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McBrien JB, Kumar NA, Silvestri G. Mechanisms of CD8 + T cell-mediated suppression of HIV/SIV replication. Eur J Immunol 2018; 48:898-914. [PMID: 29427516 DOI: 10.1002/eji.201747172] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/29/2018] [Accepted: 02/02/2018] [Indexed: 12/13/2022]
Abstract
In this article, we summarize the role of CD8+ T cells during natural and antiretroviral therapy (ART)-treated HIV and SIV infections, discuss the mechanisms responsible for their suppressive activity, and review the rationale for CD8+ T cell-based HIV cure strategies. Evidence suggests that CD8+ T cells are involved in the control of virus replication during HIV and SIV infections. During early HIV infection, the cytolytic activity of CD8+ T cells is responsible for control of viremia. However, it has been proposed that CD8+ T cells also use non-cytolytic mechanisms to control SIV infection. More recently, CD8+ T cells were shown to be required to fully suppress virus production in ART-treated SIV-infected macaques, suggesting that CD8+ T cells are involved in the control of virus transcription in latently infected cells that persist under ART. A better understanding of the complex antiviral activities of CD8+ T cells during HIV/SIV infection will pave the way for immune interventions aimed at harnessing these functions to target the HIV reservoir.
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Affiliation(s)
- Julia Bergild McBrien
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Nitasha A Kumar
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Guido Silvestri
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
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Demers KR, Reuter MA, Betts MR. CD8(+) T-cell effector function and transcriptional regulation during HIV pathogenesis. Immunol Rev 2013; 254:190-206. [PMID: 23772621 PMCID: PMC3693771 DOI: 10.1111/imr.12069] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A detailed understanding of the immune response to human immunodeficiency virus (HIV) infection is needed to inform prevention and therapeutic strategies that aim to contain the acquired immunodeficiency syndrome (AIDS) pandemic. The cellular immune response plays a critical role in controlling viral replication during HIV infection and will likely need to be a part of any vaccine approach. The qualitative feature of the cellular response most closely associated with immunological control of HIV infection is CD8(+) T-cell cytotoxic potential, which is responsible for mediating the elimination of infected CD4(+) T cells. Understanding the underlying mechanisms involved in regulating the elicitation and maintenance of this kind of effector response can provide guidance for vaccine design. In this review, we discuss the evidence for CD8(+) T cells as correlates of protection, the means by which their antiviral capacity is evaluated, and transcription factors responsible for their function, or dysfunction, during HIV infection.
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Affiliation(s)
- Korey R. Demers
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Morgan A. Reuter
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael R. Betts
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Persistently HIV-1 seronegative Nairobi sex workers are susceptible to in vitro infection. Can J Infect Dis 2007; 11:259-63. [PMID: 18159299 DOI: 10.1155/2000/390310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/1999] [Accepted: 11/10/1999] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To evaluate whether resistance to HIV-1 infection in a subset of highly exposed sex workers correlates with resistance at the cellular level. DESIGN In vitro evaluation of susceptibility to infection by Kenyan HIV-1 isolates and cellular production of potential mediators of resistance. SETTING Samples were collected in a primary care clinic in Nairobi. PATIENTS Thirteen individuals from a cohort of sex workers with a similar risk of acquiring HIV infection and six unexposed controls. INTERVENTIONS Subjects were provided with appropriate primary care and counselling on the prevention of sexually transmitted diseases. RESULTS No inherent cellular resistance to infection was identified. CD8⁺ cells from a subset of subjects strongly inhibited viral replication. CONCLUSIONS Lack of infection in this cohort was not attributable to factors inherent to CD4⁺ cells. Resistance to HIV infection is likely to be multifactorial, and products of CD8⁺ cells and unique features of mucosal sites probably contribute to this state.
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Abstract
Vaccines are an economically efficient means of controlling viral infections, and it is likely that a vaccine against HIV-1 will be the most effective way of controlling the global AIDS crisis. However, an effective vaccine has not yet been attainable and in developing countries co-infection with protozoa and other chronic diseases adds another level of complexity to the design of an HIV-1 vaccine. Helminthic and protozoan infections can result in a constant state of immune activation that is characterised by a dominant T helper (Th)2 type of cytokine profile. Such an immune profile is likely to have an adverse impact on the efficacy of an HIV-1 vaccine CD8 cellular immune response and the corresponding Th1 cytokines that are most likely to be important for clearing viral infections.
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Affiliation(s)
- Tara M Robinson
- University of Pennsylvania, 422 Curie Blvd, 505 SCL, Philadelphia, PA 19104, USA
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5
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Jiang JQ, Balasubramanian S, Hawley-Foss NC, Badley AD, Rosenthal KL, Copeland KFT. Production of CD8+ T cell nonlytic suppressive factors by CD28, CD38, and HLA-DR subpopulations. AIDS Res Hum Retroviruses 2003; 19:497-502. [PMID: 12882659 DOI: 10.1089/088922203766774540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
HIV infection may be modified by CD8(+) T cells by the production of nonlytic antiviral factors. To determine subpopulations that mediate nonlytic, antiviral activity, we examined the production of beta chemokines and of CD8 antiviral factor (CAF) by different subsets, using CD8(+) cells derived from 24 HIV-1-infected and 25 uninfected individuals. Subjects with CD8(+) cell counts greater than 200/microl produced increased levels of MIP-1alpha by CD8(+)CD28(+), CD8(+)CD38(-), and CD8(+)HLA-DR(+) subsets as compared with uninfected controls. CD8(+)CD38(-) cells produced higher levels of MIP-1beta and RANTES. CAF production was increased by CD8(+)CD38(+) and CD8(+)HLA-DR(+) cells of HIV-infected individuals as compared with uninfected controls. Chemokine production was increased by cells that do not express activation markers, whereas CAF activity was increased by cells expressing CD38 or HLA-DR. These findings shed light on CD8(+) T cell noncytotoxic antiviral factor production during HIV infection.
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Affiliation(s)
- Janina Q Jiang
- Center for Molecular Medicine, Ottawa Health Research Institute, Ottawa, Ontario K1H 8L6, Canada
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Maslove DM, Ni LW, Hawley-Foss NC, Badley AD, Copeland KF. Modulation of HIV transcription by CD8(+) cells is mediated via multiple elements of the long terminal repeat. Clin Exp Immunol 2001; 125:102-9. [PMID: 11472432 PMCID: PMC1906111 DOI: 10.1046/j.1365-2249.2001.01576.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV replication and LTR-mediated gene expression can be modulated by CD8(+) cells in a cell type-dependent manner. We have previously shown that supernatant fluids of activated CD8(+) cells of HIV-infected individuals suppress long terminal repeat (LTR)-mediated transcription of HIV in T cells while enhancing transcription in monocytic cells. Here, we have examined the effect of culture of T cells and monocytic cells with CD8(+) supernatant fluids, and subsequent binding of transcription factors to the HIV-1 LTR. In transfections using constructs in which NF kappa B or NFAT-1 sites were mutated, the LTR retained the ability to respond positively to culture with CD8 supernatant fluid in monocytic cells. Nuclear extracts prepared from both Jurkat T cells and U38 monocytic cells cultured with CD8(+) cell supernatant fluid demonstrated increased binding to the HIV-1 LTR at an AP-1 site which overlapped the chicken ovalbumin upstream promoter (COUP) site. In monocytic cells, increased binding activity was observed at the NF kappa B sites of the LTR. In contrast, an inhibition in binding at the NF kappa B sites was observed in Jurkat cells. Examination of two NFAT-1 sites revealed enhanced binding at - 260 to - 275 bp in U38 cells which was reduced by cellular activation. PMA and ionomycin-induced binding at a second NFAT-1 site (- 205 to - 216 bp) was abrogated by CD8(+) cell supernatant fluid in T cells. These results, taken together, suggest that factors present in CD8(+) supernatant fluids may act through several sites of the LTR to modulate transcription in a cell type-dependent manner.
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Affiliation(s)
- D M Maslove
- Centre for Molecular Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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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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Leith JG, Copeland KF, McKay PJ, Bienzle D, Richards CD, Rosenthal KL. T cell-derived suppressive activity: evidence of autocrine noncytolytic control of HIV type 1 transcription and replication. AIDS Res Hum Retroviruses 1999; 15:1553-61. [PMID: 10580406 DOI: 10.1089/088922299309847] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The ability of CD8+ T lymphocytes to suppress the transcription and replication of HIV-1 is well documented. We have demonstrated that the factor(s) responsible for the suppression of HIV-1 LTR-mediated gene expression are not the CC chemokines RANTES, MIP-1alpha, and MIP-1beta. Interestingly, these and other chemokines and cytokines are produced by both CD8+ and CD4+ T lymphocytes. On the presumption that CD4+ T lymphocytes may also be able to modulate HIV-1 expression in vitro we assessed the LTR-modulatory effects of a panel of culture supernatants derived from stimulated CD4+ T lymphocytes from HIV-positive patients and uninfected controls. Supernatants of both CD4+ and CD8+ T cells mediated a suppression of LTR-driven gene expression in Jurkat T cells and an enhancement of gene expression in U38 monocytic cells. On the basis of these results, and using a herpesvirus saimiri (HVS)-transformed CD4+ T lymphocyte clone (HVSCD4), we demonstrate that both suppressive and enhancing effects are dose dependent. Furthermore, we have shown that supernatants of both HVSCD4 and HVSCD8 cells suppress LTR-mediated gene expression and HIV-1 replication in transfected/infected T cells. In U1 monocytic cells, supernatants of both CD4+ and CD8+ lymphocytes from an HIV-1-infected individual enhanced LTR-mediated gene expression, HIV-1 replication, and TNF-alpha production. However, only these effects as induced by CD8+ T cells were sensitive to the G protein inhibitor pertussis toxin. These results indicate that factors produced by both CD4+ and CD8+ T cells exert dichotomous effects on HIV-1 gene expression and replication in T cells and monocytes.
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Affiliation(s)
- J G Leith
- Department of Pathology and Molecular Medicine, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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Copeland KF, McKay PJ, Newton J, Rosenthal KL. CD8+ T cell-mediated enhancement of tumour necrosis factor-alpha (TNF-alpha) production and HIV-1 LTR-driven gene expression in human monocytic cells is pertussis toxin-sensitive. Clin Exp Immunol 1999; 116:479-85. [PMID: 10361238 PMCID: PMC1905314 DOI: 10.1046/j.1365-2249.1999.00897.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
HIV replication and LTR-mediated gene expression can be modulated by CD8+ T cells in a cell type-dependent manner. We have previously shown that supernatants of activated CD8+ T cells of HIV-infected individuals greatly enhanced p24 levels in human macrophages infected with NSI or SI primary isolates of HIV-1. Here we have examined the effect of culture with CD8+ T cell supernatants on HIV-1 LTR-mediated gene expression in monocytic cells. CD8+ T cell supernatants enhanced LTR-mediated gene expression in U38 cells activated with Tat in the absence or presence of phorbol myristate acetate (PMA) and ionomycin or TNF-alpha. Further, enhancement of LTR-mediated gene expression and virus replication in U38 cells and U1 cells, respectively, was pertussis toxin-sensitive. The enhancement of gene expression and virus replication was associated with increased levels of TNF-alpha and was significantly abrogated by antibody to TNF-alpha. In contrast, the suppression of LTR-mediated gene expression by CD8+ T cell supernatants in Jurkat T cells was not pertussis toxin-sensitive and TNF-alpha levels were not affected. These results demonstrate that factors produced by CD8+ T cells utilize different cellular pathways to mediate their effects on HIV transcription and replication in different cell types.
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Affiliation(s)
- K F Copeland
- Centre for Molecular Medicine, Ottawa General Hospital Research Institute, Ottawa, Canada.
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Sharma UK, Trujillo J, Song HF, Saitta FP, Laeyendecker OB, Castillo R, Arango-Jaramillo S, Sridharan G, Dettenhofer M, Blakemore K, Yu XF, Schwartz DH. A Novel Factor Produced by Placental Cells with Activity Against HIV-1. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.11.6406] [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 factors controlling the dynamics of HIV-1 transmission from mother to infant are not clearly known. Previous studies have suggested the existence of maternal and placental protective mechanisms that inhibit viral replication in utero. Preliminary studies from our laboratory revealed that supernatant from placental stromal cells protected HIV-1-infected PBMC from virus-induced apoptosis and suppressed virus production. We have attempted to characterize the antiviral activity of this placental factor (PF) and delineate the stages of HIV-1 replication affected. This activity was not due to the presence of any known cytokine reported to have anti-HIV effect. Direct exposure to PF had no suppressive effect on the infectivity of cell-free HIV-1, and envelope-mediated membrane fusion appeared to be unaffected. Western blot analysis of HIV-1 from infected PBMC treated with PF revealed that expression of all viral proteins was reduced proportionately, both intracellularly and in released virions. However, exposure of HIV-1-infected cells to PF resulted in production of virions with 10–100-fold-reduced infectivity. PF-treated virions contained two- to threefold reduced ratios of cyclophilin A:Gag protein as compared with untreated virus. Reduced cyclophilin A content resulting in decreased binding of cyclophilin A to Gag could account, in part, for the observed reduction in infectivity. Our results suggest that placental cells produce an antiviral factor that protects the fetus during gestation and may have therapeutic potential.
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Affiliation(s)
- Usha K. Sharma
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Jorge Trujillo
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Hai-Feng Song
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Francis P. Saitta
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Oliver B. Laeyendecker
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Renan Castillo
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Silvio Arango-Jaramillo
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Gopalan Sridharan
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Markus Dettenhofer
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - Karen Blakemore
- †Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Xiao-Fang Yu
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
| | - David H. Schwartz
- *Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205; and
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Copeland KF, McKay PJ, Newton JJ, Rosenthal KL. Enhancement of HIV-1 replication in human macrophages is induced by CD8+ T cell soluble factors. Clin Exp Immunol 1998; 114:87-93. [PMID: 9764608 PMCID: PMC1905078 DOI: 10.1046/j.1365-2249.1998.00699.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that CD8+ T cell-derived factors enhanced HIV long terminal repeat (LTR)-mediated gene expression and replication in monocytic cell lines. We now report that replication of NSI and SI primary isolates of HIV-1 in human macrophages were significantly enhanced by CD8+ T cell supernatants. The CD8-mediated enhancement of HIV replication was abrogated by pertussis toxin in a dose-dependent manner. The sensitivity to pertussis toxin suggests that the CD8+ T cell-derived enhancing factor is acting through a G protein-coupled signalling pathway. Enhanced HIV replication in macrophages was accompanied by increased levels of HIV-1 mRNA, suggesting that CD8 enhancement was mediated at the transcriptional level. Interestingly, the replication of HIV(Bal), which replicates to high levels in macrophages, was not significantly modulated by culture with CD8+ T cell supernatants. Although direct co-culture of activated CD8+ T cells with HIV(Ada)-infected macrophages did not modulate replication, separation of the CD8+ T cells from macrophages in transwell cultures resulted in significant enhancement of replication. The inability to detect a modulatory effect in direct co-cultures appeared to be due to non-specific lysis of infected macrophages. Thus, soluble factors produced by CD8+ T cells exert strong enhancing effects on HIV-1 replication in human macrophages.
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Affiliation(s)
- K F Copeland
- Department of Pathology, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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Abstract
Suppression of HIV by chemokines represents a special case in virology and immunology where soluble molecules other than antibodies inhibit infection by a specific virus. The basis for this inhibition is that HIV has evolved to use certain chemokine receptors as "coreceptors" for entry into host cells. Human genotypes that reduce or prevent coreceptor expression are strongly associated with protection against infection and slower disease progression. We suggest that local production of certain chemokines can produce a similar modulation of coreceptor expression, and mounting evidence indicates that chemokine release is a major determinant of protection from HIV infection. Here we review this evidence and explore future avenues for investigating the role of chemokines in controlling HIV infection.
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Affiliation(s)
- A Garzino-Demo
- Institute of Human Virology, University of Maryland, Baltimore 21201-1192, USA
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13
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Leith JG, Copeland KF, McKay PJ, Richards CD, Rosenthal KL. CD8+ T-cell-mediated suppression of HIV-1 long terminal repeat-driven gene expression is not modulated by the CC chemokines RANTES, macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta. AIDS 1997; 11:575-80. [PMID: 9108938 DOI: 10.1097/00002030-199705000-00004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To assess the role of RANTES, macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta in modulation of HIV-1 long terminal repeat (LTR)-mediated gene expression and determine whether these chemokines share identity with CD8+ T-lymphocyte-derived HIV-1 LTR-suppressive factors. DESIGN HIV-1 LTR-directed reporter gene expression is a model for transcription that is susceptible to inhibition by factors produced by CD8+ lymphocytes of HIV-1-infected individuals. The effect of recombinant chemokines on LTR-directed gene expression was examined. The ability of chemokines found to be present in CD8 supernatants to suppress HIV-1 LTR-mediated gene expression was determined by antibody inhibition assays. METHODS The concentrations of RANTES, MIP-1 alpha and MIP-1 beta in a panel of CD8+ T-lymphocyte-derived supernatants were determined by enzyme-linked immunosorbent assay. Recombinant chemokines were added to freshly transfected (pLTR-CAT and pSV40-tat) human Jurkat T cells. Excessive polyclonal neutralizing antibodies to these chemokines were added to transfected Jurkat T cells cultured in the presence of strongly inhibitory CD8+ T-cell-derived supernatants with known chemokine concentrations. RESULTS The concentrations of RANTES, MIP-1 alpha and MIP-1 beta in a panel of CD8+ lymphocyte-derived supernatants were found to correlate with their relative ability to suppress the LTR-mediated gene expression (r = 0.679, 0.764 and 0.48, respectively). The addition of recombinant CC chemokines had no effect over a broad range of doses on HIV-1 LTR-mediated gene expression. The CD8-suppressive effect on HIV-1 LTR-driven gene expression was not abrogated by a combination of antibodies of RANTES, MIP-1 alpha and MIP-1 beta. CONCLUSIONS RANTES, MIP-1 alpha and MIP-1 beta do not alter HIV-1 LTR-directed gene expression at doses up to 100 ng/ml. Although present in varying concentrations in supernatants derived from CD8+ lymphocytes from HIV-positive individuals, these chemokines are not responsible for the powerful CD8-derived suppressive effect on HIV-1 LTR-mediated gene expression observed in our system.
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Affiliation(s)
- J G Leith
- Department of Pathology, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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Copeland KF, Leith JG, McKay PJ, Kelleher L, Smaill FM, Rosenthal KL. CD8+ T cell-mediated suppression of HIV long terminal repeat-driven gene expression is not associated with improved clinical status. AIDS 1997; 11:581-6. [PMID: 9108939 DOI: 10.1097/00002030-199705000-00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES To determine the associations between the suppression of HIV-1 long terminal repeat (LTR)-mediated gene expression by CD8+ T-cell supernatants and clinical correlates of well-being, including CD4+ and CD8+ T-cell counts, beta-chemokine production and clinical stage of disease. METHODS Culture supernatants of activated CD8+ T cells derived from a panel of HIV-1-infected subjects were assessed for their ability to suppress HIV-1 LTR-mediated chloramphenicol acetyl transferase (CAT) expression. The percentage suppression of gene expression was correlated with CD4+ and CD8+ T-cell counts and clinical stage of infection. Some individuals within this group were followed at 2-3 month intervals over time to assess the consistency of the suppression. Selected CD8+ T-cell culture supernatants of diverse suppressive ability were screened for the levels of the beta-chemokines macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta and RANTES. RESULTS The ability of CD8+ T cells of HIV-1 infected subjects to suppress HIV-1 LTR-mediated gene expression did not show a dependence upon high CD4+ T-cell counts or on the clinical stage or duration of infection. The ability to suppress gene expression did show a relationship with higher CD8+ T-cell counts and correlated with the levels of beta-chemokines in the culture supernatants. In contrast, strong suppression was mediated by CD8+ T-cell supernatants from some subjects with very low CD8+ T-cell counts and relatively low chemokine levels. CONCLUSIONS Although the suppression of gene expression by CD8+ T-cell culture supernatants showed statistical correlation with beta-chemokine levels and with higher CD8+ T-cell count, no correlation could be found with correlates of clinical well-being.
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Affiliation(s)
- K F Copeland
- Molecular Virology and Immunology Programme, McMaster University, Hamilton, Ontario, Canada
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