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He W, Gea-Mallorquí E, Colin-York H, Fritzsche M, Gillespie GM, Brackenridge S, Borrow P, McMichael AJ. Intracellular trafficking of HLA-E and its regulation. J Exp Med 2023; 220:214089. [PMID: 37140910 PMCID: PMC10165540 DOI: 10.1084/jem.20221941] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/13/2023] [Accepted: 04/17/2023] [Indexed: 05/05/2023] Open
Abstract
Interest in MHC-E-restricted CD8+ T cell responses has been aroused by the discovery of their efficacy in controlling simian immunodeficiency virus (SIV) infection in a vaccine model. The development of vaccines and immunotherapies utilizing human MHC-E (HLA-E)-restricted CD8+ T cell response requires an understanding of the pathway(s) of HLA-E transport and antigen presentation, which have not been clearly defined previously. We show here that, unlike classical HLA class I, which rapidly exits the endoplasmic reticulum (ER) after synthesis, HLA-E is largely retained because of a limited supply of high-affinity peptides, with further fine-tuning by its cytoplasmic tail. Once at the cell surface, HLA-E is unstable and is rapidly internalized. The cytoplasmic tail plays a crucial role in facilitating HLA-E internalization, which results in its enrichment in late and recycling endosomes. Our data reveal distinctive transport patterns and delicate regulatory mechanisms of HLA-E, which help to explain its unusual immunological functions.
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Affiliation(s)
- Wanlin He
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Ester Gea-Mallorquí
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Huw Colin-York
- Kennedy Institute of Rheumatology, University of Oxford , Oxford, UK
| | - Marco Fritzsche
- Kennedy Institute of Rheumatology, University of Oxford , Oxford, UK
| | - Geraldine M Gillespie
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Simon Brackenridge
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Persephone Borrow
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Andrew J McMichael
- Nuffield Department of Medicine, Center for Immuno-Oncology, University of Oxford, Oxford, UK
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2
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Nolan DJ, Rose R, Zhang R, Leong A, Fogel GB, Scholte LLS, Bethony JM, Bracci P, Lamers SL, McGrath MS. The Persistence of HIV Diversity, Transcription, and Nef Protein in Kaposi's Sarcoma Tumors during Antiretroviral Therapy. Viruses 2022; 14:v14122774. [PMID: 36560778 PMCID: PMC9782636 DOI: 10.3390/v14122774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Epidemic Kaposi's sarcoma (KS), defined by co-infection with Human Herpes Virus 8 (HHV-8) and the Human Immunodeficiency Virus (HIV), is a major cause of mortality in sub-Saharan Africa. Antiretroviral therapy (ART) significantly reduces the risk of developing KS, and for those with KS, tumors frequently resolve with ART alone. However, for unknown reasons, a significant number of KS cases do not resolve and can progress to death. To explore how HIV responds to ART in the KS tumor microenvironment, we sequenced HIV env-nef found in DNA and RNA isolated from plasma, peripheral blood mononuclear cells, and tumor biopsies, before and after ART, in four Ugandan study participants who had unresponsive or progressive KS after 180-250 days of ART. We performed immunohistochemistry experiments to detect viral proteins in matched formalin-fixed tumor biopsies. Our sequencing results showed that HIV diversity and RNA expression in KS tumors are maintained after ART, despite undetectable plasma viral loads. The presence of spliced HIV transcripts in KS tumors after ART was consistent with a transcriptionally active viral reservoir. Immunohistochemistry staining found colocalization of HIV Nef protein and tissue-resident macrophages in the KS tumors. Overall, our results demonstrated that even after ART reduced plasma HIV viral load to undetectable levels and restored immune function, HIV in KS tumors continues to be transcriptionally and translationally active, which could influence tumor maintenance and progression.
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Affiliation(s)
- David J. Nolan
- Bioinfoexperts, LLC, Thibodaux, LA 70301, USA
- Correspondence:
| | | | - Rongzhen Zhang
- Departments of Laboratory Medicine, Pathology and Medicine, The University of California at San Francisco, San Francisco, CA 94110, USA
| | - Alan Leong
- Departments of Laboratory Medicine, Pathology and Medicine, The University of California at San Francisco, San Francisco, CA 94110, USA
| | | | - Larissa L. S. Scholte
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037, USA
| | - Jeffrey M. Bethony
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037, USA
| | - Paige Bracci
- The AIDS and Cancer Specimen Resource, San Francisco, CA 94110, USA
| | | | - Michael S. McGrath
- Departments of Laboratory Medicine, Pathology and Medicine, The University of California at San Francisco, San Francisco, CA 94110, USA
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3
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Cano-Ortiz L, Gu Q, de Sousa-Pereira P, Zhang Z, Chiapella C, Penda Twizerimana A, Lin C, Cláudia Franco A, VandeWoude S, Luedde T, Baldauf HM, Münk C. Feline Leukemia Virus-B Envelope together with its GlycoGag and Human Immunodeficiency Virus-1 Nef Mediate Resistance to Feline SERINC5. J Mol Biol 2021; 434:167421. [DOI: 10.1016/j.jmb.2021.167421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 11/29/2022]
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4
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Tavares LA, Januário YC, daSilva LLP. HIV-1 Hijacking of Host ATPases and GTPases That Control Protein Trafficking. Front Cell Dev Biol 2021; 9:622610. [PMID: 34307340 PMCID: PMC8295591 DOI: 10.3389/fcell.2021.622610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) modifies the host cell environment to ensure efficient and sustained viral replication. Key to these processes is the capacity of the virus to hijack ATPases, GTPases and the associated proteins that control intracellular protein trafficking. The functions of these energy-harnessing enzymes can be seized by HIV-1 to allow the intracellular transport of viral components within the host cell or to change the subcellular distribution of antiviral factors, leading to immune evasion. Here, we summarize how energy-related proteins deviate from their normal functions in host protein trafficking to aid the virus in different phases of its replicative cycle. Recent discoveries regarding the interplay among HIV-1 and host ATPases and GTPases may shed light on potential targets for pharmacological intervention.
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Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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5
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Zhang Y, Chen Y, Li Y, Huang F, Luo B, Yuan Y, Xia B, Ma X, Yang T, Yu F, Liu J, Liu B, Song Z, Chen J, Yan S, Wu L, Pan T, Zhang X, Li R, Huang W, He X, Xiao F, Zhang J, Zhang H. The ORF8 protein of SARS-CoV-2 mediates immune evasion through down-regulating MHC-Ι. Proc Natl Acad Sci U S A 2021; 118:e2024202118. [PMID: 34021074 PMCID: PMC8201919 DOI: 10.1073/pnas.2024202118] [Citation(s) in RCA: 244] [Impact Index Per Article: 81.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic and has claimed over 2 million lives worldwide. Although the genetic sequences of SARS-CoV and SARS-CoV-2 have high homology, the clinical and pathological characteristics of COVID-19 differ significantly from those of SARS. How and whether SARS-CoV-2 evades (cellular) immune surveillance requires further elucidation. In this study, we show that SARS-CoV-2 infection leads to major histocompability complex class Ι (MHC-Ι) down-regulation both in vitro and in vivo. The viral protein encoded by open reading frame 8 (ORF8) of SARS-CoV-2, which shares the least homology with SARS-CoV among all viral proteins, directly interacts with MHC-Ι molecules and mediates their down-regulation. In ORF8-expressing cells, MHC-Ι molecules are selectively targeted for lysosomal degradation via autophagy. Thus, SARS-CoV-2-infected cells are much less sensitive to lysis by cytotoxic T lymphocytes. Because ORF8 protein impairs the antigen presentation system, inhibition of ORF8 could be a strategy to improve immune surveillance.
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Affiliation(s)
- Yiwen Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yingshi Chen
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yuzhuang Li
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Feng Huang
- Department of Respiratory Diseases, Guangzhou Women and Children Hospital, 510010, Guangzhou, Guangdong, China
| | - Baohong Luo
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yaochang Yuan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Baijin Xia
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Xiancai Ma
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Tao Yang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Fei Yu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Jun Liu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Bingfeng Liu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Zheng Song
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Jingliang Chen
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Shumei Yan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Liyang Wu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Ting Pan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Xu Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Rong Li
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Wenjing Huang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 510000, Guangzhou, Guangdong, China
| | - Xin He
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Fei Xiao
- Department of Infectious Diseases, The Fifth Affiliated Hospital, Sun Yat-sen University, 519000, Zhuhai, Guangdong, China
| | - Junsong Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 510000, Guangzhou, Guangdong, China;
| | - Hui Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China;
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6
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Zhang Y, Chen Y, Li Y, Huang F, Luo B, Yuan Y, Xia B, Ma X, Yang T, Yu F, Liu J, Liu B, Song Z, Chen J, Yan S, Wu L, Pan T, Zhang X, Li R, Huang W, He X, Xiao F, Zhang J, Zhang H. The ORF8 protein of SARS-CoV-2 mediates immune evasion through down-regulating MHC-Ι. Proc Natl Acad Sci U S A 2021; 118:2024202118. [PMID: 34021074 DOI: 10.1101/2020.05.24.111823] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
Abstract
COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic and has claimed over 2 million lives worldwide. Although the genetic sequences of SARS-CoV and SARS-CoV-2 have high homology, the clinical and pathological characteristics of COVID-19 differ significantly from those of SARS. How and whether SARS-CoV-2 evades (cellular) immune surveillance requires further elucidation. In this study, we show that SARS-CoV-2 infection leads to major histocompability complex class Ι (MHC-Ι) down-regulation both in vitro and in vivo. The viral protein encoded by open reading frame 8 (ORF8) of SARS-CoV-2, which shares the least homology with SARS-CoV among all viral proteins, directly interacts with MHC-Ι molecules and mediates their down-regulation. In ORF8-expressing cells, MHC-Ι molecules are selectively targeted for lysosomal degradation via autophagy. Thus, SARS-CoV-2-infected cells are much less sensitive to lysis by cytotoxic T lymphocytes. Because ORF8 protein impairs the antigen presentation system, inhibition of ORF8 could be a strategy to improve immune surveillance.
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Affiliation(s)
- Yiwen Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yingshi Chen
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yuzhuang Li
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Feng Huang
- Department of Respiratory Diseases, Guangzhou Women and Children Hospital, 510010, Guangzhou, Guangdong, China
| | - Baohong Luo
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Yaochang Yuan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Baijin Xia
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Xiancai Ma
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Tao Yang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Fei Yu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Jun Liu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Bingfeng Liu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Zheng Song
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Jingliang Chen
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Shumei Yan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Liyang Wu
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Ting Pan
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Xu Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Rong Li
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Wenjing Huang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 510000, Guangzhou, Guangdong, China
| | - Xin He
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China
| | - Fei Xiao
- Department of Infectious Diseases, The Fifth Affiliated Hospital, Sun Yat-sen University, 519000, Zhuhai, Guangdong, China
| | - Junsong Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 510000, Guangzhou, Guangdong, China;
| | - Hui Zhang
- Institute of Human Virology, Key Laboratory of Tropical Disease Control of Ministry of Education, Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, 510080, Guangzhou, Guangdong, China;
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7
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Kruize Z, van Nuenen AC, van Wijk SW, Girigorie AF, van Dort KA, Booiman T, Kootstra NA. Nef Obtained from Individuals with HIV-1 Vary in Their Ability to Antagonize SERINC3- and SERINC5-Mediated HIV-1 Restriction. Viruses 2021; 13:v13030423. [PMID: 33800773 PMCID: PMC8000780 DOI: 10.3390/v13030423] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/25/2021] [Accepted: 03/02/2021] [Indexed: 12/14/2022] Open
Abstract
Nef is a multifunctional viral protein that has the ability to downregulate cell surface molecules, including CD4 and major histocompatibility complex class I (MHC-I) and, as recently shown, also members of the serine incorporator family (SERINC). Here, we analyzed the impact of naturally occurring mutations in HIV-1 Nef on its ability to counteract SERINC restriction and the clinical course of infection. HIV-1 Nef sequences were obtained from 123 participants of the Amsterdam Cohort Studies and showed multiple amino acid variations and mutations. Most of the primary Nef proteins showed increased activity to counteract SERINC3 and SERINC5 as compared to NL4-3 Nef. Several mutations in Nef were associated with either an increased or decreased infectivity of Bal26-pseudotyped HIV-1 produced in the presence of SERINC3 or SERINC5. The 8R, 157N and R178G Nef mutations were shown to have an effect on disease progression. Survival analysis showed an accelerated disease progression of individuals infected with HIV-1 carrying arginine or asparagine at position 8 or 157 in Nef, respectively, or the R178G Nef mutation. Here, we observed that naturally occurring mutations in Nef affect the ability of Nef to counteract SERINC3- and SERINC5-mediated inhibition of viral infectivity. The majority of these Nef mutations had no significant effect on HIV-1 pathogenesis and only the 8R, 157N and R178G mutations were associated with disease course.
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Castro-Gonzalez S, Shi Y, Colomer-Lluch M, Song Y, Mowery K, Almodovar S, Bansal A, Kirchhoff F, Sparrer K, Liang C, Serra-Moreno R. HIV-1 Nef counteracts autophagy restriction by enhancing the association between BECN1 and its inhibitor BCL2 in a PRKN-dependent manner. Autophagy 2021; 17:553-577. [PMID: 32097085 PMCID: PMC8007141 DOI: 10.1080/15548627.2020.1725401] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 01/20/2020] [Accepted: 01/24/2020] [Indexed: 12/20/2022] Open
Abstract
Macroautophagy/autophagy is an auto-digestive pro-survival pathway activated in response to stress to target cargo for lysosomal degradation. In recent years, autophagy has become prominent as an innate antiviral defense mechanism through multiple processes, such as targeting virions and viral components for elimination. These exciting findings have encouraged studies on the ability of autophagy to restrict HIV. However, the role of autophagy in HIV infection remains unclear. Whereas some reports indicate that autophagy is detrimental for HIV, others have claimed that HIV deliberately activates this pathway to increase its infectivity. Moreover, these contrasting findings seem to depend on the cell type investigated. Here, we show that autophagy poses a hurdle for HIV replication, significantly reducing virion production. However, HIV-1 uses its accessory protein Nef to counteract this restriction. Previous studies have indicated that Nef affects autophagy maturation by preventing the fusion between autophagosomes and lysosomes. Here, we uncover that Nef additionally blocks autophagy initiation by enhancing the association between BECN1 and its inhibitor BCL2, and this activity depends on the cellular E3 ligase PRKN. Remarkably, the ability of Nef to counteract the autophagy block is more frequently observed in pandemic HIV-1 and its simian precursor SIVcpz infecting chimpanzees than in HIV-2 and its precursor SIVsmm infecting sooty mangabeys. In summary, our findings demonstrate that HIV-1 is susceptible to autophagy restriction and define Nef as the primary autophagy antagonist of this antiviral process.Abbreviations: 3-MA: 3-methyladenine; ACTB: actin, beta; ATG16L1: autophagy related 16 like 1; BCL2: bcl2 apoptosis regulator; BECN1: beclin 1; cDNA: complementary DNA; EGFP: enhanced green fluorescence protein; ER: endoplasmic reticulum; Gag/p55: group-specific antigen; GFP: green fluorescence protein; GST: glutathione S transferase; HA: hemagglutinin; HIV: human immunodeficiency virus; IP: immunoprecipitation; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; Nef: negative factor; PRKN: parkin RBR E3 ubiquitin ligase; PtdIns3K: phosphatidylinositol 3 kinase; PtdIns3P: phosphatidylinositol 3 phosphate; PTM: post-translational modification; RT-qPCR: reverse transcription followed by quantitative PCR; RUBCN: rubicon autophagy regulator; SEM: standard error of the mean; SERINC3: serine incorporator 3; SERINC5: serine incorporator 5; SIV: simian immunodeficiency virus; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; UVRAG: UV radiation resistance associated gene; VSV: vesicular stomatitis virus; ZFYVE1/DFCP1: zinc finger FYVE-type containing 1.
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Affiliation(s)
- Sergio Castro-Gonzalez
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Yuhang Shi
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Marta Colomer-Lluch
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Badalona, Spain
| | - Ying Song
- Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kaitlyn Mowery
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Sharilyn Almodovar
- Immunology and Molecular Microbiology, Texas Tech Health Sciences Center, Lubbock, TX, USA
| | - Anju Bansal
- Medicine, Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, University of Ulm, Ulm, Germany
| | | | - Chengyu Liang
- Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Ruth Serra-Moreno
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
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9
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Painter MM, Zimmerman GE, Merlino MS, Robertson AW, Terry VH, Ren X, McLeod MR, Gomez-Rodriguez L, Garcia KA, Leonard JA, Leopold KE, Neevel AJ, Lubow J, Olson E, Piechocka-Trocha A, Collins DR, Tripathi A, Raghavan M, Walker BD, Hurley JH, Sherman DH, Collins KL. Concanamycin A counteracts HIV-1 Nef to enhance immune clearance of infected primary cells by cytotoxic T lymphocytes. Proc Natl Acad Sci U S A 2020; 117:23835-23846. [PMID: 32900948 PMCID: PMC7519347 DOI: 10.1073/pnas.2008615117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nef is an HIV-encoded accessory protein that enhances pathogenicity by down-regulating major histocompatibility class I (MHC-I) expression to evade killing by cytotoxic T lymphocytes (CTLs). A potent Nef inhibitor that restores MHC-I is needed to promote immune-mediated clearance of HIV-infected cells. We discovered that the plecomacrolide family of natural products restored MHC-I to the surface of Nef-expressing primary cells with variable potency. Concanamycin A (CMA) counteracted Nef at subnanomolar concentrations that did not interfere with lysosomal acidification or degradation and were nontoxic in primary cell cultures. CMA specifically reversed Nef-mediated down-regulation of MHC-I, but not CD4, and cells treated with CMA showed reduced formation of the Nef:MHC-I:AP-1 complex required for MHC-I down-regulation. CMA restored expression of diverse allotypes of MHC-I in Nef-expressing cells and inhibited Nef alleles from divergent clades of HIV and simian immunodeficiency virus, including from primary patient isolates. Lastly, we found that restoration of MHC-I in HIV-infected cells was accompanied by enhanced CTL-mediated clearance of infected cells comparable to genetic deletion of Nef. Thus, we propose CMA as a lead compound for therapeutic inhibition of Nef to enhance immune-mediated clearance of HIV-infected cells.
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Affiliation(s)
- Mark M Painter
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109
| | | | - Madeline S Merlino
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Andrew W Robertson
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan Ann Arbor, MI 48109
| | - Valeri H Terry
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Xuefeng Ren
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Megan R McLeod
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Lyanne Gomez-Rodriguez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Graduate Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109
| | - Kirsten A Garcia
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jolie A Leonard
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Kay E Leopold
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Andrew J Neevel
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - Jay Lubow
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Eli Olson
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Alicja Piechocka-Trocha
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - David R Collins
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Natural Products Discovery Core, Life Sciences Institute, University of Michigan Ann Arbor, MI 48109
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
| | - Bruce D Walker
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Kathleen L Collins
- Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109;
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109
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10
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La Manna MP, Orlando V, Prezzemolo T, Di Carlo P, Cascio A, Delogu G, Poli G, Sullivan LC, Brooks AG, Dieli F, Caccamo N. HLA-E-restricted CD8 + T Lymphocytes Efficiently Control Mycobacterium tuberculosis and HIV-1 Coinfection. Am J Respir Cell Mol Biol 2020; 62:430-439. [PMID: 31697586 DOI: 10.1165/rcmb.2019-0261oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/07/2019] [Indexed: 12/25/2022] Open
Abstract
We investigated the contribution of human leukocyte antigen A2 (HLA-A2) and HLA-E-restricted CD8+ T cells in patients with Mycobacterium tuberculosis and human immunodeficiency virus 1 (HIV-1) coinfection. HIV-1 downregulates HLA-A, -B, and -C molecules in infected cells, thus influencing recognition by HLA class I-restricted CD8+ T cells but not by HLA-E-restricted CD8+ T cells, owing to the inability of the virus to downmodulate their expression. Therefore, antigen-specific HLA-E-restricted CD8+ T cells could play a protective role in Mycobacterium tuberculosis and HIV-1 coinfection. HLA-E- and HLA-A2-restricted Mycobacterium tuberculosis-specific CD8+ T cells were tested in vitro for cytotoxic and microbicidal activities, and their frequencies and phenotypes were evaluated ex vivo in patients with active tuberculosis and concomitant HIV-1 infection. HIV-1 and Mycobacterium tuberculosis coinfection caused downmodulation of HLA-A2 expression in human monocyte-derived macrophages associated with resistance to lysis by HLA-A2-restricted CD8+ T cells and failure to restrict the growth of intracellular Mycobacterium tuberculosis. Conversely, HLA-E surface expression and HLA-E-restricted cytolytic and microbicidal CD8 responses were not affected. HLA-E-restricted and Mycobacterium tuberculosis-specific CD8+ T cells were expanded in the circulation of patients with Mycobacterium tuberculosis/HIV-1 coinfection, as measured by tetramer staining, but displayed a terminally differentiated and exhausted phenotype that was rescued in vitro by anti-PD-1 (programmed cell death protein 1) monoclonal antibody. Together, these results indicate that HLA-E-restricted and Mycobacterium tuberculosis-specific CD8+ T cells in patients with Mycobacterium tuberculosis/HIV-1 coinfection have an exhausted phenotype and fail to expand in vitro in response to antigen stimulation, which can be restored by blocking the PD-1 pathway using the specific monoclonal antibody nivolumab.
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Affiliation(s)
- Marco Pio La Manna
- Central Laboratory for Advanced Diagnosis and Biomedical Research
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, and
| | - Valentina Orlando
- Central Laboratory for Advanced Diagnosis and Biomedical Research
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, and
| | - Teresa Prezzemolo
- Central Laboratory for Advanced Diagnosis and Biomedical Research
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, and
| | - Paola Di Carlo
- Department of Sciences for Health Promotion and Mother-Child Care "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Antonio Cascio
- Department of Sciences for Health Promotion and Mother-Child Care "G. D'Alessandro," University of Palermo, Palermo, Italy
| | - Giovanni Delogu
- Institute of Microbiology, Catholic University of the Sacred Heart, Rome, Italy
- Foundation Policlinico Universitario Gemelli, Institute for Scientific-based Care and Research (IRCCS) Rome, Italy
| | - Guido Poli
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milano, Italy
- Vita-Salute San Raffaele University School of Medicine, Milano, Italy; and
| | - Lucy C Sullivan
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Andrew G Brooks
- Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Francesco Dieli
- Central Laboratory for Advanced Diagnosis and Biomedical Research
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, and
| | - Nadia Caccamo
- Central Laboratory for Advanced Diagnosis and Biomedical Research
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, and
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11
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Tavares LA, de Carvalho JV, Costa CS, Silveira RM, de Carvalho AN, Donadi EA, daSilva LLP. Two Functional Variants of AP-1 Complexes Composed of either γ2 or γ1 Subunits Are Independently Required for Major Histocompatibility Complex Class I Downregulation by HIV-1 Nef. J Virol 2020; 94:e02039-19. [PMID: 31915283 DOI: 10.1128/JVI.02039-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/01/2020] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 accessory protein Nef downregulates the cell surface expression of major histocompatibility complex class I (MHC-I) molecules to facilitate virus spreading. The Nef-induced downregulation of MHC-I molecules such as HLA-A requires the clathrin adaptor protein 1 (AP-1) complex. The cooperative interaction of Nef, AP-1, and the cytosolic tail (CT) of HLA-A leads to a redirection of HLA-A targeting from the trans-Golgi network (TGN) to lysosomes for degradation. Although the γ-adaptin subunit of AP-1 has two distinct isoforms (γ1 and γ2), which may form two AP-1 complex variants, so far, only the importance of AP-1γ1 in MHC-I downregulation by Nef has been investigated. Here, we report that the AP-1γ2 isoform also participates in this process. We found that AP-1γ2 forms a complex with Nef and HLA-A2_CT and that this interaction depends on the Y320 residue in HLA-A2_CT and Nef expression. Moreover, Nef targets AP-1γ1 and AP-1γ2 to different compartments in T cells, and the depletion of either AP-1 variant impairs the Nef-mediated reduction of total endogenous HLA-A levels and rescues HLA-A levels on the cell surface. Finally, immunofluorescence and immunoelectron microscopy analyses reveal that the depletion of γ2 in T cells compromises both the Nef-mediated retention of HLA-A molecules in the TGN and targeting to multivesicular bodies/late endosomes. Altogether, these results show that in addition to AP-1γ1, Nef also requires the AP-1γ2 variant for efficient MHC-I downregulation.IMPORTANCE HIV-1 Nef mediates evasion of the host immune system by inhibiting MHC-I surface presentation of viral antigens. To achieve this goal, Nef modifies the intracellular trafficking of MHC-I molecules in several ways. Despite being the subject of intense study, the molecular details underlying these modifications are not yet fully understood. Adaptor protein 1 (AP-1) plays an essential role in the Nef-mediated downregulation of MHC-I molecules such as HLA-A in different cell types. However, AP-1 has two functionally distinct variants composed of either γ1 or γ2 subunit isoforms. Because previous studies on the role of AP-1 in MHC-I downregulation by Nef focused on AP-1γ1, an important open question is the participation of AP-1γ2 in this process. Here, we show that AP-1γ2 is also essential for Nef-mediated depletion of surface HLA-A molecules in T cells. Our results indicate that Nef hijacks AP-1γ2 to modify HLA-A intracellular transport, redirecting these proteins to lysosomes for degradation.
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12
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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.
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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
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13
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Shi J, Xiong R, Zhou T, Su P, Zhang X, Qiu X, Li H, Li S, Yu C, Wang B, Ding C, Smithgall TE, Zheng YH. HIV-1 Nef Antagonizes SERINC5 Restriction by Downregulation of SERINC5 via the Endosome/Lysosome System. J Virol 2018; 92:e00196-18. [PMID: 29514909 PMCID: PMC5952139 DOI: 10.1128/jvi.00196-18] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [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: 02/05/2018] [Accepted: 03/01/2018] [Indexed: 12/11/2022] Open
Abstract
The primate lentiviral accessory protein Nef downregulates CD4 and major histocompatibility complex class I (MHC-I) from the cell surface via independent endosomal trafficking pathways to promote viral pathogenesis. In addition, Nef antagonizes a novel restriction factor, SERINC5 (Ser5), to increase viral infectivity. To explore the molecular mechanism of Ser5 antagonism by Nef, we determined how Nef affects Ser5 expression and intracellular trafficking in comparison to CD4 and MHC-I. We confirm that Nef excludes Ser5 from human immunodeficiency virus type 1 (HIV-1) virions by downregulating its cell surface expression via similar functional motifs required for CD4 downregulation. We find that Nef decreases both Ser5 and CD4 expression at steady-state levels, which are rescued by NH4Cl or bafilomycin A1 treatment. Nef binding to Ser5 was detected in living cells using a bimolecular fluorescence complementation assay, where Nef membrane association is required for interaction. In addition, Nef triggers rapid Ser5 internalization via receptor-mediated endocytosis and relocalizes Ser5 to Rab5+ early, Rab7+ late, and Rab11+ recycling endosomes. Manipulation of AP-2, Rab5, Rab7, and Rab11 expression levels affects the Nef-dependent Ser5 and CD4 downregulation. Moreover, although Nef does not promote Ser5 polyubiquitination, Ser5 downregulation relies on the ubiquitination pathway, and both K48- and K63-specific ubiquitin linkages are required for the downregulation. Finally, Nef promotes Ser5 colocalization with LAMP1, which is enhanced by bafilomycin A1 treatment, suggesting that Ser5 is targeted to lysosomes for destruction. We conclude that Nef uses a similar mechanism to downregulate Ser5 and CD4, which sorts Ser5 into a point-of-no-return degradative pathway to counteract its restriction.IMPORTANCE Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) express an accessory protein called Nef to promote viral pathogenesis. Nef drives immune escape in vivo through downregulation of CD4 and MHC-I from the host cell surface. Recently, Nef was reported to counteract a novel host restriction factor, Ser5, to increase viral infectivity. Nef downregulates cell surface Ser5, thus preventing its incorporation into virus particles, resulting in disruption of its antiviral activity. Here, we report mechanistic studies of Nef-mediated Ser5 downregulation in comparison to CD4 and MHC-I. We demonstrate that Nef binds directly to Ser5 in living cells and that Nef-Ser5 interaction requires Nef association with the plasma membrane. Subsequently, Nef internalizes Ser5 from the plasma membrane via receptor-mediated endocytosis, and targets ubiquitinated Ser5 to endosomes and lysosomes for destruction. Collectively, these results provide new insights into our ongoing understanding of the Nef-Ser5 arms race in HIV-1 infection.
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Affiliation(s)
- Jing Shi
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ran Xiong
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Tao Zhou
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Peiyi Su
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Xihe Zhang
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Xusheng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Hongmei Li
- Department of Pathology, Qiqihar Medical University, Qiqihar, China
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Sunan Li
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Changqing Yu
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Bin Wang
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Yong-Hui Zheng
- Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, China
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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14
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Mwimanzi F, Toyoda M, Mahiti M, Mann JK, Martin JN, Bangsberg D, Brockman MA, Goulder P, Kirchhoff F, Brumme ZL, Ndung'u T, Ueno T. Resistance of Major Histocompatibility Complex Class B (MHC-B) to Nef-Mediated Downregulation Relative to that of MHC-A Is Conserved among Primate Lentiviruses and Influences Antiviral T Cell Responses in HIV-1-Infected Individuals. J Virol 2018; 92:e01409-17. [PMID: 29046444 DOI: 10.1128/JVI.01409-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 10/03/2017] [Indexed: 12/19/2022] Open
Abstract
Patient-derived HIV-1 subtype B Nef clones downregulate HLA-A more efficiently than HLA-B. However, it remains unknown whether this property is common to Nef proteins across primate lentiviruses and how antiviral immune responses may be affected. We examined 263 Nef clones from diverse primate lentiviruses including different pandemic HIV-1 group M subtypes for their ability to downregulate major histocompatibility complex class A (MHC-A) and MHC-B from the cell surface. Though lentiviral Nef proteins differed markedly in their absolute MHC-A and MHC-B downregulation abilities, all lentiviral Nef lineages downregulated MHC-A, on average, 11 to 32% more efficiently than MHC-B. Nef genotype/phenotype analyses in a cohort of HIV-1 subtype C-infected patients (n = 168), together with site-directed mutagenesis, revealed Nef position 9 as a subtype-specific determinant of differential HLA-A versus HLA-B downregulation activity. Nef clones harboring nonconsensus variants at codon 9 downregulated HLA-B (though not HLA-A) significantly better than those harboring the consensus sequence at this site, resulting in reduced recognition of infected target cells by HIV-1-specific CD8+ effector cells in vitro Among persons expressing protective HLA class I alleles, carriage of Nef codon 9 variants was also associated with reduced ex vivo HIV-specific T cell responses. Our results demonstrate that Nef's inferior ability to downregulate MHC-B compared to that of MHC-A is conserved across primate lentiviruses and suggest that this property influences antiviral cellular immune responses.IMPORTANCE Primate lentiviruses encode the Nef protein that plays an essential role in establishing persistent infection in their respective host species. Nef interacts with the cytoplasmic region of MHC-A and MHC-B molecules and downregulates them from the infected cell surface to escape recognition by host cellular immunity. Using a panel of Nef alleles isolated from diverse primate lentiviruses including pandemic HIV-1 group M subtypes, we demonstrate that Nef proteins across all lentiviral lineages downregulate MHC-A approximately 20% more effectively than MHC-B. We further identify a naturally polymorphic site at Nef position 9 that contributes to the MHC-B downregulation function in HIV-1 subtype C and show that carriage of Nef variants with enhanced MHC-B downregulation ability is associated with reduced breadth and magnitude of MHC-B-restricted cellular immune responses in HIV-infected individuals. Our study underscores an evolutionarily conserved interaction between lentiviruses and primate immune systems that may contribute to pathogenesis.
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15
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Sandstrom TS, Ranganath N, Angel JB. Impairment of the type I interferon response by HIV-1: Potential targets for HIV eradication. Cytokine Growth Factor Rev 2017; 37:1-16. [PMID: 28455216 DOI: 10.1016/j.cytogfr.2017.04.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/11/2022]
Abstract
By interfering with the type I interferon (IFN1) response, human immunodeficiency virus 1 (HIV-1) can circumvent host antiviral signalling and establish persistent viral reservoirs. HIV-1-mediated defects in the IFN pathway are numerous, and include the impairment of protein receptors involved in pathogen detection, downstream signalling cascades required for IFN1 upregulation, and expression or function of key IFN1-inducible, antiviral proteins. Despite this, the activation of IFN1-inducible, antiviral proteins has been shown to facilitate the killing of latently HIV-infected cells in vitro. Understanding how IFN1 signalling is blocked in physiologically-relevant models of HIV-1 infection, and whether these defects can be reversed, is therefore of great importance for the development of novel therapeutic strategies aimed at eradicating the HIV-1 reservoir.
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Affiliation(s)
- Teslin S Sandstrom
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
| | - Nischal Ranganath
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
| | - Jonathan B Angel
- Ottawa Hospital Research Institute, ORCC Room C4445, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada; Division of Infectious Diseases, Ottawa Hospital-General Campus, 501 Smyth Road, Ottawa, ON, K1H 8L6, Canada.
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16
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Abstract
The Nef protein of the human immunodeficiency virus is a crucial determinant of viral pathogenesis and disease progression. Nef is abundantly expressed early in infection and is thought to optimize the cellular environment for viral replication. Nef controls expression levels of various cell surface molecules that play important roles in immunity and virus life cycle, by directly interfering with the itinerary of these proteins within the endocytic and late secretory pathways. To exert these functions, Nef physically interacts with host proteins that regulate protein trafficking. In recent years, considerable progress was made in identifying host-cell-interacting partners for Nef, and the molecular machinery used by Nef to interfere with protein trafficking has started to be unraveled. Here, we briefly review the knowledge gained and discuss new findings regarding the mechanisms by which Nef modifies the intracellular trafficking pathways to prevent antigen presentation, facilitate viral particle release and enhance the infectivity of HIV-1 virions.
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Affiliation(s)
- Estela A Pereira
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
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17
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Druce M, Hulo C, Masson P, Sommer P, Xenarios I, Le Mercier P, De Oliveira T. Improving HIV proteome annotation: new features of BioAfrica HIV Proteomics Resource. Database (Oxford) 2016; 2016:baw045. [PMID: 27087306 PMCID: PMC4834208 DOI: 10.1093/database/baw045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/11/2016] [Indexed: 02/06/2023]
Abstract
The Human Immunodeficiency Virus (HIV) is one of the pathogens that cause the greatest global concern, with approximately 35 million people currently infected with HIV. Extensive HIV research has been performed, generating a large amount of HIV and host genomic data. However, no effective vaccine that protects the host from HIV infection is available and HIV is still spreading at an alarming rate, despite effective antiretroviral (ARV) treatment. In order to develop effective therapies, we need to expand our knowledge of the interaction between HIV and host proteins. In contrast to virus proteins, which often rapidly evolve drug resistance mutations, the host proteins are essentially invariant within all humans. Thus, if we can identify the host proteins needed for virus replication, such as those involved in transporting viral proteins to the cell surface, we have a chance of interrupting viral replication. There is no proteome resource that summarizes this interaction, making research on this subject a difficult enterprise. In order to fill this gap in knowledge, we curated a resource presents detailed annotation on the interaction between the HIV proteome and host proteins. Our resource was produced in collaboration with ViralZone and used manual curation techniques developed by UniProtKB/Swiss-Prot. Our new website also used previous annotations of the BioAfrica HIV-1 Proteome Resource, which has been accessed by approximately 10 000 unique users a year since its inception in 2005. The novel features include a dedicated new page for each HIV protein, a graphic display of its function and a section on its interaction with host proteins. Our new webpages also add information on the genomic location of each HIV protein and the position of ARV drug resistance mutations. Our improved BioAfrica HIV-1 Proteome Resource fills a gap in the current knowledge of biocuration. Database URL: http://www.bioafrica.net/proteomics/HIVproteome.html
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Affiliation(s)
- Megan Druce
- Africa Centre for Population Health, School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa Division of Genetics, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Chantal Hulo
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Patrick Masson
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Paula Sommer
- Division of Genetics, School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Ioannis Xenarios
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Philippe Le Mercier
- Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - Tulio De Oliveira
- Africa Centre for Population Health, School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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18
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Mahiti M, Toyoda M, Jia X, Kuang XT, Mwimanzi F, Mwimanzi P, Walker BD, Xiong Y, Brumme ZL, Brockman MA, Ueno T. Relative Resistance of HLA-B to Downregulation by Naturally Occurring HIV-1 Nef Sequences. mBio 2016; 7:e01516-15. [PMID: 26787826 DOI: 10.1128/mBio.01516-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
HIV-1 Nef binds to the cytoplasmic region of HLA-A and HLA-B and downregulates these molecules from the surface of virus-infected cells, thus evading immune detection by CD8+ T cells. Polymorphic residues within the HLA cytoplasmic region may affect Nef’s downregulation activity. However, the effects of HLA polymorphisms on recognition by primary Nef isolates remain elusive, as do the specific Nef regions responsible for downregulation of HLA-A versus HLA-B. Here, we examined 46 Nef clones isolated from chronically HIV-1 subtype B-infected subjects for their ability to downregulate various HLA-A, HLA-B, and HLA-C molecules on the surface of virus-infected cells. Overall, HLA-B exhibited greater resistance to Nef-mediated downregulation than HLA-A, regardless of the cell type examined. As expected, no Nef clone downregulated HLA-C. Importantly, the differential abilities of patient-derived Nef clones to downregulate HLA-A and HLA-B correlated inversely with the sensitivities of HIV-infected target cells to recognition by effector cells expressing an HIV-1 Gag-specific T cell receptor. Nef codon function analysis implicated amino acid variation at position 202 (Nef-202) in differentially affecting the ability to downregulate HLA-A and HLA-B, an observation that was subsequently confirmed by experiments using Nef mutants constructed by site-directed mutagenesis. The in silico and mutagenesis analyses further suggested that Nef-202 may interact with the C-terminal Cys-Lys-Val residues of HLA-A, which are absent in HLA-B. Taken together, the results show that natural polymorphisms within Nef modulate its interaction with natural polymorphisms in the HLA cytoplasmic tails, thereby affecting the efficiency of HLA downregulation and consequent recognition by HIV-specific T cells. These results thus extend our understanding of this complex pathway of retroviral immune evasion. Recognition of genetically diverse pathogens by the adaptive immune system represents a primary strategy for host defense; however, pathogens such as HIV-1 can evade these responses to achieve persistent infection. The HIV-1 nef gene and the HLA class I locus rank among the most diverse genes of virus and host, respectively. The HIV-1 Nef protein interacts with the cytoplasmic region of HLA-A and HLA-B and downregulates these molecules to evade cellular immunity. By combining molecular, genetic, and in silico analyses, we demonstrate that patient-derived Nef clones downregulate HLA-A more effectively than HLA-B molecules. This in turn modulates the ability of HIV-specific T cells to recognize HIV-infected cells. We also identify a naturally polymorphic site at Nef codon 202 and HLA cytoplasmic motifs (GG314,315 and CKV339–341) that contribute to differential HLA downregulation by Nef. Our results highlight new interactions between HIV-1 and the human immune system that may contribute to pathogenesis.
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19
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Weiler AM, Das A, Akinyosoye O, Cui S, O'Connor SL, Scheef EA, Reed JS, Panganiban AT, Sacha JB, Rakasz EG, Friedrich TC, Maness NJ. Acute Viral Escape Selectively Impairs Nef-Mediated Major Histocompatibility Complex Class I Downmodulation and Increases Susceptibility to Antiviral T Cells. J Virol 2016; 90:2119-26. [PMID: 26637459 DOI: 10.1128/JVI.01975-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/24/2015] [Indexed: 01/29/2023] Open
Abstract
Nef-specific CD8(+) T lymphocytes (CD8TL) are associated with control of simian immunodeficiency virus (SIV) despite extensive nef variation between and within animals. Deep viral sequencing of the immunodominant Mamu-B*017:01-restricted Nef165-173IW9 epitope revealed highly restricted evolution. A common acute escape variant, T170I, unexpectedly and uniquely degraded Nef's major histocompatibility complex class I (MHC-I) downregulatory capacity, rendering the virus more vulnerable to CD8TL targeting other epitopes. These data aid in a mechanistic understanding of Nef functions and suggest means of immunity-mediated control of lentivirus replication.
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20
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Alberti MO, Jones JJ, Miglietta R, Ding H, Bakshi RK, Edmonds TG, Kappes JC, Ochsenbauer C. Optimized Replicating Renilla Luciferase Reporter HIV-1 Utilizing Novel Internal Ribosome Entry Site Elements for Native Nef Expression and Function. AIDS Res Hum Retroviruses 2015; 31:1278-96. [PMID: 26101895 DOI: 10.1089/aid.2015.0074] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We previously developed replication-competent reporter HIV-1 (referred to herein as LucR.T2A reporter viruses), utilizing a "ribosome skipping" T2A peptide strategy to link Renilla luciferase (LucR) with Nef expression. The demonstrated utility for HIV-1 vaccine and transmission study applications included measurement of neutralizing antibody (NAb) activity in vaccine sera, improved cell-mediated virus inhibition assays, such as T cell-mediated virus inhibition and antibody-dependent cell-mediated cytotoxicity (ADCC) assays, and humanized mouse models. Herein, we extend our prior work and introduce reporter virus technology for applications that require fully functional Nef. We demonstrate that in CD4(+) T cells productively infected with LucR.T2A reporter viruses, T2A peptide-driven Nef expression and function, such as down-regulation of surface CD4 and MHC-I, were impaired. We overcame this limitation of LucR.T2A reporter viruses and achieved physiological Nef expression and function by engineering novel LucR reporter HIV-1 comprising 11 different internal ribosome entry site (IRES) elements chosen for size and relative activity. A range of Nef expression was observed in 293T cells transfected with the different LucR.IRES reporter virus constructs. Iteratively, we identified IRES reporter genomes that expressed Nef closest to physiological levels and produced virus with infectivity, titers, and replication kinetics similar to nonreporter viruses. Our results demonstrated that LucR reporter activity was stable over multiple replication cycles in peripheral blood mononuclear cells (PBMCs). Furthermore, we analyzed Nef functionality, i.e., down-modulation of MHC-I and CD4, following infection of T cell lines and PBMCs. Unlike LucR.T2A reporter virus, one of the redesigned LucR.IRES reporter viruses [containing the modified encephalomyocarditis virus (EMCV) 6ATR IRES element, "6ATRi"] demonstrated Nef expression and function similar to parental "nonreporter" virus. In a previously validated (nef-independent) T cell-based NAb neutralization assay, LucR.6ATRi reporter virus performed indistinguishably from LucR.T2A reporter virus. In summary, reporter viruses comprising the "6ATRi" element promise to augment HIV-1 vaccine and transmission research approaches requiring a sensitive reporter readout combined with wild-type Nef function.
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Affiliation(s)
- Michael O. Alberti
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jennifer J. Jones
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Riccardo Miglietta
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Rakesh K. Bakshi
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tara G. Edmonds
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for AIDS Research, University of Alabama at Birmingham, Birmingham, Alabama
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Center for AIDS Research, University of Alabama at Birmingham, Birmingham, Alabama
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama
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21
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Goyos A, Guethlein LA, Horowitz A, Hilton HG, Gleimer M, Brodsky FM, Parham P. A Distinctive Cytoplasmic Tail Contributes to Low Surface Expression and Intracellular Retention of the Patr-AL MHC Class I Molecule. J Immunol 2015; 195:3725-36. [PMID: 26371256 DOI: 10.4049/jimmunol.1500397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/07/2015] [Indexed: 01/24/2023]
Abstract
Chimpanzees have orthologs of the six fixed, functional human MHC class I genes. But, in addition, the chimpanzee has a seventh functional gene, Patr-AL, which is not polymorphic but contributes substantially to population diversity by its presence on only 50% of MHC haplotypes. The ancestral AL gene emerged long before the separation of human and chimpanzee ancestors and then subsequently and specifically lost function during human evolution, but was maintained in chimpanzees. Patr-AL is an alloantigen that participates in negative and positive selection of the T cell repertoire. The three-dimensional structure and the peptide-binding repertoire of Patr-AL and HLA-A*02 are surprisingly similar. In contrast, the expression of these two molecules is very different, as shown using specific mAbs and polyclonal Abs made against Patr-AL. Peripheral blood cells and B cell lines express low levels of Patr-AL at the cell surface. Higher levels are seen for 221-cell transfectants expressing Patr-AL, but in these cells a large majority of Patr-AL molecules are retained in the early compartments of the secretory pathway: mainly the endoplasmic reticulum, but also cis-Golgi. Replacing the cytoplasmic tail of Patr-AL with that of HLA-A*02 increased the cell-surface expression of Patr-AL substantially. Four substitutions distinguish the Patr-AL and HLA-A*02 cytoplasmic tails. Systematic mutagenesis showed that each substitution contributes changes in cell-surface expression. The combination of residues present in Patr-AL appears unique, but each individual residue is present in other primate MHC class I molecules, notably MHC-E, the most ancient of the functional human MHC class I molecules.
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Affiliation(s)
- Ana Goyos
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305; Stanford Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Lisbeth A Guethlein
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Amir Horowitz
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305; Stanford Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Hugo G Hilton
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Michael Gleimer
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305; Stanford Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Frances M Brodsky
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94143; and Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143
| | - Peter Parham
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305; Stanford Immunology, Stanford University School of Medicine, Stanford, CA 94305;
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22
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El-Far M, Ancuta P, Routy JP, Zhang Y, Bakeman W, Bordi R, DaFonseca S, Said EA, Gosselin A, Tep TS, Eichbaum Q, van Grevenynghe J, Schwartz O, Freeman GJ, Haddad EK, Chomont N, Sékaly RP. Nef promotes evasion of human immunodeficiency virus type 1-infected cells from the CTLA-4-mediated inhibition of T-cell activation. J Gen Virol 2015; 96:1463-1477. [PMID: 25626682 DOI: 10.1099/vir.0.000065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 01/19/2015] [Indexed: 01/28/2023] Open
Abstract
CTLA-4 is a negative regulator of T-cell receptor-mediated CD4(+) T-cell activation and function. Upregulation of CTLA-4 during human immunodeficiency virus type 1 (HIV-1) infection on activated T cells, particularly on HIV-specific CD4(+) T cells, correlates with immune dysfunction and disease progression. As HIV-1 infects and replicates in activated CD4(+) T cells, we investigated mechanisms by which HIV-1 modulates CTLA-4 expression to establish productive viral infection in these cells. Here, we demonstrate that HIV-1 infection in activated CD4(+) T cells was followed by Nef-mediated downregulation of CTLA-4. This was associated with a decreased T-cell activation threshold and significant resistance to CTLA-4 triggering. In line with these in vitro results, quantification of pro-viral HIV DNA from treatment-naive HIV-infected subjects demonstrated a preferential infection of memory CD4(+)CTLA-4(+) T cells, thus identifying CTLA-4 as a biomarker for HIV-infected cells in vivo. As transcriptionally active HIV-1 and Nef expression in vivo were previously shown to take place mainly in the CD3(+)CD4(-)CD8(-) [double-negative (DN)] cells, we further quantified HIV DNA in the CTLA-4(+) and CTLA-4(-) subpopulations of these cells. Our results showed that DN T cells lacking CTLA-4 expression were enriched in HIV DNA compared with DN CTLA-4(+) cells. Together, these results suggested that HIV-1 preferential infection of CD4(+)CTLA-4(+) T cells in vivo was followed by Nef-mediated concomitant downregulation of both CD4 and CTLA-4 upon transition to productive infection. This also highlights the propensity of HIV-1 to evade restriction of the key negative immune regulator CTLA-4 on cell activation and viral replication, and therefore contributes to the overall HIV-1 pathogenesis.
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Affiliation(s)
- Mohamed El-Far
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Petronela Ancuta
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Jean-Pierre Routy
- Division of Hematology and Chronic Viral Illness Service, McGill University Health Centre, McGill University, Montréal, Québec, Canada
| | - Yuwei Zhang
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Wendy Bakeman
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA
| | - Rebeka Bordi
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Sandrina DaFonseca
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Elias A Said
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Annie Gosselin
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Tévy-Suzy Tep
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | | | - Julien van Grevenynghe
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Olivier Schwartz
- Virus and Immunity Group, Department of Virology, Institut Pasteur, Paris, France
| | - Gordon J Freeman
- Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Elias K Haddad
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Nicolas Chomont
- Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Rafick-Pierre Sékaly
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.,Case Western Reserve University, Cleveland, OH, USA.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Québec, Canada.,Vaccine & Gene Therapy Institute Florida, Port St Lucie, FL, USA
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23
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Pawlak EN, Dikeakos JD. HIV-1 Nef: a master manipulator of the membrane trafficking machinery mediating immune evasion. Biochim Biophys Acta Gen Subj 2015; 1850:733-41. [PMID: 25585010 DOI: 10.1016/j.bbagen.2015.01.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/09/2014] [Accepted: 01/06/2015] [Indexed: 11/25/2022]
Abstract
BACKGROUND Many viral genomes encode a limited number of proteins, illustrating their innate efficiency in bypassing host immune surveillance. This concept of genomic efficiency is exemplified by the 9 kb RNA genome of human immunodeficiency virus 1 (HIV-1), encoding 15 proteins sub-divided according to function. The enzymatic group includes proteins such as the drug targets reverse transcriptase and protease. In contrast, the accessory proteins lack any known enzymatic or structural function, yet are essential for viral fitness and HIV-1 pathogenesis. Of these, the HIV-1 accessory protein Nef is a master manipulator of host cellular processes, ensuring efficient counterattack against the host immune response, as well as long-term evasion of immune surveillance. In particular, the ability of Nef to downmodulate major histocompatibility complex class I (MHC-I) is a key cellular event that enables HIV-1 to bypass the host's defenses by evading the adaptive immune response. SCOPE OF REVIEW In this article, we briefly review how various pathogenic viruses control cell-surface MHC-I, and then focus on the mechanisms and implications of HIV-1 Nef-mediated MHC-I downregulation via modulation of the host membrane trafficking machinery. CONCLUSION The extensive interaction network formed between Nef and numerous membrane trafficking regulators suggests that Nef's role in evading the immune surveillance system intersects multiple host membrane trafficking pathways. SIGNIFICANCE Nef's ability to evade the immune surveillance system is linked to AIDS pathogenesis. Thus, a complete understanding of the molecular pathways that are subverted by Nef in order to downregulate MHC-I will enhance our understanding of HIV-1's progression to AIDS.
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Affiliation(s)
- Emily N Pawlak
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1
| | - Jimmy D Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1.
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24
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Haller C, Müller B, Fritz JV, Lamas-Murua M, Stolp B, Pujol FM, Keppler OT, Fackler OT. HIV-1 Nef and Vpu are functionally redundant broad-spectrum modulators of cell surface receptors, including tetraspanins. J Virol 2014; 88:14241-57. [PMID: 25275127 DOI: 10.1128/JVI.02333-14] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED HIV-1 Nef and Vpu are thought to optimize virus replication in the infected host, at least in part via their ability to interfere with vesicular host cell trafficking. Despite the use of distinct molecular mechanisms, Nef and Vpu share specificity for some molecules such as CD4 and major histocompatibility complex class I (MHC-I), while disruption of intracellular transport of the host cell restriction factor CD317/tetherin represents a specialized activity of Vpu not exerted by HIV-1 Nef. To establish a profile of host cell receptors whose intracellular transport is affected by Nef, Vpu, or both, we comprehensively analyzed the effect of these accessory viral proteins on cell surface receptor levels on A3.01 T lymphocytes. Thirty-six out of 105 detectable receptors were significantly downregulated by HIV-1 Nef, revealing a previously unappreciated scope with which HIV-1 Nef remodels the cell surface of infected cells. Remarkably, the effects of HIV-1 Vpu on host cell receptor exposure largely matched those of HIV-1 Nef in breadth and specificity (32 of 105, all also targeted by Nef), even though the magnitude was generally less pronounced. Of particular note, cell surface exposure of all members of the tetraspanin (TSPAN) protein family analyzed was reduced by both Nef and Vpu, and the viral proteins triggered the enrichment of TSPANs in a perinuclear area of the cell. While Vpu displayed significant colocalization and physical association with TSPANs, interactions of Nef with TSPANs were less robust. TSPANs thus emerge as a major target of deregulation in host cell vesicular transport by HIV-1 Nef and Vpu. The conservation of this activity in two independent accessory proteins suggests its importance for the spread of HIV-1 in the infected host. IMPORTANCE In this paper, we define that HIV-1 Nef and Vpu display a surprising functional overlap and affect the cell surface exposure of a previously unexpected breadth of cellular receptors. Our analyses furthermore identify the tetraspanin protein family as a previously unrecognized target of Nef and Vpu activity. These findings have implications for the interpretation of effects detected for these accessory gene products on individual host cell receptors and illustrate the coevolution of Nef and Vpu function.
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25
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Abstract
The replication and pathogenicity of lentiviruses is crucially modulated by “auxiliary proteins” which are expressed in addition to the canonical retroviral ORFs gag, pol, and env. Strategies to inhibit the activity of such proteins are often sought and proposed as possible additions to increase efficacy of the traditional antiretroviral therapy. This requires the acquisition of an in-depth knowledge of the molecular mechanisms underlying their function. The Nef auxiliary protein is expressed uniquely by primate lentiviruses and plays an important role in virus replication in vivo and in the onset of AIDS. Among its several activities Nef enhances the intrinsic infectivity of progeny virions through a mechanism which remains today enigmatic. Here we review the current knowledge surrounding such activity and we discuss its possible role in HIV biology.
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Affiliation(s)
- Stéphane Basmaciogullari
- Hôpital Necker-Enfants Malades, Sorbonne Paris Cité, Université Paris Descartes Paris, France ; INSERM U845 Paris, France
| | - Massimo Pizzato
- Centre for Integrative Biology, University of Trento Trento, Italy
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26
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Weiser K, Barton M, Gershoony D, DasGupta R, Cardozo T. HIV's Nef interacts with β-catenin of the Wnt signaling pathway in HEK293 cells. PLoS One 2013; 8:e77865. [PMID: 24130899 PMCID: PMC3795062 DOI: 10.1371/journal.pone.0077865] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/13/2013] [Indexed: 11/18/2022] Open
Abstract
The Wnt signaling pathway is implicated in major physiologic cellular functions, such as proliferation, migration, cell fate specification, maintenance of pluripotency and induction of tumorigenicity. Proliferation and migration are important responses of T-cells, which are major cellular targets of HIV infection. Using an informatics screen, we identified a previously unsuspected interaction between HIV’s Nef protein and β-catenin, a key component of the Wnt pathway. A segment in Nef contains identical amino acids at key positions and structurally mimics the β-catenin binding sites on endogenous β-catenin ligands. The interaction between Nef and β-catenin was confirmed in vitro and in a co-immunoprecipitation from HEK293 cells. Moreover, the introduction of Nef into HEK293 cells specifically inhibited a Wnt pathway reporter.
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Affiliation(s)
- Keren Weiser
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Meredith Barton
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Dafna Gershoony
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Ramanuj DasGupta
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Timothy Cardozo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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27
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Celsi F, Catamo E, Kleiner G, Tricarico PM, Vuch J, Crovella S. HLA-G/C, miRNAs, and their role in HIV infection and replication. Biomed Res Int. 2013;2013:693643. [PMID: 23841087 PMCID: PMC3697138 DOI: 10.1155/2013/693643] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/03/2013] [Accepted: 05/07/2013] [Indexed: 12/25/2022]
Abstract
In recent years, a number of different mechanisms regulating gene expressions, either in normal or in pathological conditions, have been discovered. This review aims to highlight some of the regulatory pathways involved during the HIV-1 infection and disease progression, focusing on the novel discovered microRNAs (miRNAs) and their relation with immune system's agents. Human leukocyte antigen (HLA) family of proteins plays a key role because it is a crucial modulator of the immune response; here we will examine recent findings, centering especially on HLA-C and -G, novel players lately discovered to engage in modulation of immune system. We hope to provide novel perspectives useful to find out original therapeutic roads against HIV-1 infection and AIDS progression.
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Mwimanzi P, Markle TJ, Ueno T, Brockman MA. Human leukocyte antigen (HLA) class I down-regulation by human immunodeficiency virus type 1 negative factor (HIV-1 Nef): what might we learn from natural sequence variants? Viruses 2012; 4:1711-30. [PMID: 23170180 PMCID: PMC3499827 DOI: 10.3390/v4091711] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 09/18/2012] [Accepted: 09/21/2012] [Indexed: 12/12/2022] Open
Abstract
HIV-1 causes a chronic infection in humans that is characterized by high plasma viremia, progressive loss of CD4+ T lymphocytes, and severe immunodeficiency resulting in opportunistic disease and AIDS. Viral persistence is mediated in part by the ability of the Nef protein to down-regulate HLA molecules on the infected cell surface, thereby allowing HIV-1 to evade recognition by antiviral CD8+ T lymphocytes. Extensive research has been conducted on Nef to determine protein domains that are required for its immune evasion activities and to identify critical cellular co-factors, and our mechanistic understanding of this process is becoming more complete. This review highlights our current knowledge of Nef-mediated HLA class I down-regulation and places this work in the context of naturally occurring sequence variation in this protein. We argue that efforts to fully understand the critical role of Nef for HIV-1 pathogenesis will require greater analysis of patient-derived sequences to elucidate subtle differences in immune evasion activity that may alter clinical outcome.
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Affiliation(s)
- Philip Mwimanzi
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada; (P.M.); (T.J.M.)
| | - Tristan J. Markle
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada; (P.M.); (T.J.M.)
| | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan;
| | - Mark A. Brockman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada; (P.M.); (T.J.M.)
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
- Author to whom correspondence should be addressed; ; Tel.: +1-778-782-3341; Fax: +1-778-782-5583
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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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Wonderlich ER, Leonard JA, Kulpa DA, Leopold KE, Norman JM, Collins KL. ADP ribosylation factor 1 activity is required to recruit AP-1 to the major histocompatibility complex class I (MHC-I) cytoplasmic tail and disrupt MHC-I trafficking in HIV-1-infected primary T cells. J Virol 2011; 85:12216-26. [PMID: 21917951 DOI: 10.1128/JVI.00056-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1-infected cells are partially resistant to anti-HIV cytotoxic T lymphocytes (CTLs) due to the effects of the HIV Nef protein on antigen presentation by major histocompatibility complex class I (MHC-I), and evidence has been accumulating that this function of Nef is important in vivo. HIV Nef disrupts the normal expression of MHC-I by stabilizing a protein-protein interaction between the clathrin adaptor protein AP-1 and the MHC-I cytoplasmic tail. There is also evidence that Nef activates a phosphatidylinositol 3 kinase (PI3K)-dependent GTPase, ADP ribosylation factor 6 (ARF-6), to stimulate MHC-I internalization. However, the relative importance of these two pathways is unclear. Here we report that a GTPase required for AP-1 activity (ARF-1) was needed for Nef to disrupt MHC-I surface levels, whereas no significant requirement for ARF-6 was observed in Nef-expressing T cell lines and in HIV-infected primary T cells. An ARF-1 inhibitor blocked the ability of Nef to recruit AP-1 to the MHC-I cytoplasmic tail, and a dominant active ARF-1 mutant stabilized the Nef-MHC-I-AP-1 complex. These data support a model in which Nef and ARF-1 stabilize an interaction between MHC-I and AP-1 to disrupt the presentation of HIV-1 epitopes to CTLs.
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Abstract
NK cell effector function is regulated by a range of activating and inhibitory receptors, and many of their known ligands are MHC class I molecules. Human NK receptors encoded by the Killer immunoglobulin-like receptor (KIR) gene family recognize polymorphic HLA-C as well as some HLA-A and HLA-B molecules. KIRs are expressed by uterine NK (uNK) cells, which are distinctive NK cells directly in contact with the invading fetal placental cells that transform the uterine arteries during the first trimester. Trophoblast cells express both maternal and paternal HLA-C allotypes and can therefore potentially interact with KIRs expressed by uNK. Therefore, allorecognition of paternal HLA-C by maternal KIR might influence trophoblast invasion and vascular remodeling, with subsequent effects on placental development and the outcome of pregnancy. We discuss here the studies relating to KIR/HLA-C interactions with an emphasis on how these function during pregnancy to regulate placentation.
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Affiliation(s)
- Olympe Chazara
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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Sowrirajan B, Barker E. The natural killer cell cytotoxic function is modulated by HIV-1 accessory proteins. Viruses 2011; 3:1091-111. [PMID: 21994772 DOI: 10.3390/v3071091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 06/23/2011] [Accepted: 06/24/2011] [Indexed: 12/31/2022] Open
Abstract
Natural killer (NK) cells’ major role in the control of viruses is to eliminate established infected cells. The capacity of NK cells to kill virus-infected cells is dependent on the interactions between ligands on the infected cell and receptors on the NK cell surface. Because of the importance of ligand-receptor interactions in modulating the NK cell cytotoxic response, HIV has developed strategies to regulate various NK cell ligands making the infected cell surprisingly refractory to NK cell lysis. This is perplexing because the HIV-1 accessory protein Vpr induces expression of ligands for the NK cell activating receptor, NKG2D. In addition, the accessory protein Nef removes the inhibitory ligands HLA-A and -B. The reason for the ineffective killing by NK cells despite the strong potential to eliminate infected cells is due to HIV-1 Vpu’s ability to down modulate the co-activation ligand, NTB-A, from the cell surface. Down modulation of NTB-A prevents efficient NK cell degranulation. This review will focus on the mechanisms through which the HIV-1 accessory proteins modulate their respective ligands, and its implication for NK cell killing of HIV-infected cells.
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Leonard JA, Filzen T, Carter CC, Schaefer M, Collins KL. HIV-1 Nef disrupts intracellular trafficking of major histocompatibility complex class I, CD4, CD8, and CD28 by distinct pathways that share common elements. J Virol 2011; 85:6867-81. [PMID: 21543478 DOI: 10.1128/JVI.00229-11] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The Nef protein is an important HIV virulence factor that promotes the degradation of host proteins to augment virus production and facilitate immune evasion. The best-characterized targets of Nef are major histocompatibility complex class I (MHC-I) and CD4, but Nef also has been reported to target several other proteins, including CD8β, CD28, CD80, CD86, and CD1d. To compare and contrast the effects of Nef on each protein, we constructed a panel of chimeric proteins in which the extracellular and transmembrane regions of the MHC-I allele HLA-A2 were fused to the cytoplasmic tails of CD4, CD28, CD8β, CD80, CD86, and CD1d. We found that Nef coprecipitated with and disrupted the expression of molecules with cytoplasmic tails from MHC-I HLA-A2, CD4, CD8β, and CD28, but Nef did not bind to or alter the expression of molecules with cytoplasmic tails from CD80, CD86, and CD1d. In addition, we used short interfering RNA (siRNA) knockdown and coprecipitation experiments to implicate AP-1 as a cellular cofactor for Nef in the downmodulation of both CD28 and CD8β. The interaction with AP-1 required for CD28 and CD8β differed from the AP-1 interaction required for MHC-I downmodulation in that it was mediated through the dileucine motif within Nef (LL(164,165)AA) and did not require the tyrosine binding pocket of the AP-1 μ subunit. In addition, we demonstrate a requirement for β-COP as a cellular cofactor for Nef that was necessary for the degradation of targeted molecules HLA-A2, CD4, and CD8. These studies provide important new information on the similarities and differences with which Nef affects intracellular trafficking and help focus future research on the best potential pharmaceutical targets.
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Abstract
The biochemical properties of the HLA-C antigen differ substantially from those of HLA-A and -B molecules. For this reason, HLA-C diversity and expression at the cell surface are much lower than its counterparts and in consequence HLA-C-restricted responses have been infrequently detected and described. In this review we summarise the key differences between HLA-C and other class I molecules and provide an update on natural killer and T-cell responses restricted by HLA-C. We also discuss the different clinical settings associated with HLA-C alleles which mainly consist of autoimmune disorders, cancers and chronic infections.
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Affiliation(s)
- Marie-Eve Blais
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK
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Corrah TW, Goonetilleke N, Kopycinski J, Deeks SG, Cohen MS, Borrow P, McMichael A, Brackenridge S. Reappraisal of the relationship between the HIV-1-protective single-nucleotide polymorphism 35 kilobases upstream of the HLA-C gene and surface HLA-C expression. J Virol 2011; 85:3367-74. [PMID: 21248048 DOI: 10.1128/JVI.02276-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Previous studies have found an association between a single-nucleotide polymorphism 35 kb upstream of the HLA-C locus (-35 SNP), HLA-C expression, and HIV-1 set point viral loads. We show that the difference in HLA-C expression across -35 SNP genotypes can be attributed primarily to the very low expression of a single allelic product, HLA-Cw7, which is a common HLA type. We suggest that association of the -35 SNP and HIV-1 load manifests as a result of linkage disequilibrium of this polymorphism with both favorable and unfavorable HLA-C and -B alleles.
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36
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Sloan RD, Kuhl BD, Donahue DA, Roland A, Bar-Magen T, Wainberg MA. Transcription of preintegrated HIV-1 cDNA modulates cell surface expression of major histocompatibility complex class I via Nef. J Virol 2011; 85:2828-36. [PMID: 21209113 DOI: 10.1128/JVI.01854-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Although transcription from unintegrated human immunodeficiency virus type 1 (HIV-1) DNA can occur inside infected cells, yielding all classes of viral mRNA transcripts, the translation of viral proteins is very limited. One of the proteins made is Nef, but it is unclear whether Nef produced in this way is able to play a role in immune evasion as occurs with integrated virus. We therefore asked whether transcription from preintegrated HIV-1 cDNAs could result in Nef-mediated modulation of cell surface major histocompatibility complex class I (MHC-I) expression. We infected a Rev-CEM green fluorescent protein (GFP) reporter cell line with virus and blocked integration though use of either an inactive integrase or the integrase inhibitor raltegravir. Infected cells were assayed by flow cytometry for cell surface expression of the HLA-A, HLA-B, and HLA-C allotypes (HLA-ABC), HLA-A31, and HLA-E. Viral RNA and DNA products were assayed via quantitative PCR (qPCR). The prevention of integration had no effect, relative to productively infected cells, on levels of expression of multiply spliced viral mRNA transcripts and Nef protein. Downregulation of HLA-ABC and HLA-A31 also occurred at levels similar to those seen in cells in which integration had occurred. Parallel experiments assaying cell surface HLA-ABC expression in infected activated primary CD4(+) T cells produced a similar pattern of results. Hence, the capacity of HIV-1 to modulate MHC-I is not linked to its ability to integrate. Thus, Nef-mediated evasion of host immune responsiveness might be attributable, in part at least, to transcription from unintegrated viral DNA.
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37
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Abstract
The Human Immunodeficiency Virus (HIV) Nef protein is necessary for high viral loads and for timely progression to AIDS. Nef plays a number of roles, but its effect on antigen presentation and immune evasion are among the best characterized. Cytotoxic T lymphocytes (CTLs) recognize and lyse virally infected cells by detecting viral antigens in complex with host major histocompatibility complex class I (MHC-I) molecules on the infected cell surface. The HIV Nef protein disrupts antigen presentation at the cell surface by interfering with the normal trafficking pathway of MHC-I and thus reduces CTL recognition and lysis of infected cells. The molecular mechanism by which Nef causes MHC-I downmodulation is becoming more clear, but some questions remain. A better understanding of how Nef disrupts antigen presentation may lead to the development of drugs that enhance the ability of the anti-HIV CTLs to control HIV disease.
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Affiliation(s)
- Elizabeth R Wonderlich
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, USA
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Zhao L, Li F, Zhang Y, Elbourkadi N, Wang Z, Yu C, Taylor EW. Mechanisms and genes involved in enhancement of HIV infectivity by tobacco smoke. Toxicology 2010; 278:242-8. [PMID: 20920546 DOI: 10.1016/j.tox.2010.09.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 09/14/2010] [Accepted: 09/20/2010] [Indexed: 01/17/2023]
Abstract
HIV infection is more common among smokers than nonsmokers, and, remarkably, HIV-infected individuals are about 3 times more likely to smoke than the uninfected general population. However, the relationship between tobacco smoking and HIV/AIDS disease progression remains controversial. In this study, we demonstrate a potent enhancing effect of aqueous tobacco smoke extract (TSE) on HIV infectivity that is nicotine-independent. This increased infectivity is neither NF-κB mediated nor a direct result of oxidative stress, as it cannot be blocked by antioxidants. On the contrary, TSE itself was found to possess significant antioxidant potential, enabling it to protect the viability of both infected cells and HIV virions in the presence of peroxide. Assessment of TSE-induced alterations in cellular gene expression that may be involved in increasing HIV infectivity in T cells showed that TSE up-regulates some genes known to be capable of enhancing HIV and HCV infection, or protecting HIV, but down-regulates several genes involved in cellular defense and antigen presentation. These results demonstrate that tobacco smoke can enhance HIV infectivity, possibly by a combination of direct (antioxidant) and indirect (gene-based) mechanisms. This raises the concern that smoking may thereby increase the risk of acquisition or progression of HIV infection.
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Affiliation(s)
- Lijun Zhao
- Key Laboratory of Ministry of Education for Medicinal Plant Resource and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
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Honda K, Zheng N, Murakoshi H, Hashimoto M, Sakai K, Borghan MA, Chikata T, Koyanagi M, Tamura Y, Gatanaga H, Oka S, Takiguchi M. Selection of escape mutant by HLA-C-restricted HIV-1 Pol-specific cytotoxic T lymphocytes carrying strong ability to suppress HIV-1 replication. Eur J Immunol 2010; 41:97-106. [DOI: 10.1002/eji.201040841] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 09/22/2010] [Accepted: 10/22/2010] [Indexed: 11/08/2022]
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Laguette N, Brégnard C, Benichou S, Basmaciogullari S. Human immunodeficiency virus (HIV) type-1, HIV-2 and simian immunodeficiency virus Nef proteins. Mol Aspects Med 2010; 31:418-33. [PMID: 20594957 DOI: 10.1016/j.mam.2010.05.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 05/26/2010] [Indexed: 11/19/2022]
Abstract
The genomes of all retroviruses encode the Gag Pol and Env structural proteins. Human and simian lentiviruses have acquired non-structural proteins among which Nef plays a major role in the evolution of viral infection towards an immunodeficiency syndrome. Indeed, in the absence of a functional nef gene, primate lentiviruses are far less pathogenic than their wild type counterparts. The multiple protein-protein interactions in which Nef is involved all contribute to explain the role played by Nef in HIV- and SIV-associated disease progression. This review summarizes common and distinct features among Nef proteins and how they contribute to increasing HIV and SIV fitness towards their respective hosts.
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Affiliation(s)
- Nadine Laguette
- Institut Cochin, CNRS UMR8104, Université Paris Descartes, Paris, France
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Poe JA, Smithgall TE. HIV-1 Nef dimerization is required for Nef-mediated receptor downregulation and viral replication. J Mol Biol 2009; 394:329-42. [PMID: 19781555 DOI: 10.1016/j.jmb.2009.09.047] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 09/15/2009] [Accepted: 09/17/2009] [Indexed: 10/20/2022]
Abstract
Nef, a human immunodeficiency virus type 1 (HIV-1) accessory factor capable of interaction with a diverse array of host cell signaling molecules, is essential for high-titer HIV replication and AIDS progression. Previous biochemical and structural studies have suggested that Nef may form homodimers and higher-order oligomers in HIV-infected cells, which may be required for both immune and viral receptor downregulation as well as viral replication. Using bimolecular fluorescence complementation, we provide the first direct evidence for Nef dimers within HIV host cells and identify the structural requirements for dimerization in vivo. Bimolecular fluorescence complementation analysis shows that the multiple hydrophobic and electrostatic interactions found within the dimerization interface of the Nef X-ray crystal structure are essential for dimerization in cells. Nef dimers localized to the plasma membrane as well as the trans-Golgi network, two subcellular localizations essential for Nef function. Mutations in the Nef dimerization interface dramatically reduced both Nef-induced CD4 downregulation and HIV replication. Viruses expressing dimerization-defective Nef mutants were disabled to the same extent as HIV that fails to express Nef in terms of replication. These results identify the Nef dimerization region as a potential molecular target for antiretroviral drug discovery.
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Affiliation(s)
- Jerrod A Poe
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, E1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
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42
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Chaudhry A, Verghese DA, Das SR, Jameel S, George A, Bal V, Mayor S, Rath S. HIV-1 Nef promotes endocytosis of cell surface MHC class II molecules via a constitutive pathway. J Immunol 2009; 183:2415-24. [PMID: 19620308 DOI: 10.4049/jimmunol.0804014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
HIV-1 Nef has been reported to disrupt MHC class II (MHCII)-mediated Ag presentation by a dual strategy that comprises a reduction in cell surface levels of peptide-loaded mature MHCII molecules and a up-regulation of immature MHCII molecules. We show that Nef achieves relocation of MHCII away from the cell surface in monocytic cells by both delaying its transport to the cell surface and by accelerating endocytic removal of cell surface MHCII to a lysosomal compartment. Nef-induced MHCII endocytosis is cholesterol-sensitive but clathrin- and dynamin-independent. Internalized MHCII molecules traverse the early endosomal system and colocalize with pinocytic cargo before reaching lysosomes. Nef-triggered MHCII endocytosis requires Rab5 activity and lyst function, whereas lysosomal trafficking of internalized MHCII molecules requires Rab7 activity. We further show that a similar pathway can remove peptide-MHCII complexes from the surface of monocytic cells not expressing Nef. Our data suggest that Nef uses mechanisms involved in normal MHCII recycling and turnover to mediate the delivery of cell surface MHCII to a lysosomal destination. Thus, Nef-mediated endocytosis of MHCII provides a novel perspective on the regulation of normal MHCII trafficking.
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Thananchai H, Makadzange T, Maenaka K, Kuroki K, Peng Y, Conlon C, Rowland-Jones S, Dong T. Reciprocal recognition of an HLA-Cw4-restricted HIV-1 gp120 epitope by CD8+ T cells and NK cells. AIDS 2009; 23:189-93. [PMID: 19098488 DOI: 10.1097/QAD.0b013e32831fb55a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The HIV-1 Nef protein selectively downregulates human leukocyte antigen (HLA)-A and HLA-B but not HLA-C molecules on the surface of infected cells. This allows HIV-infected cells to evade recognition by most cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. We investigated the recognition of an HLA-Cw4-restricted HIV-1 gp120 epitope SFNCGGEFF (SF9) and its variant SFNCGGEFL (SL9) by T cells and NK receptors. DESIGN AND METHOD Recognition of HIV-1 gp120 peptides (SF9 and SL9) by T-cell clones was measured by staining with HLA-Cw4-peptide tetrameric complexes and cytolytic assays using target cell pulsed with either peptides. KIR2DL1 binding to these two peptides was measured using surface plasmon resonance and tetramer staining of an NK cell line. RESULT : CTLs could recognize SF9 better than the variant SL9, as shown by both tetramer staining and cytolytic assays. Intriguingly, an HLA-Cw4 tetramer folded with the 'escape' variant SL9 could bind to KIR2DL1 on NK cell lines with higher affinity than HLA-Cw4-SF9. The binding of KIR2DL1 to its ligand results in inhibition of NK cell function. Our results indicate that the HIV-1 gp120 variant peptide SL9 could potentially escape both from NK cell and CTL recognition by increasing its affinity for KIR2DL1 binding. CONCLUSION These data suggest that HIV-1 can acquire mutations that are capable of escaping from both CTL and NK cell recognition, a phenomenon we have termed 'double escape'.
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Abstract
The HIV and SIV Nef accessory proteins are potent enhancers of viral persistence and accelerate progression to AIDS in HIV-1-infected patients and non-human primate models. Although relatively small (27-35 kD), Nef can interact with a multitude of cellular factors and induce complex changes in trafficking, signal transduction, and gene expression that together converge to promote viral replication and immune evasion. In particular, Nef recruits several immunologically relevant cellular receptors to the endocytic machinery to reduce the recognition and elimination of virally infected cells by the host immune system, while simultaneously interacting with various kinases to promote T cell activation and viral replication. This review provides an overview on selected Nef interactions with host cell proteins, and discusses their possible relevance for viral spread and pathogenicity.
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Affiliation(s)
- Nathalie J Arhel
- Institute of Virology, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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45
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Schaefer MR, Wonderlich ER, Roeth JF, Leonard JA, Collins KL. HIV-1 Nef targets MHC-I and CD4 for degradation via a final common beta-COP-dependent pathway in T cells. PLoS Pathog 2008; 4:e1000131. [PMID: 18725938 DOI: 10.1371/journal.ppat.1000131] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Accepted: 07/22/2008] [Indexed: 01/28/2023] Open
Abstract
To facilitate viral infection and spread, HIV-1 Nef disrupts the surface expression of the viral receptor (CD4) and molecules capable of presenting HIV antigens to the immune system (MHC-I). To accomplish this, Nef binds to the cytoplasmic tails of both molecules and then, by mechanisms that are not well understood, disrupts the trafficking of each molecule in different ways. Specifically, Nef promotes CD4 internalization after it has been transported to the cell surface, whereas Nef uses the clathrin adaptor, AP-1, to disrupt normal transport of MHC-I from the TGN to the cell surface. Despite these differences in initial intracellular trafficking, we demonstrate that MHC-I and CD4 are ultimately found in the same Rab7(+) vesicles and are both targeted for degradation via the activity of the Nef-interacting protein, beta-COP. Moreover, we demonstrate that Nef contains two separable beta-COP binding sites. One site, an arginine (RXR) motif in the N-terminal alpha helical domain of Nef, is necessary for maximal MHC-I degradation. The second site, composed of a di-acidic motif located in the C-terminal loop domain of Nef, is needed for efficient CD4 degradation. The requirement for redundant motifs with distinct roles supports a model in which Nef exists in multiple conformational states that allow access to different motifs, depending upon which cellular target is bound by Nef.
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46
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Mitchell RS, Chaudhuri R, Lindwasser OW, Tanaka KA, Lau D, Murillo R, Bonifacino JS, Guatelli JC. Competition model for upregulation of the major histocompatibility complex class II-associated invariant chain by human immunodeficiency virus type 1 Nef. J Virol 2008; 82:7758-67. [PMID: 18524831 DOI: 10.1128/JVI.02668-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) Nef protein upregulates the expression of the invariant chain (Ii)/major histocompatibility complex class II (MHC-II) complex at the cell surface. This complex appears to reach the antigen-loading endosomal compartment at least in part via an indirect pathway in which it is internalized from the cell surface via the adaptor protein 2 (AP-2) complex. Here we provide evidence for a competition model to explain how Nef upregulates the expression of Ii at the cell surface. In this model, Nef and Ii compete for binding to AP-2. In support of this model, Nef decreased the rate of internalization of Ii from the cell surface. The AP-binding dileucine motif in Nef, ENTSLL(165), was necessary and sufficient for the upregulation of Ii. In addition, two leucine-based AP-binding motifs in the Ii cytoplasmic tail, DDQRDLI(8) and EQLPML(17), were critical for the efficient upregulation of Ii by Nef. Experiments using Nef variants in which the native dileucine-based sorting motif was replaced with similar motifs from cellular transmembrane proteins allowed modulation of AP-binding specificity. Analysis of these variants suggested that the binding of Nef to AP-2 is sufficient to upregulate Ii at the plasma membrane. Finally, interference with the expression of AP-2 caused an upregulation of Ii at the plasma membrane, and this decreased the effect of Nef. These data indicate that Nef usurps AP-2 complexes to dysregulate Ii trafficking and potentially interfere with antigen presentation in the context of MHC-II.
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Abstract
Major histocompatibility complex (MHC) class I molecules bind and present short antigenic peptides from endogenously or exogenously derived sources to CD8(+) cytotoxic T lymphocytes (CTL), with recognition of a foreign peptide normally targeting the cell for lysis. It is generally thought that the high level of MHC polymorphism, which is concentrated mostly within the peptide-binding groove, is driven by the 'evolutionary arms race' against pathogens. Many pathogens have developed novel and intriguing mechanisms for evading the continuous sampling of the intracellular and intercellular environments by MHC molecules, none more so than viruses. The characterization of immunoevasion mechanisms has improved our understanding of MHC biology. This review will highlight our current understanding of the MHC class I biosynthetic pathway and how it has been exploited by pathogens, especially viruses, to potentially evade CTL recognition.
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Affiliation(s)
- Antony N Antoniou
- Department of Immunology & Molecular Pathology, Division of Infection & Immunity, University College London, Windeyer Institute of Medical Science, London, UK.
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DeGottardi MQ, Specht A, Metcalf B, Kaur A, Kirchhoff F, Evans DT. Selective downregulation of rhesus macaque and sooty mangabey major histocompatibility complex class I molecules by Nef alleles of simian immunodeficiency virus and human immunodeficiency virus type 2. J Virol 2008; 82:3139-46. [PMID: 18199657 DOI: 10.1128/JVI.02102-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef downregulates HLA-A and -B molecules, but not HLA-C or -E molecules, based on amino acid differences in their cytoplasmic domains to simultaneously evade cytotoxic T lymphocyte (CTL) and natural killer cell surveillance. Rhesus macaques and sooty mangabeys express orthologues of HLA-A, -B, and -E, but not HLA-C, and many of these molecules have unique amino acid differences in their cytoplasmic tails. We found that these differences also resulted in differential downregulation by primary simian immunodeficiency virus (SIV) SIV(smm/mac) and HIV-2 Nef alleles. Thus, selective major histocompatibility complex class I downregulation is a conserved mechanism of immune evasion for pathogenic SIV infection of rhesus macaques and nonpathogenic SIV infection of sooty mangabeys.
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Klase ZA, Van Duyne R, Kashanchi F. Identification of potential drug targets using genomics and proteomics: a systems approach. Adv Pharmacol 2008; 56:327-68. [PMID: 18086417 DOI: 10.1016/s1054-3589(07)56011-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Zachary A Klase
- Department of Biochemistry, Medical Center, The George Washington University, Washington, DC 20037, USA
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Specht A, DeGottardi MQ, Schindler M, Hahn B, Evans DT, Kirchhoff F. Selective downmodulation of HLA-A and -B by Nef alleles from different groups of primate lentiviruses. Virology 2007; 373:229-37. [PMID: 18155264 DOI: 10.1016/j.virol.2007.11.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 11/16/2007] [Indexed: 10/22/2022]
Abstract
It has been demonstrated that the HIV-1 NL4-3 and IIIB Nef alleles downregulate HLA-A and -B but not -C or -E from the cell surface. It remained elusive, however, whether selective modulation of specific HLA molecules is conserved between different groups of human and simian immunodeficiency viruses, respectively. To address this, we analyzed a large panel of primate lentiviral Nef proteins and we found that this property is conserved among nef alleles from the M, N and O groups of HIV-1, as well as those from SIVcpz, the precursor of HIV-1, and a variety of other highly divergent primate lentiviruses. In conclusion, our data indicate that Nef's ability to selectively downregulate HLA-A and -B alleles to prevent CTL lysis and NK killing of virally infected cells is conserved among different primate lentiviral lineages and preceded the zoonotic transmission of SIVcpz from chimpanzees to humans.
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Affiliation(s)
- Anke Specht
- Institute of Virology, Universitätsklinikum, 89081 Ulm, Germany
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