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Abstract
The CD8+ T cell noncytotoxic antiviral response (CNAR) was discovered during studies of asymptomatic HIV-infected subjects more than 30 years ago. In contrast to CD8+ T cell cytotoxic lymphocyte (CTL) activity, CNAR suppresses HIV replication without target cell killing. This activity has characteristics of innate immunity: it acts on all retroviruses and thus is neither epitope specific nor HLA restricted. The HIV-associated CNAR does not affect other virus families. It is mediated, at least in part, by a CD8+ T cell antiviral factor (CAF) that blocks HIV transcription. A variety of assays used to measure CNAR/CAF and the effects on other retrovirus infections are described. Notably, CD8+ T cell noncytotoxic antiviral responses have now been observed with other virus families but are mediated by different cytokines. Characterizing the protein structure of CAF has been challenging despite many biologic, immunologic, and molecular studies. It represents a low-abundance protein that may be identified by future next-generation sequencing approaches. Since CNAR/CAF is a natural noncytotoxic activity, it could provide promising strategies for HIV/AIDS therapy, cure, and prevention.
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Affiliation(s)
- Maelig G Morvan
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Fernando C Teque
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | | | - Jay A Levy
- Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
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2
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Abstract
OBJECTIVE To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down-regulate human immunodeficiency virus (HIV) infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/acquired immune deficiency syndrome. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells and CD8(+) lymphocytes, key regulators of HIV infection. METHODS Ex vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication in 48 depressed and nondepressed women. For both the acute and chronic infection models, HIV reverse transcriptase activity was measured in the citalopram treatment condition and the control condition. RESULTS The SSRI significantly down-regulated the reverse transcriptase response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. CONCLUSIONS These studies suggest that an SSRI enhances natural killer/CD8 noncytolytic HIV suppression in HIV/acquired immune deficiency syndrome and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV.
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3
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Overman RG, Llorens AL, Greenberg ML, Garcia-Blanco MA, Tomaras GD. Initiation of human immunodeficiency virus type 1 (HIV-1) transcription is inhibited by noncytolytic CD8 suppression. Open Virol J 2007; 1:1-7. [PMID: 19440453 PMCID: PMC2675544 DOI: 10.2174/1874357900701010001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 07/09/2007] [Accepted: 07/20/2007] [Indexed: 11/22/2022] Open
Abstract
The replication of human immunodeficiency virus type 1 (HIV-1) can be inhibited by noncytolytic CD8(+) T cell mediated suppression, an immune response that specifically targets HIV-1 gene expression. Clinical studies demonstrate that this immune response may play an important role in the host defense against HIV infection. In this study, we examined the distinct steps in viral gene expression for inhibition by noncytolytic CD8(+) T cells. A primary HIV-1 infection system of CD4(+) enriched peripheral blood mononuclear cells was utilized to examine the HIV-1 life cycle as a relevant ex vivo system. Established CD8(+) T cell lines from two HIV(+) long-term nonprogressors were used to examine differences at the level of transcriptional initiation and elongation of the HIV genome. This infection system coupled with the results from real-time measurement of newly transcribed RNA transcripts determined that there was a significant decrease (5-8 fold) in short intracellular viral RNA transcripts. These data strongly favor a role for the initiation of virus transcription in noncytolytic CD8(+) T cell mediated suppression.
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Affiliation(s)
- R Glenn Overman
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
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4
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Rodriguez SK, Sarr AD, MacNeil A, Thakore-Meloni S, Gueye-Ndiaye A, Traoré I, Dia MC, Mboup S, Kanki PJ. Comparison of heterologous neutralizing antibody responses of human immunodeficiency virus type 1 (HIV-1)- and HIV-2-infected Senegalese patients: distinct patterns of breadth and magnitude distinguish HIV-1 and HIV-2 infections. J Virol 2007; 81:5331-8. [PMID: 17301136 PMCID: PMC1900200 DOI: 10.1128/jvi.02789-06] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neutralizing antibody responses against heterologous isolates in human immunodeficiency virus type 1 (HIV-1) and HIV-2 infections were compared, and their relationships with established clinical markers of progression were examined. Neutralizing responses against 7 heterologous primary isolates and 1 laboratory strain were compared between 32 untreated HIV-1-infected subjects and 35 untreated HIV-2-infected subjects using a pseudotyped reporter virus assay. The breadth of the neutralizing response, defined as the proportion of panel viruses positively neutralized by patient plasma, was significantly greater among HIV-2-infected subjects than among HIV-1-infected subjects. Notably, for fully one-third of HIV-2 subjects, all viruses were effectively neutralized in our panel. Magnitudes of responses, defined as reciprocal 50% inhibitory concentration (IC(50)) titers for positive reactions, were significantly greater among HIV-1-infected subjects than among HIV-2-infected subjects. When plasma samples from HIV-1 patients were tested for cross-neutralization of HIV-2 and vice versa, we found that these intertype responses are very rare and their prevalences comparable in both HIV-1 and HIV-2 infection. The significantly higher magnitude of heterologous responses for HIV-1 compared to HIV-2 prompted us to examine associations with viremia, which is known to be significantly higher in HIV-1 infection. Importantly, there was a significant positive correlation between the IC(50) titer and viral load within both the HIV-1 and HIV-2 groups, suggesting heterologous antibodies may be driven by viral replication. We conclude that HIV-2 infection is characterized by a broad, low-magnitude intratype neutralization response, while HIV-1 is characterized by a narrower but higher-magnitude intratype response and that a significant positive association between the IC(50) titer and viremia is common to both HIV-1 and HIV-2 infections.
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Affiliation(s)
- Shaun K Rodriguez
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 651 Huntington Avenue, Boston, MA 02115, USA
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5
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Dioszeghy V, Benlhassan-Chahour K, Delache B, Dereuddre-Bosquet N, Aubenque C, Gras G, Le Grand R, Vaslin B. Changes in soluble factor-mediated CD8+ cell-derived antiviral activity in cynomolgus macaques infected with simian immunodeficiency virus SIVmac251: relationship to biological markers of progression. J Virol 2007; 80:236-45. [PMID: 16352548 PMCID: PMC1317544 DOI: 10.1128/jvi.80.1.236-245.2006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cross-sectional studies have shown that the capacity of CD8+ cells from human immunodeficiency virus (HIV)-infected patients and simian immunodeficiency virus (SIV) SIVmac-infected macaques to suppress the replication of human and simian immunodeficiency viruses in vitro depends on the clinical stage of disease, but little is known about changes in this antiviral activity over time in individual HIV-infected patients or SIV-infected macaques. We assessed changes in the soluble factor-mediated noncytolytic antiviral activity of CD8+ cells over time in eight cynomolgus macaques infected with SIVmac251 to determine the pathophysiological role of this activity. CD8+ cell-associated antiviral activity increased rapidly in the first week after viral inoculation and remained detectable during the early phase of infection. The net increase in antiviral activity of CD8+ cells was correlated with plasma viral load throughout the 15 months of follow-up. CD8+ cells gradually lost their antiviral activity over time and acquired virus replication-enhancing capacity. Levels of antiviral activity correlated with CD4+ T-cell counts after viral set point. Concentrations of beta-chemokines and interleukin-16 in CD8+ cell supernatants were not correlated with this antiviral activity, and alpha-defensins were not detected. The soluble factor-mediated antiviral activity of CD8+ cells was neither cytolytic nor restricted to major histocompatibility complex. This longitudinal study strongly suggests that the increase in noncytolytic antiviral activity from baseline and the maintenance of this increase over time in cynomolgus macaques depend on both viral replication and CD4+ T cells.
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Affiliation(s)
- Vincent Dioszeghy
- CEA, Laboratoire d'Immunopathologie Expérimentale, Service de Neurovirologie, DSV/DRM, EPHE, IPSC, Université Paris XI UMRE01, 18, Route du Panorama, BP 6, 92 265 Fontenay aux Roses, France
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6
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Killian MS, Ng S, Mackewicz CE, Levy JA. A screening assay for detecting CD8+ cell non-cytotoxic anti-HIV responses. J Immunol Methods 2005; 304:137-50. [PMID: 16129447 DOI: 10.1016/j.jim.2005.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Revised: 07/07/2005] [Accepted: 07/11/2005] [Indexed: 10/25/2022]
Abstract
The rate of HIV-1 disease progression is influenced by several factors that include pathogen and host genetic variations and the quality of antiviral immune responses. The CD8+ cell non-cytotoxic antiviral response (CNAR) substantially suppresses HIV replication in CD4+ cells and is positively associated with an asymptomatic clinical state. Traditionally, the measurement of CNAR has required several culture procedures and costly reagents. Here we report the development and validation of a screening assay for detection of CNAR that accurately identifies individuals benefiting from this response. Use of the CNAR screening assay should facilitate the evaluation of this important immune parameter in studies of HIV pathogenesis, resistance to infection, and vaccine development.
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Affiliation(s)
- M Scott Killian
- AIDS Research Institute and Department of Medicine, University of California San Francisco, San Francisco, CA 94143, United States
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7
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Locher CP, Witt SA, Ashlock BM, Polacino P, Hu SL, Shiboski S, Schmidt AM, Agy MB, Anderson DM, Staprans SI, zur Megede J, Levy JA. Human immunodeficiency virus type 2 DNA vaccine provides partial protection from acute baboon infection. Vaccine 2004; 22:2261-72. [PMID: 15149785 DOI: 10.1016/j.vaccine.2003.11.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2003] [Revised: 11/06/2003] [Accepted: 11/12/2003] [Indexed: 10/26/2022]
Abstract
We determined if the genetic adjuvants, granulocyte-macrophage colony stimulating factor (GM-CSF) and B7-2, could improve the immunogenicity and efficacy of an HIV-2 DNA vaccine. The vaccine consisted of the HIV-2 tat, nef, gag, and env genes synthesized using optimized codons and formulated with cationic liposomes. Baboons (Papio cynocephalus hamadryas) were immunized by the intramuscular, intradermal, and intranasal routes with these expression constructs and challenged with HIV-2(UC2) by the intravaginal route. In the first month after HIV-2 vaginal challenge, the baboons receiving the HIV-2 DNA vaccine with or without the genetic adjuvants had significant reductions in the viral loads in the peripheral blood mononuclear cells (PBMC) (P = 0.028) while the reductions in their plasma viremia were suggestive of a protective effect (P = 0.1). These data demonstrate that partial protection against HIV-2 vaginal challenge, as measured by reduced viral load, can be achieved using only a DNA vaccine formulation.
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MESH Headings
- Adjuvants, Immunologic
- Animals
- Antigens, CD/administration & dosage
- Antigens, CD/genetics
- Antigens, CD/immunology
- B7-2 Antigen
- CD8-Positive T-Lymphocytes/immunology
- Cytotoxicity, Immunologic
- Female
- Gene Products, env/genetics
- Gene Products, env/immunology
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Gene Products, tat/genetics
- Gene Products, tat/immunology
- Granulocyte-Macrophage Colony-Stimulating Factor/administration & dosage
- Granulocyte-Macrophage Colony-Stimulating Factor/genetics
- Granulocyte-Macrophage Colony-Stimulating Factor/immunology
- HIV Antibodies/blood
- HIV Infections/prevention & control
- HIV-2/genetics
- HIV-2/immunology
- HIV-2/isolation & purification
- HIV-2/physiology
- Leukocytes, Mononuclear/virology
- Liposomes
- Membrane Glycoproteins/administration & dosage
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Papio
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Vagina/virology
- Viral Load
- nef Gene Products, Human Immunodeficiency Virus
- tat Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Christopher P Locher
- Department of Medicine, Division of Hematology and Oncology, University of California, 514 Parnassus Avenue, San Francisco, CA 94143-1270, USA
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8
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Guo CJ, Tan N, Song L, Douglas SD, Ho WZ. Alpha-defensins inhibit HIV infection of macrophages through upregulation of CC-chemokines. AIDS 2004; 18:1217-8. [PMID: 15166542 PMCID: PMC4035112 DOI: 10.1097/00002030-200405210-00020] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Ranjbar S, Ly N, Thim S, Reynes JM, Goldfeld AE. Mycobacterium tuberculosisRecall Antigens Suppress HIV-1 Replication in Anergic Donor Cells via CD8+T Cell Expansion and Increased IL-10 Levels. THE JOURNAL OF IMMUNOLOGY 2004; 172:1953-9. [PMID: 14734781 DOI: 10.4049/jimmunol.172.3.1953] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mycobacterium tuberculosis (MTb) is the leading cause of death in the setting of AIDS. MTb enhances the pathogenicity and accelerates the course of HIV disease and, furthermore, infection with HIV-1 increases the risk of reactivation or reinfection with MTb. In this study, we show that host-specific recall responses to one pathogen, MTb, has a direct effect upon the regulation of a second pathogen, HIV-1. Using cells from immunocompetent former tuberculosis (TB) patients who displayed either a persistently positive (responsive) or negative (anergic), delayed-type hypersensitivity (DTH) reaction to intradermal injection of purified protein derivative (PPD), we investigated the effect of recall Ags to MTb upon the replication of HIV-1 primary isolates in vitro. We show that HIV-1 replication of a T cell-tropic isolate was significantly impaired in MTb-stimulated PBMC from PPD-anergic donors. Furthermore, these donors displayed a significant increase in CD8(+) T cells and IL-10 levels and lower levels of IL-2 and TNF-alpha relative to PPD-responsive donors in response to PPD stimulation. Strikingly, CD8(+) T cell depletion and blocking of IL-10 significantly increased HIV-1 replication in these PPD-anergic donors, indicating that an immunosuppressive response to MTb recall Ags inhibits HIV-1 replication in PPD-anergic individuals. Therefore, immunotherapeutic approaches aimed at recapitulating Ag-specific MTb anergy in vivo could result in novel and effective approaches to inhibit HIV-1 disease progression in MTb/HIV-1 coinfection.
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Affiliation(s)
- Shahin Ranjbar
- Center for Blood Research and Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
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10
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Naghavi MH, Nowak P, Andersson J, Sönnerborg A, Yang H, Tracey KJ, Vahlne A. Intracellular high mobility group B1 protein (HMGB1) represses HIV-1 LTR-directed transcription in a promoter- and cell-specific manner. Virology 2003; 314:179-89. [PMID: 14517071 DOI: 10.1016/s0042-6822(03)00453-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We investigated whether the high mobility group B 1 (HMGB1), an abundant nuclear protein in all mammalian cells, affects HIV-1 transcription. Intracellular expression of human HMGB1 repressed HIV-1 gene expression in epithelial cells. This inhibitory effect of HMGB1 was caused by repression of long terminal repeat (LTR)-mediated transcription. Other viral promoters/enhancers, including simian virus 40 or cytomegalovirus, were not inhibited by HMGB1. In addition, HMGB1 inhibition of HIV-1 subtype C expression was dependent on the number of NF kappa B sites in the LTR region. The inhibitory effect of HMGB1 on viral gene expression observed in HeLa cells was confirmed by an upregulation of viral replication in the presence of antisense HMGB1 in monocytic cells. In contrast to what was found in HeLa cells and monocytic cells, endogenous HMGB1 expression did not affect HIV-1 replication in unstimulated Jurkat cells. Thus, intracellular HMGB1 affects HIV-1 LTR-directed transcription in a promoter- and cell-specific manner.
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Affiliation(s)
- Mojgan H Naghavi
- Division of Clinical Virology, F68, Karolinska Institutet, Huddinge University Hospital, S-141 86 Stockholm, Sweden.
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11
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Chang TLY, François F, Mosoian A, Klotman ME. CAF-mediated human immunodeficiency virus (HIV) type 1 transcriptional inhibition is distinct from alpha-defensin-1 HIV inhibition. J Virol 2003; 77:6777-84. [PMID: 12767998 PMCID: PMC156196 DOI: 10.1128/jvi.77.12.6777-6784.2003] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8(+) T lymphocytes can inhibit human immunodeficiency virus type 1 (HIV-1) replication by secreting a soluble factor(s) known as CD8(+) T-lymphocyte antiviral factor (CAF). One site of CAF action is inhibition of HIV-1 RNA transcription, particularly at the step of long terminal repeat (LTR)-driven gene expression. The inhibitory effect of CAF on HIV-1 LTR activation is mediated through STAT1 activation. A recent study reports that alpha-defensins 1 to 3 account for CAF activity against HIV-1. Here, we address whether alpha-defensins, particularly alpha-defensin-1, contribute to CAF-mediated inhibition of HIV-1 transcription. Both recombinant alpha-defensin-1 and CAF derived from herpesvirus saimiri (HVS)-transformed CD8(+) cells inhibited HIV-1 infection and gene expression. For both factors, the inhibition of HIV-1 infection did not occur at the level of viral entry. Pretreatment of cells with alpha-defensin-1 followed by a washing out prior to infection blocked infection by HIV-1, indicating that direct inactivation of virions was not required for its inhibitory effect. In contrast to CAF, alpha-defensin-1 did not inhibit phorbol myristate acetate- or Tat-mediated HIV-1 LTR activation in a transient transfection system, nor did it activate STAT1 tyrosine phosphorylation. Furthermore, alpha-defensins 1 to 3 were below the level of detection in a panel of HVS-transformed CD8(+) cells with potent HIV-1 inhibitory activity and a neutralizing antibody against alpha-defensins 1 to 3 did not reverse the inhibitory effect of CAF on HIV-1 gene expression in infected cells and on HIV-1 LTR activation in transfected cells. Taken together, our results suggest that alpha-defensin-1 inhibits HIV-1 infection following viral entry but that alpha-defensins 1 to 3 are not responsible for the HIV-1 transcriptional inhibition by CAF.
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Affiliation(s)
- Theresa Li-Yun Chang
- Department of Medicine, Mount Sinai School of Medicine, New York, New York 10029, USA
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12
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Mackewicz CE, Craik CS, Levy JA. The CD8+ cell noncytotoxic anti-HIV response can be blocked by protease inhibitors. Proc Natl Acad Sci U S A 2003; 100:3433-8. [PMID: 12624186 PMCID: PMC152310 DOI: 10.1073/pnas.0630379100] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2002] [Accepted: 01/21/2003] [Indexed: 11/18/2022] Open
Abstract
CD8+ cells from healthy HIV-infected individuals can suppress HIV replication in infected CD4(+) cells without killing the cells. This CD8+ cell noncytotoxic antiviral response (CNAR), observed by coculture of CD8+ cells with infected CD4+ cells, is associated with secretion of a CD8+ cell antiviral factor (CAF). In attempts to identify CAF, we discovered that certain protease inhibitors, particularly leupeptin, can block, by up to 95%, the anti-HIV activity in CD8+ cell culture fluids as well as inhibit CNAR. The effect is dose-dependent and is observed in up to 70% of the CAF and CNAR assays by using fluids and cells from several different subjects. Pretreatment of CD8+ cells with leupeptin reduces CNAR, further supporting an inhibitory effect on a CD8+ cell product. This inhibitory activity of protease inhibitors does not affect cell growth, expression of activation antigens, or viability of either CD8+ cells or the infected CD4+ cells. The results suggest that a part of the CD8+ cell noncytotoxic response involves the activity of a protease or a protein that interacts with protease inhibitors. Proteolysis of a CD8+ cell product(s) may be involved. This observation offers a promising approach for identifying the mechanism of CNARCAF activity.
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Affiliation(s)
- Carl E Mackewicz
- Department of Medicine, University of California School of Medicine, San Francisco, CA 94143-1270, USA
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13
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Abstract
The AIDS epidemic continues to advance, and the development of a preventive HIV vaccine has become a major objective for scientific research. An effective vaccine against this virus is not available and complete protection still has not been achieved in animal models. In this review the major challenges related to the development of a vaccine against HIV are analyzed, particularly the mechanisms involved in viral escape from the immune response, and the results obtained with the various therapeutic and preventive vaccine prototypes are summarized. Finally, the social, economic and health aspects related to research on HIV vaccines and the current controversy around the performance of clinical trials with these agents is discussed.
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Affiliation(s)
- José Alcami
- Unidad de Inmunopatología del SIDA. Centro Nacional de Microbiología. Instituto de Salud Carlos III. Madrid. España.
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14
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Zhang L, Yu W, He T, Yu J, Caffrey RE, Dalmasso EA, Fu S, Pham T, Mei J, Ho JJ, Zhang W, Lopez P, Ho DD. Contribution of human alpha-defensin 1, 2, and 3 to the anti-HIV-1 activity of CD8 antiviral factor. Science 2002; 298:995-1000. [PMID: 12351674 DOI: 10.1126/science.1076185] [Citation(s) in RCA: 380] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
It has been known since 1986 that CD8 T lymphocytes from certain HIV-1-infected individuals who are immunologically stable secrete a soluble factor, termed CAF, that suppresses HIV-1 replication. However, the identity of CAF remained elusive despite an extensive search. By means of a protein-chip technology, we identified a cluster of proteins that were secreted when CD8 T cells from long-term nonprogressors with HIV-1 infection were stimulated. These proteins were identified as alpha-defensin 1, 2, and 3 on the basis of specific antibody recognition and amino acid sequencing. CAF activity was eliminated or neutralized by an antibody specific for human alpha-defensins. Synthetic and purified preparations of alpha-defensins also inhibited the replication of HIV-1 isolates in vitro. Taken together, our results indicate that alpha-defensin 1, 2, and 3 collectively account for much of the anti-HIV-1 activity of CAF that is not attributable to beta-chemokines.
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Affiliation(s)
- Linqi Zhang
- Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Avenue, New York, NY 10016, USA.
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15
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Binninger-Schinzel D, Norley S, Adler HS, Oberg HH, Kurth R. Simian immunodeficiency viruses with defective nef genes show increased susceptibility to the noncytotoxic antiviral activity of CD8+ lymphocytes. Virology 2002; 294:209-21. [PMID: 11886279 DOI: 10.1006/viro.2001.1295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The noncytotoxic soluble factor produced by CD8+ T cells inhibits replication of HIV and SIV in vitro and is thought to play a crucial role in combatting infection in vivo. We determined the effect of human CD8+ lymphocytes on the in vitro replication potential of both wild-type and nef-defective mutants of the simian immunodeficiency virus SIVmac251. Although replication of wild-type SIVmac251 in unstimulated human PBMC supplemented with IL-2 was unaffected by the presence of CD8+ T cells, the nef mutants were susceptible to the inhibitory effects. The effect of exogenous IL-2 depended upon the culture conditions: (i) in nonstimulated human PBMC depleted of CD8+ T cells, addition of IL-2 had a positive effect on the growth of the nef-defective viruses; (ii) in total human PBMC, IL-2 appeared to reinforce the CD8+ T-cell-dependent inhibition of the same mutant viruses. This strongly suggests that IL-2 stimulates the noncytotoxic anti-HIV/SIV response of CD8+ cells present in PBMC cultures. PHA stimulation of unfractionated human PBMC overrode the suppression of viral replication by CD8+ T cells. Depletion of activated T cells expressing the IL-2 receptor alpha-chain (CD25+ T cells), present in small amounts in these primary T cell cultures, dramatically reduced viral replication, indicating that the depleted cell population harbors the target cells permissive for viral replication. Furthermore, using neutralizing antibodies we could show that inhibition by the beta-chemokines MIP-1alpha, MIP-1beta, and RANTES and the inhibitory effect of CD8+ lymphocytes on nef mutant SIVmac viruses are harbored on different levels.
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Ansari AA, Mayne AE, Sundstrom JB, Bostik P, Grimm B, Altman JD, Villinger F. Administration of recombinant rhesus interleukin-12 during acute simian immunodeficiency virus (SIV) infection leads to decreased viral loads associated with prolonged survival in SIVmac251-infected rhesus macaques. J Virol 2002; 76:1731-43. [PMID: 11799168 PMCID: PMC135900 DOI: 10.1128/jvi.76.4.1731-1743.2002] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of recombinant rhesus interleukin-12 (rMamu-IL-12) administration during acute simian immunodeficiency virus SIVmac251 infection to influence the quality of the antiviral immune responses was assessed in rhesus macaques. Group I (n = 4) was the virus-only control group. Group II and III received a conditioning regimen of rMamu-IL-12 (10 and 20 microg/kg, respectively, subcutaneously [s.c.]) on days -2 and 0. Thereafter, group II received 2 microg of IL-12 per kg and group III received 10 microg/kg s.c. twice a week for 8 weeks. On day 0 all animals were infected with SIVmac251 intravenously. While all four group I animals and three of four group II animals died by 8 and 10 months post infection (p.i.), all four group III animals remained alive for >20 months p.i. The higher IL-12 dose led to lower plasma viral loads and markedly lower peripheral blood mononuclear cell and lymph node proviral DNA loads. During the acute viremia phase, the high-IL-12-dose monkeys showed an increase in CD3(-) CD8 alpha/alpha(+) and CD3(+) CD8 alpha/alpha(+) cells and, unlike the control and low-IL-12-dose animals, did not demonstrate an increase in CD4(+) CD45RA(+) CD62L(+) naive cells. The high-IL-12-dose animals also demonstrated that both CD8 alpha/alpha(+) and CD8 alpha/beta(+) cells produced antiviral factors early p.i., whereas only CD8 alpha/beta(+) cells retained this function late p.i. Long-term survival correlated with sustained high levels of SIV gag/pol and SIV env cytotoxic T lymphocytes and retention of high memory responses against nominal antigens. This is the first study to demonstrate the capacity of IL-12 to significantly protect macaques from SIV-induced disease, and it provides a useful model to more precisely identify correlates of virus-specific disease-protective responses.
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Affiliation(s)
- A A Ansari
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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17
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Chang TLY, Mosoian A, Pine R, Klotman ME, Moore JP. A soluble factor(s) secreted from CD8(+) T lymphocytes inhibits human immunodeficiency virus type 1 replication through STAT1 activation. J Virol 2002; 76:569-81. [PMID: 11752148 PMCID: PMC136805 DOI: 10.1128/jvi.76.2.569-581.2002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8(+) T lymphocytes can suppress human immunodeficiency virus type 1 (HIV-1) replication by secreting a soluble factor(s) known as CD8(+) T-lymphocyte antiviral factor (CAF). One site of CAF action is inhibition of HIV-1 RNA transcription, particularly at the step of long terminal repeat (LTR)-driven gene expression. However, the mechanism by which CAF inhibits LTR activation is not understood. Here, we show that conditioned media from several herpesvirus saimari-transformed CD8(+) T lymphocytes inhibit, in a time- and dose-dependent manner, the replication of HIV-1 pseudotype viruses that express the envelope glycoproteins of vesicular stomatitis virus (HIV-1(VSV)). The same conditioned media also inhibit phorbol myristate acetate-induced activation of the HIV-1 LTR and activate the signal transducer and activator of transcription 1 (STAT1) protein. We have obtained direct evidence that STAT1 is necessary for CAF-mediated inhibition of LTR activation and HIV-1 replication. Thus, the inhibitory effect of CAF on HIV-1(VSV) replication was abolished in STAT1-deficient cells. Moreover, CAF inhibition of LTR activation was diminished both in STAT1-deficient cells and in cells expressing a STAT1 dominant negative mutant but was restored when STAT1 was reintroduced into the STAT1-deficient cells. We also observed that CAF induced the expression of interferon regulatory factor 1 (IRF-1), and that IRF-1 gene induction was STAT-1 dependent. Taken together, our results suggest that CAF activates STAT1, leading to IRF-1 induction and inhibition of gene expression regulated by the HIV-1 LTR. This study therefore helps clarify one molecular mechanism of host defense against HIV-1.
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Affiliation(s)
- Theresa Li-Yun Chang
- Weill Medical College of Cornell University, Department of Medicine, Mount Sinai School of Medicine, Public Health Research Institute, New York, New York 10021, USA
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18
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Rodriguez F, Slifka MK, Harkins S, Whitton JL. Two overlapping subdominant epitopes identified by DNA immunization induce protective CD8(+) T-cell populations with differing cytolytic activities. J Virol 2001; 75:7399-409. [PMID: 11462012 PMCID: PMC114975 DOI: 10.1128/jvi.75.16.7399-7409.2001] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Subdominant CD8(+) T-cell responses contribute to control of several viral infections and to vaccine-induced immunity. Here, using the lymphocytic choriomeningitis virus model, we demonstrate that subdominant epitopes can be more reliably identified by DNA immunization than by other methods, permitting the identification, in the virus nucleoprotein, of two overlapping subdominant epitopes: one presented by L(d) and the other presented by K(d). This subdominant sequence confers immunity as effective as that induced by the dominant epitope, against which >90% of the antiviral CD8(+) T cells are normally directed. We compare the kinetics of the dominant and subdominant responses after vaccination with those following subsequent viral infection. The dominant CD8(+) response expands more rapidly than the subdominant responses, but after virus infection is cleared, mice which had been immunized with the "dominant" vaccine have a pool of memory T cells focused almost entirely upon the dominant epitope. In contrast, after virus infection, mice which had been immunized with the "subdominant" vaccine retain both dominant and subdominant memory cells. During the acute phase of the immune response, the acquisition of cytokine responsiveness by subdominant CD8(+) T cells precedes their development of lytic activity. Furthermore, in both dominant and subdominant populations, lytic activity declines more rapidly than cytokine responsiveness. Thus, the lysis(low)-cytokine(competent) phenotype associated with most memory CD8(+) T cells appears to develop soon after antigen clearance. Finally, lytic activity differs among CD8(+) T-cell populations with different epitope specificities, suggesting that vaccines can be designed to selectively induce CD8(+) T cells with distinct functional attributes.
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Affiliation(s)
- F Rodriguez
- Department of Neuropharmacology, The Scripps Research Institute, La Jolla, California 92037, USA
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19
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Butera ST, Pisell TL, Limpakarnjanarat K, Young NL, Hodge TW, Mastro TD, Folks TM. Production of a novel viral suppressive activity associated with resistance to infection among female sex workers exposed to HIV type 1. AIDS Res Hum Retroviruses 2001; 17:735-44. [PMID: 11429113 DOI: 10.1089/088922201750237004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To investigate mechanisms of natural resistance to human immunodeficiency virus type 1 (HIV-1), we obtained blood samples from eight women who remained HIV-1 negative after > 3 years of high-risk sex work in Chiang Rai, Thailand. CD4+ T lymphocytes from these highly exposed, persistently seronegative (HEPS) women were readily infectable in vitro with HIV-1 subtypes B and E. Autologous CD8+ cell suppression of both HIV-1 subtypes was evident in HEPS infection cultures, but to an extent also observed in cultures from non-HIV-exposed individuals. Furthermore, production of beta-chemokines was not enhanced in HEPS cultures. However, HEPS cultures displayed significantly enhanced production of a soluble activity that suppressed postintegrated HIV-1 replication. This activity was the unique product of CD4+ T cell and monocyte cocultures. Therefore, although HEPS individuals are apparently susceptible to infection, the production of a postintegrated HIV-1 suppressive activity during monocyte-T cell interactions might protect against the establishment of infection by limiting viral dissemination.
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Affiliation(s)
- S T Butera
- HIV/AIDS and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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20
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Mosoian A, Teixeira A, Caron E, Piwoz J, Klotman ME. CD8+ cell lines isolated from HIV-1-infected children have potent soluble HIV-1 inhibitory activity that differs from beta-chemokines. Viral Immunol 2001; 13:481-95. [PMID: 11192295 DOI: 10.1089/vim.2000.13.481] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CD8+ cells from human immunodeficiency virus type 1 (HIV-1) infected individuals have been shown to suppress HIV-1 replication both through a major histocompatibility complex (MHC)-restricted cytolytic pathway as well as through a noncytolytic pathway mediated through soluble factors. To characterize this soluble activity and its potential role in disease progression further, we studied the HIV-1 inhibition by supernatants derived from herpesvirus saimiri-transformed CD8+ cells isolated from infected children. Three of the six CD8+ cell lines derived had a phenotype consistent with an unusual natural killer (NK) cells phenotype with low CD3, high CD56, and low CD16. Supernatants from some of the cell lines derived from children with rapid progression as well as long-term nonprogressors exhibited broad HIV-1-inhibitory activity in primary CD4+ cells as well as in primary macrophages. In contrast to a cocktail of beta-chemokines, the supernatants inhibited T-tropic as well as M-tropic viruses, efficiently inhibited infection in primary macrophages, and inhibited HIV-1 activation in the chronically infected U1 cell line. The HIV-1-inhibitory activity was heat stable and active over a broad pH range. Fractionation of the supernatant by size and ion exchange chromatography demonstrated activity in the complete absence of RANTES as well as interferons-alpha, beta, and gamma and in a size range of less than 10 kD and greater than 3 kD. CD8+ cell supernatants contain additional unidentified factors that have anti-HIV activity to account for this broad phenomenon.
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Affiliation(s)
- A Mosoian
- Department of Medicine, Mt. Sinai School of Medicine, New York, New York 10029, USA
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21
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Butera ST. Therapeutic targeting of human immunodeficiency virus type-1 latency: current clinical realities and future scientific possibilities. Antiviral Res 2000; 48:143-76. [PMID: 11164503 DOI: 10.1016/s0166-3542(00)00133-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Factors affecting HIV-1 latency present formidable obstacles for therapeutic intervention. As these obstacles have become a clinical reality, even with the use of potent anti-retroviral regimens, the need for novel therapeutic strategies specifically targeting HIV-1 latency is evident. However, therapeutic targeting of HIV-1 latency requires an understanding of the mechanisms regulating viral quiescence and activation. These mechanisms have been partially delineated using chronically infected cell models and, clearly, HIV-1 activation from latency involves several key viral and cellular components. Among these distinctive therapeutic targets, cellular factors involved in HIV-1 transcription especially warrant further consideration for rational drug design. Exploring the scientific possibilities of new therapies targeting HIV-1 latency may hold new promise of eventual HIV-1 eradication.
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Affiliation(s)
- S T Butera
- HIV and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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22
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Wrzesinski S, Séguin R, Liu Y, Domville S, Planelles V, Massa P, Barker E, Antel J, Feuer G. HTLV type 1 Tax transduction in microglial cells and astrocytes by lentiviral vectors. AIDS Res Hum Retroviruses 2000; 16:1771-6. [PMID: 11080825 DOI: 10.1089/08892220050193290] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Infection with human T cell leukemia virus type 1 (HTLV-1) can result in the development of HAM/TSP, a nonfatal, chronic inflammatory disease involving neuronal degeneration and demyelination of the central nervous system. Elevated levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 observed in the cerebrospinal fluid of HAM-TSP patients suggest that cytokine dysregulation within the CNS is involved in neuropathogenesis. HTLV-1 infection and enhanced expression of TNF-alpha by microglial cells, astrocytes, and macrophages has been hypothesized to lead to the destruction of myelin and oligodendrocytes in the CNS. Although the association of HTLV-2 infection and development of neurological disease is more tenuous, HTLV-2 has also been found to be associated with peripheral neuropathies. To investigate the roles of HTLV Tax(1) and Tax(2) in the induction of cytokine disregulation in these cell types, we are currently developing gene delivery vectors based on human immunodeficiency virus type-1 (HIV-1) capable of stably coexpressing the HTLV-1 or -2 tax and eGFP reporter genes in primary human cells. Transduction frequencies of up to 50%, as assessed by eGFP expression, can be achieved in human monocyte-derived macrophages and in explanted cultures of human microglia. Preliminary data suggest that Tax(1) expression is sufficient to up-regulate the proinflammatory cytokine profile in explanted human microglial cells. Future experiments will compare and evaluate the effect of tax(1) and tax(2) gene expression on the cellular proinflammatory cytokine expression profile, as well as demonstrate the effects of transducing human fetal astrocytes and PBMC-derived macrophages.
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Affiliation(s)
- S Wrzesinski
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, New York 13210, USA
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23
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Darcissac EC, Truong MJ, Dewulf J, Mouton Y, Capron A, Bahr GM. The synthetic immunomodulator murabutide controls human immunodeficiency virus type 1 replication at multiple levels in macrophages and dendritic cells. J Virol 2000; 74:7794-802. [PMID: 10933686 PMCID: PMC112309 DOI: 10.1128/jvi.74.17.7794-7802.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2000] [Accepted: 06/09/2000] [Indexed: 02/03/2023] Open
Abstract
Macrophages and dendritic cells are known to play an important role in the establishment and persistence of human immunodeficiency virus (HIV) infection. Besides antiretroviral therapy, several immune-based interventions are being evaluated with the aim of achieving better control of virus replication in reservoir cells. Murabutide is a safe synthetic immunomodulator presenting a capacity to enhance nonspecific resistance against viral infections and to target cells of the reticuloendothelial system. In this study, we have examined the ability of Murabutide to control HIV type 1 (HIV-1) replication in acutely infected monocyte-derived macrophages (MDMs) and dendritic cells (MDDCs). Highly significant suppression of viral replication was consistently observed in Murabutide-treated cultures of both cell types. Murabutide did not affect virus entry, reverse transcriptase activity, or early proviral DNA formation in the cytoplasm of infected cells. However, treated MDMs and MDDCs showed a dramatic reduction in nuclear viral two-long terminal repeat circular form and viral mRNA transcripts. This HIV-1-suppressive activity was not mediated by inhibiting cellular DNA synthesis or by activating p38 mitogen-activated protein kinase. Furthermore, Murabutide-stimulated cells expressed reduced CD4 and CCR5 receptors and secreted high levels of beta-chemokines, although neutralization of the released chemokines did not alter the HIV-1-suppressive activity of Murabutide. These results provide evidence that a clinically acceptable immunomodulator can activate multiple effector pathways in macrophages and in dendritic cells, rendering them nonpermissive for HIV-1 replication.
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Affiliation(s)
- E C Darcissac
- Laboratoire d'Immunologie Moléculaire de l'Infection et de l'Inflammation, Institut Pasteur de Lille, Tourcoing, France
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24
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Abstract
Based on T cell subset depletion studies and the analysis of gene knockout mice, it is evident that CD8(+) T cells contribute to resistance against intracellular infections with certain viral, protozoan, and bacterial pathogens. Although they are known primarily for their capacity to kill infected cells, CD8(+) T cells elaborate a variety of effector mechanisms with the potential to defend against infection. Microbes use multiple strategies to cause infection, and the nature of the pathogenhost interaction may determine which CD8(+) T cell effector mechanisms are required for immunity. In this review, we summarize our current understanding of the effector functions used by CD8(+) T cells in resistance to pathogens. Analyses of mice deficient in perforin and/or Fas demonstrate that cytolysis is critical for immunity against some, but not all, infections and also reveal the contribution of cytolysis to the pathogenesis of disease. The role of CD8(+) T cell-derived cytokines in resistance to infection has been analyzed by systemic treatment with neutralizing antibodies and cytokine gene knockout mice. These studies are complicated by the fact that few, if any, cytokines are uniquely produced by CD8(+) T cells. Thus, the requirement for CD8(+) T cell- derived cytokines in resistance against most pathogens remains to be defined. Finally, recent studies of human CD8(+) T cells reveal the potential for novel effector mechanisms in resistance to infection.
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Affiliation(s)
- J T Harty
- Department of Microbiology and Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, USA.
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25
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Arnaout RA, Nowak MA, Wodarz D. HIV-1 dynamics revisited: biphasic decay by cytotoxic T lymphocyte killing? Proc Biol Sci 2000; 267:1347-54. [PMID: 10972131 PMCID: PMC1690670 DOI: 10.1098/rspb.2000.1149] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The biphasic decay of blood viraemia in patients being treated for human immunodeficiency virus type 1 (HIV-1) infection has been explained as the decay of two distinct populations of cells: the rapid death of productively infected cells followed by the much slower elimination of a second population the identity of which remains unknown. Here we advance an alternative explanation based on the immune response against a single population of infected cells. We show that the biphasic decay can be explained simply, without invoking multiple compartments: viral load falls quickly while cytotoxic T lymphocytes (CTL) are still abundant, and more slowly as CTL disappear. We propose a method to test this idea, and develop a framework that is readily applicable to treatment of other infections.
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Affiliation(s)
- R A Arnaout
- Theoretical Biology Program, Institute for Advanced Study, Princeton, NJ 08540, USA.
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26
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27
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CD8+ T cell-mediated suppressive activity inhibits HIV-1 after virus entry with kinetics indicating effects on virus gene expression. Proc Natl Acad Sci U S A 2000. [PMID: 10725407 PMCID: PMC16269 DOI: 10.1073/pnas.070521097] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Individuals infected with HIV-1 have varying rates of progression to AIDS. Cellular immune responses, comprised of cytolytic and noncytolytic CD8(+) T cell effector functions, are considered important for controlling viremia and maintaining the clinically asymptomatic state. Although there is general agreement regarding CD8(+) T lymphocyte cytotoxic functions, considerable controversy exists over the nature of the noncytolytic antiviral activity of CD8(+) cells. The discovery that RANTES (regulated on activation, normal T cell expressed and secreted), MIP-1alpha, and MIP-1beta (macrophage inflammatory protein 1 alpha and beta) could inhibit HIV-1 replication by blocking viral entry processes led to the notion that these molecules are responsible for the CD8(+) cell suppressive activity. However, T tropic HIV isolates requiring the CXCR4 coreceptor for entry are insensitive to the antiviral effects of these beta-chemokines. Using a CXCR4-dependent virus, we determined that the mechanism of CD8(+) T cell-mediated activity did act after viral entry into the host cell. We also define the kinetics of the HIV life cycle in primary activated human CD4(+)-enriched T cells by using an HIV-1 reporter virus system pseudotyped with the CXCR4-dependent HIV-1 envelope gene of NL4-3. Analysis of these kinetic data indicates that CD8(+) T cell-mediated suppressive activity acts at a stage in the viral life cycle after entry and independently of the HIV envelope. Additionally, we show that the antiviral activity targets stages of the virus life cycle correlating with transcription and early proviral gene expression. These findings not only provide a range of possible targets for the CD8(+) T cell-mediated activity but also support the notion that this antiviral activity is multifactorial in nature.
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28
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Tomaras GD, Lacey SF, McDanal CB, Ferrari G, Weinhold KJ, Greenberg ML. CD8+ T cell-mediated suppressive activity inhibits HIV-1 after virus entry with kinetics indicating effects on virus gene expression. Proc Natl Acad Sci U S A 2000; 97:3503-8. [PMID: 10725407 PMCID: PMC16269 DOI: 10.1073/pnas.97.7.3503] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Individuals infected with HIV-1 have varying rates of progression to AIDS. Cellular immune responses, comprised of cytolytic and noncytolytic CD8(+) T cell effector functions, are considered important for controlling viremia and maintaining the clinically asymptomatic state. Although there is general agreement regarding CD8(+) T lymphocyte cytotoxic functions, considerable controversy exists over the nature of the noncytolytic antiviral activity of CD8(+) cells. The discovery that RANTES (regulated on activation, normal T cell expressed and secreted), MIP-1alpha, and MIP-1beta (macrophage inflammatory protein 1 alpha and beta) could inhibit HIV-1 replication by blocking viral entry processes led to the notion that these molecules are responsible for the CD8(+) cell suppressive activity. However, T tropic HIV isolates requiring the CXCR4 coreceptor for entry are insensitive to the antiviral effects of these beta-chemokines. Using a CXCR4-dependent virus, we determined that the mechanism of CD8(+) T cell-mediated activity did act after viral entry into the host cell. We also define the kinetics of the HIV life cycle in primary activated human CD4(+)-enriched T cells by using an HIV-1 reporter virus system pseudotyped with the CXCR4-dependent HIV-1 envelope gene of NL4-3. Analysis of these kinetic data indicates that CD8(+) T cell-mediated suppressive activity acts at a stage in the viral life cycle after entry and independently of the HIV envelope. Additionally, we show that the antiviral activity targets stages of the virus life cycle correlating with transcription and early proviral gene expression. These findings not only provide a range of possible targets for the CD8(+) T cell-mediated activity but also support the notion that this antiviral activity is multifactorial in nature.
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Affiliation(s)
- G D Tomaras
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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29
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Loetscher P, Moser B, Baggiolini M. Chemokines and their receptors in lymphocyte traffic and HIV infection. Adv Immunol 1999; 74:127-80. [PMID: 10605606 DOI: 10.1016/s0065-2776(08)60910-4] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
MESH Headings
- Animals
- Anti-HIV Agents/pharmacology
- Anti-HIV Agents/therapeutic use
- Antibodies, Monoclonal/therapeutic use
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- Chemokines/antagonists & inhibitors
- Chemokines/chemistry
- Chemokines/genetics
- Chemokines/immunology
- Chemokines/pharmacology
- Chemokines/physiology
- Chemotaxis, Leukocyte/physiology
- Chromosomes, Human/genetics
- Drug Design
- Evolution, Molecular
- Genetic Variation
- HIV/drug effects
- HIV/physiology
- HIV Infections/immunology
- HIV Infections/therapy
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/immunology
- Humans
- Immunologic Memory
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Lymphocyte Activation/physiology
- Lymphocytes/cytology
- Mice
- Receptors, Chemokine/chemistry
- Receptors, Chemokine/drug effects
- Receptors, Chemokine/genetics
- Receptors, Chemokine/immunology
- Receptors, Chemokine/physiology
- Sequence Homology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- Transfection
- Virus Replication/drug effects
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Affiliation(s)
- P Loetscher
- Theodor Kocher Institute, University of Bern, Switzerland
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30
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Xiao L, Weiss SH, Qari SH, Rudolph D, Zhao C, Denny TN, Hodge T, Lal RB. Partial resistance to infection by R5X4 primary HIV type 1 isolates in an exposed-uninfected individual homozygous for CCR5 32-base pair deletion. AIDS Res Hum Retroviruses 1999; 15:1201-8. [PMID: 10480633 DOI: 10.1089/088922299310296] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It is known that certain individuals remain persistently seronegative despite repeated exposure to HIV-1. Studies have shown that some exposed uninfected (EU) individuals who are homozygous for a 32-bp deletion in the CCR5 gene are resistant to infection with non-syncytium-inducing (R5) viruses. In the present investigation, we provide evidence that a highly exposed-uninfected individual with the CCR5 32-bp deletion (EUdelta32-1) also has partial resistance to syncytium-inducing (R5X4) HIV-1 viruses, when compared with unexposed-uninfected individuals with (UUdelta32-1 and UUdelta32-2) and without (UU-1 and UU-2) the 32-bp deletion. The partial resistance of EU cells was due neither to altered coreceptor expression, nor to specific mutation or deletion in the coding region of chemokine coreceptors CXCR4 and CCR3. While SDF-1, the ligand for CXCR4, blocked entry of R5X4 viruses to a similar extent in EUdelta32 and UUdelta32, there was a differential production of soluble factors by EUdelta32. Both CD4+ and CD8+ cells from EUdelta32-1 produced soluble factors that efficiently suppressed infection by HIV-1 R5X4 viruses when compared with supernatant from UUdelta32. These data provide evidence that additional soluble factors are involved in resistance to infection with R5X4 viruses.
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Affiliation(s)
- L Xiao
- HIV and Retrovirology Branch, Division of AIDS, STD, TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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31
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Heeney JL, Beverley P, McMichael A, Shearer G, Strominger J, Wahren B, Weber J, Gotch F. Immune correlates of protection from HIV and AIDS - more answers but yet more questions. IMMUNOLOGY TODAY 1999; 20:247-51. [PMID: 10354547 DOI: 10.1016/s0167-5699(98)01437-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- J L Heeney
- Dept of Virology, Biomedical Primate Research Centre, Lange Kleiweg 157, 2288 GJ Rijswijk, The Netherlands.
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32
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Barker E. CD8+ cell-derived anti-human immunodeficiency virus inhibitory factor. J Infect Dis 1999; 179 Suppl 3:S485-8. [PMID: 10099125 DOI: 10.1086/314808] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
CD8+ cells in human immunodeficiency virus (HIV)-infected individuals develop the ability to control HIV replication not only by destruction of the infected cells but also by controlling the virus in a noncytotoxic fashion that leaves the infected cell functionally intact. The CD8+ noncytotoxic response is mediated by a novel soluble factor known as CD8+ cell antiviral factor (CAF). CAF suppresses HIV replication in the infected cell at the level of viral transcription by interrupting the ability of Tat or host cellular factors to interact with the HIV long terminal repeats. Unlike some strain-specific anti-HIV cytokines, CAF is active against many different virus isolates, including HIV strains that are nonsyncytium- and syncytium-inducing. Of importance, the ability of CD8+ cells to produce CAF and suppress HIV replication plays a critical role in preventing disease progression following HIV infection.
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Affiliation(s)
- E Barker
- Department of Microbiology and Immunology, SUNY Health Science Center, Syracuse, NY 13210, USA.
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33
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McDyer JF, Dybul M, Goletz TJ, Kinter AL, Thomas EK, Berzofsky JA, Fauci AS, Seder RA. Differential Effects of CD40 Ligand/Trimer Stimulation on the Ability of Dendritic Cells to Replicate and Transmit HIV Infection: Evidence for CC-Chemokine-Dependent and -Independent Mechanisms. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.6.3711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The role of exogenous stimulation of CD40 by CD40 ligand (CD40L) in dendritic cell (DC) maturation, CC-chemokine production, and CCR5 receptor expression was examined using a soluble trimeric CD40L agonist protein (CD40LT). Stimulation of monocyte-derived DCs with CD40LT enhanced the production of the CC-chemokines macrophage inflammatory protein (MIP)-1α, MIP-1β, and RANTES and diminished surface expression of CCR5. Based on these findings, the functional role of CD40LT stimulation on the ability of DCs to replicate and transmit HIV viral infection was studied. The addition of CD40LT to cocultures of naive CD4+ T cells and autologous DCs (T/DC) infected with the macrophage-tropic isolate, HIVBaL, caused a striking reduction in reverse transcriptase (RT) activity after 10 and 14 days of culture. The addition of a mixture of Abs against CC-chemokines abrogated the decrease in RT activity, demonstrating that the inhibitory effect mediated by CD40LT was CC-chemokine-dependent. In contrast, the presence of CD40LT in T/DC cocultures infected with the T cell-tropic isolate, HIVIIIB, caused an increase in RT activity that was CC-chemokine-independent. Of note, CD40LT stimulation also inhibited RT activity in cultures containing macrophage-tropic virus (HIVBaL)-infected DC only. However, in contrast to the results seen in the T/DC cocultures, CD40LT stimulation inhibited RT activity in cultures of DCs alone in a CC-chemokine-independent manner. Together, these results show that CD40LT stimulation of DCs suppresses HIV replication and transmission to CD4+ T cells by two potentially different mechanisms.
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Affiliation(s)
- John F. McDyer
- *Clincial Immunology Section, Laboratory of Clinical Investigation, and
| | - Mark Dybul
- †Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, and
| | - Theresa J. Goletz
- ‡Molecular Immunogenetics and Vaccine Research Section, Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Audrey L. Kinter
- †Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, and
| | | | - Jay A. Berzofsky
- ‡Molecular Immunogenetics and Vaccine Research Section, Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Anthony S. Fauci
- †Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, and
| | - Robert A. Seder
- *Clincial Immunology Section, Laboratory of Clinical Investigation, and
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Abstract
This paper simplifies and encapsulates the past, present and future for developing vaccines, especially against AIDS. Needed technical information and how it can best be obtained are delineated. The views are my own and may not be shared by others. The science enterprise, including that for vaccines, is enmeshed in the major evolution and restructuring of many of the world's institutions. Changes brought by the knowledge revolution impinge on scientific information, technology, public policy, societal demands, private and public funding, academic and industrial organization and economic opportunity. Public-supported research is not an entitlement. It is in the scientific establishment's best interest to organize for greatest efficiency and effectiveness to bring paybacks commensurate with public investment.
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Affiliation(s)
- M R Hilleman
- Merck Research Laboratories, Merck Institute for Therapeutic Research, West Point, PA 19486, USA
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