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Tang S, Lu Y, Sun F, Qin Y, Harypursat V, Deng R, Zhang G, Chen Y, Wang T. Transcriptomic crosstalk between viral and host factors drives aberrant homeostasis of T-cell proliferation and cell death in HIV-infected immunological non-responders. J Infect 2024; 88:106151. [PMID: 38582127 DOI: 10.1016/j.jinf.2024.106151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 03/13/2024] [Accepted: 03/28/2024] [Indexed: 04/08/2024]
Abstract
BACKGROUND Immunological non-responders (INRs) among people living with HIV have inherently higher mortality and morbidity rates. The underlying immunological mechanisms whereby failure of immune reconstitution occurs in INRs require elucidation. METHOD HIV-1 DNA and HIV-1 cell-associated RNA (CA-HIV RNA) quantifications were conducted via RT-qPCR. Transcriptome sequencing (RNA-seq), bioinformatics, and biological verifications were performed to discern the crosstalk between host and viral factors. Flow cytometry was employed to analyze cellular activation, proliferation, and death. RESULTS HIV-1 DNA and CA-HIV RNA levels were observed to be significantly higher in INRs compared to immunological responders (IRs). Evaluation of CD4/CD8 ratios showed a significantly negative correlation with HIV-1 DNA in IRs, but not in INRs. Bioinformatics analyses and biological verifications showed IRF7/INF-α regulated antiviral response was intensified in INRs. PBMCs of INRs expressed significantly more HIV integrase-mRNA (p31) than IRs. Resting (CD4+CD69- T-cells) and activated (CD4+CD69+ T-cells) HIV-1 reservoir harboring cells were significantly higher in INRs, with the co-occurrence of significantly higher cellular proliferation and cell death in CD4+ T-cells of INRs. CONCLUSION In INRs, the systematic crosstalk between the HIV-1 reservoir and host cells tends to maintain a persistent antiviral response-associated inflammatory environment, which drives aberrant cellular activation, proliferation, and death of CD4+ T-cells.
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Affiliation(s)
- Shengquan Tang
- The First Affiliated Hospital, MOE Key Laboratory of Tumor Molecular Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, China; Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Yanqiu Lu
- Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Feng Sun
- Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Yuanyuan Qin
- Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Vijay Harypursat
- Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Renni Deng
- Department of Clinical Laboratory, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China
| | - Gong Zhang
- The First Affiliated Hospital, MOE Key Laboratory of Tumor Molecular Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, China
| | - Yaokai Chen
- Department of Infectious Diseases, Chongqing Public Health Medical Center, 109 Baoyu Road, Shapingba District, Chongqing 400036, China.
| | - Tong Wang
- The First Affiliated Hospital, MOE Key Laboratory of Tumor Molecular Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, China.
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Ivanov SM, Tarasova OA, Poroikov VV. Transcriptome-based analysis of human peripheral blood reveals regulators of immune response in different viral infections. Front Immunol 2023; 14:1199482. [PMID: 37795081 PMCID: PMC10546413 DOI: 10.3389/fimmu.2023.1199482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction There are difficulties in creating direct antiviral drugs for all viruses, including new, suddenly arising infections, such as COVID-19. Therefore, pathogenesis-directed therapy is often necessary to treat severe viral infections and comorbidities associated with them. Despite significant differences in the etiopathogenesis of viral diseases, in general, they are associated with significant dysfunction of the immune system. Study of common mechanisms of immune dysfunction caused by different viral infections can help develop novel therapeutic strategies to combat infections and associated comorbidities. Methods To identify common mechanisms of immune functions disruption during infection by nine different viruses (cytomegalovirus, Ebstein-Barr virus, human T-cell leukemia virus type 1, Hepatitis B and C viruses, human immunodeficiency virus, Dengue virus, SARS-CoV, and SARS-CoV-2), we analyzed the corresponding transcription profiles from peripheral blood mononuclear cells (PBMC) using the originally developed pipeline that include transcriptome data collection, processing, normalization, analysis and search for master regulators of several viral infections. The ten datasets containing transcription data from patients infected by nine viruses and healthy people were obtained from Gene Expression Omnibus. The analysis of the data was performed by Genome Enhancer pipeline. Results We revealed common pathways, cellular processes, and master regulators for studied viral infections. We found that all nine viral infections cause immune activation, exhaustion, cell proliferation disruption, and increased susceptibility to apoptosis. Using network analysis, we identified PBMC receptors, representing proteins at the top of signaling pathways that may be responsible for the observed transcriptional changes and maintain the current functional state of cells. Discussion The identified relationships between some of them and virus-induced alteration of immune functions are new and have not been found earlier, e.g., receptors for autocrine motility factor, insulin, prolactin, angiotensin II, and immunoglobulin epsilon. Modulation of the identified receptors can be investigated as one of therapeutic strategies for the treatment of severe viral infections.
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Affiliation(s)
- Sergey M. Ivanov
- Department of Bioinformatics, Institute of Biomedical Chemistry, Moscow, Russia
- Department of Bioinformatics, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Olga A. Tarasova
- Department of Bioinformatics, Institute of Biomedical Chemistry, Moscow, Russia
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Host Molecule Incorporation into HIV Virions, Potential Influences in HIV Pathogenesis. Viruses 2022; 14:v14112523. [PMID: 36423132 PMCID: PMC9694329 DOI: 10.3390/v14112523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/08/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022] Open
Abstract
During the last phase of HIV viral production, nascent HIV virions acquire a fraction of the cellular lipid membrane to create the external lipid envelope, a process by which cellular proteins present on the surface of the infected cell can be incorporated along with Env trimers. Interestingly, several studies indicated that these incorporated host molecules could conserve their biological activity and consequently contribute to HIV pathogenesis either by enhancing the infectivity of HIV virions, their tissue tropism or by affecting immune cell functions. The following review will describe the main approaches used to characterize membrane bound host molecule incorporation into HIV virions, the proposed mechanisms involved, and the role of a non-exhaustive list of incorporated molecules.
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Polymorphisms in TNF-α/TNFR1 pathway genes are associated with CD4+ T cells recovery in HIV-1-infected individuals on antiretroviral therapy. J Acquir Immune Defic Syndr 2021; 88:322-327. [PMID: 34267056 DOI: 10.1097/qai.0000000000002761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 06/15/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Antiretroviral therapy (ART) is an important hallmark of HIV-1 treatment, enabling viral load suppression to undetectable levels and CD4+ T cells recovery. However, some individuals do not recover the CD4+ T cell count to normal levels, despite viral suppression. We hypothesize that variation in genes involved in extrinsic apoptosis pathways may influence interindividual immune recovery during ART. METHODS We assessed clinic-epidemiological variables, and the allelic/genotypic distribution of functional single nucleotide polymorphisms in genes involved in extrinsic apoptosis pathways (TNFRSF1A: rs1800692, rs767455; TNFAIP3: rs2270926; NFKBIA: rs8904; TNF-α: rs1800629) and their relationship with immune recovery in ART treated (one year) HIV-1-infected individuals. We enrolled 155 HIV-1 infected individuals, 102 showing immunological success and 53 with immunological failure. RESULTS Through univariate analysis, we observed that the male sex (60.4%, p=0.002) showed higher median of age at treatment onset (34.8 years, p=0.034) and higher time until virological suppression (6 months, p=0.035), both risk factors for immune failure. Survival analysis revealed that individuals who started ART treatment with T CD4+ cells count <200 cells/mm3 took a longer time to immunological recovery (median time = 27 months, p=0.029). ART containing zidovudine (AZT) also was associated with immune recovery in univariate e multivariate analysis. Variants in TNFRSF1A (rs767455: T, TT; rs1800692-rs767455: T-T combination) and NFKBIA (rs8904: A) genes associated with immune failure, while NFKBIA (rs8904: GA) and TNF-α (rs1800629: GA), with CD4+ T cells recovery. CONCLUSIONS Clinic-epidemiological and variants in genes involved in extrinsic apoptosis pathways might influence the CD4+ T cells immune recovery.
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Ivanov S, Filimonov D, Tarasova O. A computational analysis of transcriptional profiles from CD8(+) T lymphocytes reveals potential mechanisms of HIV/AIDS control and progression. Comput Struct Biotechnol J 2021; 19:2447-2459. [PMID: 34025935 PMCID: PMC8113781 DOI: 10.1016/j.csbj.2021.04.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 01/06/2023] Open
Abstract
Cytotoxic and noncytotoxic CD8+ T lymphocyte responses are essential for the control of HIV infection. Understanding the mechanisms underlying HIV control in elite controllers (ECs), which maintain undetectable viral load in the absence of antiretroviral therapy, may facilitate the development of new effective therapeutic strategies. We developed an original pipeline for an analysis of the transcriptional profiles of CD8+ cells from ECs, treated and untreated progressors. Hierarchical cluster analysis of CD8+ cells' transcription profiles allowed us to identify five distinct groups (EC groups 1-5) of ECs. The transcriptional profiles of EC group 1 were opposite to those of groups 2-4 and similar to those of the treated progressors, which can be associated with residual activation and dysfunction of CD8+ T-lymphocytes. The profiles of groups 2-4 were associated with different numbers of differentially expressed genes compared to healthy controls, but the corresponding genes shared the same cellular processes. These three groups were associated with increased metabolism, survival, proliferation, and the absence of an "exhausted" phenotype, compared to both untreated progressors and healthy controls. The CD8+ lymphocytes from these groups of ECs may contribute to the control under HIV replication and slower disease progression. The EC group 5 was indistinguishable from normal. Application of master regulator analysis allowed us to identify 22 receptors, including interferon-gamma, interleukin-2, and androgen receptors, which may be responsible for the observed expression changes and the functional states of CD8+ cells from ECs. These receptors can be considered potential targets of therapeutic intervention, which may decelerate disease progression.
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Affiliation(s)
- Sergey Ivanov
- Department of Bioinformatics, Institute of Biomedical Chemistry, Moscow, Russia
- Department of Bioinformatics, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Dmitry Filimonov
- Department of Bioinformatics, Institute of Biomedical Chemistry, Moscow, Russia
| | - Olga Tarasova
- Department of Bioinformatics, Institute of Biomedical Chemistry, Moscow, Russia
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Lu L, Wang J, Yang Q, Xie X, Huang Y. The role of CD38 in HIV infection. AIDS Res Ther 2021; 18:11. [PMID: 33820568 PMCID: PMC8021004 DOI: 10.1186/s12981-021-00330-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 03/06/2021] [Indexed: 11/24/2022] Open
Abstract
The widely-expressed molecule CD38 is a single-stranded type II transmembrane glycoprotein that is mainly involved in regulating the differentiation and activation state of the cell. CD38 has broad and complex functions, including enzymatic activity, intercellular signal transduction, cell activation, cytokine production, receptor function and adhesion activity, and it plays an important role in the physiological and pathological processes of many diseases. Many studies have shown that CD38 is related to the occurrence and development of HIV infection, and CD38 may regulate its progression through different mechanisms. Therefore, investigating the role of CD38 in HIV infection and the potential signaling pathways that are involved may provide a new perspective on potential treatments for HIV infection. In the present review, the current understanding of the roles CD38 plays in HIV infection are summarized. In addition, the specific role of CD38 in the process of HIV infection of human CD4+ T lymphocytes is also discussed.
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Chen X, Chen H, Zhang Z, Fu Y, Han X, Zhang Y, Xu J, Ding H, Cui H, Dong T, Shang H, Jiang Y. Elevated CD54 Expression Renders CD4+ T Cells Susceptible to Natural Killer Cell-Mediated Killing. J Infect Dis 2020; 220:1892-1903. [PMID: 31433832 DOI: 10.1093/infdis/jiz413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/14/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Natural killer (NK) cells are an important type of effector cell in the innate immune response, and also have a role in regulation of the adaptive immune response. Several studies have indicated that NK cells may influence CD4+ T cells during HIV infection. METHODS In total, 51 HIV-infected individuals and 15 healthy controls participated in this study. We performed the flow cytometry assays and real-time PCR for the phenotypic analysis and the functional assays of NK cell-mediated deletion of CD4+ T cells, phosphorylation of nuclear factor-κB (NF-κB/p65) and the intervention of metformin. RESULTS Here we detected high CD54 expression on CD4+ T cells in HIV-infected individuals, and demonstrate that upregulated CD54 is associated with disease progression in individuals infected with HIV. We also show that CD54 expression leads to the deletion of CD4+ T cells by NK cells in vitro, and that this is modulated by NF-κB/p65 signaling. Further, we demonstrate that metformin can suppress CD54 expression on CD4+ T cells by inhibiting NF-κB/p65 phosphorylation. CONCLUSIONS Our data suggest that further studies to evaluate the potential role of metformin as adjunctive therapy to reconstitute immune function in HIV-infected individuals are warranted.
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Affiliation(s)
- Xi Chen
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Huihui Chen
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Clinical Laboratory, Henan Provincial Chest Hospital, Zhengzhou, China
| | - Zining Zhang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yajing Fu
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xiaoxu Han
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yue Zhang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Junjie Xu
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Haibo Ding
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Hualu Cui
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Tao Dong
- MRC Human Immunology Unit, Radcliffe Department of Medicine, Oxford University, United Kingdom
| | - Hong Shang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yongjun Jiang
- NHC Key Laboratory of AIDS Immunology (China Medical University), Department of Laboratory Medicine.,Key Laboratory of AIDS Immunology of Liaoning Province, The First Affiliated Hospital of China Medical University, Shenyang.,Key Laboratory of AIDS Immunology, Chinese Academy of Medical Sciences, Shenyang, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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Partner HIV Serostatus Impacts Viral Load, Genital HIV Shedding, and Immune Activation in HIV-Infected Individuals. J Acquir Immune Defic Syndr 2020; 82:51-60. [PMID: 31169767 DOI: 10.1097/qai.0000000000002089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Studies of seronegative individuals in HIV discordant relationships provide important insights into the effects of HIV exposure on the seronegative partner, but few have examined the impact of partner serostatus on disease progression in seropositive individuals. We investigated the impact of HIV serostatus on clinical and biological factors influencing HIV disease progression in 337 HIV-infected heterosexual individuals in stable long-term HIV-seroconcordant or HIV-serodiscordant relationships. Seroconcordant individuals had significantly higher plasma viral loads (pVLs) than HIV-infected partners in serodiscordant partnerships [4.4 log10 copies RNA/mL (interquartile range 3.7-5.0) versus 3.9 (3.3-4.5), P < 0.0001], irrespective of gender. pVLs correlated inversely with CD4 T-cell counts, although CD4 counts did not differ significantly between seroconcordant and serodiscordant individuals. HIV+ seroconcordant individuals had higher frequencies of CCR5 CD4 and CD8 T cells (P = 0.03 and P = 0.02, respectively) than HIV+ individuals in serodiscordant relationships and higher concentrations of plasma IL-1β (P = 0.04), TNF-α (P = 0.02), and IL-10 (P = 0.02). Activated CD4 T-cell frequencies and TNF-α were the most influential in determining variation in pVLs, independently of CD4 counts. In addition, HIV+ seroconcordant women had significantly higher genital VLs (gVLs) than HIV+ women in serodiscordant relationships (P < 0.001), with pVLs correlating significantly with gVLs (Rho = 0.65, P < 0.0001). Cervical and blood T-cell activation tended to correlate positively, although partner seroconcordance did not influence genital T-cell activation. We conclude that HIV+ seroconcordant individuals have higher frequencies of activated, CCR5-expressing T cells in blood and higher pVLs and gVLs than their HIV+ counterparts in discordant relationships, which could translate to faster disease progression or larger viral reservoir.
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Garg H, Joshi A. Host and Viral Factors in HIV-Mediated Bystander Apoptosis. Viruses 2017; 9:v9080237. [PMID: 28829402 PMCID: PMC5579491 DOI: 10.3390/v9080237] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis.
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Affiliation(s)
- Himanshu Garg
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
| | - Anjali Joshi
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
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Fu W, Qiu C, Zhou M, Zhu L, Yang Y, Qiu C, Zhang L, Xu X, Wang Y, Xu J, Zhang X. Immune Activation Influences SAMHD1 Expression and Vpx-mediated SAMHD1 Degradation during Chronic HIV-1 Infection. Sci Rep 2016; 6:38162. [PMID: 27922067 PMCID: PMC5138643 DOI: 10.1038/srep38162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/04/2016] [Indexed: 02/07/2023] Open
Abstract
SAMHD1 restricts human immunodeficiency virus type 1 (HIV-1) replication in myeloid cells and CD4+ T cells, while Vpx can mediate SAMHD1 degradation to promote HIV-1 replication. Although the restriction mechanisms of SAMHD1 have been well-described, SAMHD1 expression and Vpx-mediated SAMHD1 degradation during chronic HIV-1 infection were poorly understood. Flow cytometric analysis was used to directly visualize ex vivo, and after in vitro SIV-Vpx treatment, SAMHD1 expression in CD4+ T cells and monocytes. Here we report activated CD4+ T cells without SAMHD1 expression were severely reduced, and SAMHD1 in CD4+ T cells became susceptible to SIV-Vpx mediated degradation during chronic HIV-1 infection, which was absent from uninfected donors. These alterations were irreversible, even after long-term fully suppressive antiretroviral treatment. Although SAMHD1 expression in CD4+ T cells and monocytes was not found to correlate with plasma viral load, Vpx-mediated SAMHD1 degradation was associated with indicators of immune activation. In vitro assays further revealed that T-cell activation and an upregulated IFN-I pathway contributed to these altered SAMHD1 properties. These findings provide insight into how immune activation during HIV-1 infection leads to irreparable aberrations in restriction factors and in subsequent viral evasion from host antiviral defenses.
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Affiliation(s)
- Weihui Fu
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Chao Qiu
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China.,Huashan Hospital, Fudan University, Shanghai, China.,Minhang Hospital, Fudan University, Shanghai, China
| | - Mingzhe Zhou
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Lingyan Zhu
- Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Yu Yang
- Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Chenli Qiu
- Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Linxia Zhang
- Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Xuan Xu
- Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Ying Wang
- Shanghai Municipal Center for Disease Control &Prevention, Shanghai, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology of Ministry of Education/Health at Shanghai Medical College, Fudan University, Shanghai, China
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Sampath R, Cummins NW, Badley AD. Casp8p41: The Protean Mediator of Death in CD4 T-cells that Replicate HIV. J Cell Death 2016; 9:9-17. [PMID: 27721655 PMCID: PMC5040423 DOI: 10.4137/jcd.s39872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/12/2016] [Accepted: 06/14/2016] [Indexed: 01/15/2023] Open
Abstract
HIV cure is now the focus of intense research after Timothy Ray Brown (the Berlin patient) set the precedent of being the first and only person cured. A major barrier to achieving this goal on a meaningful scale is an elimination of the latent reservoir, which is thought to comprise CD4-positive cells that harbor integrated, replication-competent HIV provirus. These cells do not express viral proteins, are indistinguishable from uninfected CD4 cells, and are thought to be responsible for HIV viral rebound—that occurs within weeks of combination anti retroviral therapy (cART) interruption. Modalities to engineer transcriptional stimulation (reactivation) of this dormant integrated HIV provirus, leading to expression of cytotoxic viral proteins, are thought to be a specific way to eradicate the latently infected CD4 pool and are becoming increasingly relevant in the era of HIV cure. HIV protease is one such protein produced after HIV reactivation that cleaves procaspase-8 to generate a novel protein Casp8p41. Casp8p41 then binds to the BH3 domain of BAK, leading to BAK oligomerization, mitochondrial depolarization, and apoptosis. In central memory T cells (TCMs) from HIV-infected patients, an elevated Bcl-2/procaspase-8 ratio was observed, and Casp8p41 binding to Bcl-2 was associated with a lack of reactivation-induced cell death. This was reversed by priming cells with a specific Bcl-2 antagonist prior to reactivation, resulting in increased cell death and decreased HIV DNA in a Casp8p41-dependent pathway. This review describes the biology, clinical relevance, and implications of Casp8p41 for a potential cure.
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Affiliation(s)
- Rahul Sampath
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
| | - Nathan W Cummins
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
| | - Andrew D Badley
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
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Kumar R, Kumar Pate S, Rami Reddy B, Bhatt M, Karthik K, Gandham RK, Singh Mali Y, Dhama K. Apoptosis and Other Alternate Mechanisms of Cell Death. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/ajava.2015.646.668] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Galloway NLK, Doitsh G, Monroe KM, Yang Z, Muñoz-Arias I, Levy DN, Greene WC. Cell-to-Cell Transmission of HIV-1 Is Required to Trigger Pyroptotic Death of Lymphoid-Tissue-Derived CD4 T Cells. Cell Rep 2015; 12:1555-1563. [PMID: 26321639 PMCID: PMC4565731 DOI: 10.1016/j.celrep.2015.08.011] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 06/17/2015] [Accepted: 08/04/2015] [Indexed: 12/27/2022] Open
Abstract
The progressive depletion of CD4 T cells underlies clinical progression to AIDS in untreated HIV-infected subjects. Most dying CD4 T cells correspond to resting nonpermissive cells residing in lymphoid tissues. Death is due to an innate immune response against the incomplete cytosolic viral DNA intermediates accumulating in these cells. The viral DNA is detected by the IFI16 sensor, leading to inflammasome assembly, caspase-1 activation, and the induction of pyroptosis, a highly inflammatory form of programmed cell death. We now show that cell-to-cell transmission of HIV is obligatorily required for activation of this death pathway. Cell-free HIV-1 virions, even when added in large quantities, fail to activate pyroptosis. These findings underscore the infected CD4 T cells as the major killing units promoting progression to AIDS and highlight a previously unappreciated role for the virological synapse in HIV pathogenesis.
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Affiliation(s)
- Nicole LK Galloway
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
| | - Gilad Doitsh
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
| | - Kathryn M. Monroe
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
| | - Zhiyuan Yang
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
| | - Isa Muñoz-Arias
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
| | - David N Levy
- Department of Basic Sciences and Craniofacial Biology, New York
University College of Dentistry, New York, NY, USA
| | - Warner C. Greene
- Gladstone Institute of Virology and Immunology, 1650 Owens Street,
San Francisco, CA 94158
- Department of Medicine, University of California, San Francisco, San
Francisco, CA 94143
- Department of Microbiology and Immunology, University of California,
San Francisco, San Francisco, CA 94143
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14
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Karim R, Mack WJ, Kono N, Tien PC, Anastos K, Lazar J, Young M, Desai S, Golub ET, Kaplan RC, Hodis HN, Kovacs A. T-cell activation, both pre- and post-HAART levels, correlates with carotid artery stiffness over 6.5 years among HIV-infected women in the WIHS. J Acquir Immune Defic Syndr 2014; 67:349-56. [PMID: 25314253 PMCID: PMC4197806 DOI: 10.1097/qai.0000000000000311] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE T-cell activation is a major pathway driving HIV disease progression. Little is known regarding the impact of T-cell activation on HIV-associated atherosclerosis and cardiovascular disease, a common comorbidity in HIV infection. We hypothesized that T-cell activation will predict vascular stiffness, a measure of subclinical atherosclerosis. DESIGN Linear regression models evaluated the covariate-adjusted association of T-cell activation with vascular stiffness. METHODS CD38 and HLA-DR expression on CD4⁺ and CD8⁺ T cells was assessed by flow cytometry among 59 HIV-negative and 376 HIV-infected (185 hepatitis C coinfected) women in the Women's Interagency HIV Study. T-cell activation was defined by CD8⁺CD38⁺DR+ and CD4⁺CD3⁺8DR+. Multiple activation assessments over 6.5 years were averaged. In 140 women, T-cell activation was measured before and after highly active antiretroviral therapy (HAART) initiation. Carotid artery ultrasounds were completed a median of 6.5 years after last measurement of T-cell activation and carotid artery stiffness including distensibility and elasticity were calculated. RESULTS Percentages of CD4⁺ and CD8⁺ T-cell activation were significantly higher in HIV- infected compared with HIV-negative women. Among HIV-negative women, T-cell activation was not associated with carotid artery stiffness. Among HIV-infected women, higher CD4⁺ T-cell activation levels significantly predicted increased arterial stiffness independent of CD4⁺ cell count and HIV RNA. The association was stronger among HIV/hepatitis C-coinfected women compared with HIV-monoinfected women; however, the difference was not statistically significant (P for interaction >0.05). Pre- and post-HAART levels of CD4⁺ T-cell activation significantly predicted carotid artery stiffness. CONCLUSIONS Persistent T-cell activation, even after HAART initiation, can contribute to structural and/or functional vascular damage accelerating atherogenesis in HIV infection. These results need to be confirmed in a longitudinal prospective study.
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Affiliation(s)
- Roksana Karim
- *Maternal, Child and Adolescent Center for Infectious Disease and Virology, Department of Pediatrics, University of Southern California, Los Angeles, CA; †Department of Preventive Medicine, University of Southern California, Los Angeles, CA; ‡Atherosclerosis Research Unit, University of Southern California, Los Angeles, CA; §Department of Medicine, University of California, San Francisco, San Francisco, CA; ‖Medical Service, Department of Veterans Affairs, University of California, San Francisco, San Francisco, CA; ¶Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY; #Division of Cardiovascular Medicine, State University of New York Downstate Medical Center, Brooklyn, NY; **Georgetown University Medical Center, Georgetown University, Washington, DC; ††Departments of Medicine, Stroger Hospital and Rush University, Chicago, IL; ‡‡Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and §§Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY
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15
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Wesa AK, Mandic M, Taylor JL, Moschos S, Kirkwood JM, Kwok WW, Finke JH, Storkus WJ. Circulating Type-1 Anti-Tumor CD4(+) T Cells are Preferentially Pro-Apoptotic in Cancer Patients. Front Oncol 2014; 4:266. [PMID: 25325015 PMCID: PMC4178427 DOI: 10.3389/fonc.2014.00266] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/10/2014] [Indexed: 12/21/2022] Open
Abstract
Cancer patients frequently exhibit a deficiency in Type-1 (but not Type-2 or regulatory) CD4+ T cell responses against tumor-associated antigens (TAA), which may limit protection against disease progression or responsiveness to immunotherapy in these individuals. Since such deficiency was acutely evident in patients with active disease (AD), where chronic stimulation of anti-tumor CD4+ T cells would be expected and activation-induced cell death may be prevalent, we employed MHC Class II-peptide tetramers to characterize the frequency and apoptotic status of TAA- vs. influenza (FluM1) virus-specific CD4+ T cells in the peripheral blood of HLA-DR*0401+ patients with melanoma or renal cell carcinoma. We observed that Flu-specific CD4+ T cells ranged from 0.17 to 3.89%, while up to approximately 1% of CD4+ T cells reacted against individual TAA epitopes derived from the EphA2 or MAGE-6 proteins. The frequencies of EphA2 and MAGE-6-specific CD4+ T cells in patients were significantly correlated with AD and gender of the patient (i.e., females > males), while frequencies of Flu-specific CD4+ T cells were distributed within a normal range in all patients. Notably, patient CD4+ T cells reactive with MHC class II-TAA (but not MHC class II-Flu) tetramers were significantly enriched for a pro-apoptotic (Annexin-V+) phenotype, particularly amongst the Th1 (T-bet+) subset. These results suggest that the preferential sensitivity of TAA (but not viral)-specific CD4+ Th1 cells to apoptosis in melanoma patients with AD will need to be overcome for optimal clinical benefit of immunotherapeutic approaches to be realized.
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Affiliation(s)
- Amy K Wesa
- Department of Dermatology, University of Pittsburgh , Pittsburgh, PA , USA ; Department of Immunology, University of Pittsburgh , Pittsburgh, PA , USA
| | - Maja Mandic
- Department of Dermatology, University of Pittsburgh , Pittsburgh, PA , USA
| | - Jennifer L Taylor
- Department of Dermatology, University of Pittsburgh , Pittsburgh, PA , USA
| | - Stergios Moschos
- Department of Medicine, University of Pittsburgh , Pittsburgh, PA , USA ; University of Pittsburgh Cancer Institute , Pittsburgh, PA , USA
| | - John M Kirkwood
- Department of Medicine, University of Pittsburgh , Pittsburgh, PA , USA ; University of Pittsburgh Cancer Institute , Pittsburgh, PA , USA
| | - William W Kwok
- Benaroya Research Institute at Virginia Mason University , Seattle, WA , USA
| | - James Harold Finke
- Department of Immunology, Cleveland Clinic Lerner Research Institute , Cleveland, OH , USA
| | - Walter J Storkus
- Department of Dermatology, University of Pittsburgh , Pittsburgh, PA , USA ; Department of Immunology, University of Pittsburgh , Pittsburgh, PA , USA ; University of Pittsburgh Cancer Institute , Pittsburgh, PA , USA
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16
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Savkovic B, Nichols J, Birkett D, Applegate T, Ledger S, Symonds G, Murray JM. A quantitative comparison of anti-HIV gene therapy delivered to hematopoietic stem cells versus CD4+ T cells. PLoS Comput Biol 2014; 10:e1003681. [PMID: 24945407 PMCID: PMC4063676 DOI: 10.1371/journal.pcbi.1003681] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/05/2014] [Indexed: 02/07/2023] Open
Abstract
Gene therapy represents an alternative and promising anti-HIV modality to highly active antiretroviral therapy. It involves the introduction of a protective gene into a cell, thereby conferring protection against HIV. While clinical trials to date have delivered gene therapy to CD4+T cells or to CD34+ hematopoietic stem cells (HSC), the relative benefits of each of these two cellular targets have not been conclusively determined. In the present analysis, we investigated the relative merits of delivering a dual construct (CCR5 entry inhibitor + C46 fusion inhibitor) to either CD4+T cells or to CD34+ HSC. Using mathematical modelling, we determined the impact of each scenario in terms of total CD4+T cell counts over a 10 year period, and also in terms of inhibition of CCR5 and CXCR4 tropic virus. Our modelling determined that therapy delivery to CD34+ HSC generally resulted in better outcomes than delivery to CD4+T cells. An early one-off therapy delivery to CD34+ HSC, assuming that 20% of CD34+ HSC in the bone marrow were gene-modified (G+), resulted in total CD4+T cell counts ≥ 180 cells/ µL in peripheral blood after 10 years. If the uninfected G+ CD4+T cells (in addition to exhibiting lower likelihood of becoming productively infected) also exhibited reduced levels of bystander apoptosis (92.5% reduction) over non gene-modified (G-) CD4+T cells, then total CD4+T cell counts of ≥ 350 cells/ µL were observed after 10 years, even if initially only 10% of CD34+ HSC in the bone marrow received the protective gene. Taken together our results indicate that: 1.) therapy delivery to CD34+ HSC will result in better outcomes than delivery to CD4+T cells, and 2.) a greater impact of gene therapy will be observed if G+ CD4+T cells exhibit reduced levels of bystander apoptosis over G- CD4+T cells.
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Affiliation(s)
- Borislav Savkovic
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
| | - James Nichols
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
| | - Donald Birkett
- Department of Clinical Pharmacology, Flinders University, Adelaide, Australia
| | - Tanya Applegate
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Scott Ledger
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Geoff Symonds
- St Vincent's Centre for Applied Medical Research, Darlinghurst, New South Wales, Sydney, Australia
- Calimmune Pty Ltd, Darlinghurst, New South Wales, Australia
| | - John M. Murray
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
- * E-mail:
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17
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Deep sequencing of HIV-infected cells: insights into nascent transcription and host-directed therapy. J Virol 2014; 88:8768-82. [PMID: 24850744 DOI: 10.1128/jvi.00768-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Polyadenylated mature mRNAs are the focus of standard transcriptome analyses. However, the profiling of nascent transcripts, which often include nonpolyadenylated RNAs, can unveil novel insights into transcriptional regulation. Here, we separately sequenced total RNAs (Total RNAseq) and mRNAs (mRNAseq) from the same HIV-1-infected human CD4(+) T cells. We found that many nonpolyadenylated RNAs were differentially expressed upon HIV-1 infection, and we identified 8 times more differentially expressed genes at 12 h postinfection by Total RNAseq than by mRNAseq. These expression changes were also evident by concurrent changes in introns and were recapitulated by later mRNA changes, revealing an unexpectedly significant delay between transcriptional initiation and mature mRNA production early after HIV-1 infection. We computationally derived and validated the underlying regulatory programs, and we predicted drugs capable of reversing these HIV-1-induced expression changes followed by experimental confirmation. Our results show that combined total and mRNA transcriptome analysis is essential for fully capturing the early host response to virus infection and provide a framework for identifying candidate drugs for host-directed therapy against HIV/AIDS. IMPORTANCE In this study, we used mass sequencing to identify genes differentially expressed in CD4(+) T cells during HIV-1 infection. To our surprise, we found many differentially expressed genes early after infection by analyzing both newly transcribed unprocessed pre-mRNAs and fully processed mRNAs, but not by analyzing mRNAs alone, indicating a significant delay between transcription initiation and mRNA production early after HIV-1 infection. These results also show that important findings could be missed by the standard practice of analyzing mRNAs alone. We then derived the regulatory mechanisms driving the observed expression changes using integrative computational analyses. Further, we predicted drugs that could reverse the observed expression changes induced by HIV-1 infection and showed that one of the predicted drugs indeed potently inhibited HIV-1 infection. This shows that it is possible to identify candidate drugs for host-directed therapy against HIV/AIDS using our genomics-based approach.
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18
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Verhoeven D, George MD, Hu W, Dang AT, Smit-McBride Z, Reay E, Macal M, Fenton A, Sankaran-Walters S, Dandekar S. Enhanced innate antiviral gene expression, IFN-α, and cytolytic responses are predictive of mucosal immune recovery during simian immunodeficiency virus infection. THE JOURNAL OF IMMUNOLOGY 2014; 192:3308-18. [PMID: 24610016 DOI: 10.4049/jimmunol.1302415] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mucosa that lines the respiratory and gastrointestinal (GI) tracts is an important portal of entry for pathogens and provides the first line of innate immune defense against infections. Although an abundance of memory CD4(+) T cells at mucosal sites render them highly susceptible to HIV infection, the gut and not the lung experiences severe and sustained CD4(+) T cell depletion and tissue disruption. We hypothesized that distinct immune responses in the lung and gut during the primary and chronic stages of viral infection contribute to these differences. Using the SIV model of AIDS, we performed a comparative analysis of the molecular and cellular characteristics of host responses in the gut and lung. Our findings showed that both mucosal compartments harbor similar percentages of memory CD4(+) T cells and displayed comparable cytokine (IL-2, IFN-γ, and TNF-α) responses to mitogenic stimulations prior to infection. However, despite similar viral replication and CD4(+) T cell depletion during primary SIV infection, CD4(+) T cell restoration kinetics in the lung and gut diverged during acute viral infection. The CD4(+) T cells rebounded or were preserved in the lung mucosa during chronic viral infection, which correlated with heightened induction of type I IFN signaling molecules and innate viral restriction factors. In contrast, the lack of CD4(+) T cell restoration in the gut was associated with dampened immune responses and diminished expression of viral restriction factors. Thus, unique immune mechanisms contribute to the differential response and protection of pulmonary versus GI mucosa and can be leveraged to enhance mucosal recovery.
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Affiliation(s)
- David Verhoeven
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616
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19
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Bahr GM. Immune deficiency in HIV-1 infection: novel therapeutic approaches targeting innate and adaptive responses. Expert Rev Clin Immunol 2014; 1:529-47. [DOI: 10.1586/1744666x.1.4.529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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The majority of CD4+ T-cell depletion during acute simian-human immunodeficiency virus SHIV89.6P infection occurs in uninfected cells. J Virol 2014; 88:3202-12. [PMID: 24390339 DOI: 10.1128/jvi.03428-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Untreated human immunodeficiency virus (HIV) infection is characterized by depletion of CD4(+) T cells, ultimately leading to the impairment of host immune defenses and death. HIV-infected CD4(+) T cells die from direct virus-induced apoptosis and CD8 T-cell-mediated elimination, but a broader and more profound depletion occurs in uninfected CD4(+) T cells via multiple indirect effects of infection. We fit mathematical models to data from experiments that tested an HIV eradication strategy in which five macaques with a proportion of CD4(+) T cells resistant to simian-human immunodeficiency virus (SHIV) entry were challenged with SHIV89.6P, a highly pathogenic dual-tropic chimeric SIV-HIV viral strain that results in rapid loss of both SHIV-susceptible and SHIV-resistant CD4(+) T cells. Our results suggest that uninfected (bystander) cell death accounts for the majority of CD4(+) T-lymphocyte loss, with at least 60% and 99% of CD4(+) T cell death occurring in uninfected cells during acute and established infection, respectively. Mechanisms to limit the profound indirect killing effects associated with HIV infection may be associated with immune preservation and improved long-term survival. IMPORTANCE HIV infection induces a massive depletion of CD4(+) T cells, leading to profound immunodeficiency, opportunistic infections, and eventually death. While HIV induces apoptosis (programmed cell death) by directly entering and replicating in CD4(+) T cells, uninfected CD4(+) T cells also undergo apoptosis due to ongoing toxic inflammation in the region of infection. In this paper, we use mathematical models in conjunction with data from simian-human immunodeficiency virus SHIV89.6P infection in macaques (a model of HIV infection in humans) to estimate the percentage of cell death that occurs in uninfected cells during the initial period of infection. We reveal that the vast majority of cell death occurs in these cells, which are not infected. The "bystander effects" that lead to enormous reductions in the number of uninfected CD4(+) T cells may be a target for future interventions that aim to limit the extent of damage caused by HIV.
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21
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Merino AM, Sabbaj S, Easlick J, Goepfert P, Kaslow RA, Tang J. Dimorphic HLA-B signal peptides differentially influence HLA-E- and natural killer cell-mediated cytolysis of HIV-1-infected target cells. Clin Exp Immunol 2013; 174:414-23. [PMID: 23952339 PMCID: PMC3826307 DOI: 10.1111/cei.12187] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2013] [Indexed: 12/18/2022] Open
Abstract
As a mechanism of self-protection, signal peptides cleaved from human leukocyte antigen (HLA) class I products bind to HLA-E before the complex interacts with the natural killer (NK) cell receptor CD94/NKG2A to inhibit NK-mediated cell lysis. Two types of the signal peptides differ in their position 2 (P2) anchor residue, with P2-methionine (P2-M) having higher HLA-E binding affinity than P2-threonine (P2-T). All HLA-A and HLA-C molecules carry P2-M, whereas HLA-B products have either P2-M or P2-T. Epidemiological evidence suggests that P2-M is unfavourable in the context of HIV-1 infection, being associated with accelerated acquisition of HIV-1 infection in two African cohorts. To begin elucidating the functional mechanism, we studied NK-mediated killing of CD4(+) T cells and monocyte-derived macrophages infected with two laboratory-adapted HIV-1 strains and two transmitted/founder (T/F) viruses. In the presence of target cells derived from individuals with the three HLA-B P2 genotypes (M/M, M/T and T/T), NK-mediated cytolysis was elevated consistently for P2-T in a dose-dependent manner for all cell and virus combinations tested (P = 0·008-0·03). Treatment of target cells with an anti-HLA-E monoclonal antibody restored NK-mediated cytolysis of cells expressing P2-M. Observations on cell lysis were also substantiated by measurements of HIV-1 p24 antigen in the culture supernatants. Overall, our experiments indicate that the anti-HIV-1 function mediated by NK cells is compromised by P2-M, corroborating the association of HLA-B genotype encoding P2-M with accelerated HIV-1 acquisition.
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Affiliation(s)
- A M Merino
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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22
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Abbas W, Herbein G. T-Cell Signaling in HIV-1 Infection. Open Virol J 2013; 7:57-71. [PMID: 23986795 PMCID: PMC3751038 DOI: 10.2174/1874357920130621001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 05/31/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022] Open
Abstract
HIV exploits the T-cell signaling network to gain access to downstream cellular components, which serves as effective tools to break the cellular barriers. Multiple host factors and their interaction with viral proteins contribute to the complexity of HIV-1 pathogenesis and disease progression. HIV-1 proteins gp120, Nef, Tat and Vpr alter the T-cell signaling pathways by activating multiple transcription factors including NF-ĸB, Sp1 and AP-1. HIV-1 evades the immune system by developing a multi-pronged strategy. Additionally, HIV-1 encoded proteins influence the apoptosis in the host cell favoring or blocking T-cell apoptosis. Thus, T-cell signaling hijacked by viral proteins accounts for both viral persistence and immune suppression during HIV-1 infection. Here, we summarize past and present studies on HIV-1 T-cell signaling with special focus on the possible role of T cells in facilitating viral infection and pathogenesis
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Affiliation(s)
- Wasim Abbas
- Department of Virology, Pathogens & Inflammation Laboratory, UPRES EA4266, SFR FED 4234, University of Franche-Comte, CHRU Besançon, F-25030 Besançon, France
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23
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Ikomey G, Assoumou MCO, Atashili J, Mesembe M, Mukwele B, Lyonga E, Eyoh A, Kafando A, Ndumbe PM. The Potentials of Fas Receptors and Ligands in Monitoring HIV-1 Disease in Children in Yaoundé, Cameroon. J Int Assoc Provid AIDS Care 2013; 15:418-22. [PMID: 23744775 DOI: 10.1177/2325957413488202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE Difficulties in systematically monitoring HIV viral load in resource-limited settings prompt the search for alternate approaches. The authors aimed at assessing the correlation between the plasma levels of soluble forms of Fas receptors (Fas) and Fas ligands (FasL) with standard indicators of HIV disease progression in children. METHODS Twenty-two HIV-1-positive children were enrolled in Yaounde. CD4 counts, CD4% counts, plasma levels of Fas, FasL, and HIV-1 RNA levels were assayed. RESULTS The correlation coefficients (P values) between FasL levels and each of HIV-1 viral load, CD4 counts, and CD4% were, respectively, .56 (.01), -.29 (.18), and .30 (.18). On the other hand, the respective correlation coefficients (P values) with Fas levels were .12 (.60), -.30 (.18), and -.29 (.19). CONCLUSION The significant correlation between levels of HIV-1 viral load and FasL suggests that the latter needs to be further studied as a potential biomarker to monitor HIV-1 disease progression in children in resource-limited setting.
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Affiliation(s)
- G Ikomey
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - M-C Okomo Assoumou
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - J Atashili
- Faculty of Health Sciences, University of Buea, Cameroon
| | - M Mesembe
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - B Mukwele
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - E Lyonga
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - A Eyoh
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - A Kafando
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon
| | - P M Ndumbe
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Cameroon Faculty of Health Sciences, University of Buea, Cameroon
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24
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Association of HIV clinical disease progression with profiles of early immune activation: results from a cluster analysis approach. AIDS 2013; 27:1473-81. [PMID: 23945505 DOI: 10.1097/qad.0b013e3283601bad] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE CD4 and CD8 T-cell activation are independent predictors of AIDS. The complete activation profile of both T-cell subtypes and their predictive value for AIDS risk is largely unknown. DESIGN A total of 564 AIDS-free women in the Women's Interagency HIV Study were followed over 6.1 years (median) after T-cell activation assessment. A cluster analysis approach was used to evaluate the concurrent activation patterns of CD4 and CD8 T cells at the beginning of follow-up in relation to AIDS progression. METHODS Percentages of CD4 and CD8 T cells with HLA-DR± and CD38± were assessed by flowcytometry. Eight immunologic variables (four on each CD4+ and CD8+: DR± and CD38±) were assessed to yield a 4-cluster solution on samples obtained before clinical endpoints. Proportional hazards survival regression estimated relative risks for AIDS progression by cluster membership. RESULTS Compared with the other three clusters, outstanding activation features of each distinct cluster of women were: Cluster 1: higher CD8(+)CD38(-)DR(-) (average=41% of total CD8 T-cell pool), CD4(+)CD38(-)DR(-) (average=53% of total CD4 T-cell pool), and CD8(+)CD38(-)DR(+) (28%); Cluster 2: higher CD8(+)CD38(+)DR(-) (44%) and CD4(+)CD38(+)DR(-) (58%); Cluster 3: higher CD8(+)CD38(+)DR(+) (49%) and CD4(+)CD38(+)DR(-) (48%); Cluster 4: higher CD8(+)CD38(+)DR(+) (49%), CD4(+)CD38(+)DR(+) (36%) and CD4(+)CD38(-)DR(+) (19%). Compared with cluster 1, women in cluster 4 had two-fold increased risk of AIDS progression (Hazard ratio=2.13; 95% confidence interval=1.30-3.50) adjusted for CD4 cell count, HIV RNA, and other confounders. CONCLUSION A profile including CD4 and CD8 T-cell activation provided insight into HIV pathogenesis indicating concurrent hyperactivation of CD4 and CD8 T cells is associated with AIDS progression.
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25
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Holman AG, Gabuzda D. A machine learning approach for identifying amino acid signatures in the HIV env gene predictive of dementia. PLoS One 2012; 7:e49538. [PMID: 23166702 PMCID: PMC3498126 DOI: 10.1371/journal.pone.0049538] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 10/10/2012] [Indexed: 11/18/2022] Open
Abstract
The identification of nucleotide sequence variations in viral pathogens linked to disease and clinical outcomes is important for developing vaccines and therapies. However, identifying these genetic variations in rapidly evolving pathogens adapting to selection pressures unique to each host presents several challenges. Machine learning tools provide new opportunities to address these challenges. In HIV infection, virus replicating within the brain causes HIV-associated dementia (HAD) and milder forms of neurocognitive impairment in 20-30% of patients with unsuppressed viremia. HIV neurotropism is primarily determined by the viral envelope (env) gene. To identify amino acid signatures in the HIV env gene predictive of HAD, we developed a machine learning pipeline using the PART rule-learning algorithm and C4.5 decision tree inducer to train a classifier on a meta-dataset (n = 860 env sequences from 78 patients: 40 HAD, 38 non-HAD). To increase the flexibility and biological relevance of our analysis, we included 4 numeric factors describing amino acid hydrophobicity, polarity, bulkiness, and charge, in addition to amino acid identities. The classifier had 75% predictive accuracy in leave-one-out cross-validation, and identified 5 signatures associated with HAD diagnosis (p<0.05, Fisher's exact test). These HAD signatures were found in the majority of brain sequences from 8 of 10 HAD patients from an independent cohort. Additionally, 2 HAD signatures were validated against env sequences from CSF of a second independent cohort. This analysis provides insight into viral genetic determinants associated with HAD, and develops novel methods for applying machine learning tools to analyze the genetics of rapidly evolving pathogens.
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Affiliation(s)
- Alexander G. Holman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Neurology (Microbiology, and Immunobiology), Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Abstract
Since the initial description of apoptosis, a number of different forms of cell death have been described. In this review we will focus on classic caspase-dependent apoptosis and its variations that contribute to diseases. Over fifty years of research have clarified molecular mechanisms involved in apoptotic signaling as well and shown that alterations of these pathways lead to human diseases. Indeed both reduced and increased apoptosis can result in pathology. More recently these findings have led to the development of therapeutic approaches based on regulation of apoptosis, some of which are in clinical trials or have entered medical practice.
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Affiliation(s)
- Bartolo Favaloro
- Dipartimento di Scienze Biomediche, Universita' "G. d'Annunzio" Chieti-Pescara, Italy
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27
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Tenaya IWM, Heel K, Stumbles PA, Wilcox GE. Flow cytometric analysis of lymphocyte subset kinetics in Bali cattle experimentally infected with Jembrana disease virus. Vet Immunol Immunopathol 2012; 149:167-76. [PMID: 22776774 DOI: 10.1016/j.vetimm.2012.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 04/24/2012] [Accepted: 06/11/2012] [Indexed: 11/17/2022]
Abstract
Jembrana disease virus (JDV) is an unusual bovine lentivirus that causes an acute and sometimes fatal disease after a short incubation period in Bali cattle (Bos javanicus). The pathological changes occur primarily in lymphoid tissues, which feature proliferating lymphoblastoid-like cells predominantly throughout parafollicular (T-cell) areas, and atrophy of follicles (B-cell) areas. Five Bali cattle were experimentally infected with JDV and all developed typical clinical signs of Jembrana disease characterised by a transient febrile response, enlargement of superficial lymph nodes and a significant leukopenia. Flow cytometric analysis of PBMC during the acute (febrile) disease phase showed that the reduced number of lymphocytes was due to a significant decrease in both the proportion and absolute numbers of CD4(+) T cells, but not CD8(+) T-cells or CD21(+) B-cells. At the end of the febrile phase, total numbers of both CD8(+) T-cells and CD21(+) B-cells increased significantly, while CD4(+) T-cell numbers remained below normal values, resulting in a significantly reduced CD4(+):CD8(+) ratio. We speculate that the persistent depletion of CD4(+) T cells following JDV infection, through lack of CD4(+) T cell help to B cells, may explain the lack of production of JDV-specific antibodies for several weeks after recovery despite an increase in CD21(+) B cell numbers. Further, our previous data showing that IgG(+) plasma cells are targets for JDV infection, correlated with our current data demonstrating an increase in CD8(+) T cell numbers, supports the suggestion that anti-viral cytotoxic T cell or other cell-mediated immune responses may be critical in the recovery process, although this remains to be formally demonstrated for JDV.
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Affiliation(s)
- I W Masa Tenaya
- School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia
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28
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Geldmacher C, Koup RA. Pathogen-specific T cell depletion and reactivation of opportunistic pathogens in HIV infection. Trends Immunol 2012; 33:207-14. [PMID: 22398371 DOI: 10.1016/j.it.2012.01.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 01/05/2012] [Accepted: 01/18/2012] [Indexed: 01/28/2023]
Abstract
During HIV infection, it is unclear why different opportunistic pathogens cause disease at different CD4 T cell count thresholds. Early work has shown that CD4 T cell depletion is influenced both by cellular activation status and expression of viral entry receptors. More recently, functional characteristics of the CD4 T cells, such as cytokine and chemokine production, have also been shown to influence cellular susceptibility to HIV. Here, we examine how functional differences in pathogen-specific CD4 T cells could lead to their differential loss during HIV infection. This may have implications for when different opportunistic infections occur, and a better understanding of the mechanisms for functional imprinting of antigen-specific T cells may lead to improvements in design of vaccines against HIV and opportunistic pathogens.
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Affiliation(s)
- Christof Geldmacher
- Division of Infectious Diseases and Tropical Medicine, Medical Center of University of Munich (LMU), Munich, Germany.
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30
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Fernandez S, Tanaskovic S, Helbig K, Rajasuriar R, Kramski M, Murray JM, Beard M, Purcell D, Lewin SR, Price P, French MA. CD4+ T-cell deficiency in HIV patients responding to antiretroviral therapy is associated with increased expression of interferon-stimulated genes in CD4+ T cells. J Infect Dis 2011; 204:1927-35. [PMID: 22006994 DOI: 10.1093/infdis/jir659] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Most patients with human immunodeficiency virus (HIV) who remain CD4(+) T-cell deficient on antiretroviral therapy (ART) exhibit marked immune activation. As CD4(+) T-cell activation may be mediated by microbial translocation or interferon-alpha (IFN-α), we examined these factors in HIV patients with good or poor CD4(+) T-cell recovery on long-term ART. Messenger RNA levels for 3 interferon-stimulated genes were increased in CD4(+) T cells of patients with poor CD4(+) T-cell recovery, whereas levels in patients with good recovery did not differ from those in healthy controls. Poor CD4(+) T-cell recovery was also associated with CD4(+) T-cell expression of markers of activation, senescence, and apoptosis, and with increased serum levels of the lipopolysaccharide receptor and soluble CD14, but these were not significantly correlated with expression of the interferon-stimulated genes. Therefore, CD4(+) T-cell recovery may be adversely affected by the effects of IFN-α, which may be amenable to therapeutic intervention.
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Affiliation(s)
- Sonia Fernandez
- School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Australia.
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31
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Doitsh G, Cavrois M, Lassen KG, Zepeda O, Yang Z, Santiago ML, Hebbeler AM, Greene WC. Abortive HIV infection mediates CD4 T cell depletion and inflammation in human lymphoid tissue. Cell 2010; 143:789-801. [PMID: 21111238 DOI: 10.1016/j.cell.2010.11.001] [Citation(s) in RCA: 336] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 05/07/2010] [Accepted: 10/29/2010] [Indexed: 02/07/2023]
Abstract
The mechanism by which CD4 T cells are depleted in HIV-infected hosts remains poorly understood. In ex vivo cultures of human tonsil tissue, CD4 T cells undergo a pronounced cytopathic response following HIV infection. Strikingly, >95% of these dying cells are not productively infected but instead correspond to bystander cells. We now show that the death of these "bystander" cells involves abortive HIV infection. Inhibitors blocking HIV entry or early steps of reverse transcription prevent CD4 T cell death while inhibition of later events in the viral life cycle does not. We demonstrate that the nonpermissive state exhibited by the majority of resting CD4 tonsil T cells leads to accumulation of incomplete reverse transcripts. These cytoplasmic nucleic acids activate a host defense program that elicits a coordinated proapoptotic and proinflammatory response involving caspase-3 and caspase-1 activation. While this response likely evolved to protect the host, it centrally contributes to the immunopathogenic effects of HIV.
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Affiliation(s)
- Gilad Doitsh
- Gladstone Institute of Virology and Immunology, San Francisco, CA 94158, USA
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32
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Porter KA, Kelley LN, Nekorchuk MD, Jones JH, Hahn AB, de Noronha CMC, Harton JA, Duus KM. CIITA enhances HIV-1 attachment to CD4+ T cells leading to enhanced infection and cell depletion. THE JOURNAL OF IMMUNOLOGY 2010; 185:6480-8. [PMID: 21041720 DOI: 10.4049/jimmunol.1000830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Activated CD4(+) T cells are more susceptible to HIV infection than resting T cells; the reason for this remains unresolved. Induction of CIITA and subsequent expression of the MHC class II isotype HLA-DR are hallmarks of CD4(+) T cell activation; therefore, we investigated the role of CIITA expression in T cells during HIV infection. CIITA-expressing SupT1 cells display enhanced virion attachment in a gp160/CD4-dependent manner, which results in increased HIV infection, virus release, and T cell depletion. Although increased attachment and infection of T cells correlated with HLA-DR surface expression, Ab blocking, transient expression of HLA-DR without CIITA, and short hairpin RNA knockdown demonstrate that HLA-DR does not directly enhance susceptibility of CIITA-expressing cells to HIV infection. Further analysis of the remaining MHC class II isotypes, HLA-DP and HLA-DQ, MHC class I isotypes, HLA-A, HLA-B, and HLA-C, and the class II Ag presentation genes, invariant chain and HLA-DM, demonstrate that these proteins likely do not contribute to CIITA enhancement of HIV infection. Finally, we demonstrate that in activated primary CD4(+) T cells as HLA-DR/CIITA expression increases there is a corresponding increase in virion attachment. Overall, this work suggests that induction of CIITA expression upon CD4(+) T cell activation contributes to enhanced attachment, infection, virus release, and cell death through an undefined CIITA transcription product that may serve as a new antiviral target.
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Affiliation(s)
- Kristen A Porter
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA
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Porter KA, Kelley LN, George A, Harton JA, Duus KM. Class II transactivator (CIITA) enhances cytoplasmic processing of HIV-1 Pr55Gag. PLoS One 2010; 5:e11304. [PMID: 20585587 PMCID: PMC2892040 DOI: 10.1371/journal.pone.0011304] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 05/26/2010] [Indexed: 11/18/2022] Open
Abstract
Background The Pr55gag (Gag) polyprotein of HIV serves as a scaffold for virion assembly and is thus essential for progeny virion budding and maturation. Gag localizes to the plasma membrane (PM) and membranes of late endosomes, allowing for release of infectious virus directly from the cell membrane and/or upon exocytosis. The host factors involved in Gag trafficking to these sites are largely unknown. Upon activation, CD4+ T cells, the primary target of HIV infection, express the class II transcriptional activator (CIITA) and therefore the MHC class II isotype, HLA-DR. Similar to Gag, HLA-DR localizes to the PM and at the membranes of endosomes and specialized vesicular MHC class II compartments (MIICs). In HIV producer cells, transient HLA-DR expression induces intracellular Gag accumulation and impairs virus release. Methodology/Principal Findings Here we demonstrate that both stable and transient expression of CIITA in HIV producer cells does not induce HLA-DR-associated intracellular retention of Gag, but does increase the infectivity of virions. However, neither of these phenomena is due to recapitulation of the class II antigen presentation pathway or CIITA-mediated transcriptional activation of virus genes. Interestingly, we demonstrate that CIITA, apart from its transcriptional effects, acts cytoplasmically to enhance Pr160gag-pol (Gag-Pol) levels and thereby the viral protease and Gag processing, accounting for the increased infectivity of virions from CIITA-expressing cells. Conclusions/Significance This study demonstrates that CIITA enhances HIV Gag processing, and provides the first evidence of a novel, post-transcriptional, cytoplasmic function for a well-known transactivator.
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Affiliation(s)
- Kristen A. Porter
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Lauren N. Kelley
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Annette George
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Jonathan A. Harton
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
| | - Karen M. Duus
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York, United States of America
- * E-mail:
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34
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Raymond AD, Gekonge B, Giri MS, Hancock A, Papasavvas E, Chehimi J, Kossenkov AV, Kossevkov AV, Nicols C, Yousef M, Mounzer K, Shull J, Kostman J, Showe L, Montaner LJ. Increased metallothionein gene expression, zinc, and zinc-dependent resistance to apoptosis in circulating monocytes during HIV viremia. J Leukoc Biol 2010; 88:589-96. [PMID: 20551211 DOI: 10.1189/jlb.0110051] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Circulating monocytes exhibit an apoptotic resistance phenotype during HIV viremia in association with increased MT expression. MTs are known to play an important role in zinc metabolism and immune function. We now show, in a cross-sectional study using peripheral monocytes, that expression of MT1 isoforms E, G, H, and X is increased significantly in circulating monocyte cells from HIV+ subjects during chronic viremic episodes as compared with uninfected subjects. This increase in expression is also observed during acute viremia following interruption of suppressive ART. Circulating monocytes from HIV+ donors were also found to have elevated zinc importer gene Zip8 expression in conjunction with elevated intracellular zinc levels in contrast to CD4(+)T-lymphocytes. In vitro HIV-1 infection studies with elutriated MDM confirm a direct relation between HIV-1 infection and increased MDM MT1 (isoform G) gene expression and increased intracellular zinc levels. A direct link between elevated zinc levels and apoptosis resistance was established using a cell-permeable zinc chelator TPEN, which reversed apoptosis resistance effectively in monocytes from HIV-infected to levels comparable with uninfected controls. Taken together, increases in MT gene expression and intracellular zinc levels may contribute directly to maintenance of an immune-activated monocyte by mediating an increased resistance to apoptosis during active HIV-1 viremia.
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Affiliation(s)
- Andrea D Raymond
- The Wistar Institute, 3601 Spruce St., Philadelphia, PA 19104-4268, USA
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35
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Downregulation of the T-cell receptor by human immunodeficiency virus type 2 Nef does not protect against disease progression. J Virol 2009; 83:12968-72. [PMID: 19812166 DOI: 10.1128/jvi.01252-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Chronic immune activation is thought to play a major role in human immunodeficiency virus (HIV) pathogenesis, but the relative contributions of multiple factors to immune activation are not known. One proposed mechanism to protect against immune activation is the ability of Nef proteins from some HIV and simian immunodeficiency virus strains to downregulate the T-cell receptor (TCR)-CD3 complex of the infected cell, thereby reducing the potential for deleterious activation. HIV type 1 (HIV-1) Nef has lost this property. In contrast to HIV-1, HIV-2 infection is characterized by a marked disparity in the disease course, with most individuals maintaining a normal life span. In this study, we examined the relationship between the ability of HIV-2 Nef proteins to downregulate the TCR and immune activation, comparing progressors and nonprogressors. Representative Nef variants were isolated from 28 HIV-2-infected individuals. We assessed their abilities to downregulate the TCR from the surfaces of CD4 T cells. In the same individuals, the activation of peripheral lymphocytes was evaluated by measurement of the expression levels of HLA-DR and CD38. We observed a striking correlation of the TCR downregulation efficiency of HIV-2 Nef variants with immune activation in individuals with a low viral load. This strongly suggests that Nef expression can influence the activation state of the immune systems of infected individuals. However, the efficiency of TCR downregulation by Nef was not reduced in progressing individuals, showing that TCR downregulation does not protect against progression in HIV-2 infection.
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36
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The heptad repeat 2 domain is a major determinant for enhanced human immunodeficiency virus type 1 (HIV-1) fusion and pathogenicity of a highly pathogenic HIV-1 Env. J Virol 2009; 83:11715-25. [PMID: 19726524 DOI: 10.1128/jvi.00649-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1)-mediated depletion of CD4+ lymphocytes in an infected individual is the hallmark of progression to AIDS. However, the mechanism for this depletion remains unclear. To identify mechanisms of HIV-1-mediated CD4 T-cell death, two similar viral isolates obtained from a rapid progressor patient with significantly different pathogenic phenotypes were studied. One isolate (R3A) demonstrates enhanced pathogenesis in both in vivo models and relevant ex vivo lymphoid organ model systems compared to another isolate, R3B. The pathogenic determinants were previously mapped to the V5-gp41 envelope region, correlating functionally with enhanced fusion activity and elevated CXCR4 binding affinity. To further elucidate specific differences between R3A and R3B within the V5-gp41 domains that enhance CD4 depletion, R3A-R3B chimeras to study the V5-gp41 region were developed. Our data demonstrate that six residues in the ectodomain of R3A provide the major determinant for both enhanced Env-cell fusion and pathogenicity. Furthermore, three amino acid differences in the heptad repeat 2 (HR-2) domain of R3A determined its fusion activity and significantly elevated its pathogenic activity. The chimeric viruses with enhanced fusion activity, but not elevated CXCR4 affinity, correlated with high pathogenicity in the thymus organ. We conclude that the functional domain of a highly pathogenic HIV-1 Env is determined by mutations in the HR-2 region that contribute to enhanced fusion and CD4 T-cell depletion.
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37
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Inhibition of envelope-mediated CD4+-T-cell depletion by human immunodeficiency virus attachment inhibitors. Antimicrob Agents Chemother 2009; 53:4726-32. [PMID: 19721067 DOI: 10.1128/aac.00494-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope (Env) binding induces proapoptotic signals in CD4(+) T cells without a requirement of infection. Defective virus particles, which represent the majority of HIV-1, usually contain a functional Env and therefore represent a potentially significant cause of such CD4(+)-T-cell loss. We reasoned that an HIV-1 inhibitor that prohibits Env-host cell interactions could block the destructive effects of defective particles. HIV-1 attachment inhibitors (AIs), which potently inhibit Env-CD4 binding and subsequent downstream effects of Env, display low-nanomolar antiapoptotic potency and prevent CD4(+)-T-cell depletion from mixed lymphocyte cultures, also with low-nanomolar potency. Specific Env amino acid changes that confer resistance to AI antientry activity eliminate AI antiapoptotic effects. We observed that CD4(+)-T-cell destruction is specific for CXCR4-utilizing HIV-1 strains and that the fusion blocker enfuvirtide inhibits Env-mediated CD4(+)-T-cell killing but is substantially less potent than AIs. These observations, in conjunction with observed antiapoptotic activities of soluble CD4 and the CXCR4 blocker AMD3100, suggest that this AI activity functions through a mechanism common to AI antientry activity, e.g., prevention of Env conformation changes necessary for specific interactions with cellular factors that facilitate viral entry. Our study suggests that AIs, in addition to having potent antientry activity, could contribute to immune system homeostasis in individuals infected with HIV-1 that can engage CXCR4, thereby mitigating the increased risk of adverse clinical events observed in such individuals on current antiretroviral regimens.
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38
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Rea-Boutrois A, Villet S, Greenland T, Mehlen P, Chebloune Y, Verdier G, Legras-Lachuer C. Small ruminant lentivirus Tat protein induces apoptosis in caprine cells in vitro by the intrinsic pathway. Virology 2009; 383:93-102. [PMID: 19007964 DOI: 10.1016/j.virol.2008.09.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 08/25/2008] [Accepted: 09/26/2008] [Indexed: 01/24/2023]
Abstract
The small ruminant lentiviruses, caprine arthritis-encephalitis virus (CAEV) and maedi visna virus (MVV) naturally cause inflammatory disease in goats and sheep, provoking chronic lesions in several different organs. We have previously demonstrated that in vitro infection of caprine cells by CAEV induces apoptosis through the intrinsic pathway (Rea-Boutrois, A., Pontini, G., Greenland, T., Mehlen, P., Chebloune, Y., Verdier, G. and Legras-Lachuer, C. 2008). In the present study, we used Tat deleted viruses and SLRV Tat-expression vectors to show that the SRLV Tat proteins are responsible for this apoptosis. We have also studied the activation of caspases-3, -8 and -9 by fluorescent assays in caprine cells expressing SRLV Tat proteins, and the effects of transfected dominant negative variants of these caspases, to show that Tat-associated apoptosis depends on activation of caspases-3 and -9, but not -8. A simultaneous disruption of mitochondrial membrane potential indicates an involvement of the mitochondrial pathway.
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Affiliation(s)
- Angela Rea-Boutrois
- Université de Lyon, INRA, UMR754, Université Lyon 1, Ecole Nationale Vétérinaire de Lyon, Ecole Pratique des Hautes Etudes, IFR 128, 50 avenue Tony Garnier, 69 366 Lyon cedex 07, France
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39
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Stevceva L, Yoon V, Carville A, Pacheco B, Santosuosso M, Korioth-Schmitz B, Mansfield K, Poznansky MC. The efficacy of T cell-mediated immune responses is reduced by the envelope protein of the chimeric HIV-1/SIV-KB9 virus in vivo. THE JOURNAL OF IMMUNOLOGY 2008; 181:5510-21. [PMID: 18832708 DOI: 10.4049/jimmunol.181.8.5510] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Gp120 is a critical component of the envelope of HIV-1. Its role in viral entry is well described. In view of its position on the viral envelope, gp120 is a part of the retrovirus that immune cells encounter first and has the potential to influence antiretroviral immune responses. We propose that high levels of gp120 are present in tissues and may contribute to the failure of the immune system to fully control and ultimately clear the virus. Herein, we show for the first time that lymphoid tissues from acutely HIV-1/SIV (SHIV)-KB9-infected macaques contain deposits of gp120 at concentrations that are high enough to induce suppressive effects on T cells, thus negatively regulating the antiviral CTL response and contributing to virus survival and persistence. We also demonstrate that SHIV-KB9 gp120 influences functional T cell responses during SHIV infection in a manner that suppresses degranulation and cytokine secretion by CTLs. Finally, we show that regulatory T cells accumulate in lymphoid tissues during acute infection and that they respond to gp120 by producing TGFbeta, a known suppressant of cytotoxic T cell activity. These findings have significant implications for our understanding of the contribution of non-entry-related functions of HIV-1 gp120 to the pathogenesis of HIV/AIDS.
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Affiliation(s)
- Liljana Stevceva
- Partners AIDS Research Center and Infectious Diseases Medicine, Massachusetts General Hospital (East), Charlestown, MA 02129, USA.
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40
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Byrnes AA, Harris DM, Atabani SF, Sabundayo BP, Langan SJ, Margolick JB, Karp CL. Immune activation and IL-12 production during acute/early HIV infection in the absence and presence of highly active, antiretroviral therapy. J Leukoc Biol 2008; 84:1447-53. [PMID: 18806124 DOI: 10.1189/jlb.0708438] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Suppressed IL-12 production and maladaptive immune activation, both of which are ameliorated by successful highly active antiretroviral therapy (HAART), are thought to play important roles in the immunopathogenesis of chronic HIV infection. Despite the important effects of the immunological and virological events of early HIV infection on subsequent disease progression, IL-12 production and immune activation in early infection remain under-defined. To quantify IL-12 production and immune activation during acute/early HIV infection, in the presence and absence of HAART, we performed a prospective, longitudinal study of participants in the Baltimore site of the Acute Infection and Early Disease Research Program, with cross-sectional comparison to healthy control subjects. PBMC cytokine productive capacity and plasma immune activation markers [soluble CD8 (sCD8), sCD4, granzyme B, neopterin, beta2-microglobulin, sIL-2R, sTNFRI, sTNFRII, and IL-12p70] were quantified by ELISA. Notably, PBMC from patients with acute/early HIV infection exhibited in vivo IL-12p70 production along with increased, maximal in vitro IL-12 production. Further, despite evidence from plasma markers of generalized immune activation, no elevation in plasma levels of sCD4 was observed, suggesting relative blunting of in vivo CD4+ T cell activation from the beginning of HIV infection. Finally, despite successful virological responses to HAART, heightened in vivo CD8+ T cell activation, IL-12 production, and IFN activity were sustained for at least 6 months during primary HIV infection. These data underscore the need for comparative mechanistic analysis of the immunobiology of early and chronic HIV infection.
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Affiliation(s)
- Adriana A Byrnes
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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41
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Abstract
It has been known for some time that HIV-1 virions contain cellular proteins in addition to proteins encoded by the viral genome. Recent studies have vastly increased the number of host proteins detected in HIV-1. This review summarises the current findings on several cellular proteins present in these virions, including some functional studies on their potential roles in the viral replication cycle and pathogenesis. Because retroviruses require extensive assistance from host proteins and pathways, the data from biochemical characterisations of HIV-1 serve as an important starting point for understanding the role of cellular proteins that act in or influence the biology of HIV-1. Additionally, a better understanding of the interactions between cellular proteins and viral components might provide more targets for anti-HIV therapeutic intervention and provide for a better understanding of how HIV-1 alters the immune system. The extensive study of HIV-1 has already brought new insights to the fields of immunology and vaccine science. In the same way, knowledge of viral--cellular protein interactions might assist our understanding of important cellular pathways.
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Affiliation(s)
- David E Ott
- AIDS Vaccine Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD 21702-1201, USA.
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42
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Gulzar N, Balasubramanian S, Harris G, Sanchez-Dardon J, Copeland KFT. Infection of CD8+CD45RO+ memory T-cells by HIV-1 and their proliferative response. Open AIDS J 2008; 2:43-57. [PMID: 18923697 PMCID: PMC2556200 DOI: 10.2174/1874613600802010043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 05/26/2008] [Accepted: 05/28/2008] [Indexed: 11/23/2022] Open
Abstract
CD8+ T-cells are involved in controlling HIV-1 infection by eliminating infected cells and secreting soluble factors that inhibit viral replication. To investigate the mechanism and significance of infection of CD8+ T-cells by HIV-1 in vitro, we examined the susceptibility of these cells and their subsets to infection. CD8+ T-cells supported greater levels of replication with T-cell tropic strains of HIV-1, though viral production was lower than that observed in CD4+ T-cells. CD8+ T-cell infection was found to be productive through ELISA, RT-PCR and flow cytometric analyses. In addition, the CD8+CD45RO+ memory T-cell population supported higher levels of HIV-1 replication than CD8+CD45RA+ naïve T-cells. However, infection of CD8+CD45RO+ T-cells did not affect their proliferative response to the majority of mitogens tested. We conclude, with numerous lines of evidence detecting and measuring infection of CD8+ T-cells and their subsets, that this cellular target and potential reservoir may be central to HIV-1 pathogenesis.
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Affiliation(s)
- Naveed Gulzar
- National HIV and Retrovirology Laboratories, Public Health Agency of Canada, Ottawa, Canada
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43
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Preferential cytolysis of peripheral memory CD4+ T cells by in vitro X4-tropic human immunodeficiency virus type 1 infection before the completion of reverse transcription. J Virol 2008; 82:9154-63. [PMID: 18596085 DOI: 10.1128/jvi.00773-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
CD4+ T-cell depletion is the hallmark of AIDS pathogenesis. Multiple mechanisms may contribute to the death of productively infected CD4+ T cells and innocent-bystander cells. In this study, we characterize a novel mechanism in which human immunodeficiency virus type 1 (HIV-1) infection preferentially depletes peripheral memory CD4+ T cells before the completion of reverse transcription. Using a recombinant HIV-1 carrying the green fluorescent protein reporter gene, we demonstrate that memory CD4+ T cells were susceptible to infection-induced cell death at a low multiplicity of infection. Infected memory CD4+ T cells underwent rapid necrotic cell death. Killing of host cells was dependent on X4 envelope-mediated viral fusion, but not on virion-associated Vpr or Nef. In contrast to peripheral resting CD4+ T cells, CD4+ T cells stimulated by mitogen or certain cytokines were resistant to HIV-1-induced early cell death. These results demonstrate that early steps in HIV-1 infection have a detrimental effect on certain subsets of CD4+ T cells. The early cell death may serve as a selective disadvantage for X4-tropic HIV-1 in acute infection but may play a role in accelerated disease progression, which is associated with the emergence of X4-tropic HIV-1 in the late stage of AIDS.
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Patterson J, Jesser R, Weinberg A. Distinctive in vitro effects of T-cell growth cytokines on cytomegalovirus-stimulated T-cell responses of HIV-infected HAART recipients. Virology 2008; 378:48-57. [PMID: 18572217 DOI: 10.1016/j.virol.2008.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 03/08/2008] [Accepted: 05/16/2008] [Indexed: 12/12/2022]
Abstract
Functional immune reconstitution is limited after HAART, maintaining the interest in adjunctive immune-modulators. We compared in vitro the effects of the gamma-chain T-cell growth cytokines IL-2, IL-4, IL-7 and IL-15 on cytomegalovirus-stimulated cell-mediated immunity. IL-2 and IL-15 increased cytomegalovirus-specific lymphocyte proliferation in HAART recipients, whereas IL-4 and IL-7 did not. The boosting effect of IL-2 and IL-15 on proliferation correlated with their ability to prevent late apoptosis. However, IL-2 increased the frequency of cells in early apoptosis, whereas IL-15 increased the frequency of fully viable cells. Both IL-2 and IL-15 increased cytomegalovirus-induced CD4+ and CD8+ T-cell proliferation and the synthesis of Th1 and pro-inflammatory cytokines and chemokines. However, only IL-2 increased the frequency of regulatory T cells and Th2 cytokine production, both of which have the potential to attenuate antiviral immune responses. Overall, compared to other gamma-chain cytokines, IL-15 had the most favorable profile for boosting antiviral cell-mediated immunity.
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Affiliation(s)
- Julie Patterson
- Department of Pediatrics, University of Colorado School of Medicine, Denver, CO 80262, USA
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Rea-Boutrois A, Pontini G, Greenland T, Mehlen P, Chebloune Y, Verdier G, Legras-Lachuer C. Caprine arthritis–encephalitis virus induces apoptosis in infected cells in vitro through the intrinsic pathway. Virology 2008; 375:452-63. [DOI: 10.1016/j.virol.2008.01.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 12/13/2007] [Accepted: 01/14/2008] [Indexed: 01/01/2023]
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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: 1.1] [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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Hu H, Fernando K, Ni H, Weissman D. HIV Envelope Suppresses CD4+T Cell Activation Independent of T Regulatory Cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:5593-600. [DOI: 10.4049/jimmunol.180.8.5593] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Wachtman L, Gualtieri L, Wanke C, Shannon R, Mansfield K. Viral and host correlates of serum resistin in simian AIDS. AIDS Res Hum Retroviruses 2008; 24:34-42. [PMID: 18275346 DOI: 10.1089/aid.2007.0154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Resistin is an adipocytokine with a proposed dual role in metabolism and inflammation. In light of the ability to promote inflammatory responses, adipocytokines may prove key factors in modulating the host response to HIV. This study utilizes the simian immunodeficiency virus (SIV) model of HIV/AIDS to investigate changes in serum resistin levels following dietary intervention and SIV infection and determine associations with measures of body composition and disease severity. Resistin levels, body composition (n = 34), and insulin resistance (n = 16) were determined in healthy rhesus macaques. A subset of animals (n = 8) was placed on an atherogenic diet (AD) and subsequently inoculated with SIVmac239. Longitudinal measures of serum resistin, cytokines, viral load, lymphocyte subsets, and body composition were obtained. In healthy macaques consuming a standard diet, resistin levels correlated positively with total fat mass (r = 0.49; p < 0.01) and tissue fat percent (r = 0.53; p < 0.01) but failed to associate with measures of insulin resistance. In contrast, a negative correlation was noted between these measures of adiposity and resistin following SIV inoculation (r = -0.27; p < 0.05 and r = -0.24; p < 0.05, respectively). Viral load correlated positively with serum resistin (r = 0.32; p < 0.01). Serum levels of MCP-1 and sTNF RII demonstrated no correlation with resistin in normal animals on a standard diet, while a significant positive correlation was observed following SIV infection (r = 0.52; p < 0.0001 and r = 0.59; p < 0.0001, respectively). Findings indicate a fundamental difference in the relationship between resistin and body composition following SIV infection and suggest that elevations in resistin parallel measures of disease severity including loss of body fat and viral replication.
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Affiliation(s)
- L.M. Wachtman
- Harvard Medical School, New England Regional Primate Research Center, Southborough, Massachusetts 01772
| | - L. Gualtieri
- Department of Public Health and Family Medicine, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - C. Wanke
- Department of Public Health and Family Medicine, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - R. Shannon
- University of Massachusetts School of Medicine, Worcester, Massachusetts 01605
| | - K.G. Mansfield
- Harvard Medical School, New England Regional Primate Research Center, Southborough, Massachusetts 01772
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Baker CAR, Emenyonu N, Ssewanyana I, Jones NG, Elrefaei M, Nghania F, Nakiwala J, Andia I, Clark R, Martin J, Bangsberg DR, Cao H. Profile of immunologic recovery in HIV-infected Ugandan adults after antiretroviral therapy. AIDS Res Hum Retroviruses 2007; 23:900-5. [PMID: 17678474 DOI: 10.1089/aid.2006.0309] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
HIV infection is characterized by a decrease in total CD4 cell count, rising viral load, as well as an increase in immune activation levels. Increased activation can lead to an increase in apoptosis and contribute to CD4 depletion. We evaluated the clinical and immunologic responses of 23 HIV-positive Ugandan volunteers following initiation of antiretroviral therapy (ART). All volunteers achieved and maintained complete viral suppression within the first 3 months of therapy (p > 0.05). CD4+ and CD8+ T cell activation also decreased significantly, although it never reached the level of HIV negative Ugandan volunteers. Viral suppression and CD4 cell recovery were also associated with an improved profile in CD8+ T cell functional markers, but had no effect on HIV-specific proliferation. We conclude that ART in a cohort of therapy-naive Ugandans with AIDS partially restores but does not fully reverse the immune dysfunction observed in chronic HIV infection.
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Affiliation(s)
- Chris A R Baker
- California Department of Health Services, Richmond, California 94804, USA
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