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Sharma G, Round J, Teng F, Ali Z, May C, Yung E, Holt RA. A synthetic cytotoxic T cell platform for rapidly prototyping TCR function. NPJ Precis Oncol 2024; 8:182. [PMID: 39160299 PMCID: PMC11333705 DOI: 10.1038/s41698-024-00669-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 07/30/2024] [Indexed: 08/21/2024] Open
Abstract
Current tools for functionally profiling T cell receptors with respect to cytotoxic potency and cross-reactivity are hampered by difficulties in establishing model systems to test these proteins in the contexts of different HLA alleles and against broad arrays of potential antigens. We have implemented a granzyme-activatable sensor of T cell cytotoxicity in a universal prototyping platform which enables facile recombinant expression of any combination of TCR-, peptide-, and class I MHC-coding sequences and direct assessment of resultant responses. This system consists of an engineered cell platform based on the immortalized natural killer cell line, YT-Indy, and the MHC-null antigen-presenting cell line, K562. These cells were engineered to furnish the YT-Indy/K562 pair with appropriate protein domains required for recombinant TCR expression and function in a non-T cell chassis, integrate a fluorescence-based target-centric early detection reporter of cytotoxic function, and deploy a set of protective genetic interventions designed to preserve antigen-presenting cells for subsequent capture and downstream characterization. Our data show successful reconstitution of the surface TCR complex in the YT-Indy cell line at biologically relevant levels. We also demonstrate successful induction and highly sensitive detection of antigen-specific response in multiple distinct model TCRs. Additionally, we monitored destruction of targets in co-culture and found that our survival-optimized system allowed for complete preservation after 24 h exposure to cytotoxic effectors. With this bioplatform, we anticipate investigators will be empowered to rapidly express and characterize T cell receptor responses, generate knowledge regarding the patterns of T cell receptor recognition, and optimize therapeutic T cell receptors.
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Affiliation(s)
- Govinda Sharma
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - James Round
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Fei Teng
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Zahra Ali
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Chris May
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Eric Yung
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada
| | - Robert A Holt
- Michael Smith Genome Sciences Centre, British Columbia Cancer Research Institute, Vancouver, BC, Canada.
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
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Sharma G, Round J, Teng F, Ali Z, May C, Yung E, Holt RA. A Synthetic Cytotoxic T cell Platform for Rapidly Prototyping TCR Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567960. [PMID: 38045272 PMCID: PMC10690155 DOI: 10.1101/2023.11.20.567960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Current tools for functionally profiling T cell receptors with respect to cytotoxic potency and cross-reactivity are hampered by difficulties in establishing model systems to test these proteins in the contexts of different HLA alleles and against broad arrays of potential antigens. We have implemented and validated a granzyme-activatable sensor of T cell cytotoxicity in a novel universal prototyping platform which enables facile recombinant expression of any combination of TCR-, peptide-, and class I MHC-coding sequences and direct assessment of resultant responses. This system consists of an engineered cell platform based on the immortalized natural killer cell line, YT-Indy, and the MHC-null antigen-presenting cell line, K562. These cells were engineered using contemporary gene-editing techniques to furnish the YT-Indy/K562 pair with appropriate protein domains required for recombinant TCR expression and function in a non-T cell chassis, integrate a fluorescence-based target-centric early detection reporter of cytotoxic function, and deploy a set of protective genetic interventions designed to preserve antigen-presenting cells for subsequent capture and downstream characterization. Our data show successful reconstitution of the surface TCR complex in the YT-Indy cell line at biologically relevant levels. We also demonstrate successful induction and highly sensitive detection of antigen-specific response in multiple distinct model TCRs, with significant responses (p < 0.05 and Cohen's d >1.9) in all cases. Additionally, we monitored destruction of targets in co-culture and found that our survival-optimized system allowed for complete preservation after 24-hour exposure to cytotoxic effectors. With this bioplatform, we anticipate investigators will be empowered to rapidly express and characterize T cell receptor responses, generate new knowledge regarding the patterns of T cell receptor recognition, and optimize novel therapeutic T cell receptors for improved cytotoxic potential and reduced cross-reactivity to undesired antigenic targets.
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Affiliation(s)
- Govinda Sharma
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - James Round
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - Fei Teng
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - Zahra Ali
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - Chris May
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - Eric Yung
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
| | - Robert A. Holt
- Michael Smith Genome Sciences Centre; British Columbia Cancer Research Institute; 675 W 10 Ave, Vancouver, BC, V5Z 1L3; Canada
- Department of Medical Genetics; University of British Columbia; C201 – 4500 Oak Street, Vancouver, BC, V6H 3N1; Canada
- Department of Molecular Biology and Biochemistry; Simon Fraser University; SSB8166 – 8888 University Drive, Burnaby, BC, V5A 1S6; Canada
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Jahan F, Koski J, Schenkwein D, Ylä-Herttuala S, Göös H, Huuskonen S, Varjosalo M, Maliniemi P, Leitner J, Steinberger P, Bühring HJ, Vettenranta K, Korhonen M. Using the Jurkat reporter T cell line for evaluating the functionality of novel chimeric antigen receptors. FRONTIERS IN MOLECULAR MEDICINE 2023; 3:1070384. [PMID: 39086686 PMCID: PMC11285682 DOI: 10.3389/fmmed.2023.1070384] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/17/2023] [Indexed: 08/02/2024]
Abstract
Background: T cells that are genetically modified with chimeric antigen receptor (CAR) hold promise for immunotherapy of cancer. Currently, there are intense efforts to improve the safety and efficacy of CAR T cell therapies against liquid and solid tumors. Earlier we designed a novel CAR backbone (FiCAR) where the spacer is derived from immunoglobulin (Ig) -like domains of the signal-regulatory protein alpha (SIRPα). However, the analysis of novel CAR using primary T cells is slow and laborious. Methods: To explore the versatility of the CAR backbone, we designed a set of variant FiCARs with different spacer lengths and targeting antigens. To expedite the analysis of the novel CARs, we transduced the FiCAR genes using lentiviruses into Jurkat reporter T cells carrying fluorescent reporter genes. The expression of fluorescent markers in response to FiCAR engagement with targets was analyzed by flow cytometry, and cytotoxicity was evaluated using killing assays. Furthermore, the killing mechanisms that are employed by FiCAR-equipped Jurkat T cells were investigated by flow cytometry, and the intracellular pathways involved in signaling by FiCAR were analyzed by phosphoproteomic analysis using mass spectrometry. Results: Seven different CARs were designed and transduced into Jurkat reporter cells. We show that the SIRPα derived FiCARs can be detected by flow cytometry using the SE12B6A4 antibody recognizing SIRPα. Furthermore, FiCAR engagement leads to robust activation of NFκβ and NFAT signaling, as demonstrated by the expression of the fluorescent reporter genes. Interestingly, the Jurkat reporter system also revealed tonic signaling by a HER-2 targeting FiCAR. FiCAR-equipped Jurkat T cells were cytotoxic in cocultures with target cells and target cell engagement lead to an upregulation of CD107a on the Jurkat reporter T cell surface. Phosphoproteomic analyses confirmed signal transduction via the intracellular CD28/CD3ζ sequences upon the interaction of the FiCAR1 with its antigen. In addition, downstream signaling of CD3ζ/ZAP70- SLP-76-PLCγ, PI3K-AKT-NFκB pathways and activation of NFAT and AP-1 were observed. Conclusion: We conclude that the FiCAR backbone can be shortened and lengthened at will by engineering it with one to three SIRPα derived Ig-like domains, and the FiCARs are functional when equipped with different single chain variable fragment target binding domains. The Jurkat reporter system expedites the analysis of novel CARs as to their expression, signaling function, evaluation of tonic signaling issues and cytotoxic activity.
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Affiliation(s)
- Farhana Jahan
- R&D, Finnish Red Cross Blood Service, Helsinki, Finland
| | - Jan Koski
- R&D, Finnish Red Cross Blood Service, Helsinki, Finland
| | - Diana Schenkwein
- A.I Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Seppo Ylä-Herttuala
- A.I Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Gene Therapy Unit, Kuopio University Hospital, Kuopio, Finland
| | - Helka Göös
- R&D, Finnish Red Cross Blood Service, Helsinki, Finland
| | - Sini Huuskonen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | | | - Judith Leitner
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Peter Steinberger
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Hans-Jörg Bühring
- Department of Internal Medicine II, University Clinic of Tübingen, Tübingen, Germany
| | - Kim Vettenranta
- R&D, Finnish Red Cross Blood Service, Helsinki, Finland
- University of Helsinki and the Children’s Hospital, University of Helsinki, Helsinki, Finland
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4
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Emert-Sedlak LA, Shi H, Tice CM, Chen L, Alvarado JJ, Shu ST, Du S, Thomas CE, Wrobel JE, Reitz AB, Smithgall TE. Antiretroviral Drug Discovery Targeting the HIV-1 Nef Virulence Factor. Viruses 2022; 14:v14092025. [PMID: 36146831 PMCID: PMC9503669 DOI: 10.3390/v14092025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/06/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
While antiretroviral drugs have transformed the lives of HIV-infected individuals, chronic treatment is required to prevent rebound from viral reservoir cells. People living with HIV also are at higher risk for cardiovascular and neurocognitive complications, as well as cancer. Finding a cure for HIV-1 infection is therefore an essential goal of current AIDS research. This review is focused on the discovery of pharmacological inhibitors of the HIV-1 Nef accessory protein. Nef is well known to enhance HIV-1 infectivity and replication, and to promote immune escape of HIV-infected cells by preventing cell surface MHC-I display of HIV-1 antigens. Recent progress shows that Nef inhibitors not only suppress HIV-1 replication, but also restore sufficient MHC-I to the surface of infected cells to trigger a cytotoxic T lymphocyte response. Combining Nef inhibitors with latency reversal agents and therapeutic vaccines may provide a path to clearance of viral reservoirs.
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Affiliation(s)
- Lori A. Emert-Sedlak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Colin M. Tice
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Li Chen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John J. Alvarado
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Sherry T. Shu
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Shoucheng Du
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Catherine E. Thomas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jay E. Wrobel
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Allen B. Reitz
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, Doylestown, PA 18902, USA
| | - Thomas E. Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
- Correspondence:
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Sooda A, Rwandamuriye F, Wanjalla CN, Jing L, Koelle DM, Peters B, Leary S, Chopra A, Calderwood MA, Mallal SA, Pavlos R, Watson M, Phillips EJ, Redwood AJ. Abacavir inhibits but does not cause self-reactivity to HLA-B*57:01-restricted EBV specific T cell receptors. Commun Biol 2022; 5:133. [PMID: 35173258 PMCID: PMC8850454 DOI: 10.1038/s42003-022-03058-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 01/14/2022] [Indexed: 01/11/2023] Open
Abstract
Pre-existing pathogen-specific memory T cell responses can contribute to multiple adverse outcomes including autoimmunity and drug hypersensitivity. How the specificity of the T cell receptor (TCR) is subverted or seconded in many of these diseases remains unclear. Here, we apply abacavir hypersensitivity (AHS) as a model to address this question because the disease is linked to memory T cell responses and the HLA risk allele, HLA-B*57:01, and the initiating insult, abacavir, are known. To investigate the role of pathogen-specific TCR specificity in mediating AHS we performed a genome-wide screen for HLA-B*57:01 restricted T cell responses to Epstein-Barr virus (EBV), one of the most prevalent human pathogens. T cell epitope mapping revealed HLA-B*57:01 restricted responses to 17 EBV open reading frames and identified an epitope encoded by EBNA3C. Using these data, we cloned the dominant TCR for EBNA3C and a previously defined epitope within EBNA3B. TCR specificity to each epitope was confirmed, however, cloned TCRs did not cross-react with abacavir plus self-peptide. Nevertheless, abacavir inhibited TCR interactions with their cognate ligands, demonstrating that TCR specificity may be subverted by a drug molecule. These results provide an experimental road map for future studies addressing the heterologous immune responses of TCRs including T cell mediated adverse drug reactions.
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Affiliation(s)
- Anuradha Sooda
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Francois Rwandamuriye
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Telethon Kids Institute, Nedlands, WA, Australia
| | - Celestine N Wanjalla
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lichen Jing
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - David M Koelle
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Department of Global Health, University of Washington, Seattle, WA, USA
- Benaroya Research Institute, Seattle, WA, USA
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Bjoern Peters
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
| | - Shay Leary
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Michael A Calderwood
- Department of Medicine, The Channing Laboratory, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, 02115, USA
| | - Simon A Mallal
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Rebecca Pavlos
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Telethon Kids Institute, Nedlands, WA, Australia
| | - Mark Watson
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Elizabeth J Phillips
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia.
- Center for Drug Safety & Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Alec J Redwood
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Institute for Respiratory Health, Level 2, 6 Verdun Street, Nedlands, WA, 6009, Australia
- School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
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6
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Currenti J, Law BM, Qin K, John M, Pilkinton MA, Bansal A, Leary S, Ram R, Chopra A, Gangula R, Yue L, Warren C, Barnett L, Alves E, McDonnell WJ, Sooda A, Heath SL, Mallal S, Goepfert P, Kalams SA, Gaudieri S. Cross-Reactivity to Mutated Viral Immune Targets Can Influence CD8 + T Cell Functionality: An Alternative Viral Adaptation Strategy. Front Immunol 2021; 12:746986. [PMID: 34764960 PMCID: PMC8577586 DOI: 10.3389/fimmu.2021.746986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/07/2021] [Indexed: 11/25/2022] Open
Abstract
Loss of T cell immunogenicity due to mutations in virally encoded epitopes is a well-described adaptation strategy to limit host anti-viral immunity. Another described, but less understood, adaptation strategy involves the selection of mutations within epitopes that retain immune recognition, suggesting a benefit for the virus despite continued immune pressure (termed non-classical adaptation). To understand this adaptation strategy, we utilized a single cell transcriptomic approach to identify features of the HIV-specific CD8+ T cell responses targeting non-adapted (NAE) and adapted (AE) forms of epitopes containing a non-classical adaptation. T cell receptor (TCR) repertoire and transcriptome were obtained from antigen-specific CD8+ T cells of chronic (n=7) and acute (n=4) HIV-infected subjects identified by either HLA class I tetramers or upregulation of activation markers following peptide stimulation. CD8+ T cells were predominantly dual tetramer+, confirming a large proportion of cross-reactive TCR clonotypes capable of recognizing the NAE and AE form. However, single-reactive CD8+ T cells were identified in acute HIV-infected subjects only, providing the potential for the selection of T cell clones over time. The transcriptomic profile of CD8+ T cells was dependent on the autologous virus: subjects whose virus encoded the NAE form of the epitope (and who transitioned to the AE form at a later timepoint) exhibited an 'effective' immune response, as indicated by expression of transcripts associated with polyfunctionality, cytotoxicity and apoptosis (largely driven by the genes GZMB, IFNɣ, CCL3, CCL4 and CCL5). These data suggest that viral adaptation at a single amino acid residue can provide an alternative strategy for viral survival by modulating the transcriptome of CD8+ T cells and potentially selecting for less effective T cell clones from the acute to chronic phase.
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Affiliation(s)
- Jennifer Currenti
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Becker M.P. Law
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Kai Qin
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mina John
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Department of Clinical Immunology, Royal Perth Hospital, Perth, WA, Australia
| | - Mark A. Pilkinton
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Anju Bansal
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Shay Leary
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Ramesh Ram
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Rama Gangula
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Ling Yue
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, United States
| | - Christian Warren
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Louise Barnett
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Eric Alves
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Wyatt J. McDonnell
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Anuradha Sooda
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Sonya L. Heath
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Simon Mallal
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Paul Goepfert
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Spyros A. Kalams
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Silvana Gaudieri
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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7
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Jin SW, Alsahafi N, Kuang XT, Swann SA, Toyoda M, Göttlinger H, Walker BD, Ueno T, Finzi A, Brumme ZL, Brockman MA. Natural HIV-1 Nef Polymorphisms Impair SERINC5 Downregulation Activity. Cell Rep 2020; 29:1449-1457.e5. [PMID: 31693887 PMCID: PMC6925589 DOI: 10.1016/j.celrep.2019.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/26/2019] [Accepted: 10/01/2019] [Indexed: 11/30/2022] Open
Abstract
HIV-1 Nef enhances virion infectivity by counteracting host restriction factor SERINC5; however, the impact of natural Nef polymorphisms on this function is largely unknown. We characterize SERINC5 downregulation activity of 91 primary HIV-1 subtype B nef alleles, including isolates from 45 elite controllers and 46 chronic progressors. Controller-derived Nef clones display lower ability to downregulate SERINC5 (median 80% activity) compared with progressor-derived clones (median 96% activity) (p = 0.0005). We identify 18 Nef polymorphisms associated with differential function, including two CTL escape mutations that contribute to lower SERINC5 downregulation: K94E, driven by HLA-B∗08, and H116N, driven by the protective allele HLA-B∗57. HIV-1 strains encoding Nef K94E and/or H116N display lower infectivity and replication capacity in the presence of SERINC5. Our results demonstrate that natural polymorphisms in HIV-1 Nef can impair its ability to internalize SERINC5, indicating that variation in this recently described function may contribute to differences in viral pathogenesis.
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Affiliation(s)
- Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Nirmin Alsahafi
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Xiaomei T Kuang
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Shayda A Swann
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Mako Toyoda
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Heinrich Göttlinger
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Bruce D Walker
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA
| | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Andrés Finzi
- Centre de Recherche du CHUM, Montreal, QC, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada; Department of Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
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8
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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] [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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9
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Staudt RP, Smithgall TE. Nef homodimers down-regulate SERINC5 by AP-2-mediated endocytosis to promote HIV-1 infectivity. J Biol Chem 2020; 295:15540-15552. [PMID: 32873704 DOI: 10.1074/jbc.ra120.014668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/24/2020] [Indexed: 12/13/2022] Open
Abstract
SERINC5 is a multipass intrinsic membrane protein that suppresses HIV-1 infectivity when incorporated into budding virions. The HIV-1 Nef virulence factor prevents viral incorporation of SERINC5 by triggering its down-regulation from the producer cell membrane through an AP-2-dependent endolysosomal pathway. However, the mechanistic basis for SERINC5 down-regulation by Nef remains elusive. Here we demonstrate that Nef homodimers are important for SERINC5 down-regulation, trafficking to late endosomes, and exclusion from newly synthesized viral particles. Based on previous X-ray crystal structures, we mutated three conserved residues in the Nef dimer interface (Leu112, Tyr115, and Phe121) and demonstrated attenuated homodimer formation in a cell-based fluorescence complementation assay. Point mutations at each position reduced the infectivity of HIV-1 produced from transfected 293T cells, the Jurkat TAg T-cell line, and donor mononuclear cells in a SERINC5-dependent manner. In SERINC5-transfected 293T cells, virion incorporation of SERINC5 was increased by dimerization-defective Nef mutants, whereas down-regulation of SERINC5 from the membrane of transfected Jurkat cells by these mutants was significantly reduced. Nef dimer interface mutants also failed to trigger internalization of SERINC5 and localization to Rab7+ late endosomes in T cells. Importantly, fluorescence complementation assays demonstrated that dimerization-defective Nef mutants retained interaction with both SERINC5 and AP-2. These results show that down-regulation of SERINC5 and subsequent enhancement of viral infectivity require Nef homodimers and support a mechanism by which the Nef dimer bridges SERINC5 to AP-2 for endocytosis. Pharmacological disruption of Nef homodimers may control HIV-1 infectivity and viral spread by enhancing virion incorporation of SERINC5.
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Affiliation(s)
- Ryan P Staudt
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA.
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10
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An HIV-1 Nef genotype that diminishes immune control mediated by protective human leucocyte antigen alleles. AIDS 2020; 34:1325-1330. [PMID: 32590431 DOI: 10.1097/qad.0000000000002559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Certain human leucocyte antigen (HLA)-B alleles (protective alleles) associate with durable immune control of HIV-1, but with substantial heterogeneity in the level of control. It remains elusive whether viral factors including Nef-mediated immune evasion function diminish protective allele effect on viral control. DESIGN The naturally occurring non-Ser variant at position 9 of HIV-1 subtype C Nef has recently exhibited an association with enhanced HLA-B downregulation function and decreased susceptibility to recognition by CD8 T cells. We therefore hypothesized this Nef genotype leads to diminished immune control mediated by protective HLA alleles. METHODS Nef sequences were isolated from HIV-1 subtype C-infected patients harboring protective alleles and several Nef functions including downregulation of HLA-A, HLA-B, CD4, and SERINC5 were examined. Association between Nef non-Ser9 and plasma viral load was examined in two independent South African and Botswanan treatment-naïve cohorts. RESULTS Nef clones isolated from protective allele individuals encoding Nef non-Ser9 variant exhibited greater ability to downregulate HLA-B when compared with the Ser9 variant, while other Nef functions including HLA-A, CD4, and SERINC5 downregulation activity were unaltered. By analyzing a cohort of South African participants chronically infected with subtype C HIV-1, Nef non-Ser9 associated with higher plasma viral load in patients harboring protective alleles. Corroboratively, the Nef non-Ser9 correlated with higher plasma viral load in an independent cohort in Botswana. CONCLUSION Taken together, our study identifies the Nef genotype, non-Ser9 that subverts host immune control in HIV-1 subtype C infection.
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11
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Shi H, Tice CM, Emert-Sedlak L, Chen L, Li WF, Carlsen M, Wrobel JE, Reitz AB, Smithgall TE. Tight-Binding Hydroxypyrazole HIV-1 Nef Inhibitors Suppress Viral Replication in Donor Mononuclear Cells and Reverse Nef-Mediated MHC-I Downregulation. ACS Infect Dis 2020; 6:302-312. [PMID: 31775511 DOI: 10.1021/acsinfecdis.9b00382] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The HIV-1 Nef accessory factor is critical to the viral life cycle in vivo and promotes immune escape of infected cells via downregulation of cell-surface MHC-I. Previously, we discovered small molecules that bind directly to Nef and block many of its functions, including enhancement of viral infectivity and replication in T cell lines. These compounds also restore cell-surface MHC-I expression in HIV-infected CD4 T cells from AIDS patients, enabling recognition and killing by autologous cytotoxic T lymphocytes (CTLs). In this study, we describe the synthesis and evaluation of a diverse set of analogs based on the original hydroxypyrazole Nef inhibitor core. All analogs were screened for the interaction with recombinant HIV-1 Nef by surface plasmon resonance (SPR) and for antiretroviral activity in TZM-bl reporter cells infected with HIV-1. Active analogs were ranked on the basis of an activity score that integrates three aspects of the SPR data (affinity, residence time, and extent of binding) with antiretroviral activity. The top scoring compounds bound tightly to Nef by SPR, with KD values in the low nM to pM range, and displayed very slow dissociation from their Nef target. These analogs also suppressed HIV-1 replication in donor peripheral blood mononuclear cells (PBMCs) with IC50 values in the 1-10 nM range without cytotoxicity, inhibited Nef-mediated IL-2-inducible tyrosine kinase (Itk) and hematopoietic cell kinase (Hck) activation, and rescued MHC-I downregulation in a Nef-transfected T cell line. The development of Nef inhibitors based on the structure-activity relationships defined here has promise as a new approach to antiretroviral therapy that includes a path to eradication of HIV-infected cells via the adaptive immune response.
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Affiliation(s)
- Haibin Shi
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Suite 523 Bridgeside Point II, 450 Technology Drive, Pittsburgh, Pennsylvania 15219, United States
| | - Colin M. Tice
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Lori Emert-Sedlak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Suite 523 Bridgeside Point II, 450 Technology Drive, Pittsburgh, Pennsylvania 15219, United States
| | - Li Chen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Suite 523 Bridgeside Point II, 450 Technology Drive, Pittsburgh, Pennsylvania 15219, United States
| | - Wing Fai Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Suite 523 Bridgeside Point II, 450 Technology Drive, Pittsburgh, Pennsylvania 15219, United States
| | - Marianne Carlsen
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Jay E. Wrobel
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Allen B. Reitz
- Fox Chase Chemical Diversity Center, Inc., Pennsylvania Biotechnology Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Thomas E. Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Suite 523 Bridgeside Point II, 450 Technology Drive, Pittsburgh, Pennsylvania 15219, United States
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12
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Mann JK, Rajkoomar E, Jin SW, Mkhize Q, Baiyegunhi O, Mbona P, Brockman MA, Ndung'u T. Consequences of HLA-associated mutations in HIV-1 subtype C Nef on HLA-I downregulation ability. J Med Virol 2020; 92:1182-1190. [PMID: 31944317 DOI: 10.1002/jmv.25676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/07/2020] [Indexed: 11/10/2022]
Abstract
Identification of CD8+ T lymphocyte (CTL) escape mutations that compromise the pathogenic functions of the Nef protein may be relevant for an HIV-1 attenuation-based vaccine. Previously, HLA-associated mutations 102H, 105R, 108D, and 199Y were individually statistically associated with decreased Nef-mediated HLA-I downregulation ability in a cohort of 298 HIV-1 subtype C infected individuals. In the present study, these mutations were introduced by site-directed mutagenesis into different patient-derived Nef sequence backgrounds of high similarity to the consensus C Nef sequence, and their ability to downregulate HLA-I was measured by flow cytometry in a CEM-derived T cell line. A substantial negative effect of 199Y on HLA-I downregulation and Nef expression was observed, while 102H and 105R displayed negative effects on HLA-I downregulation ability and Nef expression to a lesser extent. The total magnitude of CTL responses in individuals harboring the 199Y mutation was lower than those without the mutation, although this was not statistically significant. Overall, a modest positive relationship between Nef-mediated HLA-I downregulation ability and total magnitude of CTL responses was observed, suggesting that there is a higher requirement for HLA-I downregulation with increased CTL pressure. These results highlight a region of Nef that could be targeted by vaccine-induced CTL to reduce HLA-I downregulation and maximize CTL efficacy.
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Affiliation(s)
- Jaclyn K Mann
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa
| | - Erasha Rajkoomar
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa
| | - Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Burnaby, BC, Canada
| | - Qiniso Mkhize
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa
| | | | - Pholisiwe Mbona
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Burnaby, BC, Canada.,Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Thumbi Ndung'u
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, South Africa.,Africa Health Research Institute, Durban, South Africa.,Ragon Institute of MGH, MIT and Harvard University, Cambridge, Maryland.,Max Planck Institute for Infection Biology, Berlin, Germany.,Division of Infection and Immunity, University College London, London, United Kingdom
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13
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Sudderuddin H, Kinloch NN, Jin SW, Miller RL, Jones BR, Brumme CJ, Joy JB, Brockman MA, Brumme ZL. Longitudinal within-host evolution of HIV Nef-mediated CD4, HLA and SERINC5 downregulation activity: a case study. Retrovirology 2020; 17:3. [PMID: 31918727 PMCID: PMC6953280 DOI: 10.1186/s12977-019-0510-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/26/2019] [Indexed: 11/29/2022] Open
Abstract
The HIV accessory protein Nef downregulates the viral entry receptor CD4, the Human Leukocyte Antigen (HLA)-A and -B molecules, the Serine incorporator 5 (SERINC5) protein and other molecules from the infected cell surface, thereby promoting viral infectivity, replication and immune evasion. The nef locus also represents one of the most genetically variable regions in the HIV genome, and nef sequences undergo substantial evolution within a single individual over the course of infection. Few studies however have simultaneously characterized the impact of within-host nef sequence evolution on Nef protein function over prolonged timescales. Here, we isolated 50 unique Nef clones by single-genome amplification over an 11-year period from the plasma of an individual who was largely naïve to antiretroviral treatment during this time. Together, these clones harbored nonsynonymous substitutions at 13% of nef’s codons. We assessed their ability to downregulate cell-surface CD4, HLA and SERINC5 and observed that all three Nef functions declined modestly over time, where the reductions in CD4 and HLA downregulation (an average of 0.6% and 2.0% per year, respectively) achieved statistical significance. The results from this case study support all three Nef activities as being important to maintain throughout untreated HIV infection, but nevertheless suggest that, despite nef’s mutational plasticity, within-host viral evolution can compromise Nef function, albeit modestly, over prolonged periods.
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Affiliation(s)
- Hanwei Sudderuddin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.,BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Natalie N Kinloch
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.,BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Rachel L Miller
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | | | - Chanson J Brumme
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jeffrey B Joy
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.,BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada. .,BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
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14
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Rapid selection and identification of functional CD8 + T cell epitopes from large peptide-coding libraries. Nat Commun 2019; 10:4553. [PMID: 31591401 PMCID: PMC6779888 DOI: 10.1038/s41467-019-12444-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/10/2019] [Indexed: 12/18/2022] Open
Abstract
Cytotoxic CD8+ T cells recognize and eliminate infected or malignant cells that present peptide epitopes derived from intracellularly processed antigens on their surface. However, comprehensive profiling of specific major histocompatibility complex (MHC)-bound peptide epitopes that are naturally processed and capable of eliciting a functional T cell response has been challenging. Here, we report a method for deep and unbiased T cell epitope profiling, using in vitro co-culture of CD8+ T cells together with target cells transduced with high-complexity, epitope-encoding minigene libraries. Target cells that are subject to cytotoxic attack from T cells in co-culture are isolated prior to apoptosis by fluorescence-activated cell sorting, and characterized by sequencing the encoded minigenes. We then validate this highly parallelized method using known murine T cell receptor/peptide-MHC pairs and diverse minigene-encoded epitope libraries. Our data thus suggest that this epitope profiling method allows unambiguous and sensitive identification of naturally processed and MHC-presented peptide epitopes.
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15
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HIV Subtype and Nef-Mediated Immune Evasion Function Correlate with Viral Reservoir Size in Early-Treated Individuals. J Virol 2019; 93:JVI.01832-18. [PMID: 30602611 DOI: 10.1128/jvi.01832-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/30/2018] [Indexed: 11/20/2022] Open
Abstract
The HIV accessory protein Nef modulates key immune evasion and pathogenic functions, and its encoding gene region exhibits high sequence diversity. Given the recent identification of early HIV-specific adaptive immune responses as novel correlates of HIV reservoir size, we hypothesized that viral factors that facilitate the evasion of such responses-namely, Nef genetic and functional diversity-might also influence reservoir establishment and/or persistence. We isolated baseline plasma HIV RNA-derived nef clones from 30 acute/early-infected individuals who participated in a clinical trial of early combination antiretroviral therapy (cART) (<6 months following infection) and assessed each Nef clone's ability to downregulate CD4 and human leukocyte antigen (HLA) class I in vitro We then explored the relationships between baseline clinical, immunological, and virological characteristics and the HIV reservoir size measured 48 weeks following initiation of suppressive cART (where the reservoir size was quantified in terms of the proviral DNA loads as well as the levels of replication-competent HIV in CD4+ T cells). Maximal within-host Nef-mediated downregulation of HLA, but not CD4, correlated positively with post-cART proviral DNA levels (Spearman's R = 0.61, P = 0.0004) and replication-competent reservoir sizes (Spearman's R = 0.36, P = 0.056) in univariable analyses. Furthermore, the Nef-mediated HLA downregulation function was retained in final multivariable models adjusting for established clinical and immunological correlates of reservoir size. Finally, HIV subtype B-infected persons (n = 25) harbored significantly larger viral reservoirs than non-subtype B-infected persons (2 infected with subtype CRF01_AE and 3 infected with subtype G). Our results highlight a potentially important role of viral factors-in particular, HIV subtype and accessory protein function-in modulating viral reservoir establishment and persistence.IMPORTANCE While combination antiretroviral therapies (cART) have transformed HIV infection into a chronic manageable condition, they do not act upon the latent HIV reservoir and are therefore not curative. As HIV cure or remission should be more readily achievable in individuals with smaller HIV reservoirs, achieving a deeper understanding of the clinical, immunological, and virological determinants of reservoir size is critical to eradication efforts. We performed a post hoc analysis of 30 participants of a clinical trial of early cART who had previously been assessed in detail for their clinical, immunological, and reservoir size characteristics. We observed that the HIV subtype and autologous Nef-mediated HLA downregulation function correlated with the viral reservoir size measured approximately 1 year post-cART initiation. Our findings highlight virological characteristics-both genetic and functional-as possible novel determinants of HIV reservoir establishment and persistence.
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16
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Rydzek J, Nerreter T, Peng H, Jutz S, Leitner J, Steinberger P, Einsele H, Rader C, Hudecek M. Chimeric Antigen Receptor Library Screening Using a Novel NF-κB/NFAT Reporter Cell Platform. Mol Ther 2019; 27:287-299. [PMID: 30573301 PMCID: PMC6369451 DOI: 10.1016/j.ymthe.2018.11.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 12/16/2022] Open
Abstract
Chimeric antigen receptor (CAR)-T cell immunotherapy is under intense preclinical and clinical investigation, and it involves a rapidly increasing portfolio of novel target antigens and CAR designs. We established a platform that enables rapid and high-throughput CAR-screening campaigns with reporter cells derived from the T cell lymphoma line Jurkat. Reporter cells were equipped with nuclear factor κB (NF-κB) and nuclear factor of activated T cells (NFAT) reporter genes that generate a duplex output of enhanced CFP (ECFP) and EGFP, respectively. As a proof of concept, we modified reporter cells with CD19-specific and ROR1-specific CARs, and we detected high-level reporter signals that allowed distinguishing functional from non-functional CAR constructs. The reporter data were highly reproducible, and the time required for completing each testing campaign was substantially shorter with reporter cells (6 days) compared to primary CAR-T cells (21 days). We challenged the reporter platform to a large-scale screening campaign on a ROR1-CAR library, and we showed that reporter cells retrieved a functional CAR variant that was present with a frequency of only 6 in 1.05 × 106. The data illustrate the potential to implement this reporter platform into the preclinical development path of novel CAR-T cell products and to inform and accelerate the selection of lead CAR candidates for clinical translation.
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Affiliation(s)
- Julian Rydzek
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Thomas Nerreter
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Haiyong Peng
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Sabrina Jutz
- Institut für Immunologie, Medizinische Universität Wien, Wien, Austria
| | - Judith Leitner
- Institut für Immunologie, Medizinische Universität Wien, Wien, Austria
| | - Peter Steinberger
- Institut für Immunologie, Medizinische Universität Wien, Wien, Austria
| | - Hermann Einsele
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany
| | - Christoph Rader
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Michael Hudecek
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Würzburg, Würzburg, Germany.
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17
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Ogunshola F, Anmole G, Miller RL, Goering E, Nkosi T, Muema D, Mann J, Ismail N, Chopera D, Ndung'u T, Brockman MA, Ndhlovu ZM. Dual HLA B*42 and B*81-reactive T cell receptors recognize more diverse HIV-1 Gag escape variants. Nat Commun 2018; 9:5023. [PMID: 30479346 PMCID: PMC6258674 DOI: 10.1038/s41467-018-07209-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/16/2018] [Indexed: 11/17/2022] Open
Abstract
Some closely related human leukocyte antigen (HLA) alleles are associated with variable clinical outcomes following HIV-1 infection despite presenting the same viral epitopes. Mechanisms underlying these differences remain unclear but may be due to intrinsic characteristics of the HLA alleles or responding T cell repertoires. Here we examine CD8+ T cell responses against the immunodominant HIV-1 Gag epitope TL9 (TPQDLNTML180–188) in the context of the protective allele B*81:01 and the less protective allele B*42:01. We observe a population of dual-reactive T cells that recognize TL9 presented by both B*81:01 and B*42:01 in individuals lacking one allele. The presence of dual-reactive T cells is associated with lower plasma viremia, suggesting a clinical benefit. In B*42:01 expressing individuals, the dual-reactive phenotype defines public T cell receptor (TCR) clones that recognize a wider range of TL9 escape variants, consistent with enhanced control of viral infection through containment of HIV-1 sequence adaptation. Closely related HLA alleles presenting similar HIV-1 epitopes can be associated with variable clinical outcome. Here the authors report their findings on CD8+ T cell responses to the HIV-1 Gag-p24 TL9 immunodominant epitope in the context of closely related protective and less protective HLA alleles, and their differential effect on viral control
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Affiliation(s)
- Funsho Ogunshola
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa.,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Gursev Anmole
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Rachel L Miller
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Emily Goering
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, 02139, USA
| | - Thandeka Nkosi
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa.,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Daniel Muema
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Jaclyn Mann
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Nasreen Ismail
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Denis Chopera
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Thumbi Ndung'u
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa.,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa.,Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, 02139, USA.,Max Planck Institute for Infection Biology, Berlin, Germany
| | - Mark A Brockman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada. .,Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada. .,British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, V6Z 1Y6, Canada.
| | - Zaza M Ndhlovu
- Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa. .,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa. .,Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, 02139, USA.
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18
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Rosskopf S, Leitner J, Paster W, Morton LT, Hagedoorn RS, Steinberger P, Heemskerk MHM. A Jurkat 76 based triple parameter reporter system to evaluate TCR functions and adoptive T cell strategies. Oncotarget 2018; 9:17608-17619. [PMID: 29707134 PMCID: PMC5915142 DOI: 10.18632/oncotarget.24807] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/26/2018] [Indexed: 12/12/2022] Open
Abstract
Adoptive T cell therapy using TCR transgenic autologous T cells has shown great potential for the treatment of tumor patients. Thorough characterization of genetically reprogrammed T cells is necessary to optimize treatment success. Here, we describe the generation of triple parameter reporter T cells based on the Jurkat 76 T cell line for the evaluation of TCR and chimeric antigen receptor functions as well as adoptive T cell strategies. This Jurkat subline is devoid of endogenous TCR alpha and TCR beta chains, thereby circumventing the problem of TCR miss-pairing and unexpected specificities. The resultant reporter cells allow simultaneous determination of the activity of the transcription factors NF-κB, NFAT and AP-1 that play key roles in T cell activation. Human TCRs directed against tumor and virus antigens were introduced and reporter responses were determined using tumor cell lines endogenously expressing the antigens of interest or via addition of antigenic peptides. Finally, we demonstrate that coexpression of adhesion molecules like CD2 and CD226 as well as CD28 chimeric receptors represents an effective strategy to augment the response of TCR-transgenic reporters to cells presenting cognate antigens.
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Affiliation(s)
- Sandra Rosskopf
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Judith Leitner
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Paster
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Laura T Morton
- Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands
| | - Renate S Hagedoorn
- Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter Steinberger
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Mirjam H M Heemskerk
- Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands
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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 2017; 92:JVI.01409-17. [PMID: 29046444 DOI: 10.1128/jvi.01409-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [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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20
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Abana CO, Pilkinton MA, Gaudieri S, Chopra A, McDonnell WJ, Wanjalla C, Barnett L, Gangula R, Hager C, Jung DK, Engelhardt BG, Jagasia MH, Klenerman P, Phillips EJ, Koelle DM, Kalams SA, Mallal SA. Cytomegalovirus (CMV) Epitope-Specific CD4 + T Cells Are Inflated in HIV + CMV + Subjects. THE JOURNAL OF IMMUNOLOGY 2017; 199:3187-3201. [PMID: 28972094 DOI: 10.4049/jimmunol.1700851] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/28/2017] [Indexed: 01/24/2023]
Abstract
Select CMV epitopes drive life-long CD8+ T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4+ T cells specific for human CMV (HCMV) are elevated in HIV+ HCMV+ subjects. To determine whether HCMV epitope-specific CD4+ T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4+ T cells in coinfected HLA-DR7+ long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4+ T cells were inflated among these HIV+ subjects compared with those from an HIV- HCMV+ HLA-DR7+ cohort or with HLA-DR7-restricted CD4+ T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4+ T cells consisted of effector memory or effector memory-RA+ subsets with restricted TCRβ usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX3CR1, CD38, or HLA-DR but less often coexpressed CD38+ and HLA-DR+ The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4+ T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease.
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Affiliation(s)
- Chike O Abana
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Mark A Pilkinton
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Silvana Gaudieri
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,School of Human Sciences, University of Western Australia, Perth, Western Australia 6009, Australia.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Wyatt J McDonnell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Celestine Wanjalla
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Louise Barnett
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Rama Gangula
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Cindy Hager
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Dae K Jung
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Brian G Engelhardt
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Madan H Jagasia
- Stem Cell Transplantation, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford OX1 3SY, United Kingdom; and
| | - Elizabeth J Phillips
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - David M Koelle
- Department of Medicine, Laboratory Medicine, and Global Health, University of Washington, Seattle, WA 98195
| | - Spyros A Kalams
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Simon A Mallal
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232; .,Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232.,Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia 6150, Australia
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21
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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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22
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Consequences of HLA-B*13-Associated Escape Mutations on HIV-1 Replication and Nef Function. J Virol 2015; 89:11557-71. [PMID: 26355081 DOI: 10.1128/jvi.01955-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/31/2015] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED HLA-B*13 is associated with superior in vivo HIV-1 viremia control. Protection is thought to be mediated by sustained targeting of key cytotoxic T lymphocyte (CTL) epitopes and viral fitness costs of CTL escape in Gag although additional factors may contribute. We assessed the impact of 10 published B*13-associated polymorphisms in Gag, Pol, and Nef, in 23 biologically relevant combinations, on HIV-1 replication capacity and Nef-mediated reduction of cell surface CD4 and HLA class I expression. Mutations were engineered into HIV-1NL4.3, and replication capacity was measured using a green fluorescent protein (GFP) reporter T cell line. Nef-mediated CD4 and HLA-A*02 downregulation was assessed by flow cytometry, and T cell recognition of infected target cells was measured via coculture with an HIV-specific luciferase reporter cell line. When tested individually, only Gag-I147L and Gag-I437L incurred replicative costs (5% and 17%, respectively), consistent with prior reports. The Gag-I437L-mediated replication defect was rescued to wild-type levels by the adjacent K436R mutation. A novel B*13 epitope, comprising 8 residues and terminating at Gag147, was identified in p24(Gag) (GQMVHQAIGag140-147). No other single or combination Gag, Pol, or Nef mutant impaired viral replication. Single Nef mutations did not affect CD4 or HLA downregulation; however, the Nef double mutant E24Q-Q107R showed 40% impairment in HLA downregulation with no evidence of Nef stability defects. Moreover, target cells infected with HIV-1-NefE24Q-Q107R were recognized better by HIV-specific T cells than those infected with HIV-1NL4.3 or single Nef mutants. Our results indicate that CTL escape in Gag and Nef can be functionally costly and suggest that these effects may contribute to long-term HIV-1 control by HLA-B*13. IMPORTANCE Protective effects of HLA-B*13 on HIV-1 disease progression are mediated in part by fitness costs of CTL escape mutations in conserved Gag epitopes, but other mechanisms remain incompletely known. We extend our knowledge of the impact of B*13-driven escape on HIV-1 replication by identifying Gag-K436R as a compensatory mutation for the fitness-costly Gag-I437L. We also identify Gag-I147L, the most rapidly and commonly selected B*13-driven substitution in HIV-1, as a putative C-terminal anchor residue mutation in a novel B*13 epitope. Most notably, we identify a novel escape-driven fitness defect: B*13-driven substitutions E24Q and Q107R in Nef, when present together, substantially impair this protein's ability to downregulate HLA class I. This, in turn, increases the visibility of infected cells to HIV-specific T cells. Our results suggest that B*13-associated escape mutations impair HIV-1 replication by two distinct mechanisms, that is, by reducing Gag fitness and dampening Nef immune evasion function.
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