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Cecil C, West A, Collier M, Jurgens C, Madden V, Whitmore A, Johnston R, Moore DT, Swanstrom R, Davis NL. Structure and immunogenicity of alternative forms of the simian immunodeficiency virus gag protein expressed using Venezuelan equine encephalitis virus replicon particles. Virology 2007; 362:362-73. [PMID: 17275057 PMCID: PMC1991297 DOI: 10.1016/j.virol.2006.12.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 12/08/2006] [Accepted: 12/21/2006] [Indexed: 11/15/2022]
Abstract
Venezuelan equine encephalitis virus replicon particles (VRP) were engineered to express different forms of SIV Gag to compare expression in vitro, formation of intra- and extracellular structures and induction of humoral and cellular immunity in mice. The three forms examined were full-length myristylated SIV Gag (Gagmyr+), full-length Gag lacking the myristylation signal (Gagmyr-) or a truncated form of Gagmyr- comprising only the matrix and capsid domains (MA/CA). Comparison of VRP-infected primary mouse embryo fibroblasts, mouse L929 cells and primate Vero cells showed comparable expression levels for each protein, as well as extracellular virus-like particles (VRP-Gagmyr+) and distinctive cytoplasmic aggregates (VRP-Gagmyr-) with each cell type. VRP were used to immunize BALB/c mice, and immune responses were compared using an interferon (IFN)-gamma ELISPOT assay and a serum antibody ELISA. Although all three VRP generated similar levels of IFN-gamma-producing cells at 1 week post-boost, at 10 weeks post-boost the MA/CA-VRP-induced response was maintained at a significantly higher level relative to that induced by Gagmyr+-VRP. Antibody responses to MA/CA-VRP and Gagmyr+-VRP were not significantly different.
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MESH Headings
- Animals
- Antibodies, Viral/blood
- Cell Line
- Cells, Cultured
- Chlorocebus aethiops
- Embryo, Mammalian/cytology
- Encephalitis Virus, Venezuelan Equine/genetics
- Enzyme-Linked Immunosorbent Assay
- Female
- Fibroblasts
- Gene Products, gag/chemistry
- Gene Products, gag/immunology
- Genetic Vectors/genetics
- H-2 Antigens/immunology
- Interferon-gamma/biosynthesis
- Lymphocytes/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred Strains
- Microscopy, Electron, Transmission
- Models, Animal
- Pregnancy
- Replicon/genetics
- Simian Immunodeficiency Virus/immunology
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vero Cells
- Viral Vaccines/genetics
- Viral Vaccines/immunology
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Affiliation(s)
- Chad Cecil
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Lin WL, Fincke JE, Sharer LR, Monos DS, Lu S, Gaughan J, Platsoucas CD, Oleszak EL. Oligoclonal T cells are infiltrating the brains of children with AIDS: sequence analysis reveals high proportions of identical beta-chain T-cell receptor transcripts. Clin Exp Immunol 2005; 141:338-56. [PMID: 15996199 PMCID: PMC1809433 DOI: 10.1111/j.1365-2249.2005.02845.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We have recently described the presence of perivascular CD3+ CD45RO+ T cells infiltrating the brains of children with AIDS. To determine whether these infiltrates contain oligoclonal populations of T cells, we amplified by PCR beta-chain T-cell receptor (TCR) transcripts from autopsy brains of four paediatric patients with AIDS. The amplified transcripts were cloned and sequenced. Sequence analysis of the beta-chain TCR transcripts from all four patients revealed multiple identical copies of TCR beta-chain transcripts, suggesting the presence of oligoclonal populations of T-cells. These TCR transcripts were novel. The presence of oligoclonal populations of T cells in the brains of these four paediatric patients with AIDS suggests that these T cells have undergone antigen-driven proliferation and clonal expansion very likely in situ, in the brains of these AIDS patients, in response to viral or self-antigens. Although the specificity of the clonally expanded beta-chain TCR transcripts remains to be elucidated, none of the beta-chain TCR transcripts identified in this study were identical to those specific for HIV-1 antigens that are currently reported in the GENBANK/EMBL databases. Certain common CDR3 motifs were observed in brain-infiltrating T cells within and between certain patients. Large proportions (24 of 61; 39%) of beta-chain TCR clones from one patient (NP95-73) and 2 of 27 (7%) of another patient (NP95-184-O) exhibited substantial CDR3 homology to myelin basic protein (MBP)-specific TCR derived from normal donors or TCR expressed in the brain of patients with multiple sclerosis (MS) or with viral encephalitis. These two patients (NP95-73 and NP95-184-O) also shared HLA class II with the normal donors and the MS patients who expressed these homologous TCR. Pathologic examination at autopsy of the brains revealed the presence of myelin pallor only in patient NP95-73. T-cell clones identified in the brain of patients NP95-73 and NP95-184-O may recognize MBP or another CNS self antigen and this recognition may be restricted by either DRB1*15 or DQB1*0602 specificities.
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Affiliation(s)
- W L Lin
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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3
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Abstract
This review is intended to provide a fundamental perspective on the dynamic interplay between HIV-1 and the immune system, an essential aspect in defining the pathogenesis and treatment of AIDS. HIV-1 infection, the cause of AIDS, is a worldwide pandemic with enormous adverse heath and economic implications, particularly in the developing world. This bloodborne and sexually transmitted disease, which evolved from simian immunodeficiency virus, infects and replicates in helper T cells and macrophages and utilizes CD4 and a chemokine coreceptor for entry. Immune deficiency occurs as a result of virally induced attrition of CD4 T cells, resulting in the development of opportunistic infections and malignancy. Prophylaxis against opportunistic infections is required according to the extent of immune deficiency. HIV-specific immunity can control viral replication and delay disease progression but does not clear infection. Antiretroviral treatment consists of inhibitors that target for viral entry, reverse transcriptase, and viral protease. Therapy can control viral replication, restore immunity, and delay disease progression, but it cannot eliminate infection. Thus chronic infection persists even in treated patients. Antiretroviral drugs have been highly effective in preventing mother-to-child transmission and for postexposure prophylaxis. Several novel vaccines in development hold promise for either effective infection prevention or attenuation of disease progression.
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Affiliation(s)
- John W Sleasman
- Department of Pediatrics, College of Medicine, University of Florida, Box 100296, Gainesville, FL 32610, USA
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4
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Pierson T, McArthur J, Siliciano RF. Reservoirs for HIV-1: mechanisms for viral persistence in the presence of antiviral immune responses and antiretroviral therapy. Annu Rev Immunol 2000; 18:665-708. [PMID: 10837072 DOI: 10.1146/annurev.immunol.18.1.665] [Citation(s) in RCA: 382] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The success of combination antiretroviral therapy for HIV-1 infection has generated interest in mechanisms by which the virus can persist in the body despite the presence of drugs that effectively inhibit key steps in the virus life cycle. It is becoming clear that viral reservoirs established early in the infection not only prevent sterilizing immunity but also represent a major obstacle to curing the infection with the potent antiretroviral drugs currently in use. Mechanisms of viral persistence are best considered in the context of the dynamics of viral replication in vivo. Virus production in infected individuals is largely the result of a dynamic process involving continuous rounds of de novo infection of and replication in activated CD4(+) T cells with rapid turnover of both free virus and virus-producing cells. This process is largely, but not completely, interrupted by effective antiretroviral therapy. After a few months of therapy, plasma virus levels become undetectable in many patients. Analysis of viral decay rates initially suggested that eradication of the infection might be possible. However, there are several potential cellular and anatomical reservoirs for HIV-1 that may contribute to long-term persistence of HIV-1. These include infected cell in the central nervous system and the male urogenital tract. However, the most worrisome reservoir consists of latently infected resting memory CD4(+) T cells carrying integrated HIV-1 DNA. Definitive demonstration of the presence of this form of latency required development of methods for isolating extremely pure populations of resting CD4(+) T cells and for demonstrating that a small fraction of these cells contain integrated HIV-1 DNA that is competent for replication if the cells undergo antigen-driven activation. Most of the latent virus in resting CD4(+) T cells is found in cells of the memory phenotype. The half-life of this latent reservoir is extremely long (44 months). At this rate, eradication of this reservoir would require over 60 years of treatment. Thus, latently infected resting CD4(+) T cells provide a mechanism for life-long persistence of replication-competent forms of HIV-1, rendering unrealistic hopes of virus eradication with current antiretroviral regimens. The extraordinary stability of the reservoir may reflect gradual reseeding by a very low level of ongoing viral replication and/or mechanisms that contribute to the intrinsic stability of the memory T cell compartment. Given the substantial long-term toxicities of current combination therapy regimens, novel approaches to eradicating this latent reservoir are urgently needed.
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Affiliation(s)
- T Pierson
- Department of Medicine and Neurology, Johns Hopkins University School of Medicine Baltimore, Maryland 21205, USA
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5
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Abstract
High-level viral replication is the primary determinant of CD4 depletion or disease development in HIV-1--infected children. The developing immune system of infants might allow for more efficient viral replication and less efficient immune containment of viral replication. Advances in the understanding of the pathogenesis of vertical HIV-1 infection suggest that the use of potent combination regimens to control HIV-1 replication offers the best opportunity to prevent or reverse the sequelae of HIV-1 infection.
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Affiliation(s)
- K Luzuriaga
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, USA.
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6
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Mackewicz CE, Garovoy MR, Levy JA. HLA compatibility requirements for CD8(+)-T-cell-mediated suppression of human immunodeficiency virus replication. J Virol 1998; 72:10165-70. [PMID: 9811757 PMCID: PMC110558 DOI: 10.1128/jvi.72.12.10165-10170.1998] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD8(+) T cells from human immunodeficiency virus (HIV)-infected individuals can suppress HIV replication in cultured CD4(+) cells by a noncytotoxic mechanism. Efficient suppression of HIV replication (>90% reduction) does not require HLA class I or class II histocompatibility between the effector CD8(+) T cells and the infected target CD4(+) T cells. However, maximal control of HIV production occurs when the CD8(+) effector cells and CD4(+) target cells are syngeneic. In some cases, more than 20-fold fewer syngeneic CD8(+) T cells were required to achieve the same degree of HIV inhibition as HLA-mismatched CD8(+) T cells. The increased antiviral activity seen in the syngeneic setting did not map exclusively to either the HLA class I or class II locus. These findings suggest that genetic compatibility (potentially, but not necessarily, at the HLA class I and class II loci) regulates CD8(+) T-cell noncytotoxic antiviral activity against infected CD4(+) T cells.
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Affiliation(s)
- C E Mackewicz
- Department of Medicine, Department of Surgery, School of Medicine, University of California, San Francisco, San Francisco, California 94143-1270, USA
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7
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Abstract
The murine CD8(+) cytotoxic-T-lymphocyte (CTL) repertoire appears to be quite limited in response to influenza A viruses. The CTL responses to influenza A virus in humans were examined to determine if the CTL repertoire is also very limited. Bulk cultures revealed that a number of virus proteins were recognized in CTL assays. CTL lines were isolated from three donors for detailed study and found to be specific for epitopes on numerous influenza A viral proteins. Eight distinct CD8(+) CTL lines were isolated from donor 1. The proteins recognized by these cell lines included the nucleoprotein (NP), matrix protein (M1), nonstructural protein 1 (NS1), polymerases (PB1 and PB2), and hemagglutinin (HA). Two CD4(+) cell lines, one specific for neuraminidase (NA) and the other specific for M1, were also characterized. These CTL results were confirmed by precursor frequency analysis of peptide-specific gamma interferon-producing cells detected by ELISPOT. The epitopes recognized by 6 of these 10 cell lines have not been previously described; 8 of the 10 cell lines were cross-reactive to subtype H1N1, H2N2, and H3N2 viruses, 1 cell line was cross-reactive to subtypes H1N1 and H2N2, and 1 cell line was subtype H1N1 specific. A broad CTL repertoire was detected in the two other donors, and cell lines specific for the NP, NA, HA, M1, NS1, and M2 viral proteins were isolated. These findings indicate that the human memory CTL response to influenza A virus is broadly directed to epitopes on a wide variety of proteins, unlike the limited response observed following infection of mice.
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Affiliation(s)
- J Jameson
- Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical Center, Worcester, Massachusetts 01655, USA
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Klein MR, van der Burg SH, Pontesilli O, Miedema F. Cytotoxic T lymphocytes in HIV-1 infection: a killing paradox? IMMUNOLOGY TODAY 1998; 19:317-24. [PMID: 9666605 DOI: 10.1016/s0167-5699(98)01288-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- M R Klein
- Dept of Clinical Viro-Immunology, University of Amsterdam, The Netherlands
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9
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Yang OO, Walker BD. CD8+ cells in human immunodeficiency virus type I pathogenesis: cytolytic and noncytolytic inhibition of viral replication. Adv Immunol 1997; 66:273-311. [PMID: 9328644 DOI: 10.1016/s0065-2776(08)60600-8] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- O O Yang
- AIDS Research Center, Massachusetts General Hospital, Boston 02114, USA
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10
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Yang OO, Kalams SA, Trocha A, Cao H, Luster A, Johnson RP, Walker BD. Suppression of human immunodeficiency virus type 1 replication by CD8+ cells: evidence for HLA class I-restricted triggering of cytolytic and noncytolytic mechanisms. J Virol 1997; 71:3120-8. [PMID: 9060675 PMCID: PMC191444 DOI: 10.1128/jvi.71.4.3120-3128.1997] [Citation(s) in RCA: 283] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Although CD8+ lymphocytes in human immunodeficiency virus type 1 (HIV-1)-infected individuals have been demonstrated to suppress viral replication, the mechanisms of inhibition have not been defined precisely. A large body of evidence indicates that these cells act via soluble inhibitory factors, but the potential role of HLA class I-restricted cytolysis has remained controversial. Here we demonstrate that HIV-1-specific cytotoxic T lymphocytes (CTL) mediate antiviral suppression by both cytolytic and noncytolytic mechanisms. The predominant mechanism requires direct contact of CTL with the infected cells, is HLA class I restricted, and can achieve complete elimination of detectable virus in infected cell cultures. Inhibition occurs even at high multiplicities of infection or at ratios of CTL to CD4 cells as low as 1:1,000. The other mechanism is mediated by soluble inhibitory factors which are triggered in an antigen-specific and HLA-restricted fashion but then act without HLA restriction. These include MIP-1alpha, MIP-1beta, and RANTES, as well as a distinct factor(s) capable of inhibiting HIV-1 strains insensitive to these chemokines. These data indicate that HIV-1-specific CTL are potent mediators of HIV-1 suppression at cell ratios existing in vivo and demonstrate an antigen-specific trigger for CD8+ cell-derived soluble inhibitory factors. These results suggest that CTL play an important role in the observed antiviral activity of CD8+ cells from infected individuals.
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Affiliation(s)
- O O Yang
- AIDS Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown 02129, USA
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11
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Koziel MJ, Dudley D, Afdhal N, Grakoui A, Rice CM, Choo QL, Houghton M, Walker BD. HLA class I-restricted cytotoxic T lymphocytes specific for hepatitis C virus. Identification of multiple epitopes and characterization of patterns of cytokine release. J Clin Invest 1995; 96:2311-21. [PMID: 7593618 PMCID: PMC185882 DOI: 10.1172/jci118287] [Citation(s) in RCA: 232] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cytotoxic T lymphocytes (CTL) are important to the control of viral replication and their presence may be important to disease outcome. An understanding of the spectrum of proteins recognized by hepatitis C virus (HCV)-specific CTL and the functional properties of these cells is an important step in understanding the disease process and the mechanisms of persistent infection, which occurs in the majority of HCV-infected individuals. In this report we identify HCV-specific CTL responses restricted by the HLA class I molecules A2, A3, A11, A23, B7, B8, and B53. The epitopes recognized by these intrahepatic CTL conform to published motifs for binding to HLA class I molecules, although in some cases we have identified CTL epitopes for which no published motif exists. The use of vectors expressing two different strains of HCV, HCV-1 and HCV-H, revealed both strain-specific and cross-reactive CTL. These HCV-specific CTL were shown to produce cytokines including IFN-gamma, TNF-alpha, GM-CSF, IL-8, and IL-10 in an antigen- and HLA class I-specific manner. These studies indicate that the CTL response to HCV is broadly directed and that as many as five different epitopes may be targeted in a single individual. The identification of minimal epitopes may facilitate peptide-specific immunization strategies. In addition, the release of proinflammatory cytokines by these cells may contribute to the pathogenesis of HCV-induced liver damage.
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Affiliation(s)
- M J Koziel
- Infectious Disease Unit, Massachusetts General Hospital, Boston 02114, USA
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