1
|
van Stigt Thans T, Akko JI, Niehrs A, Garcia-Beltran WF, Richert L, Stürzel CM, Ford CT, Li H, Ochsenbauer C, Kappes JC, Hahn BH, Kirchhoff F, Martrus G, Sauter D, Altfeld M, Hölzemer A. Primary HIV-1 Strains Use Nef To Downmodulate HLA-E Surface Expression. J Virol 2019; 93:e00719-19. [PMID: 31375574 PMCID: PMC6798123 DOI: 10.1128/jvi.00719-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/19/2019] [Indexed: 02/08/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has evolved elaborate ways to evade immune cell recognition, including downregulation of classical HLA class I (HLA-I) from the surfaces of infected cells. Recent evidence identified HLA-E, a nonclassical HLA-I, as an important part of the antiviral immune response to HIV-1. Changes in HLA-E surface levels and peptide presentation can prompt both CD8+ T-cell and natural killer (NK) cell responses to viral infections. Previous studies reported unchanged or increased HLA-E levels on HIV-1-infected cells. Here, we examined HLA-E surface levels following infection of CD4+ T cells with primary HIV-1 strains and observed that a subset downregulated HLA-E. Two primary strains of HIV-1 that induced the strongest reduction in surface HLA-E expression were chosen for further testing. Expression of single Nef or Vpu proteins in a T-cell line, as well as tail swap experiments exchanging the cytoplasmic tail of HLA-A2 with that of HLA-E, demonstrated that Nef modulated HLA-E surface levels and targeted the cytoplasmic tail of HLA-E. Furthermore, infection of primary CD4+ T cells with HIV-1 mutants showed that a lack of functional Nef (and Vpu to some extent) impaired HLA-E downmodulation. Taken together, the results of this study demonstrate for the first time that HIV-1 can downregulate HLA-E surface levels on infected primary CD4+ T cells, potentially rendering them less vulnerable to CD8+ T-cell recognition but at increased risk of NKG2A+ NK cell killing.IMPORTANCE For almost two decades, it was thought that HIV-1 selectively downregulated the highly expressed HLA-I molecules HLA-A and HLA-B from the cell surface in order to evade cytotoxic-T-cell recognition, while leaving HLA-C and HLA-E molecules unaltered. It was stipulated that HIV-1 infection thereby maintained inhibition of NK cells via inhibitory receptors that bind HLA-C and HLA-E. This concept was recently revised when a study showed that primary HIV-1 strains reduce HLA-C surface levels, whereas the cell line-adapted HIV-1 strain NL4-3 lacks this ability. Here, we demonstrate that infection with distinct primary HIV-1 strains results in significant downregulation of surface HLA-E levels. Given the increasing evidence for HLA-E as an important modulator of CD8+ T-cell and NKG2A+ NK cell functions, this finding has substantial implications for future immunomodulatory approaches aimed at harnessing cytotoxic cellular immunity against HIV.
Collapse
Affiliation(s)
| | - Janet I Akko
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
| | - Annika Niehrs
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
| | | | - Laura Richert
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- Université Bordeaux, Inserm, Bordeaux Population Health Research Center, UMR 1219, Inria SISTM, Bordeaux, France
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Christopher T Ford
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Hui Li
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Christina Ochsenbauer
- Department of Medicine, Division of Hematology and Oncology, and CFAR, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - John C Kappes
- Department of Medicine, Division of Hematology and Oncology, and CFAR, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Beatrice H Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Glòria Martrus
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Marcus Altfeld
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
- Institute for Immunology, University Medical Center Eppendorf, Hamburg, Germany
| | - Angelique Hölzemer
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
- German Center for Infection Research (DZIF), Site Hamburg-Lübeck-Borstel-Riems, Germany
- First Department of Internal Medicine, University Medical Center Eppendorf, Hamburg, Germany
| |
Collapse
|