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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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Wahren B, Biswas P, Borggren M, Coleman A, Da Costa K, De Haes W, Dieltjens T, Dispinseri S, Grupping K, Hallengärd D, Hornig J, Klein K, Mainetti L, Palma P, Reudelsterz M, Seifried J, Selhorst P, Sköld A, van Gils MJ, Weber C, Shattock R, Scarlatti G. Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference. J Transl Med 2010; 8:72. [PMID: 20659333 PMCID: PMC2922088 DOI: 10.1186/1479-5876-8-72] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 07/26/2010] [Indexed: 11/23/2022] Open
Abstract
EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.
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Affiliation(s)
| | | | | | | | | | | | | | - Stefania Dispinseri
- San Raffaele Scientific Institute, Milan, Italy
- Università degli Studi di Milano, Milan, Italy
| | | | | | | | | | - Lara Mainetti
- San Raffaele Scientific Institute, Milan, Italy
- Università Vita-Salute San Raffaele, Milan, Italy
| | - Paolo Palma
- University of Rome "Tor Vergata", Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | | | | | | | | | | | - Caroline Weber
- Institut de Biologie et Chimie des Protéines, Lyon, France
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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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Antibodies to CD4-induced sites in HIV gp120 correlate with the control of SHIV challenge in macaques vaccinated with subunit immunogens. Proc Natl Acad Sci U S A 2007; 104:17477-82. [PMID: 17956985 DOI: 10.1073/pnas.0707399104] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Epitopes located in and around the coreceptor binding site of HIV-1 envelope glycoprotein (gp120) exhibit enhanced exposure after attachment to the CD4 receptor and comprise some of the most conserved and functionally important residues on the viral envelope. Therefore, antibody responses to these epitopes [designated as CD4-induced (CD4i)] should be highly cross-reactive and potentially useful for HIV vaccine development. To address this question, rhesus macaques were vaccinated with subunit immunogens designed to raise humoral responses against CD4i epitopes and challenged rectally with SHIV(162P3), which encodes a heterologous envelope versus the immunogen. We found that animals vaccinated with a rhesus full-length single-chain (rhFLSC) complex exhibited significantly accelerated clearance of plasma viremia and an absence of long-term tissue viremia compared with unvaccinated control animals. Such control of infection correlated with stronger responses to CD4i epitopes in the rhFLSC-vaccinated animals, compared with macaques immunized with gp120, cross-linked gp120-CD4 complexes, or soluble CD4 alone. These responses were strongly boosted in the rhFLSC-vaccinated animals by SHIV(162P3) infection. The control of infection was not associated with anti-CD4 responses, overall anti-gp120-binding titers, or neutralizing activity measured in conventional assays. Vaccine-naive animals also developed anti-CD4i epitope responses after simian/ human immunodeficiency virus (SHIV) challenge, which appeared later than the overall anti-gp120 responses and in concert with the decline of viremia to a low set point. Collectively, these data suggest that antibodies to CD4i epitopes may play a role in controlling SHIV infection and provide insights for HIV vaccine development.
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