque-specific oligonucleotide microarrays also revealed distinct expression patterns of genes between the HIV-1- and SIV-infected mPBMCs; in particular, genes associated with the antigen presentation, T cell receptor, ERK/MAPK signaling, Wnt/beta-catenin signaling, and natural killer cell signaling pathways were differentially regulated between these two viruses. Most interestingly, despite the lower levels of replication, HIV-1 triggered a more robust regulation of immune response genes early after infection; the converse was true in SIV-infected mPBMCs. Our results therefore suggest that macaques may be controlling the infection of HIV-1 at an early stage through coordinated regulation of host defense pathways.
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Affiliation(s)
- Yu Li
- Department of Microbiology and Washington National Primate Research Center, University of Washington, Box 358070, Seattle, WA 98195-8070, USA
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Parris GE. Why G3139 works poorly in cancer trials but might work well against HIV. Med Hypotheses 2007; 69:537-40. [PMID: 17363184 PMCID: PMC7126701 DOI: 10.1016/j.mehy.2007.01.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2006] [Accepted: 01/07/2007] [Indexed: 11/10/2022]
Abstract
The antisense drug G3139 (oblimersen sodium, Genta, Inc.) is a phosphorothioate oligodeoxynucleotide (ODN) containing unmethylated CpG units, which is targeted to suppress Bcl-2. To date, its effectiveness in cancer clinical trials has been minimal. Some suggestions are provided for that disappointment and recent citations are provided that support the idea that G3139 may be effective at clearing viral infections, specifically HIV. At the time G3139 was conceived as an anti-cancer drug candidate, it was viewed optimistically because Bcl-2 was widely believed to be the most important protein blocking p53-dependent apoptosis caused by internal stress. Since that time, we have learnt that Bcl-2 is not the only protein that inhibits apoptosis and that p53 itself is frequently malfunctioning in tumors. Thus, the anti-cancer utility of suppressing Bcl-2 in cancer cells is limited. Moreover, Bcl-2 has a role in halting the cell cycle (though p27), which may slow down tumor growth; and Bcl-2 even has pro-apoptotic roles in the execution of apoptosis initiated by external death signals (via Fas/CD95 and caspase 3). Overall, in the clinical setting, G3139 usually has statistically significant but medically unimportant benefit. These results have greatly diminished the enthusiasm for the drug especially when the side effects are considered. Specifically, the unmethylated CpG ODN (and/or the phosphorothioate group) activates the immune system, but this potentially important anti-cancer effect is lost when the immune cells undergo premature apoptosis apparently because their Bcl-2 levels have been lowered by the antisense effect of G3139. While this effect on immune cells is usually undesirable, it is exactly what would be useful for activating immune cells, initiating provirus transcription in retrovirus-infected cells, and facilitating selective apoptosis of these infected cells. In general, G3139 might have benefit in clearing chronic infections by intracellular parasites including viruses (HIV, SIV, HTLV, HBV, coronavirus, etc.). Indeed, G3139 has been shown to cause apoptosis in EBV-infected cells leading to clearance of the virus.
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Parris GE. Mechanism and history of evolution of symbiotic HIV strains into lethal pandemic strains: the key event may have been a 1927 trial of pamaquine in Leopoldville (Kinshasa), Congo. Med Hypotheses 2007; 69:838-48. [PMID: 17368749 DOI: 10.1016/j.mehy.2007.01.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 01/24/2007] [Indexed: 02/04/2023]
Abstract
In previous papers, I have rejected both the zoonosis and the serial transfer hypotheses of the origin and evolution of the current lethal pandemic strains of HIV. The hypothesis that fits the critical observations is that all the human and nonhuman primate species in central Africa (an area of hyper-endemic malaria) have shared (through inter-species transfers) a "primate T-cell retrovirus" (PTRV), which has adapted to each host species. This retrovirus is believed to assist primate T-cells attack the liver stage of the malaria infection. Each geographic region has a dominant primate host and a characteristic virus. Starting in 1955 and continuing into the late 1970s, chloroquine was provided by the WHO and used for prophylaxis against malaria. Chloroquine has a number of biochemical activities but two of the most important are blocking transcription of cellular genes and proviruses activated by NF-kappaB and blocking the glycosylation of surface proteins on viruses and cells. Concurrent with the development of resistance of the malaria parasite to chloroquine, HIV strains were quickly selected, which have enhanced transcription rates (by inclusion of multiple kappaB binding sites in their long terminal repeats by recombination) and enhanced infectivity (fusogenicity) (most likely by mutations in multiple viral genes that regulate glycosylation of Env). There also may have been mutations that enhanced activation of NF-kappaB in the host cell. These changes in the retrovirus genome were not manifest in effects of the HIV strains as long as the hosts were under the influence of chloroquine. But, when the virus infects people who are not protected by chloroquine, the virus multiplies more rapidly and is more communicable. Fortunately, most of these strains (i.e., HIV-2 groups, and HIV-1 O and HIV-1 N) self-regulate (i.e., infected cells kill infected cells) well enough that viral loads remain subdued and bystander cells of the immune system are not excessively attrited. In the case of HIV-1 group M, however, there is more going on. Following the work of Korber et al. on the phylogenetics of HIV-1 groups M, I reach the conclusion that the major subgroups giving rise to the worldwide pandemic, were founded in a 1927 clinical trial of pamaquine (plasmoquine) in Leopoldville (Kinshasa). This drug is much more toxic that chloroquine and appears to have strongly selected for resistance to apoptosis in infected cells, which allows these subgroups to attrite bystander cells leading to AIDS.
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Bahbouhi B, Landay A, Tenorio A, Al-Harthi L. HIV infection of primary CD4+ Th2 cells, defined by expression of the chemoattractant receptor-homologous (CRTH2), induces a Th0 phenotype. AIDS Res Hum Retroviruses 2007; 23:269-77. [PMID: 17331033 DOI: 10.1089/aid.2006.0151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The association between HIV, cytokine profile, and disease progression is controversial. In this study, we evaluated whether HIV infection of a primary T helper-like type 2 cytokine (Th2) cell subset augments their cytokine profile. We utilized the CRTH2 (chemoattractant receptor-homologous) marker to identify CD4+ Th2 cells. Approximately 2-4% of CD4+ T cells are CRTH2+. CRTH2+ expression is confirmed to delineate a Th2 subset as indicated by robust inducible IL-4 response. CD4+ CRTH2+ T cells were also more inherently activated than their CRTH2-negative counterpart as indicated by a higher percent expression of CD69, CD45RO, CD95, CD25, and HLA-DR. CD4+CRTH2+ T cells were not terminally differentiated as indicated by expression of CD27 and CD28. In vitro HIV infection of primary human CD4 CRTH2T cells, independent of chemokine coreceptor usage, potently upregulated IFN-gamma production while still maintaining robust IL-4 expression. This Th0 (IFNgamma+ IL-4+) phenotype was upregulated in CD4+CRTH2+ T cells post-HIV infection by 18-fold, demonstrating a shift to a Th0 phenotype. Ex vivo studies also demonstrated that HIV+ patients exhibited a decline in CD4+CRTH2+ cells and a shift of this population toward cells that express both IFN-gamma and IL-4. Collectively, these data indicate that HIV replication in Th2 cells induces a Th0 phenotype. This phenomenon may be a deliberate viral escape mechanism to prevent the skewing of the immune response toward Th1 or Th2.
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Affiliation(s)
- Bouchaib Bahbouhi
- Department of Immunology/Microbiology , Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, USA
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Minami R, Yamamoto M, Takahama S, Miyamura T, Watanabe H, Suematsu E. RCAS1 induced by HIV-Tat is involved in the apoptosis of HIV-1 infected and uninfected CD4+ T cells. Cell Immunol 2007; 243:41-7. [PMID: 17250817 DOI: 10.1016/j.cellimm.2006.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 10/25/2006] [Accepted: 11/27/2006] [Indexed: 12/28/2022]
Abstract
HIV-1 infection is known to lead to a massive depletion of CD4(+) T cells, and the Fas/FasL and TRAIL/TRAIL-receptor systems have been reported to be one of the mechanisms of CD4(+) T cell apoptosis in HIV-1 infection. RCAS1 (a receptor-binding cancer antigen expressed on SiSo cells) is also an apoptosis-associated protein that induces apoptosis in receptor positive-cells including T cells, and NK cells. To investigate the role of RCAS1 in HIV-1 infection, we stimulated CD4(+) T cells, monocytes, and several cell lines by HIV-Tat protein and thus showed that Tat significantly increased the mRNA transcription levels and the secretion of soluble RCAS1 in CD4(+) T cells and monocytes. We also showed that the apoptosis induced by HIV-Tat was blocked by inhibiting the expression of RCAS1, using small interfering RNA (siRNA), which was specific for RCAS1. These results indicate that RCAS1 is one of the mechanisms of CD4(+) T cell depletion induced by HIV infection.
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Affiliation(s)
- Rumi Minami
- Internal Medicine, Clinical Research Institute, National Hospital Organization, Kyushu Medical Center, Fukuoka, Japan.
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Parris GE. HIV-infection of CD4+ T-cells enhances their effectiveness against hepatocytes infected with malaria parasites. Med Hypotheses 2006; 68:1187-8. [PMID: 17098375 DOI: 10.1016/j.mehy.2006.09.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 09/16/2006] [Indexed: 11/16/2022]
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Abstract
Human immunodeficiency virus-1 (HIV-1) neuroinvasion occurs early (during period of initial viremia), leading to infection of a limited amount of susceptible cells with low CD4 expression. Protective cellular and humoral immunity eliminate and suppress viral replication relatively quickly due to peripheral immune responses and the low level of initial central nervous system (CNS) infection. Upregulation of the brain protective mechanisms against lymphocyte entry and survival (related to immune privilege) helps reduce viral load in the brain. The local immune compartment dictates local viral evolution as well as selection of cytotoxic lymphocytes and immunoglobulin G specificity. Such status can be sustained until peripheral immune anti-viral responses fail. Activation of microglia and astrocytes, due to local or peripheral triggers, increases chemokine production, enhances traffic of infected cells into the CNS, upregulates viral replication in resident brain macrophages, and significantly augments the spread of viral species. The combination of these factors leads to the development of HIV-1 encephalitis-associated neurocognitive decline and patient death. Understanding the immune-privileged state created by virus, the brain microenvironment, and the ability to enhance anti-viral immunity offer new therapeutic strategies for treatment of HIV-1 CNS infection.
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Affiliation(s)
- Yuri Persidsky
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE 68198-5215, USA.
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Groot F, van Capel TMM, Schuitemaker JHN, Berkhout B, de Jong EC. Differential susceptibility of naïve, central memory and effector memory T cells to dendritic cell-mediated HIV-1 transmission. Retrovirology 2006; 3:52. [PMID: 16916447 PMCID: PMC1562438 DOI: 10.1186/1742-4690-3-52] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Accepted: 08/17/2006] [Indexed: 02/02/2023] Open
Abstract
Background Dendritic cells (DC) have been proposed to facilitate sexual transmission of HIV-1 by capture of the virus in the mucosa and subsequent transmission to CD4+ T cells. Several T cell subsets can be identified in humans: naïve T cells (TN) that initiate an immune response to new antigens, and memory T cells that respond to previously encountered pathogens. The memory T cell pool comprises central memory (TCM) and effector memory cells (TEM), which are characterized by distinct homing and effector functions. The TEM cell subset, which can be further divided into effector Th1 and Th2 cells, has been shown to be the prime target for viral replication after HIV-1 infection, and is abundantly present in mucosal tissues. Results We determined the susceptibility of TN, TCM and TEM cells to DC-mediated HIV-1 transmission and found that co-receptor expression on the respective T cell subsets is a decisive factor for transmission. Accordingly, CCR5-using (R5) HIV-1 was most efficiently transmitted to TEM cells, and CXCR4-using (X4) HIV-1 was preferentially transmitted to TN cells. Conclusion The highly efficient R5 transfer to TEM cells suggests that mucosal T cells are an important target for DC-mediated transmission. This may contribute to the initial burst of virus replication that is observed in these cells. TN cells, which are the prime target for DC-mediated X4 virus transmission in our study, are considered to inefficiently support HIV-1 replication. Our results thus indicate that DC may play a decisive role in the susceptibility of TN cells to X4 tropic HIV-1.
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Affiliation(s)
- Fedde Groot
- Dept. of Human Retrovirology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- Dept. of Cell Biology and Histology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Toni MM van Capel
- Dept. of Cell Biology and Histology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Joost HN Schuitemaker
- Dept. of Cell Biology and Histology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Ben Berkhout
- Dept. of Human Retrovirology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Esther C de Jong
- Dept. of Cell Biology and Histology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
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Choi J, Walker J, Talbert-Slagle K, Wright P, Pober JS, Alexander L. Endothelial cells promote human immunodeficiency virus replication in nondividing memory T cells via Nef-, Vpr-, and T-cell receptor-dependent activation of NFAT. J Virol 2005; 79:11194-204. [PMID: 16103171 PMCID: PMC1193601 DOI: 10.1128/jvi.79.17.11194-11204.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human endothelial cells (ECs) enhance human immunodeficiency virus (HIV) replication within CD4(+) memory T cells by 50,000-fold in a Nef-dependent manner. Here, we report that EC-mediated HIV type 1 replication is also dependent on an intact vpr gene. Moreover, we demonstrate that despite a requirement for engaging major histocompatibility complex (MHC) class II molecules and costimulators, EC-stimulated virus-producing cells (p24(high) T cells) do not proliferate, nor are they arrested in the cell cycle. Rather, they are minimally activated, sometimes expressing CD69 but not CD25, HLA-DR, VLA-1, or effector cytokines. Blocking antibodies to interleukin 2 (IL-2), IL-6, IL-7, or tumor necrosis factor do not inhibit viral replication. Cyclosporine effectively inhibits viral replication, as does disruption of the NFAT binding site in the viral long terminal repeat. Furthermore, in the presence of ECs, suboptimal T-cell receptor (TCR) stimulation with phytohemagglutinin L supports efficient viral replication, and suboptimal stimulation with toxic shock syndrome toxin 1 leads to viral replication selectively in the TCR-stimulated, Vbeta2-expressing T cells. Collectively, these data indicate that ECs provide signals that promote Nef- and Vpr-dependent HIV replication in memory T cells that have been minimally activated through their TCRs. Our studies suggest a mechanism for HIV replication in vivo within the reservoir of circulating memory CD4(+) T cells that persist despite antiretroviral therapy and further suggest that maintenance of immunological memory by MHC class II-expressing ECs via TCR signaling may contribute to HIV rebound following cessation of antiretroviral therapy.
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Affiliation(s)
- Jaehyuk Choi
- Section of Immunology, Yale University School of Medicine, New Haven, CT 06520, USA
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Kulkarni A, Ravi DS, Singh K, Rampalli S, Parekh V, Mitra D, Chattopadhyay S. HIV-1 Tat modulates T-bet expression and induces Th1 type of immune response. Biochem Biophys Res Commun 2005; 329:706-12. [PMID: 15737643 DOI: 10.1016/j.bbrc.2005.02.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Indexed: 11/18/2022]
Abstract
The HIV-1 transactivator Tat performs various viral and cellular functions. Primarily, it induces processive transcription from the HIV-1 LTR promoter. However, Tat secreted from infected cells is known to activate uninfected lymphocytes through receptors. To further delineate the specific target genes, extracellular Tat was expressed on the cell membrane of stimulator cells and co-cultured with human PBMCs. Along with induced CD4(+) T cell proliferation and IFN-gamma secretion, there was strong upregulation of T-bet expression which is majorly implicated in generating T(H)1 type of immune response. To further delineate the effect of extracellular Tat on HIV replication, both p24 analysis and in vivo GFP expression were performed. There was a significant inhibition of HIV-1 replication in human CEM-GFP cell line and hPBMCs. Thus, for the first time we report that apart from its transactivation activity, extracellular Tat acts as a costimulatory molecule that affects viral replication by modulating host immune response through induction of T-bet expression and IFN-gamma secretion.
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Affiliation(s)
- Asavari Kulkarni
- National Center for Cell Science, Pune University Campus, Ganeshkhind, Pune 411 007, India
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