1
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Masenga SK, Mweene BC, Luwaya E, Muchaili L, Chona M, Kirabo A. HIV-Host Cell Interactions. Cells 2023; 12:1351. [PMID: 37408185 DOI: 10.3390/cells12101351] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 07/07/2023] Open
Abstract
The development of antiretroviral drugs (ARVs) was a great milestone in the management of HIV infection. ARVs suppress viral activity in the host cell, thus minimizing injury to the cells and prolonging life. However, an effective treatment has remained elusive for four decades due to the successful immune evasion mechanisms of the virus. A thorough understanding of the molecular interaction of HIV with the host cell is essential in the development of both preventive and curative therapies for HIV infection. This review highlights several inherent mechanisms of HIV that promote its survival and propagation, such as the targeting of CD4+ lymphocytes, the downregulation of MHC class I and II, antigenic variation and an envelope complex that minimizes antibody access, and how they collaboratively render the immune system unable to mount an effective response.
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Affiliation(s)
- Sepiso K Masenga
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
- Vanderbilt University Medical Center, Department of Medicine, Division of Clinical Pharmacology, Room 536 Robinson Research Building, Nashville, TN 37232-6602, USA
| | - Bislom C Mweene
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Emmanuel Luwaya
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Lweendo Muchaili
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Makondo Chona
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Annet Kirabo
- Vanderbilt University Medical Center, Department of Medicine, Division of Clinical Pharmacology, Room 536 Robinson Research Building, Nashville, TN 37232-6602, USA
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2
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Selective Disruption of SERINC5 Antagonism by Nef Impairs SIV Replication in Primary CD4 + T Cells. J Virol 2021; 95:JVI.01911-20. [PMID: 33504599 PMCID: PMC8103682 DOI: 10.1128/jvi.01911-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Nef proteins of HIV-1 and SIV enhance viral infectivity by preventing the incorporation of the multipass transmembrane protein serine incorporator 5 (SERINC5), and to a lesser extent SERINC3, into virions. In addition to counteracting SERINCs, SIV Nef also downmodulates several transmembrane proteins from the surface of virus-infected cells, including simian tetherin, CD4 and MHC class I (MHC I) molecules. From a systematic analysis of alanine substitutions throughout the SIVmac239 Nef protein, we identified residues that are required to counteract SERINC5. This information was used to engineer an infectious molecular clone of SIV (SIVmac239nef AV), which differs by two amino acids in the N-terminal domain of Nef that make the virus sensitive to SERINC5 while retaining other activities of Nef. SIVmac239nef AV downmodulates CD3, CD4, MHC I and simian tetherin, but cannot counteract SERINC5. In primary rhesus macaque CD4+ T cells, SIVmac239nef AV exhibits impaired infectivity and replication compared to wild-type SIVmac239. These results demonstrate that SERINC5 antagonism can be separated from other Nef functions and reveal the impact of SERINC5 on lentiviral replication.Importance: SERINC5, a multipass transmembrane protein, is incorporated into retroviral particles during assembly. This leads to a reduction of particle infectivity by inhibiting virus fusion with the target cell membrane. The Nef proteins of HIV-1 and SIV enhance viral infectivity by preventing the incorporation of SERINC5 into virions. However, the relevance of this restriction factor in viral replication has not been elucidated. Here we report a systematic mapping of Nef residues required for SERINC5 antagonism. Counter screens for three other functions of Nef helped identify two residues in the N-terminal domain of Nef, which when mutated make Nef selectively susceptible to SERINC5. Since Nef is multi-functional, genetic separation of SERINC5 antagonism from its other functions affords comparison of the replication of isogenic viruses that are or are not sensitive to SERINC5. Such a strategy revealed the impact of SERINC5 on SIV replication in primary rhesus macaque CD4+ T-cells.
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3
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Joas S, Sauermann U, Roshani B, Klippert A, Daskalaki M, Mätz-Rensing K, Stolte-Leeb N, Heigele A, Tharp GK, Gupta PM, Nelson S, Bosinger S, Parodi L, Giavedoni L, Silvestri G, Sauter D, Stahl-Hennig C, Kirchhoff F. Nef-Mediated CD3-TCR Downmodulation Dampens Acute Inflammation and Promotes SIV Immune Evasion. Cell Rep 2021; 30:2261-2274.e7. [PMID: 32075764 PMCID: PMC7052273 DOI: 10.1016/j.celrep.2020.01.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/10/2019] [Accepted: 01/21/2020] [Indexed: 01/05/2023] Open
Abstract
The inability of Nef to downmodulate the CD3-T cell receptor (TCR) complex distinguishes HIV-1 from other primate lentiviruses and may contribute to its high virulence. However, the role of this Nef function in virus-mediated immune activation and pathogenicity remains speculative. Here, we selectively disrupted this Nef activity in SIVmac239 and analyzed the consequences for the virological, immunological, and clinical outcome of infection in rhesus macaques. The inability to downmodulate CD3-TCR does not impair viral replication during acute infection but is associated with increased immune activation and antiviral gene expression. Subsequent early reversion in three of six animals suggests strong selective pressure for this Nef function and is associated with high viral loads and progression to simian AIDS. In the absence of reversions, however, viral replication and the clinical course of infection are attenuated. Thus, Nef-mediated downmodulation of CD3 dampens the inflammatory response to simian immunodeficiency virus (SIV) infection and seems critical for efficient viral immune evasion. HIV-1 lacks the CD3 downmodulation function of Nef that is otherwise conserved in primate lentiviruses. Joas et al. disrupted this Nef activity in SIVmac239 and show that Nef-mediated downmodulation of CD3 dampens inflammatory responses to SIV. This promotes effective immune evasion and maintenance of high viral loads in infected rhesus macaques.
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Affiliation(s)
- Simone Joas
- Institute of Molecular Virology - Ulm University Medical Center, Meyerhofstraße 1, 89081 Ulm, Germany
| | | | - Berit Roshani
- German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | | | - Maria Daskalaki
- German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | | | | | - Anke Heigele
- Institute of Molecular Virology - Ulm University Medical Center, Meyerhofstraße 1, 89081 Ulm, Germany
| | - Gregory K Tharp
- Yerkes Primate Research Center, Emory Vaccine Center, and Department of Pathology, Emory University, Atlanta, GA, USA
| | - Prachi Mehrotra Gupta
- Yerkes Primate Research Center, Emory Vaccine Center, and Department of Pathology, Emory University, Atlanta, GA, USA
| | - Sydney Nelson
- Yerkes Primate Research Center, Emory Vaccine Center, and Department of Pathology, Emory University, Atlanta, GA, USA
| | - Steven Bosinger
- Yerkes Primate Research Center, Emory Vaccine Center, and Department of Pathology, Emory University, Atlanta, GA, USA
| | - Laura Parodi
- Host-Pathogen Interactions Program, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Luis Giavedoni
- Host-Pathogen Interactions Program, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Guido Silvestri
- Yerkes Primate Research Center, Emory Vaccine Center, and Department of Pathology, Emory University, Atlanta, GA, USA
| | - Daniel Sauter
- Institute of Molecular Virology - Ulm University Medical Center, Meyerhofstraße 1, 89081 Ulm, Germany
| | | | - Frank Kirchhoff
- Institute of Molecular Virology - Ulm University Medical Center, Meyerhofstraße 1, 89081 Ulm, Germany.
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4
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Tavakoli-Tameh A, Janaka SK, Zarbock K, O’Connor S, Crosno K, Capuano S, Uno H, Lifson JD, Evans DT. Loss of tetherin antagonism by Nef impairs SIV replication during acute infection of rhesus macaques. PLoS Pathog 2020; 16:e1008487. [PMID: 32302364 PMCID: PMC7190186 DOI: 10.1371/journal.ppat.1008487] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/29/2020] [Accepted: 03/21/2020] [Indexed: 12/13/2022] Open
Abstract
Most simian immunodeficiency viruses use Nef to counteract the tetherin proteins of their nonhuman primate hosts. Nef also downmodulates cell-surface CD4 and MHC class I (MHC I) molecules and enhances viral infectivity by counteracting SERINC5. We previously demonstrated that tetherin antagonism by SIV Nef is genetically separable from CD4- and MHC I-downmodulation. Here we show that disruption of tetherin antagonism by Nef impairs virus replication during acute SIV infection of rhesus macaques. A combination of mutations was introduced into the SIVmac239 genome resulting in three amino acid substitutions in Nef that impair tetherin antagonism, but not CD3-, CD4- or MHC I-downmodulation. Further characterization of this mutant (SIVmac239AAA) revealed that these changes also result in partial sensitivity to SERINC5. Separate groups of four rhesus macaques were infected with either wild-type SIVmac239 or SIVmac239AAA, and viral RNA loads in plasma and sequence changes in the viral genome were monitored. Viral loads were significantly lower during acute infection in animals infected with SIVmac239AAA than in animals infected with wild-type SIVmac239. Sequence analysis of the virus population in plasma confirmed that the substitutions in Nef were retained during acute infection; however, changes were observed by week 24 post-infection that fully restored anti-tetherin activity and partially restored anti-SERINC5 activity. These observations reveal overlap in the residues of SIV Nef required for counteracting tetherin and SERINC5 and selective pressure to overcome these restriction factors in vivo.
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Affiliation(s)
- Aidin Tavakoli-Tameh
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Sanath Kumar Janaka
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Katie Zarbock
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Shelby O’Connor
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kristin Crosno
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Saverio Capuano
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Hajime Uno
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - David T. Evans
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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5
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Sannier G, Dubé M, Kaufmann DE. Single-Cell Technologies Applied to HIV-1 Research: Reaching Maturity. Front Microbiol 2020; 11:297. [PMID: 32194526 PMCID: PMC7064469 DOI: 10.3389/fmicb.2020.00297] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/10/2020] [Indexed: 12/11/2022] Open
Abstract
The need for definitive answers probably explains our natural tendency to seek simplicity. The reductionist “bulk” approach, in which a mean behavior is attributed to a heterogeneous cell population, fulfills this need by considerably helping the conceptualization of complex biological processes. However, the limits of this methodology are becoming increasingly clear as models seek to explain biological events occurring in vivo, where heterogeneity is the rule. Research in the HIV-1 field is no exception: the challenges encountered in the development of preventive and curative anti-HIV-1 strategies may well originate in part from inadequate assumptions built on bulk technologies, highlighting the need for new perspectives. The emergence of diverse single-cell technologies set the stage for potential breakthrough discoveries, as heterogeneous processes can now be investigated with an unprecedented depth in topics as diverse as HIV-1 tropism, dynamics of the replication cycle, latency, viral reservoirs and immune control. In this review, we summarize recent advances in the HIV-1 field made possible by single-cell technologies, and contextualize their importance.
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Affiliation(s)
- Gérémy Sannier
- Research Centre of the Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada.,Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Mathieu Dubé
- Research Centre of the Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - Daniel E Kaufmann
- Research Centre of the Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada.,Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Consortium for HIV/AIDS Vaccine Development (Scripps CHAVD), La Jolla, CA, United States
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6
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Munusamy Ponnan S, Hayes P, Fernandez N, Thiruvengadam K, Pattabiram S, Nesakumar M, Srinivasan A, Kathirvel S, Shankar J, Goyal R, Singla N, Mukherjee J, Chatrath S, Gilmour J, Subramanyam S, Prasad Tripathy S, Swaminathan S, Hanna LE. Evaluation of antiviral T cell responses and TSCM cells in volunteers enrolled in a phase I HIV-1 subtype C prophylactic vaccine trial in India. PLoS One 2020; 15:e0229461. [PMID: 32097435 PMCID: PMC7041807 DOI: 10.1371/journal.pone.0229461] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
T cells play an important role in controlling viral replication during HIV infection. An effective vaccine should, therefore, lead to the induction of a strong and early viral-specific CD8+ T cell response. While polyfunctional T cell responses are thought to be important contributors to the antiviral response, there is evidence to show that polyfunctional HIV- specific CD8+ T cells are just a small fraction of the total HIV-specific CD8+ T cells and may be absent in many individuals who control HIV replication, suggesting that other HIV-1 specific CD8+ effector T cell subsets may be key players in HIV control. Stem cell-like memory T cells (TSCM) are a subset of T cells with a long half-life and self-renewal capacity. They serve as key reservoirs for HIV and contribute a significant barrier to HIV eradication. The present study evaluated vaccine-induced antiviral responses and TSCM cells in volunteers vaccinated with a subtype C prophylactic HIV-1 vaccine candidate administered in a prime-boost regimen. We found that ADVAX DNA prime followed by MVA boost induced significantly more peripheral CD8+ TSCM cells and higher levels of CD8+ T cell-mediated inhibition of replication of different HIV-1 clades as compared to MVA alone and placebo. These findings are novel and provide encouraging evidence to demonstrate the induction of TSCM and cytotoxic immune responses by a subtype C HIV-1 prophylactic vaccine administered using a prime-boost strategy.
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Affiliation(s)
| | - Peter Hayes
- IAVI Human Immunology Laboratory, Imperial College, London, England, United Kingdom
| | - Natalia Fernandez
- IAVI Human Immunology Laboratory, Imperial College, London, England, United Kingdom
| | - Kannan Thiruvengadam
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Sathyamurthi Pattabiram
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Manohar Nesakumar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Ashokkumar Srinivasan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Sujitha Kathirvel
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Janani Shankar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Rajat Goyal
- International AIDS Vaccine Initiative, New Delhi, India
| | - Nikhil Singla
- International AIDS Vaccine Initiative, New Delhi, India
| | | | | | - Jill Gilmour
- IAVI Human Immunology Laboratory, Imperial College, London, England, United Kingdom
| | - Sudha Subramanyam
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Srikanth Prasad Tripathy
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Soumya Swaminathan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Luke Elizabeth Hanna
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
- * E-mail:
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7
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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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8
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Gonzalez-Nieto L, Castro IM, Bischof GF, Shin YC, Ricciardi MJ, Bailey VK, Dang CM, Pedreño-Lopez N, Magnani DM, Ejima K, Allison DB, Gil HM, Evans DT, Rakasz EG, Lifson JD, Desrosiers RC, Martins MA. Vaccine protection against rectal acquisition of SIVmac239 in rhesus macaques. PLoS Pathog 2019; 15:e1008015. [PMID: 31568531 PMCID: PMC6791558 DOI: 10.1371/journal.ppat.1008015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/14/2019] [Accepted: 08/02/2019] [Indexed: 02/07/2023] Open
Abstract
A prophylactic vaccine against human immunodeficiency virus (HIV) remains a top priority in biomedical research. Given the failure of conventional immunization protocols to confer robust protection against HIV, new and unconventional approaches may be needed to generate protective anti-HIV immunity. Here we vaccinated rhesus macaques (RMs) with a recombinant (r)DNA prime (without any exogenous adjuvant), followed by a booster with rhesus monkey rhadinovirus (RRV)-a herpesvirus that establishes persistent infection in RMs (Group 1). Both the rDNA and rRRV vectors encoded a near-full-length simian immunodeficiency virus (SIVnfl) genome that assembles noninfectious SIV particles and expresses all nine SIV gene products. This rDNA/rRRV-SIVnfl vaccine regimen induced persistent anti-Env antibodies and CD8+ T-cell responses against the entire SIV proteome. Vaccine efficacy was assessed by repeated, marginal-dose, intrarectal challenges with SIVmac239. Encouragingly, vaccinees in Group 1 acquired SIVmac239 infection at a significantly delayed rate compared to unvaccinated controls (Group 3). In an attempt to improve upon this outcome, a separate group of rDNA/rRRV-SIVnfl-vaccinated RMs (Group 2) was treated with a cytotoxic T-lymphocyte antigen-4 (CTLA-4)-blocking monoclonal antibody during the vaccine phase and then challenged in parallel with Groups 1 and 3. Surprisingly, Group 2 was not significantly protected against SIVmac239 infection. In sum, SIVnfl vaccination can protect RMs against rigorous mucosal challenges with SIVmac239, a feat that until now had only been accomplished by live-attenuated strains of SIV. Further work is needed to identify the minimal requirements for this protection and whether SIVnfl vaccine efficacy can be improved by means other than anti-CTLA-4 adjuvant therapy.
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Affiliation(s)
- Lucas Gonzalez-Nieto
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Isabelle M. Castro
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Georg F. Bischof
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Young C. Shin
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Michael J. Ricciardi
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Varian K. Bailey
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Christine M. Dang
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Nuria Pedreño-Lopez
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Diogo M. Magnani
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Keisuke Ejima
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, Bloomington, Indiana, United States of America
| | - David B. Allison
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, Bloomington, Indiana, United States of America
| | - Hwi Min Gil
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - David T. Evans
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Eva G. Rakasz
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Ronald C. Desrosiers
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Mauricio A. Martins
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
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9
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Barton JP, Rajkoomar E, Mann JK, Murakowski DK, Toyoda M, Mahiti M, Mwimanzi P, Ueno T, Chakraborty AK, Ndung'u T. Modelling and in vitro testing of the HIV-1 Nef fitness landscape. Virus Evol 2019; 5:vez029. [PMID: 31392033 PMCID: PMC6680064 DOI: 10.1093/ve/vez029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An effective vaccine is urgently required to curb the HIV-1 epidemic. We have previously described an approach to model the fitness landscape of several HIV-1 proteins, and have validated the results against experimental and clinical data. The fitness landscape may be used to identify mutation patterns harmful to virus viability, and consequently inform the design of immunogens that can target such regions for immunological control. Here we apply such an analysis and complementary experiments to HIV-1 Nef, a multifunctional protein which plays a key role in HIV-1 pathogenesis. We measured Nef-driven replication capacities as well as Nef-mediated CD4 and HLA-I down-modulation capacities of thirty-two different Nef mutants, and tested model predictions against these results. Furthermore, we evaluated the models using 448 patient-derived Nef sequences for which several Nef activities were previously measured. Model predictions correlated significantly with Nef-driven replication and CD4 down-modulation capacities, but not HLA-I down-modulation capacities, of the various Nef mutants. Similarly, in our analysis of patient-derived Nef sequences, CD4 down-modulation capacity correlated the most significantly with model predictions, suggesting that of the tested Nef functions, this is the most important in vivo. Overall, our results highlight how the fitness landscape inferred from patient-derived sequences captures, at least in part, the in vivo functional effects of mutations to Nef. However, the correlation between predictions of the fitness landscape and measured parameters of Nef function is not as accurate as the correlation observed in past studies for other proteins. This may be because of the additional complexity associated with inferring the cost of mutations on the diverse functions of Nef.
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Affiliation(s)
- John P Barton
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Erasha Rajkoomar
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Jaclyn K Mann
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Dariusz K Murakowski
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mako Toyoda
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | | | | | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan.,International Research Center for Medical Sciences (IRCMS), Kumamoto University, Kumamoto, Japan
| | - Arup K Chakraborty
- Departments of Chemical Engineering, Physics, and Chemistry, Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA
| | - Thumbi Ndung'u
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, MA, USA.,HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,Africa Health Research Institute, Durban, South Africa.,Max Planck Institute for Infection Biology, Chariteplatz, D-10117 Berlin, Germany
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10
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Martins MA, Gonzalez-Nieto L, Shin YC, Domingues A, Gutman MJ, Maxwell HS, Magnani DM, Ricciardi MJ, Pedreño-Lopez N, Bailey VK, Altman JD, Parks CL, Allison DB, Ejima K, Rakasz EG, Capuano S, Desrosiers RC, Lifson JD, Watkins DI. The Frequency of Vaccine-Induced T-Cell Responses Does Not Predict the Rate of Acquisition after Repeated Intrarectal SIVmac239 Challenges in Mamu-B*08+ Rhesus Macaques. J Virol 2019; 93:e01626-18. [PMID: 30541854 PMCID: PMC6384082 DOI: 10.1128/jvi.01626-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/04/2018] [Indexed: 01/01/2023] Open
Abstract
Approximately 50% of rhesus macaques (RMs) expressing the major histocompatibility complex class I (MHC-I) allele Mamu-B*08 spontaneously control chronic-phase viremia after infection with the pathogenic simian immunodeficiency virus mac239 (SIVmac239) clone. CD8+ T-cell responses in these animals are focused on immunodominant Mamu-B*08-restricted SIV epitopes in Vif and Nef, and prophylactic vaccination with these epitopes increases the incidence of elite control in SIVmac239-infected Mamu-B*08-positive (Mamu-B*08+ ) RMs. Here we evaluated if robust vaccine-elicited CD8+ T-cell responses against Vif and Nef can prevent systemic infection in Mamu-B*08+ RMs following mucosal SIV challenges. Ten Mamu-B*08+ RMs were vaccinated with a heterologous prime/boost/boost regimen encoding Vif and Nef, while six sham-vaccinated MHC-I-matched RMs served as the controls for this experiment. Vaccine-induced CD8+ T cells against Mamu-B*08-restricted SIV epitopes reached high frequencies in blood but were present at lower levels in lymph node and gut biopsy specimens. Following repeated intrarectal challenges with SIVmac239, all control RMs became infected by the sixth SIV exposure. By comparison, four vaccinees were still uninfected after six challenges, and three of them remained aviremic after 3 or 4 additional challenges. The rate of SIV acquisition in the vaccinees was numerically lower (albeit not statistically significantly) than that in the controls. However, peak viremia was significantly reduced in infected vaccinees compared to control animals. We found no T-cell markers that distinguished vaccinees that acquired SIV infection from those that did not. Additional studies will be needed to validate these findings and determine if cellular immunity can be harnessed to prevent the establishment of productive immunodeficiency virus infection.IMPORTANCE It is generally accepted that the antiviral effects of vaccine-induced classical CD8+ T-cell responses against human immunodeficiency virus (HIV) are limited to partial reductions in viremia after the establishment of productive infection. Here we show that rhesus macaques (RMs) vaccinated with Vif and Nef acquired simian immunodeficiency virus (SIV) infection at a lower (albeit not statistically significant) rate than control RMs following repeated intrarectal challenges with a pathogenic SIV clone. All animals in the present experiment expressed the elite control-associated major histocompatibility complex class I (MHC-I) molecule Mamu-B*08 that binds immunodominant epitopes in Vif and Nef. Though preliminary, these results provide tantalizing evidence that the protective efficacy of vaccine-elicited CD8+ T cells may be greater than previously thought. Future studies should examine if vaccine-induced cellular immunity can prevent systemic viral replication in RMs that do not express MHC-I alleles associated with elite control of SIV infection.
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Affiliation(s)
| | | | - Young C Shin
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - Aline Domingues
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - Martin J Gutman
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - Helen S Maxwell
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - Diogo M Magnani
- Department of Pathology, University of Miami, Miami, Florida, USA
| | | | | | - Varian K Bailey
- Department of Pathology, University of Miami, Miami, Florida, USA
| | - John D Altman
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, USA
| | - Christopher L Parks
- International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn, New York, USA
| | - David B Allison
- School of Public Health, Indiana University-Bloomington, Bloomington, Indiana, USA
| | - Keisuke Ejima
- School of Public Health, Indiana University-Bloomington, Bloomington, Indiana, USA
| | - Eva G Rakasz
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Saverio Capuano
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - David I Watkins
- Department of Pathology, University of Miami, Miami, Florida, USA
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11
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Naidoo L, Mzobe Z, Jin SW, Rajkoomar E, Reddy T, Brockman MA, Brumme ZL, Ndung'u T, Mann JK. Nef-mediated inhibition of NFAT following TCR stimulation differs between HIV-1 subtypes. Virology 2019; 531:192-202. [PMID: 30927712 DOI: 10.1016/j.virol.2019.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/13/2019] [Accepted: 02/16/2019] [Indexed: 01/11/2023]
Abstract
Functional characterisation of different HIV-1 subtypes may improve understanding of viral pathogenesis and spread. Here, we evaluated the ability of 345 unique HIV-1 Nef clones representing subtypes A, B, C and D to inhibit NFAT signalling following TCR stimulation. The contribution of this Nef function to disease progression was also assessed in 211 additional Nef clones isolated from unique subtype C infected individuals in early or chronic infection. On average, subtype A and C Nef clones exhibited significantly lower ability to inhibit TCR-mediated NFAT signalling compared to subtype B and D Nef clones. While this observation corroborates accumulating evidence supporting relative attenuation of subtypes A and C that may paradoxically contribute to their increased global prevalence and spread, no significant correlations between Nef-mediated NFAT inhibition activity and clinical markers of HIV-1 infection were observed, indicating that the relationship between Nef function and pathogenesis is complex.
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Affiliation(s)
- Lisa Naidoo
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Zinhle Mzobe
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Steven W Jin
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Erasha Rajkoomar
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Tarylee Reddy
- Medical Research Council, Biostatistics Unit, Durban 4001, South Africa
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada V6Z 1Y6
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada V6Z 1Y6
| | - Thumbi Ndung'u
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban 4001, South Africa; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA; Africa Health Research Institute, Durban 4001, South Africa; Max Planck Institute for Infection Biology, Chariteplatz, D-10117 Berlin, Germany
| | - Jaclyn K Mann
- HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban 4001, South Africa.
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12
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Martins MA, Bischof GF, Shin YC, Lauer WA, Gonzalez-Nieto L, Watkins DI, Rakasz EG, Lifson JD, Desrosiers RC. Vaccine protection against SIVmac239 acquisition. Proc Natl Acad Sci U S A 2019; 116:1739-1744. [PMID: 30642966 PMCID: PMC6358712 DOI: 10.1073/pnas.1814584116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The biological characteristics of HIV pose serious difficulties for the success of a preventive vaccine. Molecularly cloned SIVmac239 is difficult for antibodies to neutralize, and a variety of vaccine approaches have had great difficulty achieving protective immunity against it in rhesus monkey models. Here we report significant protection against i.v. acquisition of SIVmac239 using a long-lasting approach to vaccination. The vaccine regimen includes a replication-competent herpesvirus engineered to contain a near-full-length SIV genome that expresses all nine SIV gene products, assembles noninfectious SIV virion particles, and is capable of eliciting long-lasting effector-memory cellular immune responses to all nine SIV gene products. Vaccinated monkeys were significantly protected against acquisition of SIVmac239 following repeated marginal dose i.v. challenges over a 4-month period. Further work is needed to define the critical components necessary for eliciting this protective immunity, evaluate the breadth of the protection against a variety of strains, and explore how this approach may be extended to human use.
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Affiliation(s)
- Mauricio A Martins
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Georg F Bischof
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Young C Shin
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - William A Lauer
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Lucas Gonzalez-Nieto
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - David I Watkins
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Eva G Rakasz
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701
| | - Ronald C Desrosiers
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, FL 33136;
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13
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Veazey RS, Lackner AA. Nonhuman Primate Models and Understanding the Pathogenesis of HIV Infection and AIDS. ILAR J 2018; 58:160-171. [PMID: 29228218 DOI: 10.1093/ilar/ilx032] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 11/04/2017] [Indexed: 12/16/2022] Open
Abstract
Research using nonhuman primates (NHPs) as models for human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) has resulted in tremendous achievements not only in the prevention and treatment of HIV, but also in biomedical research more broadly. Once considered a death sentence, HIV infection is now fairly well controlled with combination antiretroviral treatments, almost all of which were first tested for efficacy and safety in nonhuman primates or other laboratory animals. Research in NHP has led to "dogma changing" discoveries in immunology, infectious disease, and even our own genetics. We now know that many of our genes are retroviral remnants, or developed in response to archaic HIV-like retroviral infections. Early studies involving blood from HIV patients and in experiments in cultured tissues contributed to confusion regarding the cause of AIDS and impeded progress in the development of effective interventions. Research on the many retroviruses of different NHP species have broadened our understanding of human immunology and perhaps even our origins and evolution as a species. In combination with recent advances in molecular biology and computational analytics, research in NHPs has unique potential for discoveries that will directly lead to new cures for old human and animal diseases, including HIV/AIDS.
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Affiliation(s)
- Ronald S Veazey
- Division of Comparative Pathology, Tulane National Primate Research Center, Tulane University School of Medicine.,Department of Pathology and Laboratory Medicine, Tulane University School of Medicine
| | - Andrew A Lackner
- Tulane National Primate Research Center, Tulane University School of Medicine.,Department of Microbiology and Pathology and Laboratory Medicine, Tulane University School of Medicine
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14
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Bachtel ND, Umviligihozo G, Pickering S, Mota TM, Liang H, Del Prete GQ, Chatterjee P, Lee GQ, Thomas R, Brockman MA, Neil S, Carrington M, Bwana B, Bangsberg DR, Martin JN, Kallas EG, Donini CS, Cerqueira NB, O’Doherty UT, Hahn BH, Jones RB, Brumme ZL, Nixon DF, Apps R. HLA-C downregulation by HIV-1 adapts to host HLA genotype. PLoS Pathog 2018; 14:e1007257. [PMID: 30180214 PMCID: PMC6138419 DOI: 10.1371/journal.ppat.1007257] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/14/2018] [Accepted: 08/02/2018] [Indexed: 01/09/2023] Open
Abstract
HIV-1 can downregulate HLA-C on infected cells, using the viral protein Vpu, and the magnitude of this downregulation varies widely between primary HIV-1 variants. The selection pressures that result in viral downregulation of HLA-C in some individuals, but preservation of surface HLA-C in others are not clear. To better understand viral immune evasion targeting HLA-C, we have characterized HLA-C downregulation by a range of primary HIV-1 viruses. 128 replication competent viral isolates from 19 individuals with effective anti-retroviral therapy, show that a substantial minority of individuals harbor latent reservoir virus which strongly downregulates HLA-C. Untreated infections display no change in HLA-C downregulation during the first 6 months of infection, but variation between viral quasispecies can be detected in chronic infection. Vpu molecules cloned from plasma of 195 treatment naïve individuals in chronic infection demonstrate that downregulation of HLA-C adapts to host HLA genotype. HLA-C alleles differ in the pressure they exert for downregulation, and individuals with higher levels of HLA-C expression favor greater viral downregulation of HLA-C. Studies of primary and mutant molecules identify 5 residues in the transmembrane region of Vpu, and 4 residues in the transmembrane domain of HLA-C, which determine interactions between Vpu and HLA. The observed adaptation of Vpu-mediated downregulation to host genotype indicates that HLA-C alleles differ in likelihood of mediating a CTL response that is subverted by viral downregulation, and that preservation of HLA-C expression is favored in the absence of these responses. Finding that latent reservoir viruses can downregulate HLA-C could have implications for HIV-1 cure therapy approaches in some individuals.
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Affiliation(s)
- Nathaniel D. Bachtel
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | | | - Suzanne Pickering
- Department of Infectious Disease, King’s College London School of Medicine, Guy’s Hospital, London, United Kingdom
| | - Talia M. Mota
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Hua Liang
- Department of Statistics and Biostatistics, George Washington University, Washington DC, United States of America
| | - Gregory Q. Del Prete
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
| | - Pramita Chatterjee
- Cancer and Inflammation Program, HLA Immunogenetics Section, Basic Science Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
| | - Guinevere Q. Lee
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Rasmi Thomas
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Mark A. Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Stuart Neil
- Department of Infectious Disease, King’s College London School of Medicine, Guy’s Hospital, London, United Kingdom
| | - Mary Carrington
- Cancer and Inflammation Program, HLA Immunogenetics Section, Basic Science Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States of America
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Bosco Bwana
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - David R. Bangsberg
- Mbarara University of Science and Technology, Mbarara, Uganda
- Oregon Health & Science University, Portland State University School of Public Health, Portland, Oregon, United States of America
| | - Jeffrey N. Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, United States of America
| | | | | | | | - Una T. O’Doherty
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - R. Brad Jones
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Zabrina L. Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
| | - Douglas F. Nixon
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
| | - Richard Apps
- Department of Microbiology, Immunology & Tropical Medicine, The George Washington University, Washington DC, United States of America
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15
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HLA Class I Downregulation by HIV-1 Variants from Subtype C Transmission Pairs. J Virol 2018; 92:JVI.01633-17. [PMID: 29321314 DOI: 10.1128/jvi.01633-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/23/2017] [Indexed: 02/08/2023] Open
Abstract
HIV-1 downregulates human leukocyte antigen A (HLA-A) and HLA-B from the surface of infected cells primarily to evade CD8 T cell recognition. HLA-C was thought to remain on the cell surface and bind inhibitory killer immunoglobulin-like receptors, preventing natural killer (NK) cell-mediated suppression. However, a recent study found HIV-1 primary viruses have the capacity to downregulate HLA-C. The goal of this study was to assess the heterogeneity of HLA-A, HLA-B, and HLA-C downregulation among full-length primary viruses from six chronically infected and six newly infected individuals from transmission pairs and to determine whether transmitted/founder variants exhibit common HLA class I downregulation characteristics. We measured HLA-A, HLA-B, HLA-C, and total HLA class I downregulation by flow cytometry of primary CD4 T cells infected with 40 infectious molecular clones. Primary viruses mediated a range of HLA class I downregulation capacities (1.3- to 6.1-fold) which could differ significantly between transmission pairs. Downregulation of HLA-C surface expression on infected cells correlated with susceptibility to in vitro NK cell suppression of virus release. Despite this, transmitted/founder variants did not share a downregulation signature and instead were more similar to the quasispecies of matched donor partners. These data indicate that a range of viral abilities to downregulate HLA-A, HLA-B, and HLA-C exist within and between individuals that can have functional consequences on immune recognition.IMPORTANCE Subtype C HIV-1 is the predominant subtype involved in heterosexual transmission in sub-Saharan Africa. Authentic subtype C viruses that contain natural sequence variations throughout the genome often are not used in experimental systems due to technical constraints and sample availability. In this study, authentic full-length subtype C viruses, including transmitted/founder viruses, were examined for the ability to disrupt surface expression of HLA class I molecules, which are central to both adaptive and innate immune responses to viral infections. We found that the HLA class I downregulation capacity of primary viruses varied, and HLA-C downregulation capacity impacted viral suppression by natural killer cells. Transmitted viruses were not distinct in the capacity for HLA class I downregulation or natural killer cell evasion. These results enrich our understanding of the phenotypic variation existing among natural HIV-1 viruses and how that might impact the ability of the immune system to recognize infected cells in acute and chronic infection.
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16
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Bolton DL, McGinnis K, Finak G, Chattopadhyay P, Gottardo R, Roederer M. Combined single-cell quantitation of host and SIV genes and proteins ex vivo reveals host-pathogen interactions in individual cells. PLoS Pathog 2017; 13:e1006445. [PMID: 28654687 PMCID: PMC5507340 DOI: 10.1371/journal.ppat.1006445] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/10/2017] [Accepted: 06/04/2017] [Indexed: 12/27/2022] Open
Abstract
CD4 T cells harboring HIV-1/SIV represent a formidable hurdle to eradicating infection, and yet their detailed phenotype remains unknown. Here we integrate two single-cell technologies, flow cytometry and highly multiplexed quantitative RT-PCR, to characterize SIV-infected CD4 T cells directly ex vivo. Within individual cells, we correlate the cellular phenotype, in terms of host protein and RNA expression, with stages of the viral life cycle defined by combinatorial expression of viral RNAs. Spliced RNA+ infected cells display multiple memory and activation phenotypes, indicating virus production by diverse CD4 T cell subsets. In most (but not all) cells, progressive infection accompanies post-transcriptional downregulation of CD4 protein, while surface MHC class I is largely retained. Interferon-stimulated genes were also commonly upregulated. Thus, we demonstrate that combined quantitation of transcriptional and post-transcriptional regulation at the single-cell level informs in vivo mechanisms of viral replication and immune evasion. HIV-1, and its simian counterpart, SIV, infect and kill CD4 T cells, resulting in their massive depletion that ultimately leads to AIDS in the absence of antiretroviral therapy. With effective therapy, these cells are largely preserved, but a subset harbors latent virus that can persist for decades and reemerge upon therapy interruption, preventing HIV-1 cure. To prevent or eliminate productive cellular infection, there is tremendous demand to identify host factors expressed by these cells in vivo, which may serve as unique biomarkers or drug targets. Here we provide the first detailed combined transcriptomic and protein expression profile of SIV-infected cells directly ex vivo using novel single-cell technologies. Our survey of activation markers, interferon-stimulated genes, and viral restriction factors identified multiple host genes differentially expressed by SIV-infected cells and will inform future therapeutic strategies.
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Affiliation(s)
- Diane L. Bolton
- US Military HIV Research Program, Henry M. Jackson Foundation, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- * E-mail:
| | - Kathleen McGinnis
- ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Greg Finak
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Pratip Chattopadhyay
- ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Raphael Gottardo
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Mario Roederer
- ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, Maryland, United States of America
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17
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Apps R, Del Prete GQ, Chatterjee P, Lara A, Brumme ZL, Brockman MA, Neil S, Pickering S, Schneider DK, Piechocka-Trocha A, Walker BD, Thomas R, Shaw GM, Hahn BH, Keele BF, Lifson JD, Carrington M. HIV-1 Vpu Mediates HLA-C Downregulation. Cell Host Microbe 2016; 19:686-95. [PMID: 27173934 PMCID: PMC4904791 DOI: 10.1016/j.chom.2016.04.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/08/2016] [Accepted: 04/05/2016] [Indexed: 12/31/2022]
Abstract
Many pathogens evade cytotoxic T lymphocytes (CTLs) by downregulating HLA molecules on infected cells, but the loss of HLA can trigger NK cell-mediated lysis. HIV-1 is thought to subvert CTLs while preserving NK cell inhibition by Nef-mediated downregulation of HLA-A and -B but not HLA-C molecules. We find that HLA-C is downregulated by most primary HIV-1 clones, including transmitted founder viruses, in contrast to the laboratory-adapted NL4-3 virus. HLA-C reduction is mediated by viral Vpu and reduces the ability of HLA-C restricted CTLs to suppress viral replication in CD4+ cells in vitro. HLA-A/B are unaffected by Vpu, and primary HIV-1 clones vary in their ability to downregulate HLA-C, possibly in response to whether CTLs or NK cells dominate immune pressure through HLA-C. HIV-2 also suppresses HLA-C expression through distinct mechanisms, underscoring the immune pressure HLA-C exerts on HIV. This viral immune evasion casts new light on the roles of CTLs and NK cells in immune responses against HIV.
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Affiliation(s)
- Richard Apps
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Pramita Chatterjee
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Abigail Lara
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC V67 1Y6, Canada
| | - Mark A Brockman
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC V67 1Y6, Canada
| | - Stuart Neil
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Suzanne Pickering
- Department of Infectious Disease, King's College London School of Medicine, Guy's Hospital, London SE1 9RT, UK
| | - Douglas K Schneider
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Alicja Piechocka-Trocha
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA
| | - Bruce D Walker
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA
| | - Rasmi Thomas
- Host Genetics Section, US Military HIV Research Program, Silver Spring, MD 20910, USA
| | - George M Shaw
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA
| | - Mary Carrington
- Cancer and Inflammation Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD 21702, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139-3583, USA.
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18
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Acute Viral Escape Selectively Impairs Nef-Mediated Major Histocompatibility Complex Class I Downmodulation and Increases Susceptibility to Antiviral T Cells. J Virol 2015; 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] [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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19
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Nef Is Dispensable for Resistance of Simian Immunodeficiency Virus-Infected Macrophages to CD8+ T Cell Killing. J Virol 2015; 89:10625-36. [PMID: 26269172 DOI: 10.1128/jvi.01699-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/04/2015] [Indexed: 01/29/2023] Open
Abstract
UNLABELLED Simian immunodeficiency virus (SIV)-specific CD8(+) T cells kill SIV-infected CD4(+) T cells in an major histocompatibility complex class I (MHC-I)-dependent manner. However, they are reportedly less efficient at killing SIV-infected macrophages. Since the viral accessory protein Nef has been shown to downregulate MHC-I molecules and enhance cytotoxic T lymphocyte (CTL) evasion in human immunodeficiency virus type 1 (HIV-1)-infected CD4(+) T cells, we examined whether Nef played a role in protecting SIV-infected macrophages from killing by SIV-specific CD8(+) T cells. To explore the role of Nef in CD8(+) T cell evasion, we compared the ability of freshly sorted SIV-specific CD8(+) T cells to readily suppress viral replication or eliminate CD4(+) T cells or monocyte-derived macrophages infected with SIV variants containing wild-type (WT) or mutated nef genes. As expected, SIV-specific CD8(+) T cells suppressed viral replication and eliminated the majority of SIV-infected CD4(+) T cells, and this killing was enhanced in CD4(+) T cells infected with the nef variants. However, macrophages infected with nef variants that disrupt MHC-I downregulation did not promote rapid killing by freshly isolated CD8(+) T cells. These results suggest that mechanisms other than Nef-mediated MHC-I downregulation govern the resistance of SIV-infected macrophages to CD8(+) T cell-mediated killing. This study has implications for viral persistence and suggests that macrophages may afford primate lentiviruses some degree of protection from immune surveillance. IMPORTANCE Myeloid cells are permissive for HIV/SIV replication in vitro and may contribute to viral persistence in vivo. While many studies have been geared to understanding how CD8(+) T cells control viral replication in CD4(+) T cells, the role of these cells in controlling viral replication in macrophages is less clear. Primary, unstimulated CD8(+) T cells insignificantly suppress viral replication or eliminate SIV-infected macrophages. Since the viral Nef protein downregulates MHC-I and provides infected cells some degree of protection from CD8(+) T cell-mediated effector functions, we evaluated whether Nef may be contributing to the resistance of macrophages to CD8(+) T cell suppression. Our results suggest that Nef is not involved in protecting infected macrophages from CD8(+) T cell killing and suggest that other mechanisms are involved in macrophage evasion from CD8 surveillance.
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Apps R, Meng Z, Del Prete GQ, Lifson JD, Zhou M, Carrington M. Relative expression levels of the HLA class-I proteins in normal and HIV-infected cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:3594-600. [PMID: 25754738 PMCID: PMC4390493 DOI: 10.4049/jimmunol.1403234] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 02/07/2015] [Indexed: 02/02/2023]
Abstract
The expression level of HLA class-I proteins is known to influence pathological outcomes: pathogens downregulate HLA to evade host immune responses, host inflammatory reactions upregulate HLA, and differences among people with regard to the steady-state expression levels of HLA associate with disease susceptibility. Yet precise quantification of relative expression levels of the various HLA loci is difficult because of the tremendous polymorphism of HLA. We report relative expression levels of HLA-A, HLA-B, HLA-C, and HLA-E proteins for the specific haplotype A*02:01, B*44:02, C*05:01, which were characterized using two independent methods based on flow cytometry and mass spectrometry. PBLs from normal donors showed that HLA-A and HLA-B proteins are expressed at similar levels, which are 13-18 times higher than HLA-C by flow cytometry and 4-5 times higher than HLA-C by mass spectrometry; these differences may reflect variation in the conformation or location of proteins detected. HLA-E was detected at a level 25 times lower than that of HLA-C by mass spectrometry. Primary CD4(+) T cells infected with HIV in vitro were also studied because HIV downregulates selective HLA types. HLA-A and HLA-B were reduced on HIV-infected cells by a magnitude that varied between cells in an infected culture. Averaging all infected cells from an individual showed HLA-A to be 1-3 times higher and HLA-B to be 2-5 times higher than HLA-C by flow cytometry. These results quantify substantial differences in expression levels of the proteins from different HLA loci, which are very likely physiologically significant on both uninfected and HIV-infected cells.
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Affiliation(s)
- Richard Apps
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Zhaojing Meng
- Protein Characterization Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Gregory Q Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702; and
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702; and
| | - Ming Zhou
- Protein Characterization Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Mary Carrington
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702; Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139
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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] [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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Sebastian NT, Collins KL. Targeting HIV latency: resting memory T cells, hematopoietic progenitor cells and future directions. Expert Rev Anti Infect Ther 2014; 12:1187-201. [PMID: 25189526 DOI: 10.1586/14787210.2014.956094] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Current therapy for HIV effectively suppresses viral replication and prolongs life, but the infection persists due, at least in part, to latent infection of long-lived cells. One favored strategy toward a cure targets latent virus in resting memory CD4(+) T cells by stimulating viral production. However, the existence of an additional reservoir in bone marrow hematopoietic progenitor cells has been detected in some treated HIV-infected people. This review describes approaches investigators have used to reactivate latent proviral genomes in resting CD4(+) T cells and hematopoietic progenitor cells. In addition, the authors review approaches for clearance of these reservoirs along with other important topics related to HIV eradication.
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Affiliation(s)
- Nadia T Sebastian
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
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Mann JK, Chopera D, Omarjee S, Kuang XT, Le AQ, Anmole G, Danroth R, Mwimanzi P, Reddy T, Carlson J, Radebe M, Goulder PJR, Walker BD, Abdool Karim S, Novitsky V, Williamson C, Brockman MA, Brumme ZL, Ndung'u T. Nef-mediated down-regulation of CD4 and HLA class I in HIV-1 subtype C infection: association with disease progression and influence of immune pressure. Virology 2014; 468-470:214-225. [PMID: 25193656 DOI: 10.1016/j.virol.2014.08.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 06/08/2014] [Accepted: 08/11/2014] [Indexed: 11/30/2022]
Abstract
Nef plays a major role in HIV-1 pathogenicity. We studied HIV-1 subtype C infected individuals in acute/early (n = 120) or chronic (n = 207) infection to investigate the relationship between Nef-mediated CD4/HLA-I down-regulation activities and disease progression, and the influence of immune-driven sequence variation on these Nef functions. A single Nef sequence per individual was cloned into an expression plasmid, followed by transfection of a T cell line and measurement of CD4 and HLA-I expression. In early infection, a trend of higher CD4 down-regulation ability correlating with higher viral load set point was observed (r = 0.19, p = 0.05), and higher HLA-I down-regulation activity was significantly associated with faster rate of CD4 decline (p = 0.02). HLA-I down-regulation function correlated inversely with the number HLA-associated polymorphisms previously associated with reversion in the absence of the selecting HLA allele (r = -0.21, p = 0.0002). These data support consideration of certain Nef regions in HIV-1 vaccine strategies designed to attenuate the infection course.
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Affiliation(s)
- Jaclyn K Mann
- HIV Pathogenesis Programme, University of KwaZulu-Natal, 719 Umbilo Road, Durban 4001, South Africa; KwaZulu-Natal Research Institute for Tuberculosis and HIV, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Denis Chopera
- HIV Pathogenesis Programme, University of KwaZulu-Natal, 719 Umbilo Road, Durban 4001, South Africa; KwaZulu-Natal Research Institute for Tuberculosis and HIV, University of KwaZulu-Natal, Durban 4001, South Africa; Institute of Infectious Disease and Molecular Medicine, and the Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town 7925, South Africa
| | - Saleha Omarjee
- HIV Pathogenesis Programme, University of KwaZulu-Natal, 719 Umbilo Road, Durban 4001, South Africa; KwaZulu-Natal Research Institute for Tuberculosis and HIV, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Xiaomei T Kuang
- Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Anh Q Le
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Gursev Anmole
- Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Ryan Danroth
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Philip Mwimanzi
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Tarylee Reddy
- Medical Research Council, Biostatistics Unit, Durban 4001, South Africa
| | - Jonathan Carlson
- Microsoft Research, Los Angeles, CA 90024, United States of America
| | - Mopo Radebe
- HIV Pathogenesis Programme, University of KwaZulu-Natal, 719 Umbilo Road, Durban 4001, South Africa; KwaZulu-Natal Research Institute for Tuberculosis and HIV, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Philip J R Goulder
- Department of Paediatrics, University of Oxford, Oxford OX1 3SY, United Kingdom; Ragon Institute of MGH, MIT and Harvard University, Cambridge, MA 02139, USA
| | - Bruce D Walker
- Ragon Institute of MGH, MIT and Harvard University, Cambridge, MA 02139, USA; Massachusetts General Hospital and Harvard University, Boston, MA 02114, USA; Howard Hughes Medical Research Institute, Chevy Chase, MD 20815, USA
| | - Salim Abdool Karim
- Centre for the AIDS Programme of Research in South Africa, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Vladimir Novitsky
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA; Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research and Education, P/Bag BO 320, Gaborone, Botswana
| | - Carolyn Williamson
- Institute of Infectious Disease and Molecular Medicine, and the Division of Medical Virology, University of Cape Town and National Health Laboratory Services, Cape Town 7925, South Africa
| | - Mark A Brockman
- Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada V6Z 1Y6
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada V6Z 1Y6
| | - Thumbi Ndung'u
- HIV Pathogenesis Programme, University of KwaZulu-Natal, 719 Umbilo Road, Durban 4001, South Africa; KwaZulu-Natal Research Institute for Tuberculosis and HIV, University of KwaZulu-Natal, Durban 4001, South Africa; Ragon Institute of MGH, MIT and Harvard University, Cambridge, MA 02139, USA; Max Planck Institute for Infection Biology, Chariteplatz, D-10117 Berlin, Germany.
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Mann JK, Byakwaga H, Kuang XT, Le AQ, Brumme CJ, Mwimanzi P, Omarjee S, Martin E, Lee GQ, Baraki B, Danroth R, McCloskey R, Muzoora C, Bangsberg DR, Hunt PW, Goulder PJR, Walker BD, Harrigan PR, Martin JN, Ndung'u T, Brockman MA, Brumme ZL. Ability of HIV-1 Nef to downregulate CD4 and HLA class I differs among viral subtypes. Retrovirology 2013; 10:100. [PMID: 24041011 PMCID: PMC3849644 DOI: 10.1186/1742-4690-10-100] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 09/09/2013] [Indexed: 11/29/2022] Open
Abstract
Background The highly genetically diverse HIV-1 group M subtypes may differ in their biological properties. Nef is an important mediator of viral pathogenicity; however, to date, a comprehensive inter-subtype comparison of Nef in vitro function has not been undertaken. Here, we investigate two of Nef’s most well-characterized activities, CD4 and HLA class I downregulation, for clones obtained from 360 chronic patients infected with HIV-1 subtypes A, B, C or D. Results Single HIV-1 plasma RNA Nef clones were obtained from N=360 antiretroviral-naïve, chronically infected patients from Africa and North America: 96 (subtype A), 93 (B), 85 (C), and 86 (D). Nef clones were expressed by transfection in an immortalized CD4+ T-cell line. CD4 and HLA class I surface levels were assessed by flow cytometry. Nef expression was verified by Western blot. Subset analyses and multivariable linear regression were used to adjust for differences in age, sex and clinical parameters between cohorts. Consensus HIV-1 subtype B and C Nef sequences were synthesized and functionally assessed. Exploratory sequence analyses were performed to identify potential genotypic correlates of Nef function. Subtype B Nef clones displayed marginally greater CD4 downregulation activity (p = 0.03) and markedly greater HLA class I downregulation activity (p < 0.0001) than clones from other subtypes. Subtype C Nefs displayed the lowest in vitro functionality. Inter-subtype differences in HLA class I downregulation remained statistically significant after controlling for differences in age, sex, and clinical parameters (p < 0.0001). The synthesized consensus subtype B Nef showed higher activities compared to consensus C Nef, which was most pronounced in cells expressing lower protein levels. Nef clones exhibited substantial inter-subtype diversity: cohort consensus residues differed at 25% of codons, while a similar proportion of codons exhibited substantial inter-subtype differences in major variant frequency. These amino acids, along with others identified in intra-subtype analyses, represent candidates for mediating inter-subtype differences in Nef function. Conclusions Results support a functional hierarchy of subtype B > A/D > C for Nef-mediated CD4 and HLA class I downregulation. The mechanisms underlying these differences and their relevance to HIV-1 pathogenicity merit further investigation.
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Affiliation(s)
- Jaclyn K Mann
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
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Mann JK, Byakwaga H, Kuang XT, Le AQ, Brumme CJ, Mwimanzi P, Omarjee S, Martin E, Lee GQ, Baraki B, Danroth R, McCloskey R, Muzoora C, Bangsberg DR, Hunt PW, Goulder PJR, Walker BD, Harrigan PR, Martin JN, Ndung'u T, Brockman MA, Brumme ZL. Ability of HIV-1 Nef to downregulate CD4 and HLA class I differs among viral subtypes. Retrovirology 2013. [PMID: 24041011 DOI: 10.1186/742-4690-10-100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND The highly genetically diverse HIV-1 group M subtypes may differ in their biological properties. Nef is an important mediator of viral pathogenicity; however, to date, a comprehensive inter-subtype comparison of Nef in vitro function has not been undertaken. Here, we investigate two of Nef's most well-characterized activities, CD4 and HLA class I downregulation, for clones obtained from 360 chronic patients infected with HIV-1 subtypes A, B, C or D. RESULTS Single HIV-1 plasma RNA Nef clones were obtained from N=360 antiretroviral-naïve, chronically infected patients from Africa and North America: 96 (subtype A), 93 (B), 85 (C), and 86 (D). Nef clones were expressed by transfection in an immortalized CD4+ T-cell line. CD4 and HLA class I surface levels were assessed by flow cytometry. Nef expression was verified by Western blot. Subset analyses and multivariable linear regression were used to adjust for differences in age, sex and clinical parameters between cohorts. Consensus HIV-1 subtype B and C Nef sequences were synthesized and functionally assessed. Exploratory sequence analyses were performed to identify potential genotypic correlates of Nef function. Subtype B Nef clones displayed marginally greater CD4 downregulation activity (p = 0.03) and markedly greater HLA class I downregulation activity (p < 0.0001) than clones from other subtypes. Subtype C Nefs displayed the lowest in vitro functionality. Inter-subtype differences in HLA class I downregulation remained statistically significant after controlling for differences in age, sex, and clinical parameters (p < 0.0001). The synthesized consensus subtype B Nef showed higher activities compared to consensus C Nef, which was most pronounced in cells expressing lower protein levels. Nef clones exhibited substantial inter-subtype diversity: cohort consensus residues differed at 25% of codons, while a similar proportion of codons exhibited substantial inter-subtype differences in major variant frequency. These amino acids, along with others identified in intra-subtype analyses, represent candidates for mediating inter-subtype differences in Nef function. CONCLUSIONS Results support a functional hierarchy of subtype B > A/D > C for Nef-mediated CD4 and HLA class I downregulation. The mechanisms underlying these differences and their relevance to HIV-1 pathogenicity merit further investigation.
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Affiliation(s)
- Jaclyn K Mann
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
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HIV-1 Nef sequence and functional compartmentalization in the gut is not due to differential cytotoxic T lymphocyte selective pressure. PLoS One 2013; 8:e75620. [PMID: 24058696 PMCID: PMC3772905 DOI: 10.1371/journal.pone.0075620] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 08/14/2013] [Indexed: 11/29/2022] Open
Abstract
The gut is the largest lymphoid organ in the body and a site of active HIV-1 replication and immune surveillance. The gut is a reservoir of persistent infection in some individuals with fully suppressed plasma viremia on combination antiretroviral therapy (cART) although the cause of this persistence is unknown. The HIV-1 accessory protein Nef contributes to persistence through multiple functions including immune evasion and increasing infectivity. Previous studies showed that Nef’s function is shaped by cytotoxic T lymphocyte (CTL) responses and that there are distinct populations of Nef within tissue compartments. We asked whether Nef’s sequence and/or function are compartmentalized in the gut and how compartmentalization relates to local CTL immune responses. Primary nef quasispecies from paired plasma and sigmoid colon biopsies from chronically infected subjects not on therapy were sequenced and cloned into Env− Vpu− pseudotyped reporter viruses. CTL responses were mapped by IFN-γ ELISpot using expanded CD8+ cells from blood and gut with pools of overlapping peptides covering the entire HIV proteome. CD4 and MHC Class I Nef-mediated downregulation was measured by flow cytometry. Multiple tests indicated compartmentalization of nef sequences in 5 of 8 subjects. There was also compartmentalization of function with MHC Class I downregulation relatively well preserved, but significant loss of CD4 downregulation specifically by gut quasispecies in 5 of 7 subjects. There was no compartmentalization of CTL responses in 6 of 8 subjects, and the selective pressure on quasispecies correlated with the magnitude CTL response regardless of location. These results demonstrate that Nef adapts via diverse pathways to local selective pressures within gut mucosa, which may be predominated by factors other than CTL responses such as target cell availability. The finding of a functionally distinct population within gut mucosa offers some insight into how HIV-1 may persist in the gut despite fully suppressed plasma viremia on cART.
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Adaptor protein 1 promotes cross-presentation through the same tyrosine signal in major histocompatibility complex class I as that targeted by HIV-1. J Virol 2013; 87:8085-98. [PMID: 23678182 DOI: 10.1128/jvi.00701-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Certain antigen-presenting cells (APCs) process and present extracellular antigen with major histocompatibility complex class I (MHC-I) molecules to activate naive CD8(+) T cells in a process termed cross-presentation. We used insights gained from HIV immune evasion strategies to demonstrate that the clathrin adaptor protein adaptor protein 1 (AP-1) is necessary for cross-presentation by MHC-I molecules containing a cytoplasmic tail tyrosine signal (murine MHC-I molecules, human MHC-I HLA-A and HLA-B allotypes). In contrast, AP-1 activity was not needed for cross-presentation by MHC-I molecules containing a human MHC-I HLA-C cytoplasmic tail, which does not contain a tyrosine signal. AP-1 activity was also dispensable for presentation of endogenous antigens by MHC-I via the classical pathway. In APCs, we show that HIV Nef disrupts cross-presentation by MHC-I containing the tyrosine signal but does not affect cross-presentation by MHC-I containing the HLA-C cytoplasmic tail. Thus, we provide evidence for two separable cross-presentation pathways, only one of which is targeted by HIV.
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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] [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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HLA-B may be more protective against HIV-1 than HLA-A because it resists negative regulatory factor (Nef) mediated down-regulation. Proc Natl Acad Sci U S A 2012; 109:13353-8. [PMID: 22826228 DOI: 10.1073/pnas.1204199109] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human leukocyte antigen HLA-B alleles have better protective activity against HIV-1 than HLA-A alleles, possibly due to differences in HLA-restricted HIV-1-specific CD8+ cytotoxic T lymphocyte (CTL) function, but the mechanism is unknown. HIV-1 negative regulatory factor (Nef) mediates down-regulation of surface expression of class I HLA (HLA-I) and may therefore impair immune recognition by CTL. Because of sequence differences in the cytoplasmic domains, HLA-A and -B are down-regulated by Nef but HLA-C and -E are not affected. However, the latter are expressed at low levels and are not of major importance in the CTL responses to HIV-1. Here, we compared the role of the cytoplasmic domains of HLA-A and -B in Nef-mediated escape from CTL. We found HLA-B cytoplasmic domains were more resistant to Nef-mediated down-regulation than HLA-A cytoplasmic domains and demonstrated that these differences affect CTL recognition of virus-infected cells in vitro. We propose that the relative resistance to Nef-mediated down-regulation by the cytoplasmic domains of HLA-B compared with HLA-A contributes to the better control of HIV-1 infection associated with HLA-B-restricted CTLs.
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Lifson JD, Haigwood NL. Lessons in nonhuman primate models for AIDS vaccine research: from minefields to milestones. Cold Spring Harb Perspect Med 2012; 2:a007310. [PMID: 22675663 PMCID: PMC3367532 DOI: 10.1101/cshperspect.a007310] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nonhuman primate (NHP) disease models for AIDS have made important contributions to the search for effective vaccines for AIDS. Viral diversity, persistence, capacity for immune evasion, and safety considerations have limited development of conventional approaches using killed or attenuated vaccines, necessitating the development of novel approaches. Here we highlight the knowledge gained and lessons learned in testing vaccine concepts in different virus/NHP host combinations.
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Affiliation(s)
- Jeffrey D Lifson
- AIDS and Cancer Virus Program, SAIC Frederick, Inc., National Cancer Institute, Frederick, Maryland, USA
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Epitope targeting and viral inoculum are determinants of Nef-mediated immune evasion of HIV-1 from cytotoxic T lymphocytes. Blood 2012; 120:100-11. [PMID: 22613796 DOI: 10.1182/blood-2012-02-409870] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The impact of HIV-1 Nef-mediated HLA-I down-regulation on CD8(+) cytotoxic T lymphocytes (CTLs) varies by epitope, but the determining factors have not been elucidated. In the present study, we investigated the impact of Nef on the antiviral efficiency of HIV-1-specific CTLs targeting 17 different epitopes to define properties that determine susceptibility to Nef. The impact of Nef was not correlated with the presenting HLA-I type or functional avidity of CTLs, but instead was related directly to the kinetics of infected cell clearance. Whereas Gag-specific CTLs generally were less susceptible to Nef than those targeting other proteins, this was determined by the ability to eliminate infected cells before de novo synthesis of viral proteins, which was also observed for CTLs targeting a Nef epitope. This very early clearance of infected cells depended on virus inoculum, and the required inoculum varied by epitope. These results suggest that whereas Gag-specific CTLs are more likely to recognize infected cells before Nef-mediated HLA-I down-regulation, this varies depending on the specific epitope and virus inoculum. Reduced susceptibility to Nef therefore may contribute to the overall association of Gag-specific CTL responses to better immune control if a sufficient multiplicity of infection is attained in vivo, but this property is not unique to Gag.
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Immune selection in vitro reveals human immunodeficiency virus type 1 Nef sequence motifs important for its immune evasion function in vivo. J Virol 2012; 86:7126-35. [PMID: 22553319 DOI: 10.1128/jvi.00878-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef downregulates major histocompatibility complex class I (MHC-I), impairing the clearance of infected cells by CD8(+) cytotoxic T lymphocytes (CTLs). While sequence motifs mediating this function have been determined by in vitro mutagenesis studies of laboratory-adapted HIV-1 molecular clones, it is unclear whether the highly variable Nef sequences of primary isolates in vivo rely on the same sequence motifs. To address this issue, nef quasispecies from nine chronically HIV-1-infected persons were examined for sequence evolution and altered MHC-I downregulatory function under Gag-specific CTL immune pressure in vitro. This selection resulted in decreased nef diversity and strong purifying selection. Site-by-site analysis identified 13 codons undergoing purifying selection and 1 undergoing positive selection. Of the former, only 6 have been reported to have roles in Nef function, including 4 associated with MHC-I downregulation. Functional testing of naturally occurring in vivo polymorphisms at the 7 sites with no previously known functional role revealed 3 mutations (A84D, Y135F, and G140R) that ablated MHC-I downregulation and 3 (N52A, S169I, and V180E) that partially impaired MHC-I downregulation. Globally, the CTL pressure in vitro selected functional Nef from the in vivo quasispecies mixtures that predominately lacked MHC-I downregulatory function at the baseline. Overall, these data demonstrate that CTL pressure exerts a strong purifying selective pressure for MHC-I downregulation and identifies novel functional motifs present in Nef sequences in vivo.
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Zuo J, Suen J, Wong A, Lewis M, Ayub A, Belzer M, Church J, Yang OO, Krogstad P. Functional analysis of HIV type 1 Nef gene variants from adolescent and adult survivors of perinatal infection. AIDS Res Hum Retroviruses 2012; 28:486-92. [PMID: 21861776 DOI: 10.1089/aid.2011.0172] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Throughout the world, infants and children with HIV-1 infection are increasingly surviving into adolescence and adulthood. As HIV Nef is an important determinant of the pathogenic potential of the virus, we examined nef alleles in a cohort of extreme long-term survivors of HIV infection (average age of 16.6 years) to determine if Nef defects might have contributed to patient survival. HIV nef gene sequences were amplified for phylogenetic analysis from 15 adolescents and adults infected by mother-to-child transmission (n=10) or by blood transfusion (n=5). Functional analysis was performed by inserting patient-derived nef sequences into an HIV-derived vector that permits simultaneous evaluation of the impact of the Nef protein on MHC-I and CD4 cell surface expression. We found evidence of extensive nef gene diversity, including changes in known functional domains involved in the downregulation of cell surface MHC-I and CD4. Only 3 of 15 individuals (20%) had nef alleles with a loss of the ability to downregulate either CD4 or MHC-I. Survival into adulthood with HIV infection acquired in infancy is not uniformly linked to loss of function in nef. The Nef protein remains a potential target for immunization or pharmacologic intervention.
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Affiliation(s)
- Jun Zuo
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Jeffrey Suen
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Alanna Wong
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Martha Lewis
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Ali Ayub
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Marvin Belzer
- Childrens Hospital Los Angeles and the Keck School of Medicine at USC, Los Angeles, California
| | - Joseph Church
- Childrens Hospital Los Angeles and the Keck School of Medicine at USC, Los Angeles, California
| | - Otto O. Yang
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Paul Krogstad
- UCLA AIDS Institute and the David Geffen School of Medicine at UCLA, Los Angeles, California
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Bilello JP, Manrique JM, Shin YC, Lauer W, Li W, Lifson JD, Mansfield KG, Johnson RP, Desrosiers RC. Vaccine protection against simian immunodeficiency virus in monkeys using recombinant gamma-2 herpesvirus. J Virol 2011; 85:12708-20. [PMID: 21900170 PMCID: PMC3209374 DOI: 10.1128/jvi.00865-11] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 08/27/2011] [Indexed: 12/21/2022] Open
Abstract
Recombinant strains of replication-competent rhesus monkey rhadinovirus (RRV) were constructed in which strong promoter/enhancer elements were used to drive expression of simian immunodeficiency virus (SIV) Env or Gag or a Rev-Tat-Nef fusion protein. Cultured rhesus monkey fibroblasts infected with each recombinant strain were shown to express the expected protein. Three RRV-negative and two RRV-positive rhesus monkeys were inoculated intravenously with a mixture of these three recombinant RRVs. Expression of SIV Gag was readily detected in lymph node biopsy specimens taken at 3 weeks postimmunization. Impressive anti-SIV cellular immune responses were elicited on the basis of major histocompatibility complex (MHC) tetramer staining and gamma interferon enzyme-linked immunospot (ELISPOT) assays. Responses were much greater in magnitude in the monkeys that were initially RRV negative but were still readily detected in the two monkeys that were naturally infected with RRV at the time of immunization. By 3 weeks postimmunization, responses measured by MHC tetramer staining in the two Mamu-A*01(+) RRV-negative monkeys reached 9.3% and 13.1% of all CD8(+) T cells in peripheral blood to the Gag CM9 epitope and 2.3% and 7.3% of all CD8(+) T cells in peripheral blood to the Tat SL8 epitope. Virus-specific CD8(+) T cell responses persisted at high levels up to the time of challenge at 18 weeks postimmunization, and responding cells maintained an effector memory phenotype. Despite the ability of the RRVenv recombinant to express high levels of Env in cultured cells, and despite the appearance of strong anti-RRV antibody responses in immunized monkeys, anti-Env antibody responses were below our ability to detect them. Immunized monkeys, together with three unimmunized controls, were challenged intravenously with 10 monkey infectious doses of SIVmac239. All five immunized monkeys and all three controls became infected with SIV, but peak viral loads were 1.2 to 3.0 log(10) units lower and chronic-phase viral loads were 1.0 to 3.0 log(10) units lower in immunized animals than the geometric mean of unimmunized controls. These differences were statistically significant. Anti-Env antibody responses following challenge indicated an anamnestic response in the vaccinated monkeys. These findings further demonstrate the potential of recombinant herpesviruses as preventive vaccines for AIDS. We hypothesize that this live, replication-competent, persistent herpesvirus vector could match, or come close to matching, live attenuated strains of SIV in the degree of protection if the difficulty with elicitation of anti-Env antibody responses can be overcome.
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MESH Headings
- Animals
- Antibodies, Viral/immunology
- Blotting, Western
- Enzyme-Linked Immunosorbent Assay
- Flow Cytometry
- Gammaherpesvirinae/genetics
- Gammaherpesvirinae/immunology
- Gene Products, env/administration & dosage
- Gene Products, env/genetics
- Gene Products, env/immunology
- Gene Products, gag/administration & dosage
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Genetic Vectors
- Herpesviridae Infections/genetics
- Herpesviridae Infections/metabolism
- Herpesviridae Infections/virology
- Humans
- Immunity, Cellular
- Immunoenzyme Techniques
- Kidney/cytology
- Kidney/metabolism
- Kidney/virology
- Macaca mulatta/genetics
- Macaca mulatta/immunology
- Macaca mulatta/virology
- Neutralization Tests
- Plasmids
- Recombination, Genetic
- SAIDS Vaccines/administration & dosage
- SAIDS Vaccines/genetics
- SAIDS Vaccines/immunology
- Simian Acquired Immunodeficiency Syndrome/immunology
- Simian Acquired Immunodeficiency Syndrome/prevention & control
- Simian Acquired Immunodeficiency Syndrome/virology
- Simian Immunodeficiency Virus/immunology
- Vaccination
- Viral Load
- Virus Replication
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Affiliation(s)
- John P. Bilello
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Julieta M. Manrique
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Young C. Shin
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - William Lauer
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Wenjun Li
- University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC Frederick Inc., National Cancer Institute, NCI Frederick, Frederick, Maryland 21702
| | - Keith G. Mansfield
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - R. Paul Johnson
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
| | - Ronald C. Desrosiers
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102
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35
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Down-modulation of CD8αβ is a fundamental activity of primate lentiviral Nef proteins. J Virol 2011; 86:36-48. [PMID: 22013062 DOI: 10.1128/jvi.00717-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It is well established that the Nef proteins of human and simian immunodeficiency viruses (HIV and SIV) modulate major histocompatibility complex class I (MHC-I) cell surface expression to protect infected cells against lysis by cytotoxic T lymphocytes (CTLs). Recent data supported the observation that Nef also manipulates CTLs directly by down-modulating CD8αβ (J. A. Leonard, T. Filzen, C. C. Carter, M. Schaefer, and K. L. Collins, J. Virol. 85:6867-6881, 2011), but it remained unknown whether this Nef activity is conserved between different lineages of HIV and SIV. In this study, we examined a total of 42 nef alleles from 16 different primate lentiviruses representing most major lineages of primate lentiviruses, as well as nonpandemic HIV-1 strains and the direct precursors of HIV-1 (SIVcpz and SIVgor). We found that the vast majority of these nef alleles strongly down-modulate CD8β in human T cells. Primate lentiviral Nefs generally interacted specifically with the cytoplasmic tail of CD8β, and down-modulation of this receptor was dependent on the conserved dileucine-based motif and two adjacent acidic residues (DD/E) in the C-terminal flexible loop of SIV Nef proteins. Both of these motifs are known to be important for the interaction of HIV-1 Nef with AP-2, and they were also shown to be critical for down-modulation of CD4 and CD28, but not MHC-I, by SIV Nefs. Our results show that down-modulation of CD4, CD8β, and CD28 involves largely overlapping (but not identical) domains and is most likely dependent on conserved interactions of primate lentiviral Nefs with cellular adaptor proteins. Furthermore, our data demonstrate that Nef-mediated down-modulation of CD8αβ is a fundamental property of primate lentiviruses and suggest that direct manipulation of CD8+ T cells plays a relevant role in viral immune evasion.
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Mwimanzi P, Hasan Z, Hassan R, Suzu S, Takiguchi M, Ueno T. Effects of naturally-arising HIV Nef mutations on cytotoxic T lymphocyte recognition and Nef's functionality in primary macrophages. Retrovirology 2011; 8:50. [PMID: 21696586 PMCID: PMC3131245 DOI: 10.1186/1742-4690-8-50] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 06/22/2011] [Indexed: 11/10/2022] Open
Abstract
Background Although HIV can infect several cellular subsets, such as CD4+ T lymphocytes and macrophages, it remains unclear whether an HIV infection in macrophages supports cytotoxic T lymphocyte (CTL) escape. Here, we tested two naturally-arising mutations located in the well-conserved polyproline region of Nef for their effects on CTL recognition, Nef's functionality, and viral replication capacity in macrophages. These mutations were selected because they are known to cause CTL escape in the context of T lymphocytes. Findings Monocyte-derived macrophages (MDMs) infected with the wild-type virus, but not with variant viruses, were efficiently killed by CTL clones targeting Nef epitopes, VY8 (VPLRPMTY) and RY11 (RPQVPLRPMTY). The CTL-escape mutation, Arg75Thr, or Arg75Thr/Tyr85Phe double mutation, reduced the HLA class I down-regulation activity and, interestingly, increased the susceptibility of virus-infected MDMs to recognition by CTLs targeting a different epitope. The same mutations reduced the CCR5, but not CD4, down-regulation activity. Moreover, the Nef variants were impaired for Hck activation and enhancement of viral replication in MDMs. Conclusions These results suggest that HIV-infected MDMs are killed by CTLs targeting Nef epitopes, contributing to selection and adaptation of CTL-escape viral variants.
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Affiliation(s)
- Philip Mwimanzi
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
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37
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Foster JL, Denial SJ, Temple BRS, Garcia JV. Mechanisms of HIV-1 Nef function and intracellular signaling. J Neuroimmune Pharmacol 2011; 6:230-46. [PMID: 21336563 DOI: 10.1007/s11481-011-9262-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 02/01/2011] [Indexed: 11/29/2022]
Abstract
Advances in the last several years have enhanced mechanistic understanding of Nef-induced CD4 and MHCI downregulation and have suggested a new paradigm for analyzing Nef function. In both of these cases, Nef acts by forming ternary complexes with significant contributions to stability imparted by non-canonical interactions. The mutational analyses and binding assays that have led to these conclusions are discussed. The recent progress has been dependent on conservative mutations and multi-protein binding assays. The poorly understood Nef functions of p21 activated protein kinase (PAK2) activation, enhancement of virion infectivity, and inhibition of immunoglobulin class switching are also likely to involve ternary complexes and non-canonical interactions. Hence, investigation of these latter Nef functions should benefit from a similar approach. Six historically used alanine substitutions for determining structure-function relationships of Nef are discussed. These are M20A, E62A/E63A/E64A/E65A (AAAA), P72A/P75A (AXXA), R106A, L164A/L165A, and D174A/D175A. Investigations of less-disruptive mutations in place of AAAA and AXXA have led to different interpretations of mechanism. Two recent examples of this alternate approach, F191I for studying PAK2 activation and D123E for the critical residue D123 are discussed. The implications of the new findings and the resulting new paradigm for Nef structure-function are discussed with respect to creating a map of Nef functions on the protein surface. We report the results of a PPI-Pred analysis for protein-protein interfaces. There are three predicted patches produced by the analysis which describe regions consistent with the currently known mutational analyses of Nef function.
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Affiliation(s)
- John L Foster
- Division of Infectious Diseases, Center for AIDS Research, Chapel Hill, NC 27599-7042, USA.
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38
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Althaus CL, De Boer RJ. Implications of CTL-mediated killing of HIV-infected cells during the non-productive stage of infection. PLoS One 2011; 6:e16468. [PMID: 21326882 PMCID: PMC3034731 DOI: 10.1371/journal.pone.0016468] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 12/20/2010] [Indexed: 11/23/2022] Open
Abstract
Patients infected with HIV exhibit orders of magnitude differences in their set-point levels of the plasma viral load. As to what extent this variation is due to differences in the efficacy of the cytotoxic T lymphocyte (CTL) response in these patients is unclear. Several studies have shown that HIV-infected CD4+ T cells also present viral epitopes that are recognized by CTLs before the productive stage of infection, i.e., during the intracellular eclipse phase before the infected cell starts to produce new viral particles. Here, we use mathematical modeling to investigate the potential impact of early killing of HIV-infected cells on viral replication. We suggest that the majority of CTL-mediated killing could occur during the viral eclipse phase, and that the killing of virus-producing cells could be substantially lower at later stages due to MHC-I-down-regulation. Such a mechanism is in agreement with several experimental observations that include CD8+ T cell depletion and antiretroviral drug treatment. This indicates a potentially important role of CTL-mediated killing during the non-productive stage of HIV-infected cells.
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39
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Wonderlich ER, Leonard JA, Collins KL. HIV immune evasion disruption of antigen presentation by the HIV Nef protein. Adv Virus Res 2011; 80:103-27. [PMID: 21762823 PMCID: PMC3782996 DOI: 10.1016/b978-0-12-385987-7.00005-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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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40
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Kirchhoff F. Immune evasion and counteraction of restriction factors by HIV-1 and other primate lentiviruses. Cell Host Microbe 2010; 8:55-67. [PMID: 20638642 DOI: 10.1016/j.chom.2010.06.004] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/14/2010] [Accepted: 05/27/2010] [Indexed: 10/19/2022]
Abstract
Retroviruses have evolved effective strategies to evade the host immune response, such as high variability and latent infection. In addition, primate lentiviruses, such as HIV-1, have acquired several "accessory" genes that antagonize antiviral host restriction factors and facilitate viral immune evasion, thereby allowing continuous and efficient viral replication despite apparently strong innate and acquired immune responses. Here, I summarize some of our current knowledge on the acquisition and function of the viral vif, vpr, vpu, and nef genes, with a particular focus on the evolution and specific properties of pandemic HIV-1 strains that may contribute to their efficient spread and high virulence.
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Affiliation(s)
- Frank Kirchhoff
- Institute of Molecular Virology, University Hospital Ulm, Meyerhofstrasse 1, 89081 Ulm, Germany.
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41
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Specht A, Telenti A, Martinez R, Fellay J, Bailes E, Evans DT, Carrington M, Hahn BH, Goldstein DB, Kirchhoff F. Counteraction of HLA-C-mediated immune control of HIV-1 by Nef. J Virol 2010; 84:7300-11. [PMID: 20463068 PMCID: PMC2898263 DOI: 10.1128/jvi.00619-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/04/2010] [Indexed: 11/20/2022] Open
Abstract
A host genetic variant (-35C/T) correlates with increased human leukocyte antigen C (HLA-C) expression and improved control of HIV-1. HLA-C-mediated immunity may be particularly protective because HIV-1 is unable to remove HLA-C from the cell surface, whereas it can avoid HLA-A- and HLA-B-mediated immunity by Nef-mediated down-modulation. However, some individuals with the protective -35CC genotype exhibit high viral loads. Here, we investigated whether the ability of HIV-1 to replicate efficiently in the "protective" high-HLA-C-expression host environment correlates with specific functional properties of Nef. We found that high set point viral loads (sVLs) were not associated with the emergence of Nef variants that had acquired the ability to down-modulate HLA-C or were more effective in removing HLA-A and HLA-B from the cell surface. However, in individuals with the protective -35CC genotype we found a significant association between sVLs and the efficiency of Nef-mediated enhancement of virion infectivity and modulation of CD4, CD28, and the major histocompatibility complex class II (MHC-II)-associated invariant chain (Ii), while this was not observed in subjects with the -35TT genotype. Since the latter Nef functions all influence the stimulation of CD4(+) T helper cells by antigen-presenting cells, they may cooperate to affect both the activation status of infected T cells and the generation of an antiviral cytotoxic T-lymphocyte (CTL) response. In comparison, different levels of viremia in individuals with the common -35TT genotype were not associated with differences in Nef function but with differences in HLA-C mRNA expression levels. Thus, while high HLA-C expression may generally facilitate control of HIV-1, Nef may counteract HLA-C-mediated immune control in some individuals indirectly, by manipulating T-cell function and MHC-II antigen presentation.
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Affiliation(s)
- Anke Specht
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Amalio Telenti
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Raquel Martinez
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jacques Fellay
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Elizabeth Bailes
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - David T. Evans
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Mary Carrington
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Beatrice H. Hahn
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - David B. Goldstein
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Frank Kirchhoff
- Institute of Molecular Virology, University Hospital of Ulm, 89081 Ulm, Germany, Institute of Microbiology, University Hospital Center and University of Lausanne, 1011 Lausanne, Switzerland, Center for Human Genome Variation, Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27710, Institute of Genetics, University of Nottingham, Queens Medical Centre, NH7 2UH, Nottingham, United Kingdom, Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts 01772, Cancer and Inflammation Program, Laboratory of Experimental Immunology, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Ragon Institute of MGH, MIT and Harvard, Boston, Massachusetts 02114, Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Mechanism of protection of live attenuated simian immunodeficiency virus: coevolution of viral and immune responses. AIDS 2010; 24:637-48. [PMID: 20186034 DOI: 10.1097/qad.0b013e328337795a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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High viremia is associated with high levels of in vivo major histocompatibility complex class I Downregulation in rhesus macaques infected with simian immunodeficiency virus SIVmac239. J Virol 2010; 84:5443-7. [PMID: 20219903 DOI: 10.1128/jvi.02452-09] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human and simian immunodeficiency viruses (HIV and SIV) downregulate major histocompatibility complex class I (MHC-I) molecules from the surface of infected cells. Although this activity is conserved across viral isolates, its importance in AIDS pathogenesis is not clear. We therefore developed an assay to detect the level of MHC-I expression of SIV-infected cells directly ex vivo. Here we show that the extent of MHC-I downregulation is greatest in SIVmac239-infected macaques that never effectively control virus replication. Our results suggest that a high level of MHC-I downregulation is a hallmark of fast disease progression in SIV infection.
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Minang JT, Trivett MT, Coren LV, Barsov EV, Piatak M, Ott DE, Ohlen C. Nef-mediated MHC class I down-regulation unmasks clonal differences in virus suppression by SIV-specific CD8(+) T cells independent of IFN-gamma and CD107a responses. Virology 2009; 391:130-9. [PMID: 19555986 PMCID: PMC2716421 DOI: 10.1016/j.virol.2009.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 05/21/2009] [Accepted: 06/03/2009] [Indexed: 11/22/2022]
Abstract
CD8(+) T lymphocytes (CTL) play a role in controlling HIV/SIV infection. CTL antiviral activity is dependent on recognition of antigenic peptides associated with MHC class I molecules on infected target cells, and CTL activation can be impaired by Nef-mediated down-regulation of MHC class I molecules. We tested the ability of a series of rhesus macaque CD8(+) T-cell clones specific for the SIV Gag CM9 peptide to suppress SIV infection of autologous CD4(+) T cells. We used a set of SIV(mac)239 viruses with either wild-type Nef or Nef mutations that impair MHC class I down-regulation. All CTL clones efficiently suppressed virus replication in cells infected with mutant viruses with altered Nef function, phenotypically MHC class I(high) or MHC class I(intermediate). However, the ability of the clones to suppress virus replication was variably reduced in the presence of wild-type Nef (MHC class I(low)) despite the observations that all CTL clones showed similar IFN-gamma responses to titrated amounts of cognate peptide as well as to SIV-infected cells. In addition, the CTL clones showed variable CD107a (CTL degranulation marker) responses that did not correlate with their capacity to suppress virus replication. Thus, the clonal differences are not attributable to TCR avidity or typical effector responses, and point to a potential as yet unknown mechanism for CTL-mediated suppression of viral replication. These data emphasize that current assays for evaluating CTL responses in infected or vaccinated individuals do not fully capture the complex requirements for effective CTL-mediated control of virus replication.
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Affiliation(s)
- Jacob T. Minang
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Matthew T. Trivett
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Lori V. Coren
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Eugene V. Barsov
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - David E. Ott
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
| | - Claes Ohlen
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA
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Ali A, Realegeno S, Yang OO, Lewis MJ. Simultaneous assessment of CD4 and MHC-I downregulation by Nef primary isolates in the context of infection. J Virol Methods 2009; 161:297-304. [PMID: 19643141 DOI: 10.1016/j.jviromet.2009.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 07/16/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
Abstract
The HIV-1 Nef protein plays a key role in pathogenesis, as demonstrated by strong selective pressure to maintain its open reading frame, and disease attenuation when it is deleted. Among myriad cellular effects attributed to Nef, downregulation of cell surface CD4 and major histocompatibility complex class I (MHC-I) proteins are the best documented. However, few data regarding primary isolate Nef functions are available, and most studies have been performed using transient transfections to express Nef driven by a non-physiologic promoter. A novel assay system to measure simultaneously the downregulation of CD4 and MHC-I by primary HIV-1 nef in a more physiologic viral genomic context is presented. Examination of plasma nef mixtures allowed comprehensive profiling of these Nef functions within the quasispecies in vivo. Subsets within the circulating nef population were observed that are either fully functional or non-functional. These data demonstrated that this assay system allows rapid characterization of bulk and clonal Nef functional profiles that can be used in pathogenesis studies to define further its important role in pathogenesis.
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Affiliation(s)
- Ayub Ali
- Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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Abstract
OBJECTIVE HIV infection induces a progressive depletion of CD4 T cells. We showed that NKp44L, a cellular ligand for an activating natural killer (NK) receptor, is expressed on CD4 T cells during HIV infection and is correlated with both CD4 cell depletion and increase in viral load. NKp44LCD4 T cells are highly sensitive to the NK lysis activity. In contrast, HIV-infected CD4 T cells are resistant to NK killing, suggesting that HIV-1 developed strategies to avoid detection by the host cell immunity. DESIGN To assess whether viral protein can affect NKp44L expression, using Nef-deficient virus as well as a panel of recombinant vaccinia viruses expressing all HIV-1 viral proteins was tested. The involvement of Nef in the downmodulation of NKp44L was determined using defined mutants of Nef. Functional consequences of Nef on NK-cell recognition were evaluated by either 51Cr-release assays and degranulation assays in presence of anti-NKp44L mAb. RESULTS We observed that during HIV-1 infection, noninfected CD4 T cells exclusively expressed NKp44L, and demonstrate that Nef mediates NKp44L intracellular retention in HIV-infected cells. This has functional consequences on HIV-infected CD4 T cells recognition by NK cells, causing a decreased susceptibility to NK cytotoxicity. Furthermore, experiments in presence of neutralizing NKp44L mAb revealed that Nef inhibitory effect on NK cytotoxicity mainly depends on the NKp44L pathway. CONCLUSION This novel escape mechanism could explain the resistance of HIV-infected cells to NK lysis and as a result play a key role in maintaining the HIV reservoir by avoiding recognition by NK cells.
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Jia B, Ng SK, DeGottardi MQ, Piatak M, Yuste E, Carville A, Mansfield KG, Li W, Richardson BA, Lifson JD, Evans DT. Immunization with single-cycle SIV significantly reduces viral loads after an intravenous challenge with SIV(mac)239. PLoS Pathog 2009; 5:e1000272. [PMID: 19165322 PMCID: PMC2621341 DOI: 10.1371/journal.ppat.1000272] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 12/15/2008] [Indexed: 12/24/2022] Open
Abstract
Strains of simian immunodeficiency virus (SIV) that are limited to a single cycle of infection were evaluated for the ability to elicit protective immunity against wild-type SIVmac239 infection of rhesus macaques by two different vaccine regimens. Six animals were inoculated at 8-week intervals with 6 identical doses consisting of a mixture of three different envelope variants of single-cycle SIV (scSIV). Six additional animals were primed with a mixture of cytoplasmic domain-truncated envelope variants of scSIV and boosted with two doses of vesicular stomatitis virus glycoprotein (VSV G) trans-complemented scSIV. While both regimens elicited detectable virus-specific T cell responses, SIV-specific T cell frequencies were more than 10-fold higher after boosting with VSV G trans-complemented scSIV (VSV G scSIV). Broad T cell recognition of multiple viral antigens and Gag-specific CD4+ T cell responses were also observed after boosting with VSV G scSIV. With the exception of a single animal in the repeated immunization group, all of the animals became infected following an intravenous challenge with SIVmac239. However, significantly lower viral loads and higher memory CD4+ T cell counts were observed in both immunized groups relative to an unvaccinated control group. Indeed, both scSIV immunization regimens resulted in containment of SIVmac239 replication after challenge that was as good as, if not better than, what has been achieved by other non-persisting vaccine vectors that have been evaluated in this challenge model. Nevertheless, the extent of protection afforded by scSIV was not as good as typically conferred by persistent infection with live, attenuated SIV. These observations have potentially important implications to the design of an effective AIDS vaccine, since they suggest that ongoing stimulation of virus-specific immune responses may be essential to achieving the degree of protection afforded by live, attenuated SIV. AIDS vaccine candidates based on recombinant DNA and/or viral vectors stimulate potent cellular immune responses. However, the extent of protection achieved by these vaccines has so far been disappointing. While live, attenuated strains of SIV afford more reliable protection in animal models, there are justifiable safety concerns with the use of live, attenuated HIV-1 in humans. As an experimental vaccine approach designed to uncouple immune activation from ongoing virus replication, we developed a genetic system for producing strains of SIV that are limited to a single cycle of infection. We compared repeated versus prime-boost vaccine regimens with single-cycle SIV for the ability to elicit protective immunity in rhesus macaques against a strain of SIV that is notoriously difficult to control by vaccination. Both vaccine regimens afforded significant containment of virus replication after challenge. Nevertheless, the extent of protection achieved by immunization with single-cycle SIV was not as good as the protection typically provided by persistent infection of animals with live, attenuated SIV. These observations have important implications for the design of an effective AIDS vaccine, since they suggest that ongoing stimulation of virus-specific immune responses may ultimately be necessary for achieving the robust protection afforded by live, attenuated SIV.
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Affiliation(s)
- Bin Jia
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Sharon K. Ng
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - M. Quinn DeGottardi
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC Frederick, Inc., National Cancer Institute at Frederick, Frederick, Maryland, United States of America
| | - Eloísa Yuste
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Angela Carville
- Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Keith G. Mansfield
- Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Wenjun Li
- Biostatistics Research Group, Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Barbra A. Richardson
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC Frederick, Inc., National Cancer Institute at Frederick, Frederick, Maryland, United States of America
| | - David T. Evans
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
- * E-mail:
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Arhel NJ, Kirchhoff F. Implications of Nef: host cell interactions in viral persistence and progression to AIDS. Curr Top Microbiol Immunol 2009; 339:147-75. [PMID: 20012528 DOI: 10.1007/978-3-642-02175-6_8] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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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Predicting the impact of blocking human immunodeficiency virus type 1 Nef in vivo. J Virol 2008; 83:2349-56. [PMID: 19091857 DOI: 10.1128/jvi.00821-08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef is a multifunctional protein that confers an ability to evade killing by cytotoxic T lymphocytes (CTLs) as well as other advantages to the virus in vivo. Here we exploited mathematical modeling and related statistical methods to estimate the impact of Nef activity on viral replication in vivo in relation to CTLs. Our results indicate that downregulation of major histocompatibility complex class I (MHC-I) A and B by wild-type Nef confers an advantage to the virus of about 82% in decreased CTL killing efficiency on average, meaning that abolishing the MHC-I downregulation function of Nef would increase killing by more than fivefold. We incorporated this estimate, as well as prior estimates of replicative enhancement by Nef, into a previously published model of HIV-1 and CTLs in vivo (W. D. Wick, O. O. Yang, L. Corey, and S. G. Self, J. Virol. 79:13579-13586, 2005), generalized to permit CTL recognition of multiple epitopes. A sequence database analysis revealed that 92.9% of HIV-1 epitopes are A or B restricted, and a previous study found an average of about 19 epitopes recognized (M. M. Addo et al., J. Virol. 77:2081-2092, 2003). We combined these estimates in the model in order to predict the impact of inhibiting Nef function in the general (chronically infected) population by a drug. The predicted impact on viral load ranged from negligible to 2.4 orders of magnitude, depending on the effects of the drug and the CTL dynamical scenario assumed. We conclude that inhibiting Nef could make a substantial reduction in disease burden, lengthening the time before the necessity of undertaking combination therapy with other antiretroviral drugs.
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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 PMCID: PMC2515349 DOI: 10.1371/journal.ppat.1000131] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [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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