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Persaud AT, Khela J, Fernandes C, Chaphekar D, Burnie J, Tang VA, Colpitts CC, Guzzo C. Virion-incorporated CD14 enables HIV-1 to bind LPS and initiate TLR4 signaling in immune cells. J Virol 2024; 98:e0036324. [PMID: 38661384 PMCID: PMC11092368 DOI: 10.1128/jvi.00363-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
HIV-1 has a broad range of nuanced interactions with the immune system, and the incorporation of cellular proteins by nascent virions continues to redefine our understanding of the virus-host relationship. Proteins located at the sites of viral egress can be selectively incorporated into the HIV-1 envelope, imparting new functions and phenotypes onto virions, and impacting viral spread and disease. Using virion capture assays and western blot, we show that HIV-1 can incorporate the myeloid antigen CD14 into its viral envelope. Virion-incorporated CD14 remained biologically active and able to bind its natural ligand, bacterial lipopolysaccharide (LPS), as demonstrated by flow virometry and immunoprecipitation assays. Using a Toll-like receptor 4 (TLR4) reporter cell line, we also demonstrated that virions with bound LPS can trigger TLR4 signaling to activate transcription factors that regulate inflammatory gene expression. Complementary assays with THP-1 monocytes demonstrated enhanced secretion of inflammatory cytokines like tumor necrosis factor alpha (TNF-α) and the C-C chemokine ligand 5 (CCL5), when exposed to LPS-loaded virus. These data highlight a new type of interplay between HIV-1 and the myeloid cell compartment, a previously well-established cellular contributor to HIV-1 pathogenesis and inflammation. Persistent gut inflammation is a hallmark of chronic HIV-1 infection, and contributing to this effect is the translocation of microbes across the gut epithelium. Our data herein provide proof of principle that virion-incorporated CD14 could be a novel mechanism through which HIV-1 can drive chronic inflammation, facilitated by HIV-1 particles binding bacterial LPS and initiating inflammatory signaling in TLR4-expressing cells.IMPORTANCEHIV-1 establishes a lifelong infection accompanied by numerous immunological changes. Inflammation of the gut epithelia, exacerbated by the loss of mucosal T cells and cytokine dysregulation, persists during HIV-1 infection. Feeding back into this loop of inflammation is the translocation of intestinal microbes across the gut epithelia, resulting in the systemic dissemination of bacterial antigens, like lipopolysaccharide (LPS). Our group previously demonstrated that the LPS receptor, CD14, can be readily incorporated by HIV-1 particles, supporting previous clinical observations of viruses derived from patient plasma. We now show that CD14 can be incorporated by several primary HIV-1 isolates and that this virion-incorporated CD14 can remain functional, enabling HIV-1 to bind to LPS. This subsequently allowed CD14+ virions to transfer LPS to monocytic cells, eliciting pro-inflammatory signaling and cytokine secretion. We posit here that virion-incorporated CD14 is a potential contributor to the dysregulated immune responses present in the setting of HIV-1 infection.
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Affiliation(s)
- Arvin T. Persaud
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jasmin Khela
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Claire Fernandes
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Deepa Chaphekar
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vera A. Tang
- Flow Cytometry and Virometry Core Facility, Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Che C. Colpitts
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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2
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Celerino da Silva R, Segat L, Kuhn L, Chies JAB, Crovella S. Association of SNPs in HLA-C and ZNRD1 Genes With HIV-1 Mother-to-Child Transmission in Zambia Population. J Acquir Immune Defic Syndr 2021; 86:509-515. [PMID: 33252547 DOI: 10.1097/qai.0000000000002584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 10/15/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Human leukocyte antigen C (HLA-C) and Zinc ribbon domain containing 1 (ZNRD1) are considered HIV-1 restriction factors and are expressed in the placenta. Variations in HLA-C and ZNRD1 genes are known to influence HIV-1 infection, including viral replication and progression to AIDS. Little is known about the role of variants in these genes in HIV-1 mother-to-child transmission. METHODS We evaluated the distribution of HLA-C (rs10484554, rs9264942) and ZNRD1 (rs8321, rs3869068) variants in a Zambian population composed of 333 children born to HIV-1+ mothers (248 HIV-1 noninfected/85 HIV-1 infected) and 97 HIV-1+ mothers. RESULTS Genotypic distribution of HLA-C and ZNRD1 were in Hardy-Weinberg equilibrium, except for HLA-C rs10484554 in both groups. In mothers, no significant differences were observed in their allele and genotypic distributions for both genes. The T and TT variants (rs10484554-HLA-C) were significantly more frequent among HIV-1+ children, specifically those who acquired the infection in utero (IU) and intrapartum (IP). For ZNRD1, the T allele (rs3869068) was more frequent in HIV-1- children, showing significant differences in relation to those infected via IP and postpartum (PP). The CT and TT genotypes were significantly more frequent in HIV-1- children. CONCLUSIONS Variations in HLA-C (T and TT-rs10484554) and ZNRD1 (T and CT/TT-rs3869068) can increase and decrease the susceptibility to HIV-1 infection via mother-to-child transmission, respectively. Further studies are encouraged focusing on a greater number of variants and sample size, with functional validation and in other populations.
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Affiliation(s)
- Ronaldo Celerino da Silva
- Department of Genetics, Federal University of Pernambuco (UFPE), Recife, Brazil
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE) Recife, Brazil
| | - Ludovica Segat
- Department of Surgical and Health Medical Sciences, Azienda Sanitaria Universitaria Integrata Giuliano Isontina (ASUGI), UCO Hygiene and Public Health, University of Trieste, Trieste, Italy
| | - Louise Kuhn
- Gertrude H. Sergievsky Center and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY; and
| | - José Artur Bogo Chies
- Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Sergio Crovella
- Department of Genetics, Federal University of Pernambuco (UFPE), Recife, Brazil
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE) Recife, Brazil
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3
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Hopfensperger K, Richard J, Stürzel CM, Bibollet-Ruche F, Apps R, Leoz M, Plantier JC, Hahn BH, Finzi A, Kirchhoff F, Sauter D. Convergent Evolution of HLA-C Downmodulation in HIV-1 and HIV-2. mBio 2020; 11:e00782-20. [PMID: 32665270 PMCID: PMC7360927 DOI: 10.1128/mbio.00782-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/11/2020] [Indexed: 12/13/2022] Open
Abstract
HLA-C-mediated antigen presentation induces the killing of human immunodeficiency virus (HIV)-infected CD4+ T cells by cytotoxic T lymphocytes (CTLs). To evade killing, many HIV-1 group M strains decrease HLA-C surface levels using their accessory protein Vpu. However, some HIV-1 group M isolates lack this activity, possibly to prevent the activation of natural killer (NK) cells. Analyzing diverse primate lentiviruses, we found that Vpu-mediated HLA-C downregulation is not limited to pandemic group M but is also found in HIV-1 groups O and P as well as several simian immunodeficiency viruses (SIVs). We show that Vpu targets HLA-C primarily at the protein level, independently of its ability to suppress NF-κB-driven gene expression, and that in some viral lineages, HLA-C downregulation may come at the cost of efficient counteraction of the restriction factor tetherin. Remarkably, HIV-2, which does not carry a vpu gene, uses its accessory protein Vif to decrease HLA-C surface expression. This Vif activity requires intact binding sites for the Cullin5/Elongin ubiquitin ligase complex but is separable from its ability to counteract APOBEC3G. Similar to HIV-1 Vpu, the degree of HIV-2 Vif-mediated HLA-C downregulation varies considerably among different virus isolates. In agreement with opposing selection pressures in vivo, we show that the reduction of HLA-C surface levels by HIV-2 Vif is accompanied by increased NK cell-mediated killing. In summary, our results highlight the complex role of HLA-C in lentiviral infections and demonstrate that HIV-1 and HIV-2 have evolved at least two independent mechanisms to decrease HLA-C levels on infected cells.IMPORTANCE Genome-wide association studies suggest that HLA-C expression is a major determinant of viral load set points and CD4+ T cell counts in HIV-infected individuals. On the one hand, efficient HLA-C expression enables the killing of infected cells by cytotoxic T lymphocytes (CTLs). On the other hand, HLA-C sends inhibitory signals to natural killer (NK) cells and enhances the infectivity of newly produced HIV particles. HIV-1 group M viruses modulate HLA-C expression using the accessory protein Vpu, possibly to balance CTL- and NK cell-mediated immune responses. Here, we show that the second human immunodeficiency virus, HIV-2, can use its accessory protein Vif to evade HLA-C-mediated restriction. Furthermore, our mutational analyses provide insights into the underlying molecular mechanisms. In summary, our results reveal how the two human AIDS viruses modulate HLA-C, a key component of the antiviral immune response.
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Affiliation(s)
| | - Jonathan Richard
- Centre de Recherche du CHUM, Montreal, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frederic Bibollet-Ruche
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Richard Apps
- NIH Center for Human Immunology, National Institutes of Health, Bethesda, Maryland, USA
| | - Marie Leoz
- Normandie Université, UNIROUEN, UNICAEN, GRAM 2.0, Rouen, France
| | - Jean-Christophe Plantier
- Normandie Université, UNIROUEN, UNICAEN, GRAM 2.0, Rouen University Hospital, Department of Virology, Laboratory Associated with the National Reference Center on HIV, Rouen, France
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
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4
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Burnie J, Guzzo C. The Incorporation of Host Proteins into the External HIV-1 Envelope. Viruses 2019; 11:v11010085. [PMID: 30669528 PMCID: PMC6356245 DOI: 10.3390/v11010085] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/15/2019] [Accepted: 01/16/2019] [Indexed: 02/07/2023] Open
Abstract
The incorporation of biologically active host proteins into HIV-1 is a well-established phenomenon, particularly due to the budding mechanism of viral egress in which viruses acquire their external lipid membrane directly from the host cell. While this mechanism might seemingly imply that host protein incorporation is a passive uptake of all cellular antigens associated with the plasma membrane at the site of budding, this is not the case. Herein, we review the evidence indicating that host protein incorporation can be a selective and conserved process. We discuss how HIV-1 virions displaying host proteins on their surface can exhibit a myriad of altered phenotypes, with notable impacts on infectivity, homing, neutralization, and pathogenesis. This review describes the canonical and emerging methods to detect host protein incorporation, highlights the well-established host proteins that have been identified on HIV-1 virions, and reflects on the role of these incorporated proteins in viral pathogenesis and therapeutic targeting. Despite many advances in HIV treatment and prevention, there remains a global effort to develop increasingly effective anti-HIV therapies. Given the broad range of biologically active host proteins acquired on the surface of HIV-1, additional studies on the mechanisms and impacts of these incorporated host proteins may inform the development of novel treatments and vaccine designs.
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Affiliation(s)
- Jonathan Burnie
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.
| | - Christina Guzzo
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.
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5
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Stability and Expression Levels of HLA-C on the Cell Membrane Modulate HIV-1 Infectivity. J Virol 2017; 92:JVI.01711-17. [PMID: 29070683 PMCID: PMC5730790 DOI: 10.1128/jvi.01711-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 10/16/2017] [Indexed: 12/17/2022] Open
Abstract
HLA-C expression is associated with a differential ability to control HIV-1 infection. Higher HLA-C levels may lead to better control of HIV-1 infection through both a higher efficiency of antigen presentation to cytotoxic T lymphocytes and the triggering of activating killer immunoglobulin-like receptors on NK cells, whereas lower levels may provide poor HIV-1 control and rapid progression to AIDS. We characterized the relative amounts of HLA-C heterotrimers (heavy chain/β2 microglobulin [β2m]/peptide) and HLA-C free heavy chains on peripheral blood mononuclear cells (PBMCs) from healthy blood donors harboring both alleles with stable or unstable binding to β2m/peptide. We analyzed the stability of HLA-C heterotrimers of different allotypes and the infectivity of HIV-1 virions produced by PBMCs with various allotypes. We observed significant differences in HLA-C heterotrimer stability and in expression levels. We found that R5 HIV-1 virions produced by PBMCs harboring unstable HLA-C alleles were more infectious than those produced by PBMCs carrying the stable variants. We propose that HIV-1 infectivity might depend both on the amounts of HLA-C molecules and on their stability as trimeric complex. According to this model, individuals with low-expression HLA-C alleles and unstable binding to β2m/peptide might have worse control of HIV-1 infection and an intrinsically higher capacity to support viral replication. IMPORTANCE Following HIV-1 infection, some people advance rapidly to AIDS while others have slow disease progression. HLA-C, a molecule involved in immunity, is a key determinant of HIV-1 control. Here we reveal how HLA-C variants contribute to the modulation of viral infectivity. HLA-C is present on the cell surface in two different conformations. The immunologically active conformation is part of a complex that includes β2 microglobulin/peptide; the other conformation is not bound to β2 microglobulin/peptide and can associate with HIV-1, increasing its infectivity. Individuals with HLA-C variants with a predominance of immunologically active conformations would display stronger immunity to HIV-1, reduced viral infectivity and effective control of HIV-1 infection, while subjects with HLA-C variants that easily dissociate from β2 microglobulin/peptide would have a reduced immunological response to HIV-1 and produce more infectious virions. This study provides new information that could be useful in the design of novel vaccine strategies and therapeutic approaches to HIV-1.
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6
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Crux NB, Elahi S. Human Leukocyte Antigen (HLA) and Immune Regulation: How Do Classical and Non-Classical HLA Alleles Modulate Immune Response to Human Immunodeficiency Virus and Hepatitis C Virus Infections? Front Immunol 2017; 8:832. [PMID: 28769934 PMCID: PMC5513977 DOI: 10.3389/fimmu.2017.00832] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/30/2017] [Indexed: 12/13/2022] Open
Abstract
The genetic factors associated with susceptibility or resistance to viral infections are likely to involve a sophisticated array of immune response. These genetic elements may modulate other biological factors that account for significant influence on the gene expression and/or protein function in the host. Among them, the role of the major histocompatibility complex in viral pathogenesis in particular human immunodeficiency virus (HIV) and hepatitis C virus (HCV), is very well documented. We, recently, added a novel insight into the field by identifying the molecular mechanism associated with the protective role of human leukocyte antigen (HLA)-B27/B57 CD8+ T cells in the context of HIV-1 infection and why these alleles act as a double-edged sword protecting against viral infections but predisposing the host to autoimmune diseases. The focus of this review will be reexamining the role of classical and non-classical HLA alleles, including class Ia (HLA-A, -B, -C), class Ib (HLA-E, -F, -G, -H), and class II (HLA-DR, -DQ, -DM, and -DP) in immune regulation and viral pathogenesis (e.g., HIV and HCV). To our knowledge, this is the very first review of its kind to comprehensively analyze the role of these molecules in immune regulation associated with chronic viral infections.
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Affiliation(s)
- Nicole B Crux
- Faculty of Medicine and Dentistry, Department of Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Shokrollah Elahi
- Faculty of Medicine and Dentistry, Department of Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
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7
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Serena M, Parolini F, Biswas P, Sironi F, Blanco Miranda A, Zoratti E, Scupoli MT, Ziglio S, Valenzuela-Fernandez A, Gibellini D, Romanelli MG, Siccardi A, Malnati M, Beretta A, Zipeto D. HIV-1 Env associates with HLA-C free-chains at the cell membrane modulating viral infectivity. Sci Rep 2017; 7:40037. [PMID: 28051183 PMCID: PMC5209703 DOI: 10.1038/srep40037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/30/2016] [Indexed: 12/13/2022] Open
Abstract
HLA-C has been demonstrated to associate with HIV-1 envelope glycoprotein (Env). Virions lacking HLA-C have reduced infectivity and increased susceptibility to neutralizing antibodies. Like all others MHC-I molecules, HLA-C requires β2-microglobulin (β2m) for appropriate folding and expression on the cell membrane but this association is weaker, thus generating HLA-C free-chains on the cell surface. In this study, we deepen the understanding of HLA-C and Env association by showing that HIV-1 specifically increases the amount of HLA-C free chains, not bound to β2m, on the membrane of infected cells. The association between Env and HLA-C takes place at the cell membrane requiring β2m to occur. We report that the enhanced infectivity conferred to HIV-1 by HLA-C specifically involves HLA-C free chain molecules that have been correctly assembled with β2m. HIV-1 Env-pseudotyped viruses produced in the absence of β2m are less infectious than those produced in the presence of β2m. We hypothesize that the conformation and surface expression of HLA-C molecules could be a discriminant for the association with Env. Binding stability to β2m may confer to HLA-C the ability to preferentially act either as a conventional immune-competent molecule or as an accessory molecule involved in HIV-1 infectivity.
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Affiliation(s)
- Michela Serena
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
| | - Francesca Parolini
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
| | - Priscilla Biswas
- IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Francesca Sironi
- IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Almudena Blanco Miranda
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
| | - Elisa Zoratti
- University Laboratory of Medical Research, Piazzale L. A. Scuro 10, 37134 Verona, Italy
| | - Maria Teresa Scupoli
- University Laboratory of Medical Research, Piazzale L. A. Scuro 10, 37134 Verona, Italy
| | - Serena Ziglio
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy.,Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Campus de Ofra s/n, 38071, Tenerife, Spain
| | - Agustin Valenzuela-Fernandez
- Laboratorio de Inmunología Celular y Viral, Unidad de Virología IUETSPC, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), Campus de Ofra s/n, 38071, Tenerife, Spain
| | - Davide Gibellini
- Department of Diagnostics and Public Health, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
| | - Maria Grazia Romanelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
| | - Antonio Siccardi
- IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Mauro Malnati
- IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Alberto Beretta
- IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy
| | - Donato Zipeto
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada le Grazie 8, 37134, Verona, Italy
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8
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René C, Lozano C, Eliaou JF. Expression of classical HLA class I molecules: regulation and clinical impacts: Julia Bodmer Award Review 2015. HLA 2016; 87:338-49. [PMID: 27060357 DOI: 10.1111/tan.12787] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/04/2016] [Indexed: 12/19/2022]
Abstract
Human leukocyte antigen (HLA) class I genes are ubiquitously expressed, but in a tissue specific-manner. Their expression is primarily regulated at the transcriptional level and can be modulated both positively and negatively by different stimuli. Advances in sequencing technologies led to the identification of new regulatory variants located in the untranslated regions (UTRs), which could influence the expression. After a brief description of the mechanisms underlying the transcriptional regulation of HLA class I genes expression, we will review how the expression levels of HLA class I genes could affect biological and pathological processes. Then, we will discuss on the differential expression of HLA class I genes according to the locus, allele and UTR polymorphisms and its clinical impact. This interesting field of study led to a new dimension of HLA typing, going beyond a qualitative aspect.
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Affiliation(s)
- C René
- Department of Immunology, CHRU de Montpellier, University Hospital Saint-Eloi, Montpellier, France.,Faculté de Médecine, University of Montpellier, Montpellier, France.,INSERM U1183, Institute for Regenerative Medicine and Biotherapy (IRMB), CHU Montpellier, Montpellier, France
| | - C Lozano
- Department of Immunology, CHRU de Montpellier, University Hospital Saint-Eloi, Montpellier, France
| | - J-F Eliaou
- Department of Immunology, CHRU de Montpellier, University Hospital Saint-Eloi, Montpellier, France.,Faculté de Médecine, University of Montpellier, Montpellier, France.,INSERM U1194, IRCM, University of Montpellier, Montpellier, France
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9
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Iordanskiy S, Santos S, Bukrinsky M. Nature, nurture and HIV: The effect of producer cell on viral physiology. Virology 2013; 443:208-13. [PMID: 23747196 DOI: 10.1016/j.virol.2013.05.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 04/23/2013] [Accepted: 05/15/2013] [Indexed: 01/13/2023]
Abstract
Macrophages and CD4-positive T lymphocytes are the major targets and producers of HIV-1. While the molecular details underlying HIV replication in macrophages and T cells become better understood, it remains unclear whether viruses produced by these target cells differ in their biological properties. Recent reports suggest that HIV virions incorporate a large number of producer cell proteins and lipids which have an effect on subsequent viral replication in newly infected cells. The identity and abundance of these incorporated factors varies between different types of producer cells, suggesting that they may influence the replication capacity and pathogenic activity of the virions produced by T cells and macrophages.
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Affiliation(s)
- Sergey Iordanskiy
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, George Washington University, 2300 I Street NW, Ross Hall, Washington, DC 20037, USA.
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10
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Zipeto D, Beretta A. HLA-C and HIV-1: friends or foes? Retrovirology 2012; 9:39. [PMID: 22571741 PMCID: PMC3386009 DOI: 10.1186/1742-4690-9-39] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 05/09/2012] [Indexed: 12/20/2022] Open
Abstract
The major histocompatibility complex class I protein HLA-C plays a crucial role as a molecule capable of sending inhibitory signals to both natural killer (NK) cells and cytotoxic T lymphocytes (CTL) via binding to killer cell Ig-like receptors (KIR). Recently HLA-C has been recognized as a key molecule in the immune control of HIV-1. Expression of HLA-C is modulated by a microRNA binding site. HLA-C alleles that bear substitutions in the microRNA binding site are more expressed at the cell surface and associated with the control of HIV-1 viral load, suggesting a role of HLA-C in the presentation of antigenic peptides to CTLs. This review highlights the role of HLA-C in association with HIV-1 viral load, but also addresses the contradiction of the association between high cell surface expression of an inhibitory molecule and strong cell-mediated immunity. To explore additional mechanisms of control of HIV-1 replication by HLA-C, we address specific features of the molecule, like its tendency to be expressed as open conformer upon cell activation, which endows it with a unique capacity to associate with other cell surface molecules as well as with HIV-1 proteins.
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Affiliation(s)
- Donato Zipeto
- Department of Life and Reproduction Sciences, Section of Biology and Genetics, University of Verona, Verona, Italy
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11
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Rapid dissociation of HIV-1 from cultured cells severely limits infectivity assays, causes the inactivation ascribed to entry inhibitors, and masks the inherently high level of infectivity of virions. J Virol 2009; 84:3106-10. [PMID: 20042508 DOI: 10.1128/jvi.01958-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
By using immunofluorescence microscopy to observe and analyze freshly made HIV-1 virions adsorbed onto cells, we found that they are inherently highly infectious, rather than predominantly defective as previously suggested. Surprisingly, polycations enhance titers 20- to 30-fold by stabilizing adsorption and preventing a previously undescribed process of rapid dissociation, strongly implying that infectivity assays for many viruses are limited not only by inefficient virus diffusion onto cells but also by a postattachment race between entry and dissociation. This kinetic competition underlies inhibitory effects of CCR5 antagonists and explains why adaptive HIV-1 mutations overcome many cell entry limitations by accelerating entry.
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12
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Baroni M, Matucci A, Scarlatti G, Soprana E, Rossolillo P, Lopalco L, Zipeto D, Siccardi AG, De Santis C. HLA-C is necessary for optimal human immunodeficiency virus type 1 infection of human peripheral blood CD4 lymphocytes. J Gen Virol 2009; 91:235-41. [PMID: 19776241 DOI: 10.1099/vir.0.015230-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hypothesis that open conformers of HLA-C on target cells might directly exert an effect on their infectability by human immunodeficiency virus (HIV) has been suggested previously. This was tested by exploiting the peculiar specificity of monoclonal antibody (mAb) L31 for HLA-C open conformers to show that normal levels of Env-driven fusion were restored in HLA-C transfectants of a major histocompatibility complex-deleted (fusion-incompetent) cell line. The physiological relevance of this finding is now confirmed in this report, where small interfering RNA (siRNA) technology was used to silence HLA-C expression in peripheral blood lymphocytes (PBLs) from 11 healthy donors. Infectability by HIV (strains IIIB and Bal and primary isolates) was significantly reduced (P=0.016) in silenced cells compared with cells that maintained HLA-C expression in 10 of the 11 PBL donors. Normal infectability was resumed, together with HLA-C expression, when the effect of siRNA interference waned after several days in culture. Additional confirmation of the HLA-C effect was obtained in several assays employing HLA-C-positive and -negative cell lines, a number of HIV strains and also pseudoviruses. In particular, viruses pseudotyped with env genes from HIV strains AC10 and QH0692.42 were assayed on siRNA-silenced lymphocytes from three healthy donors: the differences in infection with pseudoviruses were even higher than those observed in infections with normal viruses.
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Affiliation(s)
- Miriam Baroni
- Department of Biology and Genetics, University of Milan, Via Viotti 3/5, 20132 Milan, Italy
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13
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Novak MT, Bryers JD, Reichert WM. Biomimetic strategies based on viruses and bacteria for the development of immune evasive biomaterials. Biomaterials 2009; 30:1989-2005. [PMID: 19185345 PMCID: PMC2673477 DOI: 10.1016/j.biomaterials.2008.11.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 11/26/2008] [Indexed: 12/30/2022]
Abstract
The field of biomaterials has begun to focus upon materials strategies for modulating the immune response. While certain approaches appear promising, they are currently limited to isolated facets of inflammation process. It is well documented that both bacteria and viruses have highly developed methods for evading the immune system, providing inspiration for a more biomimetic approach to materials design. This review presents the immune evasive tactics employed by viruses and bacteria, and offers suggestions for future directions that apply these principles to design of immune evasive biomaterials.
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Affiliation(s)
- Matthew T. Novak
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, NC, 27708
| | - James D. Bryers
- Department of Bioengineering, University of Washington, PO Box 355061, 1705 NE Pacific Street, Seattle, WA, 98195
| | - William M. Reichert
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, NC, 27708
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14
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Abstract
Therapeutic options aimed at tackling the HIV pandemic face many obstacles. The lack of readily accessible and affordable therapies means that most of those affected go untreated. The array of escape mechanisms used by HIV has undermined the efficiency of many antiviral products and continually represents a barrier to the development of an effective vaccine. Recent developments have seen a shift away from a cytopathic viral model of HIV pathogenesis towards the crucial role of immunopathogenic features--notably generalised immune activation--in the development of AIDS. As conventional vaccine strategies have sought to promote viral neutralisation and suppressive cellular responses, novel strategies that aim to address HIV immunopathogenesis should be sought. We review current opinion on HIV-induced pathogenic immune activation and strategies aimed at eliminating HIV, including a potential role for non-neutralising antibodies as part of a therapeutic vaccine option.
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15
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Matucci A, Rossolillo P, Baroni M, Siccardi AG, Beretta A, Zipeto D. HLA-C increases HIV-1 infectivity and is associated with gp120. Retrovirology 2008; 5:68. [PMID: 18673537 PMCID: PMC2531131 DOI: 10.1186/1742-4690-5-68] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 08/01/2008] [Indexed: 11/13/2022] Open
Abstract
Background A recently identified genetic polymorphism located in the 5' region of the HLA-C gene is associated with individual variations in HIV-1 viral load and with differences in HLA-C expression levels. HLA-C has the potential to restrict HIV-1 by presenting epitopes to cytotoxic T cells but it is also a potent inhibitor of NK cells. In addition, HLA-C molecules incorporated within the HIV-1 envelope have been shown to bind to the envelope glycoprotein gp120 and enhance viral infectivity. We investigated this last property in cell fusion assays where the expression of HLA-C was silenced by small interfering RNA sequences. Syncytia formation was analyzed by co-cultivating cell lines expressing HIV-1 gp120/gp41 from different laboratory and primary isolates with target cells expressing different HIV-1 co-receptors. Virus infectivity was analyzed using pseudoviruses. Molecular complexes generated during cell fusion (fusion complexes) were purified and analyzed for their HLA-C content. Results HLA-C positive cells co-expressing HIV-1 gp120/gp41 fused more rapidly and produced larger syncytia than HLA-C negative cells. Transient transfection of gp120/gp41 from different primary isolates in HLA-C positive cells resulted in a significant cell fusion increase. Fusion efficiency was reduced in HLA-C silenced cells compared to non-silenced cells when co-cultivated with different target cell lines expressing HIV-1 co-receptors. Similarly, pseudoviruses produced from HLA-C silenced cells were significantly less infectious. HLA-C was co-purified with gp120 from cells before and after fusion and was associated with the fusion complex. Conclusion Virionic HLA-C molecules associate to Env and increase the infectivity of both R5 and X4 viruses. Genetic polymorphisms associated to variations in HLA-C expression levels may therefore influence the individual viral set point not only by means of a regulation of the virus-specific immune response but also via a direct effect on the virus replicative capacity. These findings have implications for the understanding of the HIV-1 entry mechanism and of the role of Env conformational modifications induced by virion-associated host proteins.
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Affiliation(s)
- Andrea Matucci
- Laboratory of Molecular Biology, Department of Mother and Child, Biology and Genetics, Section of Biology and Genetics, University of Verona, Strada le Grazie 8, 37134, Verona, Italy.
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16
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17
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Modulation of human immunodeficiency virus type 1 infectivity through incorporation of tetraspanin proteins. J Virol 2007; 82:1021-33. [PMID: 17989173 DOI: 10.1128/jvi.01044-07] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Accumulating evidence indicates that human immunodeficiency virus type 1 (HIV-1) acquires various cellular membrane proteins in the lipid bilayer of the viral envelope membrane. Although some virion-incorporated cellular membrane proteins are known to potently affect HIV-1 infectivity, the virological functions of most virion-incorporated membrane proteins remain unclear. Among these host proteins, we found that CD63 was eliminated from the plasma membranes of HIV-1-producing T cells after activation, followed by a decrease in the amount of virion-incorporated CD63, and in contrast, an increase in the infectivity of the released virions. On the other hand, we found that CD63 at the cell surface was preferentially embedded on the membrane of released virions in an HIV-1 envelope protein (Env)-independent manner and that virion-incorporated CD63 had the potential to inhibit HIV-1 Env-mediated infection in a strain-specific manner at the postattachment entry step(s). In addition, these behaviors were commonly observed in other tetraspanin proteins, such as CD9, CD81, CD82, and CD231. However, L6 protein, whose topology is similar to that of tetraspanins but which does not belong to the tetraspanin superfamily, did not have the potential to prevent HIV-1 infection, despite its successful incorporation into the released particles. Taken together, these results suggest that tetraspanin proteins have the unique potential to modulate HIV-1 infectivity through incorporation into released HIV-1 particles, and our findings may provide a clue to undiscovered aspects of HIV-1 entry.
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18
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HLA-C increases fusion efficiency between the HIV-1 envelope and the cell membrane and is part of the fusion complex. Retrovirology 2006. [PMCID: PMC1716894 DOI: 10.1186/1742-4690-3-s1-p70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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19
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Cantin R, Méthot S, Tremblay MJ. Plunder and stowaways: incorporation of cellular proteins by enveloped viruses. J Virol 2005; 79:6577-87. [PMID: 15890896 PMCID: PMC1112128 DOI: 10.1128/jvi.79.11.6577-6587.2005] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Réjean Cantin
- Laboratory of Human Immuno-Retrovirology, Research Center in Infectious Diseases, CHUL Research Center, Quebec (QC), Canada
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20
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Bounou S, Giguere JF, Cantin R, Gilbert C, Imbeault M, Martin G, Tremblay MJ. The importance of virus-associated host ICAM-1 in human immunodeficiency virus type 1 dissemination depends on the cellular context. FASEB J 2004; 18:1294-6. [PMID: 15208262 DOI: 10.1096/fj.04-1755fje] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The primary objective of this study was to define whether the nature of virion-bound host cell membrane proteins influenced the process of human immunodeficiency virus 1 (HIV-1) capture and transmission. We pulsed cells of monocytoid lineage (established and primary) and CD4-negative epithelial cells transiently expressing DC-SIGN or LFA-1 with isogenic HIV-1 particles either devoid or bearing host-derived ICAM-1 or ICAM-3 before incubation with an indicator cell line. To our surprise, the ICAM-1/LFA-1 association was a more efficient transmission factor than the combined gp120/DC-SIGN and ICAM-3/DC-SIGN interactions. The involvement of the association between virus-bound ICAM-1 and its natural ligand LFA-1 in virus binding and carriage was confirmed when using more physiological cellular targets, i.e., human lymphoid tissues cultured ex vivo. However, the contribution of virus-anchored host ICAM-1 to the process of retention and transmission of HIV-1 could not be confirmed when using primary human cells of macrophage/dendritic lineage as transmitter cells and autologous CD4+ T lymphocytes as targets. Altogether these data underscore the complexity of factors participating in virus-cell contact and efficient dissemination of HIV-1 to target cells.
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Affiliation(s)
- Salim Bounou
- Research Center in Infectious Diseases, CHUL Research Center, and Faculty of Medicine, Laval University, Quebec, Canada
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21
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Plumelle Y. HIV, 'an evolving species'. Roles of cellular activation and co-infections. Med Hypotheses 2003; 61:136-57. [PMID: 12781657 DOI: 10.1016/s0306-9877(03)00147-6] [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: 10/27/2022]
Abstract
Each small variation of the genome of a species can be preserved if it is useful for the survival of the species in a given environment. Within this framework, the finality of the biological cycle of HIV consists in a search for harmony (biological coherence) with man, which is to say a stable condition. Cellular activation appears to be the strategy developed by HIV in order to achieve this coherence. The price of this strategy is the AIDS. The first contact between HIV and immune system appears to determine the subsequent clinical outcome and the future of HIV. Lymphocytic activation varies during the course of the vital cycle of HIV. For each individual, this lymphocytic activation depends on both the HLA repertoire acquired during thymic ontogenesis and the antigenic experience before and after HIV infection. Thus intercurrent infections alter the immune condition of the organism and influence the outcome of HIV. We described a synthetic analysis of the effects of HIV on the surface protein expression and the cellular activation pathways which should provide insights in the evolutionary relationship between HIV and man and should permit to do a more physiological therapeutic approach.
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Affiliation(s)
- Yves Plumelle
- Department of Hematobiology, University Hospital, France.
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22
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Wilfingseder D, Spruth M, Ammann CG, Döpper S, Speth C, Dierich MP, Stoiber H. Complement-mediated enhancement of HIV-1 neutralisation by anti-HLA antibodies derived from polytransfused patients. Int Arch Allergy Immunol 2003; 131:62-72. [PMID: 12759492 DOI: 10.1159/000070437] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2002] [Accepted: 12/19/2002] [Indexed: 11/19/2022] Open
Abstract
We have recently shown that 'alloimmune sera' derived from polytransfused patients (PTP sera) are able to recognise and neutralise HIV in vitro. In this study we try to identify the protein(s), which are recognised by the PTP sera and elucidate mechanisms responsible for the neutralising capacity of these sera. The PTP sera allowed immunoprecipitation (IP) of HLA class II molecules on HIV-infected cells. To detect a potential cross-reactivity of alloreactive antibodies (Ab) with the HIV envelope protein gp160 or its subunits gp120/gp41 and HLA proteins, ELISA and FACS analyses were performed. The lack of reactivity of the PTP sera against rsgp160 in ELISA or FACS analysis indicated that recognition of cells was independent of HIV infection. To clarify whether interaction of the PTP sera with target cells has any effect on the infection process, virus neutralisation assays were performed. Inhibition of HIV infection was observed only when virus was pre-incubated with the PTP sera. Complement enhanced neutralisation of HIV-1 significantly. This enhancement was not due to complement-mediated lysis, because pre-incubation of the target cells with PTP sera did not inhibit HIV replication. Therefore, the neutralising effect of the Ab was due to blocking of the viral attachment/fusion process and not to negative signalling after infection. Since steric hindrance is possible only when HLA and gp120/gp41 are in close vicinity, isolation of rafts and IP assays were performed. These experiments revealed that gp120 and MHC class II molecules are indeed co-localised. The close physical association of gp120/gp41 and HLA strongly supports a mechanism for neutralisation of HIV by anti-HLA-Ab based on steric hindrance.
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23
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Giguère JF, Paquette JS, Bounou S, Cantin R, Tremblay MJ. New insights into the functionality of a virion-anchored host cell membrane protein: CD28 versus HIV type 1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:2762-71. [PMID: 12193751 DOI: 10.4049/jimmunol.169.5.2762] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It is now well established that the HIV type 1 (HIV-1) incorporates a vast array of host-encoded molecules in its envelope during the budding process. Interestingly, it was demonstrated that the attachment process is accentuated by supplementary interactions between virion-anchored host molecules and their cognate ligands. Such an enhancement of the viral attachment process was found to result in an increase of infectivity for both T and macrophage-tropic strains of HIV-1. Given that previous work indicates that HIV-1 is budding at the site of cell-to-cell contact, a location rich in the costimulatory CD28 glycoprotein, we investigated whether CD28 could be efficiently acquired by HIV-1. We have been able to generate progeny viruses bearing or not bearing on their surfaces host-derived CD28 using our previously described transient transfection and expression system. The physical presence of CD28 was found to markedly increase virus infectivity in a CD28/B7-dependent manner following infection of two human lymphoid cell lines expressing high levels of surface B7-1/B7-2, two natural ligands of CD28. The physiological significance of CD28 incorporation was provided by the observation that an anti-CD28 Ab decreased replication in primary human mononuclear cells of clinical isolates of HIV-1 propagated in such cells. A virus precipitation assay revealed that M-, T-, and dual-tropic clinical strains of HIV-1 produced in primary human mononuclear cells do indeed incorporate CD28. These results show for the first time that HIV-1 can incorporate CD28 and the acquisition of this specific host surface glycoprotein modulates the virus life cycle.
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Affiliation(s)
- Jean-François Giguère
- Centre de Recherche en Infectiologie, Département de Biologie Médicale, Université Laval, Sainte-Foy, Québec, Canada
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24
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Olinger GG, Saifuddin M, Hart ML, Spear GT. Cellular factors influence the binding of HIV type 1 to cells. AIDS Res Hum Retroviruses 2002; 18:259-67. [PMID: 11860673 DOI: 10.1089/088922202753472838] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The goal of this study was to determine the importance of cellular factors for binding of HIV to cells. HIV primary isolates (PIs) produced in peripheral blood mononuclear cells (PBMCs) bound at relatively high levels to PBMCs but at low levels to cell lines, whereas T cell line-adapted (TCLA) virus produced in the H9 T cell line bound at high levels to both cell lines and PBMCs. Expression of CD4 in CD4-negative cells or blocking CD4 with antibody on CD4-positive cells did not affect virus binding. Blocking of gp120/gp41 with antibodies or a lack of expression of gp120/gp41 in virus particles also did not affect virus binding. However, the cell type from which virus was produced did affect virus binding. Thus, the binding pattern of TCLA virus shifted to that of a PI virus when produced in PBMCs. A PI binding pattern also occurred when a cloned TCLA virus (NL4-3) was produced in PBMCs, indicating that the virus-producing cell type has more of an effect on virus binding than the virus strain. These experiments show that both the virus-producing cell and the target cell have a major influence on HIV binding and suggest that host cell factors incorporated into virions are important for virus binding.
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Affiliation(s)
- Gene G Olinger
- Department of Immunology/Microbiology, Rush University, Chicago, Illinois 60612, USA
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25
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Dalgleish AG, O'Byrne KJ. Chronic immune activation and inflammation in the pathogenesis of AIDS and cancer. Adv Cancer Res 2002; 84:231-76. [PMID: 11883529 DOI: 10.1016/s0065-230x(02)84008-8] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Infection with the human immunodeficiency virus (HIV) invariably leads to the development of acquired immunodeficiency syndrome (AIDS) in most infected humans, yet does so rarely, if at all, in HIV-infected chimpanzees. The differences between the two species are not due to differences in cellular receptors or an inability of the chimpanzee to be infected, but rather to the lack of pan-immune activation in the infected primate. This results in reduced apoptotic death in CD4+ T-helper lymphocytes and a lower viral load. In humans the degree of chronic immune activation correlates with virus load and clinical outcome with high immune activation leading to high viral loads and the more rapid progression to AIDS and death. The type of immune perturbation seen in HIV-associated AIDS is similar to that of chronic graft-versus-host disease (GVHD) where reduced cell-mediated immune (CMI) responses occur early in the course of the disease and where humoral responses (HI) predominate. A reduced CMI response occurs in a number of chronic infectious diseases, including tuberculosis and leishmaniasis. More recently, it has become increasingly apparent that the CMI response is suppressed in virtually all malignant diseases, including melanoma and colorectal and prostate cancer. This raises the possibility that, as the malignant process develops, the cancer cells evolve to subvert the CMI response. Moreover, the reduced CMI response seen in colorectal cancer (CRC) patients is completely reversed following curative surgery strongly supporting the hypothesis that CRC can suppress the systemic immune response. Wound healing, ovulation, embryo implantation, and fetal growth are all associated with suppressed CMI and neovascularization (the formation of new blood vessels) or angiogenesis (the formation of new blood vessels from an existing vasculature). If unresolved, wound healing results in chronic inflammation, which can give rise to the phenomenon of "scar cancers." Indeed all the chronic inflammatory conditions known to be associated with the subsequent development of malignant disease, including chronic obstructive airway disease (COPD), ulcerative colitis (UC), and asbestosis, give rise to similar proangiogenic, suppressed CMI, and HI-predominant environments. In keeping with this CMI-associated cytokines such as interleukin (IL)-2 and interferon (IFN)-gamma tend to be antiangiogenic, whereas HI cytokines such as IL-6 tend to be proangiogenic. Furthermore, chronic immune activation leads to the synthesis and release of factors such as macrophage inflammatory protein (MIP)-1 that inhibit apoptosis through suppression of p53 activity. The "Golden Triangle" of suppressed CMI, angiogenesis, and reduced apoptosis would provide the ideal environment for the serial mutations to occur that are required for the development of malignant disease. If the observed association is relevant to carcinogenesis, then treatments aimed at reducing the components of these inflammatory conditions may be useful both in the setting of chemoprevention and the therapeutic management of established disease.
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Affiliation(s)
- Angus G Dalgleish
- Department of Oncology, St George's Hospital Medical School, London, United Kingdom
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26
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Lagaye S, Derrien M, Menu E, Coïto C, Tresoldi E, Mauclère P, Scarlatti G, Chaouat G, Barré-Sinoussi F, Bomsel M. Cell-to-cell contact results in a selective translocation of maternal human immunodeficiency virus type 1 quasispecies across a trophoblastic barrier by both transcytosis and infection. J Virol 2001; 75:4780-91. [PMID: 11312350 PMCID: PMC114233 DOI: 10.1128/jvi.75.10.4780-4791.2001] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mother-to-child transmission can occur in utero, mainly intrapartum and postpartum in case of breastfeeding. In utero transmission is highly restricted and results in selection of viral variant from the mother to the child. We have developed an in vitro system that mimics the interaction between viruses, infected cells present in maternal blood, and the trophoblast, the first barrier protecting the fetus. Trophoblastic BeWo cells were grown as a tight polarized monolayer in a two-chamber system. Cell-free virions applied to the apical pole neither crossed the barrier nor productively infected BeWo cells. In contrast, apical contact with human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells (PBMCs) resulted in transcytosis of infectious virus across the trophoblastic monolayer and in productive infection correlating with the fusion of HIV-infected PBMCs with trophoblasts. We showed that viral variants are selected during these two steps and that in one case of in utero transmission, the predominant maternal viral variant characterized after transcytosis was phylogenetically indistinguishable from the predominant child's virus. Hence, the first steps of transmission of HIV-1 in utero appear to involve the interaction between HIV type 1-infected cells and the trophoblastic layer, resulting in the passage of infectious HIV by transcytosis and by fusion/infection, both leading to a selection of virus quasispecies.
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Affiliation(s)
- S Lagaye
- Institut Pasteur, Unité de Biologie des Rétrovirus, 75 724 Paris Cedex 15, France.
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27
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Robey FA, Robert-Guroff M. A defined conformational epitope from the C4 domain of HIV type 1 glycoprotein 120: anti-cyclic C4 antibodies from HIV-positive donors magnify glycoprotein 120 suppression of interleukin 2 produced by T cells. AIDS Res Hum Retroviruses 2001; 17:533-41. [PMID: 11350667 DOI: 10.1089/08892220151126625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The C4 domain of HIV gp120 plays a functionally vital role in the binding of gp120 to CD4 receptors on target cells. Antibodies to an 11-amino acid cyclic C4 peptide were obtained from immunized rabbits and from the serum of an HIV-positive human and were found to recognize gp120 bound to CD4. Anti-cyclic C4 antibodies magnified gp120-induced suppression of IL-2 produced by T cells in vitro. Rabbit antibodies to the 11-amino acid linear C4 peptide did not recognize gp120 in the free state or when bound to CD4. These results indicate that a conformationally defined, highly conserved epitope in the gp120 C4 region remains exposed on CD4 binding. Naturally occurring antibodies to this epitope can augment gp120-induced immunosuppression and may contribute to disease progression.
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Affiliation(s)
- F A Robey
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, USA
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28
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Bounou S, Dumais N, Tremblay MJ. Attachment of human immunodeficiency virus-1 (HIV-1) particles bearing host-encoded B7-2 proteins leads to nuclear factor-kappa B- and nuclear factor of activated T cells-dependent activation of HIV-1 long terminal repeat transcription. J Biol Chem 2001; 276:6359-69. [PMID: 11096063 DOI: 10.1074/jbc.m002198200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies have shown that human immunodeficiency virus type-1 (HIV-1) can incorporate several surface proteins of host origin. Recent findings indicate that host-encoded cell surface constituents retain their functionality when found embedded into the viral envelope. The primary objective of the current study was to define whether interaction between some specific virion-bound host proteins with their natural cognate ligands present on target cells could mediate intracellular signaling cascade(s). For this purpose, we have generated a whole series of isogenic virus stocks (NL4-3 backbone) bearing or not bearing on their surface foreign CD28, CD54 (ICAM-1), CD80 (B7-1) or CD86 (B7-2) proteins. Our results indicate that incubation of human T lymphoid cells with virions bearing host-derived B7-2 proteins and anti-CD3 antibody can potently activate HIV-1 long terminal repeat-driven gene expression. This up-regulating effect necessitates the involvement of nuclear factor-kappa B (NF-kappa B) and nuclear factor of activated T cells (NFAT) as revealed by the use of vectors coding for dominant negative versions of both transcription factors (i.e. I kappa B alpha S32A/36A and dnNFAT) and band shift assays. The increase of NF-kappa B activity was abolished when infection with B7-2-bearing HIV-1 particles was performed in the presence of the fusion protein CTLA-4 Ig suggesting that the interaction between virally embedded B7-2 and CD28 on the target cell is responsible for the observed NF-kappa B induction. The findings presented here provide the first demonstration that host-encoded proteins acquired by HIV-1 can mediate signal transduction events.
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Affiliation(s)
- S Bounou
- Centre de Recherche en Infectiologie, Centre Hospitalier Universitaire de Québec, Pavillon CHUL, Ste-Foy, Québec G1V 4G2, Canada
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29
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Means RE, Desrosiers RC. Resistance of native, oligomeric envelope on simian immunodeficiency virus to digestion by glycosidases. J Virol 2000; 74:11181-90. [PMID: 11070015 PMCID: PMC113208 DOI: 10.1128/jvi.74.23.11181-11190.2000] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stocks of simian immunodeficiency virus (SIV) from the supernatants of infected cell cultures were used to examine the sensitivity of envelope glycoprotein gp120 to enzymatic deglycosylation and the effects of enzyme treatment on infectivity. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and Western blot analysis revealed little or no change in the mobility of virion-associated gp120 after digestion with high concentrations of N-glycosidase F, endoglycosidase F, endoglycosidase H, and endo-beta-galactosidase. Soluble gp120, which was not pelletable after the enzymatic reaction, was sensitive to digestion by the same enzymes within the same reaction mix and was only slightly less sensitive than gp120 that had been completely denatured by boiling in the presence of SDS and beta-mercaptoethanol. Digestion by three of the seven glycosidases tested significantly changed the infectivity titer compared to that of mock-treated virus. Digestion by endo-beta-galactosidase increased infectivity titers by about 2.5-fold, and neuraminidase from Newcastle disease virus typically increased infectivity titers by 8-fold. Most or all of the increase in infectivity titer resulting from treatment with neuraminidase could be accounted for by effects on the virus, not the cells; SIV produced in the presence of the sialic acid analog 2,3-dehydro-2-deoxy-N-acetylneuraminic acid also exhibited increased infectivity, and the effects could not be duplicated by neuraminidase treatment of cells. Digestion with mannosidase reduced infectivity by fivefold. Our results indicate that carbohydrates on native oligomeric gp120 as it exists on the surface of virus particles are largely occluded and are refractory to digestion by glycosidases. Furthermore, the sialic acid residues at the ends of carbohydrate side chains significantly reduce the inherent infectivity of SIV.
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Affiliation(s)
- R E Means
- Department of Microbiology and Molecular Genetics, New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102, USA
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Saifuddin M, Spear GT, Chang C, Roebuck KA. Expression of MHC class II in T cells is associated with increased HIV-1 expression. Clin Exp Immunol 2000; 121:324-31. [PMID: 10931149 PMCID: PMC1905707 DOI: 10.1046/j.1365-2249.2000.01290.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 replicates in activated T cells at significantly higher levels than in resting cells. Thus, certain molecules up-regulated during T cell activation appear to be important for HIV-1 replication. In this study, we present evidence suggesting that expression of MHC class II (class II) molecules on CD4+ T cells facilitate HIV-1 replication. T cells that expressed class II supported greater virus replication than T cells lacking class II. The class II+ cells, when either infected with HIV-1 or transfected with an env-minus HIV-1 provirus plasmid, produced 10-20-fold greater virus expression than class II- cells. Anti-class II antibody markedly inhibited virus expression in class II+ cells (but not class II- cells) and also decreased the nuclear binding activity of AP-1, an inducible transcription factor important in T cell activation and HIV-1 expression. Most importantly, the induction of class II expression by transfection of the MHC class II transactivator (CIITA) stimulated HIV-1 replication in Jurkat T cells. Taken together, these data suggest that expression of MHC class II molecules and/or CIITA in T cells enhances HIV-1 transcription.
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Affiliation(s)
- M Saifuddin
- Department of Immunology/Microbiology, Rush University, Chicago, IL, USA.
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