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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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Matteucci C, Minutolo A, Pollicita M, Balestrieri E, Grelli S, D’Ettorre G, Vullo V, Bucci I, Luchini A, Aquaro S, Sinibaldi-Vallebona P, Macchi B, Perno CF, Mastino A, Garaci E. Thymosin α 1 potentiates the release by CD8+cells of soluble factors able to inhibit HIV-1 and human T lymphotropic virus 1 infectionin vitro. Expert Opin Biol Ther 2015; 15 Suppl 1:S83-100. [DOI: 10.1517/14712598.2015.1021677] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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3
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Mosoian A, Teixeira A, Burns CS, Sander LE, Gusella GL, He C, Blander JM, Klotman P, Klotman ME. Prothymosin-alpha inhibits HIV-1 via Toll-like receptor 4-mediated type I interferon induction. Proc Natl Acad Sci U S A 2010; 107:10178-83. [PMID: 20479248 PMCID: PMC2890444 DOI: 10.1073/pnas.0914870107] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Induction of type I interferons (IFN) is a central feature of innate immune responses to microbial pathogens and is mediated via Toll-like receptor (TLR)-dependent and -independent pathways. Prothymosin-alpha (ProTalpha), a small acidic protein produced and released by CD8(+) T cells, inhibits HIV-1, although the mechanism for its antiviral activity was not known. We demonstrate that exogenous ProTalpha acts as a ligand for TLR4 and stimulates type I IFN production to potently suppress HIV-1 after entry into cells. These activities are induced by native and recombinant ProTalpha, retained by an acidic peptide derived from ProTalpha, and lost in the absence of TLR4. Furthermore, we demonstrate that ProTalpha accounts for some of the soluble postintegration HIV-1 inhibitory activity long ascribed to CD8(+) cells. Thus, a protein produced by CD8(+) T cells of the adaptive immune system can exert potent viral suppressive activity through an innate immune response. Understanding the mechanism of IFN induction by ProTalpha may provide therapeutic leads for IFN-sensitive viruses.
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Affiliation(s)
- Arevik Mosoian
- Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
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4
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Feng Y, He F, Zhang P, Wu Q, Huang N, Tang H, Kong X, Li Y, Lu J, Chen Q, Wang B. Inhibitory effect of HMGN2 protein on human hepatitis B virus expression and replication in the HepG2.2.15 cell line. Antiviral Res 2009; 81:277-82. [DOI: 10.1016/j.antiviral.2008.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 12/10/2008] [Accepted: 12/16/2008] [Indexed: 02/08/2023]
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5
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Mosoian A, Teixeira A, Burns CS, Khitrov G, Zhang W, Gusella L, Klotman P, Klotman M. Influence of prothymosin-alpha on HIV-1 target cells. Ann N Y Acad Sci 2007; 1112:269-85. [PMID: 17600282 DOI: 10.1196/annals.1415.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The important role of CD8(+) T cells in controlling HIV-1 infection through the innate as well as the adaptive immune system is well established. In addition to the major histocompatibility complex (MHC)-dependent cytotoxic activity of CD8(+) T cells, they produce soluble factors that suppress HIV-1 replication in an MHC-independent manner. Several of those factors have been identified, including beta-chemokines, Rantes, MIP-1alpha, MIP-1beta, and MDC. We previously identified that prothymosin alpha (ProTalpha) in the conditioned medium of HVS transformed CD8(+) T cells was a potent inhibitor of HIV-1 replication following proviral integration. In this report we further characterize the anti-HIV-1 activity of ProTalpha by demonstrating its target-cell specificity, distinction from additional inhibitors of HIV-1 transcription in CD8(+) T cell supernatants, as well as the differential regulation of host cell antiviral genes that could impact HIV-1 replication. These genes include a number of transcription factors as well IFN-alpha-inducible genes including PKR, IRF1, and Rantes, in the absence of induction of IFN-alpha. These data suggest that the anti-HIV-1 activity of ProTalpha is mediated through the modulation of a number of genes that have been reported to suppress HIV-1 replication including the dysregulation of transcription factors and the induction of PKR and Rantes mRNA.
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Affiliation(s)
- Arevik Mosoian
- Division of Infectious Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
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Reading C, Dowding C, Schramm B, Garsd A, Onizuka-Handa N, Stickney D, Frincke J. Improvement in immune parameters and human immunodeficiency virus-1 viral response in individuals treated with 16alpha-bromoepiandrosterone (HE2000). Clin Microbiol Infect 2006; 12:1082-8. [PMID: 17002607 DOI: 10.1111/j.1469-0691.2006.01520.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A randomised, double-blind, placebo-controlled study examined the safety, tolerance, immunological effect and anti-human immunodeficiency virus (HIV) activity of sub-cutaneously administered HE2000 (16alpha-bromoepiandrosterone) as monotherapy in treatment-naïve patients with HIV-1. Twenty-four patients received five sequential daily doses of 50 or 100 mg of HE2000 or placebo every 6 weeks for up to three courses, and were followed thereafter for 3 months. HE2000 was safe, with transient injection site reactions being the main side-effect. Peripheral blood samples, collected serially, were analysed for changes in immune cell phenotypes. Significant increases were observed in the numbers of circulating dendritic cells, early activated (CD69+ CD25-) CD8 T-cells and T-NK cells after administration of 50-mg doses of HE2000 (p < 0.05). Gene expression in peripheral blood mononuclear cells was analysed by real-time RT-PCR. Before treatment, HIV-1-infected patients had significantly elevated transcripts for a number of inflammatory mediators (p < 0.012). After 50 mg or 100 mg HE2000, but not after placebo, there were significant sustained decreases in IL-1beta, TNF-alpha, IL-6 and Cox-2 transcripts (p < 0.05). There were no significant differences in CD4 cell numbers, although patients receiving 50-mg doses demonstrated a significant decrease in viral load (- 0.6 log; p < 0.01). Anti-HIV-1 T-cell responses were analysed serially using GAG-peptides to stimulate cytoplasmic IFN-gamma responses. After three courses, the 50-mg dose group demonstrated a significant increase in CD8 T-cell response against two distinct GAG peptide pools (p < 0.03). These findings suggest that immune-based therapies may be able to impact viral load by decreasing inflammation and/or stimulating CD8 T-cells.
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Affiliation(s)
- C Reading
- Hollis Eden Pharmaceuticals Inc., San Diego, CA, USA.
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Fakruddin JM, Lempicki RA, Gorelick RJ, Yang J, Adelsberger JW, Garcia-Pineres AJ, Pinto LA, Lane HC, Imamichi T. Noninfectious papilloma virus-like particles inhibit HIV-1 replication: implications for immune control of HIV-1 infection by IL-27. Blood 2006; 109:1841-9. [PMID: 17068156 PMCID: PMC1801045 DOI: 10.1182/blood-2006-02-001578] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Human papilloma virus (HPV)-like particles (VLPs) have been used as a vaccine to prevent HPV infection. Recent studies demonstrate that VLPs bind to dendritic cells and induce the expression of antiviral cytokines such as interferon-alpha (IFN-alpha), interleukin-10 (IL-10) and IFN-gamma. In the present study, we evaluated the effect of VLPs on HIV-1 replication in peripheral blood mononuclear cells (PBMCs), CD4+ T cells, and macrophages. Here, we show that VLPs suppress the replication of both X4 and R5 HIV-1 without affecting the expression of CD4, CXCR4, and CCR5. Soluble factor(s) released by PBMCs and macrophages on VLPs treatment inhibited HIV-1 replication. To determine the inhibitory factors, DNA microarray analysis was performed using VLP-treated PBMCs and macrophages. VLPs induced the genes associated with IFN induction, immune responses, and antiviral responses, among with the recently described cytokine IL-27. Subsequently, IL-27 was found to be a potent inhibitor of HIV-1 replication in PBMCs, CD4+ T cells, and macrophages. Taken together, our studies identify a novel role of IL-27 in restricting HIV-1 replication and suggest that further examination of the inhibitory property of IL-27 may pave the way for a novel therapy for HIV-1 infection.
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Affiliation(s)
- J Mohamad Fakruddin
- Laboratory of Human Retrovirology, Clinical Services Program (CSP), Science Applications International Corporation (SAIC)-Frederick, National Cancer Institute (NCI), MD, USA
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8
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Mosoian A, Teixeira A, High AA, Christian RE, Hunt DF, Shabanowitz J, Liu X, Klotman M. Novel function of prothymosin alpha as a potent inhibitor of human immunodeficiency virus type 1 gene expression in primary macrophages. J Virol 2006; 80:9200-6. [PMID: 16940531 PMCID: PMC1563913 DOI: 10.1128/jvi.00589-06] [Citation(s) in RCA: 36] [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 control human immunodeficiency virus type 1 (HIV-1) infection by a cytotoxic major histocompatibility complex-restricted pathway as well as by secretion of noncytotoxic soluble inhibitory factors. Several components of CD8(+) cell supernatants have been identified that contribute to the latter activity. In this study we report that prothymosin alpha (ProTalpha), a protein found in the cell culture medium of the herpesvirus saimiri-transformed CD8(+) T-cell line, K#1 50K, has potent HIV-1-inhibitory activity. Depletion of native ProTalpha from an HIV-1-inhibitory fraction of CD8(+) cell supernatants removes the inhibitory activity, supporting its role in inhibition via soluble mediators. ProTalpha is an abundant, acidic peptide that has been reported to be localized in the nucleus and associated with cell proliferation and activation of transcription. In this report we demonstrate that ProTalpha suppresses HIV-1 replication, its activity is target cell specific, and inhibition occurs following viral integration. Native and recombinant ProTalpha protein potently inhibit HIV-1 long terminal repeat (LTR)-driven gene expression in macrophages. Furthermore studies using different promoters in lentiviral vectors (cytomegalovirus and phosphoglycerate kinase) revealed that suppression of viral replication by ProTalpha is not HIV LTR specific.
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Affiliation(s)
- Arevik Mosoian
- Department of Medicine, Division of Infectious Diseases, Mount Sinai School of Medicine, Box 1090, New York, NY 10029, USA
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9
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Abstract
Herpesvirus saimiri (Saimiriine herpesvirus-2), a gamma2-herpesvirus (rhadinovirus) of non-human primates, causes T-lymphoproliferative diseases in susceptible organisms and transforms human and non-human T lymphocytes to continuous growth in vitro in the absence of stimulation. T cells transformed by H. saimiri retain many characteristics of intact T lymphocytes, such as the sensitivity to interleukin-2 and the ability to recognize the corresponding antigens. As a result, H. saimiri is widely used in immunobiology for immortalization of various difficult-to-obtain and/or -to-maintain T cells in order to obtain useful experimental models. In particular, H. saimiri-transformed human T cells are highly susceptible to infection with HIV-1 and -2. This makes them a convenient tool for propagation of poorly replicating strains of HIV, including primary clinical isolates. Therefore, the mechanisms mediating transformation of T cells by H. saimiri are of considerable interest. A single transformation-associated protein, StpA or StpB, mediates cell transformation by H. saimiri strains of group A or B, respectively. Strains of group C, which exhibit the highest oncogenic potential, have two proteins involved in transformation-StpC and Tip. Both proteins have been shown to dramatically affect signal transduction pathways leading to the activation of crucial transcription factors. This review is focused on the biological effects and molecular mechanisms of action of proteins involved in H. saimiri-dependent transformation.
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MESH Headings
- Animals
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Gene Expression Regulation, Viral/genetics
- HIV-1/genetics
- HIV-1/metabolism
- Herpesviridae Infections/genetics
- Herpesviridae Infections/metabolism
- Herpesvirus 2, Saimiriine/genetics
- Herpesvirus 2, Saimiriine/metabolism
- Humans
- Lymphoma, T-Cell/genetics
- Lymphoma, T-Cell/metabolism
- Models, Biological
- Oncogene Proteins, Viral/biosynthesis
- Oncogene Proteins, Viral/genetics
- Tumor Virus Infections/genetics
- Tumor Virus Infections/metabolism
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Affiliation(s)
- Alexander Y Tsygankov
- Department of Microbiology and Immunology, Temple University School of Medicine, 3400 N. Broad Street, Philadelphia, PA 19104, USA.
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10
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Ahmed RKS, Norrgren H, da Silva Z, Blaxhult A, Fredriksson EL, Biberfeld G, Andersson S, Thorstensson R. Antigen-specific beta-chemokine production and CD8 T-cell noncytotoxic antiviral activity in HIV-2-infected individuals. Scand J Immunol 2005; 61:63-71. [PMID: 15644124 DOI: 10.1111/j.0300-9475.2005.01530.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human immunodeficiency virus-2 (HIV-2) is less pathogenic than HIV-1, and the disease progression in HIV-2-infected individuals seems to be similar to that seen in HIV-1-infected long-term nonprogressors. Cell-mediated immune responses and the production of noncytotoxic CD8+ T-cell antiviral factors (CAF) and beta-chemokines have been correlated to protection against HIV-1 and associated with asymptomatic infection and slower disease progression. We investigated the antigen-induced beta-chemokine production in HIV-2-infected patients living in Sweden and in Guinea-Bissau. We also compared in vitro CD8+ T-cell-mediated noncytotoxic antiviral activity against beta-chemokine-sensitive R5 virus (HIV-1Bal) and beta-chemokine-insensitive X4 virus (HIV-1IIIB) in HIV-2-infected patients with that in HIV-1-infected patients. HIV-2-specific beta-chemokine production was demonstrated in a majority of the HIV-2-infected subjects. CD8+ T cells of both HIV-1 and HIV-2-infected individuals suppressed R5 virus replication in vitro in a similar manner, while the inhibition of X4 virus replication seemed to be more frequent and of a higher magnitude among HIV-2-infected patients compared to HIV-1-infected subjects. Taken together, our results indicate that the production of CD8+ T-cell noncytotoxic antiviral factors may contribute to the low transmission of the virus and slower disease progression in HIV-2-infected patients.
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Affiliation(s)
- R K S Ahmed
- Tumorbiology Center, Karolinska Institute, Solna, Sweden.
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11
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Phadke AP, Choi IS, Li Z, Weaver E, Collisson EW. The role of inducer cells in mediating in vitro suppression of feline immunodeficiency virus replication. Virology 2004; 320:63-74. [PMID: 15003863 DOI: 10.1016/j.virol.2003.11.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2003] [Revised: 10/23/2003] [Accepted: 11/03/2003] [Indexed: 11/28/2022]
Abstract
CD8+ T-cell-mediated suppression of feline immunodeficiency virus (FIV) replication has been described by several groups, although the mechanisms of activation and conditions for viral suppression vary with the methodologies. We have previously reported that CD8+ T-cell-mediated suppression of FIV replication required inducer cell stimulation of the effector cells. The focus of the present study was to examine the essential role of inducer cells required for the induction of this soluble anti-FIV activity. Both FIV-PPR-infected T cells and feline skin fibroblasts (FSF) infected with an alphavirus vector expressing FIV capsid or the irrelevant antigen lacZ, stimulated autologous or heterologous effector cells to produce supernatants that suppressed FIV replication. Thus, induction of this suppression of FIV replication did not strictly require autologous inducer cells and did not require the presence of FIV antigen. Anti-viral activity correlated with the presence of CD8+ T cells. Suppression was maximal when the inducer cells and the effector cells were in contact with each other, because separation of the inducer and effector cells by a 0.45-microm membrane reduced FIV suppression by approximately 50%. These findings emphasize the importance for membrane antigen interactions and cytokines in the optimal induction of effector cell synthesis of the soluble anti-FIV activity.
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Affiliation(s)
- Anagha P Phadke
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
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12
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DeVico AL, Gallo RC. Control of HIV-1 infection by soluble factors of the immune response. Nat Rev Microbiol 2004; 2:401-13. [PMID: 15100693 DOI: 10.1038/nrmicro878] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Anthony L DeVico
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21202, USA.
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14
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Abstract
Efforts to control HIV infection have led to the development of several antiretroviral drugs that can limit virus replication, however, these therapies do not offer a long-term solution to the infection. We can learn a great deal from HIV-infected individuals who have lived for more than ten years and remain healthy without receiving antiviral drugs. These long-term survivors or long-term non-progressors have an immune system that can control HIV infection. A major component of this immune response is innate immunity, particularly the CD8(+) cell antiviral non-cytotoxic response (CNAR), mediated by a novel CD8(+) cell antiviral factor (CAF). The characteristics of CNAR and CAF will be described and progress made toward identifying CAF will be reviewed. These studies have uncovered several potentially important natural anti-HIV factors and their relationship to the originally described CAF is considered.
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Affiliation(s)
- Jay A Levy
- University of California, San Francisco, Department of Medicine, 513 Parnassus, S1280, Box 1270, San Francisco, CA 94143-1270, USA.
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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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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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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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