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Azizi H, Knapp JP, Li Y, Berger A, Lafrance MA, Pedersen J, de la Vega MA, Racine T, Kang CY, Mann JFS, Dikeakos JD, Kobinger G, Arts EJ. Optimal Expression, Function, and Immunogenicity of an HIV-1 Vaccine Derived from the Approved Ebola Vaccine, rVSV-ZEBOV. Vaccines (Basel) 2023; 11:977. [PMID: 37243081 PMCID: PMC10223473 DOI: 10.3390/vaccines11050977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Vesicular stomatitis virus (VSV) remains an attractive platform for a potential HIV-1 vaccine but hurdles remain, such as selection of a highly immunogenic HIV-1 Envelope (Env) with a maximal surface expression on recombinant rVSV particles. An HIV-1 Env chimera with the transmembrane domain (TM) and cytoplasmic tail (CT) of SIVMac239 results in high expression on the approved Ebola vaccine, rVSV-ZEBOV, also harboring the Ebola Virus (EBOV) glycoprotein (GP). Codon-optimized (CO) Env chimeras derived from a subtype A primary isolate (A74) are capable of entering a CD4+/CCR5+ cell line, inhibited by HIV-1 neutralizing antibodies PGT121, VRC01, and the drug, Maraviroc. The immunization of mice with the rVSV-ZEBOV carrying the CO A74 Env chimeras results in anti-Env antibody levels as well as neutralizing antibodies 200-fold higher than with the NL4-3 Env-based construct. The novel, functional, and immunogenic chimeras of CO A74 Env with the SIV_Env-TMCT within the rVSV-ZEBOV vaccine are now being tested in non-human primates.
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Affiliation(s)
- Hiva Azizi
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
- Human Health Therapeutics, National Research Council Canada, Ottawa, ON K1N 5A2, Canada
| | - Jason P. Knapp
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada; (J.P.K.); (Y.L.); (C.-Y.K.); (J.D.D.)
| | - Yue Li
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada; (J.P.K.); (Y.L.); (C.-Y.K.); (J.D.D.)
| | - Alice Berger
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
| | - Marc-Alexandre Lafrance
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
| | - Jannie Pedersen
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
| | - Marc-Antoine de la Vega
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
- Galveston National Laboratory, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - Trina Racine
- Département de Microbiologie-Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada; (H.A.); (A.B.); (M.-A.L.); (J.P.); (M.-A.d.l.V.); (T.R.)
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Chil-Yong Kang
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada; (J.P.K.); (Y.L.); (C.-Y.K.); (J.D.D.)
| | - Jamie F. S. Mann
- Bristol Veterinary School, University of Bristol, Langford House, Langford, BS40 5DU Bristol, UK;
| | - Jimmy D. Dikeakos
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada; (J.P.K.); (Y.L.); (C.-Y.K.); (J.D.D.)
| | - Gary Kobinger
- Galveston National Laboratory, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - Eric J. Arts
- Department of Microbiology and Immunology, Western University, London, ON N6A 3K7, Canada; (J.P.K.); (Y.L.); (C.-Y.K.); (J.D.D.)
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Thomas AS, Coote C, Moreau Y, Isaac JE, Ewing AC, Kourtis AP, Sagar M. Antibody-dependent cellular cytotoxicity (ADCC) responses along with ADCC susceptibility influence HIV-1 mother to child transmission. JCI Insight 2022; 7:159435. [PMID: 35324477 PMCID: PMC9090239 DOI: 10.1172/jci.insight.159435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND HIV-1 vaccine efforts are primarily directed towards eliciting neutralizing antibodies (nAbs). However, vaccine trials and mother to child natural history cohort investigations indicate that antibody-dependent cellular cytotoxicity (ADCC), not nAbs, correlate with prevention. The ADCC characteristics associated with lack of HIV-1 acquisition remain unclear. METHODS Here we examine ADCC and nAb properties in pre-transmission plasma from HIV-1 exposed infants and from the corresponding transmitting and non-transmitting mothers' breast milk and plasma. Breadth and potency (BP) is assessed against a panel of heterologous, non-maternal, variants. ADCC and neutralization sensitivity is estimated for the strains present in the infected mothers. RESULTS Infants that eventually acquire HIV-1 and those that remain uninfected have similar pre-transmission ADCC BP. The viruses circulating in the transmitting and the non-transmitting mothers also have similar ADCC susceptibility. Infants with a combination of higher pre-transmission ADCC BP and exposure to more ADCC susceptible strains are less likely to acquire HIV-1. In contrast, higher pre-existing infant neutralization BP and greater maternal virus neutralization sensitivity does not associate with transmission. Infants have higher ADCC BP closer to birth and in the presence of high plasma IgG relative to IgA levels. Mothers with potent humoral responses against their autologous viruses harbor more ADCC sensitive strains. CONCLUSION ADCC sensitivity of the exposure variants along with preexisting ADCC BP influence mother to child HIV-1 transmission during breastfeeding. Vaccination strategies that enhance ADCC responses are likely not sufficient to prevent HIV-1 transmission because strains present in chronically infected individuals can have low ADCC susceptibility. TRIAL REGISTRATION NCT00164736 for BAN study.
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Affiliation(s)
- Allison S Thomas
- Department of Microbiology, Boston University School of Medicine, Boston, United States of America
| | - Carolyn Coote
- Department of Medicine, Boston Medical Center, Boston, United States of America
| | - Yvetane Moreau
- Department of Medicine, Boston Medical Center, Boston, United States of America
| | - John E Isaac
- Department of Medicine, Boston Medical Center, Boston, United States of America
| | - Alexander C Ewing
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, United States of America
| | - Athena P Kourtis
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, United States of America
| | - Manish Sagar
- Department of Medicine, Boston Medical Center, Boston, United States of America
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Thomas AS, Moreau Y, Jiang W, Isaac JE, Ewing A, White LF, Kourtis AP, Sagar M. Pre-existing infant antibody-dependent cellular cytotoxicity associates with reduced HIV-1 acquisition and lower morbidity. Cell Rep Med 2021; 2:100412. [PMID: 34755132 PMCID: PMC8561235 DOI: 10.1016/j.xcrm.2021.100412] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/18/2021] [Accepted: 09/22/2021] [Indexed: 11/24/2022]
Abstract
In humans, pre-existing anti-HIV-1 neutralizing antibodies (nAbs) have not been associated with decreased HIV-1 acquisition. Here, we evaluate antibody-dependent cellular cytotoxicity (ADCC) present in pre-transmission infant and maternal plasma and breast milk (BM) against the contemporaneous maternal HIV-1 variants. HIV-1-exposed uninfected compared with HIV-1-exposed infected infants have higher ADCC and a combination of ADCC and nAb responses against their corresponding mother's strains. ADCC does not correlate with nAbs, suggesting they are independent activities. The infected infants with high ADCC compared with low ADCC, but not those with higher ADCC plus nAbs, have lower morbidity up to 1 year after birth. A higher IgA to IgG ratio, observed in BM supernatants and in a higher proportion of the infected compared with the uninfected infants, associates with lower ADCC. Against the exposure strains, ADCC, more than nAbs, associates with both lower mother-to-child transmission and decreased post-infection infant morbidity.
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Affiliation(s)
- Allison S. Thomas
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA
| | - Yvetane Moreau
- Department of Medicine, Boston Medical Center, Boston, MA, USA
| | - Wenqing Jiang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - John E. Isaac
- Department of Medicine, Boston Medical Center, Boston, MA, USA
| | - Alexander Ewing
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Laura F. White
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Athena P. Kourtis
- Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Manish Sagar
- Department of Medicine, Boston Medical Center, Boston, MA, USA
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An Amino Acid Polymorphism within the HIV-1 Nef Dileucine Motif Functionally Uncouples Cell Surface CD4 and SERINC5 Downregulation. J Virol 2021; 95:e0058821. [PMID: 34037423 DOI: 10.1128/jvi.00588-21] [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
Serine incorporator 5 (SERINC5) reduces the infectivity of progeny HIV-1 virions by incorporating into the outer host-derived viral membrane during egress. To counter SERINC5, the HIV-1 accessory protein Nef triggers SERINC5 internalization by engaging the adaptor protein 2 (AP-2) complex using the [D/E]xxxL[L/I]167 Nef dileucine motif. Nef also engages AP-2 via its dileucine motif to downregulate the CD4 receptor. Although these two Nef functions are related, the mechanisms governing SERINC5 downregulation are incompletely understood. Here, we demonstrate that two primary Nef isolates, referred to as 2410 and 2391 Nef, acquired from acutely HIV-1 infected women from Zimbabwe, both downregulate CD4 from the cell surface. However, only 2410 Nef retains the ability to downregulate cell surface SERINC5. Using a series of Nef chimeras, we mapped the region of 2391 Nef responsible for the functional uncoupling of these two antagonistic pathways to the dileucine motif. Modifications of the first and second x positions of the 2410 Nef dileucine motif to asparagine and aspartic acid residues, respectively (ND164), impaired cell surface SERINC5 downregulation, which resulted in reduced infectious virus yield in the presence of SERINC5. The ND164 mutation additionally partially impaired, but did not completely abrogate, Nef-mediated cell surface CD4 downregulation. Furthermore, the patient infected with HIV-1 encoding 2391 Nef had stable CD4+ T cell counts, whereas infection with HIV-1 encoding 2410 Nef resulted in CD4+ T cell decline and disease progression. IMPORTANCE A contributing factor to HIV-1 persistence is evasion of the host immune response. HIV-1 uses the Nef accessory protein to evade the antiviral roles of the adaptive and intrinsic innate immune responses. Nef targets SERINC5, a restriction factor which potently impairs HIV-1 infection by triggering SERINC5 removal from the cell surface. The molecular determinants underlying this Nef function remain incompletely understood. Recent studies have found a correlation between the extent of Nef-mediated SERINC5 downregulation and the rate of disease progression. Furthermore, single-residue polymorphisms outside the known Nef functional motifs can modulate SERINC5 downregulation. The identification of a naturally occurring Nef polymorphism impairing SERINC5 downregulation in this study supports a link between Nef downregulation of SERINC5 and the rate of plasma CD4+ T cell decline. Moreover, the observed functional impairments of this polymorphism could provide clues to further elucidate unknown aspects of the SERINC5 antagonistic pathway via Nef.
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Ndashimye E, Avino M, Olabode AS, Poon AFY, Gibson RM, Li Y, Meadows A, Tan C, Reyes PS, Kityo CM, Kyeyune F, Nankya I, Quiñones-Mateu ME, Arts EJ. Accumulation of integrase strand transfer inhibitor resistance mutations confers high-level resistance to dolutegravir in non-B subtype HIV-1 strains from patients failing raltegravir in Uganda. J Antimicrob Chemother 2021; 75:3525-3533. [PMID: 32853364 DOI: 10.1093/jac/dkaa355] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/03/2020] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Increasing first-line treatment failures in low- and middle-income countries (LMICs) have led to increased use of integrase strand transfer inhibitors (INSTIs) such as dolutegravir. However, HIV-1 susceptibility to INSTIs in LMICs, especially with previous raltegravir exposure, is poorly understood due to infrequent reporting of INSTI failures and testing for INSTI drug resistance mutations (DRMs). METHODS A total of 51 non-subtype B HIV-1 infected patients failing third-line (raltegravir-based) therapy in Uganda were initially selected for the study. DRMs were detected using Sanger and deep sequencing. HIV integrase genes of 13 patients were cloned and replication capacities (RCs) and phenotypic susceptibilities to dolutegravir, raltegravir and elvitegravir were determined with TZM-bl cells. Spearman's correlation coefficient was used to determine cross-resistance between INSTIs. RESULTS INSTI DRMs were detected in 47% of patients. HIV integrase-recombinant virus carrying one primary INSTI DRM (N155H or Y143R/S) was susceptible to dolutegravir but highly resistant to raltegravir and elvitegravir (>50-fold change). Two patients, one with E138A/G140A/Q148R/G163R and one with E138K/G140A/S147G/Q148K, displayed the highest reported resistance to raltegravir, elvitegravir and even dolutegravir. The former multi-DRM virus had WT RC whereas the latter had lower RCs than WT. CONCLUSIONS In HIV-1 subtype A- and D-infected patients failing raltegravir and harbouring INSTI DRMs, there is high-level resistance to elvitegravir and raltegravir. More routine monitoring of INSTI treatment may be advised in LMICs, considering that multiple INSTI DRMs may have accumulated during prolonged exposure to raltegravir during virological failure, leading to high-level INSTI resistance, including dolutegravir resistance.
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Affiliation(s)
- Emmanuel Ndashimye
- Department of Microbiology and Immunology, Western University, London, Canada.,Center for AIDS Research Uganda Laboratories, Joint Clinical Research Centre, Kampala, Uganda
| | - Mariano Avino
- Department of Pathology and Laboratory Medicine, Western University, London, Canada
| | - Abayomi S Olabode
- Department of Pathology and Laboratory Medicine, Western University, London, Canada
| | - Art F Y Poon
- Department of Microbiology and Immunology, Western University, London, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, Canada.,Department of Applied Mathematics, Western University, London, Canada
| | - Richard M Gibson
- Department of Microbiology and Immunology, Western University, London, Canada
| | - Yue Li
- Department of Microbiology and Immunology, Western University, London, Canada
| | - Adam Meadows
- Department of Microbiology and Immunology, Western University, London, Canada
| | - Christine Tan
- Department of Microbiology and Immunology, Western University, London, Canada
| | - Paul S Reyes
- Department of Microbiology and Immunology, Western University, London, Canada
| | | | - Fred Kyeyune
- Center for AIDS Research Uganda Laboratories, Joint Clinical Research Centre, Kampala, Uganda
| | - Immaculate Nankya
- Center for AIDS Research Uganda Laboratories, Joint Clinical Research Centre, Kampala, Uganda
| | | | - Eric J Arts
- Department of Microbiology and Immunology, Western University, London, Canada
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Cataldo VF, Salgado V, Saa PA, Agosin E. Genomic integration of unclonable gene expression cassettes in Saccharomyces cerevisiae using rapid cloning-free workflows. Microbiologyopen 2020; 9:e978. [PMID: 31944620 PMCID: PMC7066455 DOI: 10.1002/mbo3.978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/22/2019] [Accepted: 11/22/2019] [Indexed: 11/11/2022] Open
Abstract
Most DNA assembly methods require bacterial amplification steps, which restrict its application to genes that can be cloned in the bacterial host without significant toxic effects. However, genes that cannot be cloned in bacteria do not necessarily exert toxic effects on the final host. In order to tackle this issue, we adapted two DNA assembly workflows for rapid, cloning-free construction and genomic integration of expression cassettes in Saccharomyces cerevisiae. One method is based on a modified Gibson assembly, while the other relies on a direct assembly and integration of linear PCR products by yeast homologous recombination. The methods require few simple experimental steps, and their performance was evaluated for the assembly and integration of unclonable zeaxanthin epoxidase expression cassettes in yeast. Results showed that up to 95% integration efficiency can be reached with minimal experimental effort. The presented workflows can be employed as rapid gene integration tools for yeast, especially tailored for integrating unclonable genes.
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Affiliation(s)
- Vicente F Cataldo
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Valeria Salgado
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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Evolution-Guided Structural and Functional Analyses of the HERC Family Reveal an Ancient Marine Origin and Determinants of Antiviral Activity. J Virol 2018; 92:JVI.00528-18. [PMID: 29669830 PMCID: PMC6002735 DOI: 10.1128/jvi.00528-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 04/10/2018] [Indexed: 01/24/2023] Open
Abstract
In humans, homologous to the E6-AP carboxyl terminus (HECT) and regulator of chromosome condensation 1 (RCC1)-like domain-containing protein 5 (HERC5) is an interferon-induced protein that inhibits replication of evolutionarily diverse viruses, including human immunodeficiency virus type 1 (HIV-1). To better understand the origin, evolution, and function of HERC5, we performed phylogenetic, structural, and functional analyses of the entire human small-HERC family, which includes HERC3, HERC4, HERC5, and HERC6. We demonstrated that the HERC family emerged >595 million years ago and has undergone gene duplication and gene loss events throughout its evolution. The structural topology of the RCC1-like domain and HECT domains from all HERC paralogs is highly conserved among evolutionarily diverse vertebrates despite low sequence homology. Functional analyses showed that the human small HERCs exhibit different degrees of antiviral activity toward HIV-1 and that HERC5 provides the strongest inhibition. Notably, coelacanth HERC5 inhibited simian immunodeficiency virus (SIV), but not HIV-1, particle production, suggesting that the antiviral activity of HERC5 emerged over 413 million years ago and exhibits species- and virus-specific restriction. In addition, we showed that both HERC5 and HERC6 are evolving under strong positive selection, particularly blade 1 of the RCC1-like domain, which we showed is a key determinant of antiviral activity. These studies provide insight into the origin, evolution, and biological importance of the human restriction factor HERC5 and the other HERC family members. IMPORTANCE Intrinsic immunity plays an important role as the first line of defense against viruses. Studying the origins, evolution, and functions of proteins responsible for effecting this defense will provide key information about virus-host relationships that can be exploited for future drug development. We showed that HERC5 is one such antiviral protein that belongs to an evolutionarily conserved family of HERCs with an ancient marine origin. Not all vertebrates possess all HERC members, suggesting that different HERCs emerged at different times during evolution to provide the host with a survival advantage. Consistent with this, two of the more recently emerged HERC members, HERC5 and HERC6, displayed strong signatures of having been involved in an ancient evolutionary battle with viruses. Our findings provide new insights into the evolutionary origin and function of the HERC family in vertebrate evolution, identifying HERC5 and possibly HERC6 as important effectors of intrinsic immunity in vertebrates.
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Pankrac J, Klein K, McKay PF, King DFL, Bain K, Knapp J, Biru T, Wijewardhana CN, Pawa R, Canaday DH, Gao Y, Fidler S, Shattock RJ, Arts EJ, Mann JFS. A heterogeneous human immunodeficiency virus-like particle (VLP) formulation produced by a novel vector system. NPJ Vaccines 2018; 3:2. [PMID: 29367885 PMCID: PMC5775397 DOI: 10.1038/s41541-017-0040-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/06/2017] [Accepted: 12/08/2017] [Indexed: 01/12/2023] Open
Abstract
First identified as the etiological agent behind Acquired Immunodeficiency Syndrome (AIDS) in the early 1980s, HIV-1 has continued to spread into a global pandemic and major public health concern. Despite the success of antiretroviral therapy at reducing HIV-1 viremia and preventing the dramatic CD4+ T-cell collapse, infected individuals remain HIV positive for life. Unfortunately, it is increasingly clear that natural immunity is not, and may never be, protective against this pathogen. Therefore, efficacious vaccine interventions, which can either prevent infection or eradicate the latent viral reservoir and effect cure, are a major medical priority. Here we describe the development of a safe vaccine platform, currently being utilized in on-going prophylactic and therapeutic preclinical studies and consisting of highly heterogeneous virus-like particle formulations that represent the virus diversity within infected individuals. These VLPs contain no 5'LTR, no functional integrase, and have a severely mutated stem loop 1-thereby preventing any potential reverse transcription, integration, and RNA packaging. Furthermore, we demonstrate that these VLPs are morphologically identical to wild-type virus with polyvalent Env in a functional form. Finally, we show that the VLPs are antigenic and capable of generating strong immune recall responses.
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Affiliation(s)
- Joshua Pankrac
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
| | - Katja Klein
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Paul F. McKay
- Division of Medicine, Department of Infectious Diseases, Imperial College London, Norfolk Place, London, W2 1PG UK
| | - Deborah F. L. King
- Division of Medicine, Department of Infectious Diseases, Imperial College London, Norfolk Place, London, W2 1PG UK
| | - Katie Bain
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
| | - Jason Knapp
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
| | - Tsigereda Biru
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Chanuka N. Wijewardhana
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
| | - Rahul Pawa
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
| | - David H. Canaday
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Yong Gao
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Sarah Fidler
- Department of Medicine, Imperial College London, London, UK
| | - Robin J. Shattock
- Division of Medicine, Department of Infectious Diseases, Imperial College London, Norfolk Place, London, W2 1PG UK
| | - Eric J. Arts
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Jamie F. S. Mann
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
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Pawlak EN, Dirk BS, Jacob RA, Johnson AL, Dikeakos JD. The HIV-1 accessory proteins Nef and Vpu downregulate total and cell surface CD28 in CD4 + T cells. Retrovirology 2018; 15:6. [PMID: 29329537 PMCID: PMC5767034 DOI: 10.1186/s12977-018-0388-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 12/20/2017] [Indexed: 12/20/2022] Open
Abstract
Background The HIV-1 accessory proteins Nef and Vpu alter cell surface levels of multiple host proteins to modify the immune response and increase viral persistence. Nef and Vpu can downregulate cell surface levels of the co-stimulatory molecule CD28, however the mechanism of this function has not been completely elucidated. Results Here, we provide evidence that Nef and Vpu decrease cell surface and total cellular levels of CD28. Moreover, using inhibitors we implicate the cellular degradation machinery in the downregulation of CD28. We shed light on the mechanisms of CD28 downregulation by implicating the Nef LL165 and DD175 motifs in decreasing cell surface CD28 and Nef DD175 in decreasing total cellular CD28. Moreover, the Vpu LV64 and S52/56 motifs were required for cell surface CD28 downregulation, while, unlike for CD4 downregulation, Vpu W22 was dispensable. The Vpu S52/56 motif was also critical for Vpu-mediated decreases in total CD28 protein level. Finally, the ability of Vpu to downregulate CD28 is conserved between multiple group M Vpu proteins and infection with viruses encoding or lacking Nef and Vpu have differential effects on activation upon stimulation. Conclusions We report that Nef and Vpu downregulate cell surface and total cellular CD28 levels. We identified inhibitors and mutations within Nef and Vpu that disrupt downregulation, shedding light on the mechanisms utilized to downregulate CD28. The conservation and redundancy between the abilities of two HIV-1 proteins to downregulate CD28 highlight the importance of this function, which may contribute to the development of latently infected cells. Electronic supplementary material The online version of this article (10.1186/s12977-018-0388-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emily N Pawlak
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, Dental Sciences Building, Room 3007J, London, ON, N6A 5C1, Canada
| | - Brennan S Dirk
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, Dental Sciences Building, Room 3007J, London, ON, N6A 5C1, Canada
| | - Rajesh Abraham Jacob
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, Dental Sciences Building, Room 3007J, London, ON, N6A 5C1, Canada
| | - Aaron L Johnson
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, Dental Sciences Building, Room 3007J, London, ON, N6A 5C1, Canada
| | - Jimmy D Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, Dental Sciences Building, Room 3007J, London, ON, N6A 5C1, Canada.
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10
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Ahmed Y, Tian M, Gao Y. Development of an anti-HIV vaccine eliciting broadly neutralizing antibodies. AIDS Res Ther 2017; 14:50. [PMID: 28893278 PMCID: PMC5594608 DOI: 10.1186/s12981-017-0178-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/11/2017] [Indexed: 11/17/2022] Open
Abstract
The extreme HIV diversity posts a great challenge on development of an effective anti-HIV vaccine. To solve this problem, it is crucial to discover an appropriate immunogens and strategies that are able to prevent the transmission of the diverse viruses that are circulating in the world. Even though there have been a number of broadly neutralizing anti-HIV antibodies (bNAbs) been discovered in recent years, induction of such antibodies to date has only been observed in HIV-1 infection. Here, in this mini review, we review the progress in development of HIV vaccine in eliciting broad immune response, especially production of bNAbs, discuss possible strategies, such as polyvalent sequential vaccination, that facilitates B cell maturation leading to bNAb response.
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11
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Bagaya BS, Tian M, Nickel GC, Vega JF, Li Y, He P, Klein K, Mann JFS, Jiang W, Arts EJ, Gao Y. An in vitro Model to Mimic Selection of Replication-Competent HIV-1 Intersubtype Recombination in Dual or Superinfected Patients. J Mol Biol 2017; 429:2246-2264. [PMID: 28472629 PMCID: PMC6202033 DOI: 10.1016/j.jmb.2017.04.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/24/2017] [Accepted: 04/24/2017] [Indexed: 11/23/2022]
Abstract
The low frequency of HIV-1 recombinants within entire viral populations in both individual patients and culture-based infection models impedes investigation of the underlying factors contributing to either the occurrence of recombinants or the survival of recombinants once they are formed. So far, most of the related studies have no consideration of recombinants' functionality. Here, we established a functional recombinant production (FRP) system to produce pure and functional HIV-1 intersubtype Env recombinants and utilized 454 pyrosequencing to investigate the distribution of over 4000 functional and non-functional recombination breakpoints from either the FRP system or dual infection cultures. The results revealed that most of the breakpoints converged in gp41 (62%) and C1 (25.3%) domains of gp120, which has strong correlation with the similarity between the two recombining sequences. Yet, the breakpoints also appeared in C2 (5.2%) and C5 (4.6%) domains not correlated with the recombining sequence similarity. Interestingly, none of the intersubtype gp120 recombinants recombined between C1 and gp41 regions either from the FRP system or from the dual infection culture, and very few from the HIV epidemic were functional. The present study suggests that the selection of functional Env recombinants is one of the reasons for the predominance of C1 and gp41 Env recombinants in the HIV epidemic, and it provides an in vitro model to mimic the selection of replication-competent HIV-1 intersubtype recombination in dual or superinfected patients.
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Affiliation(s)
- Bernard S Bagaya
- Department of Molecular Biology and Microbiology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, N6A 3K7, Uganda
| | - Meijuan Tian
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada
| | - Gabrielle C Nickel
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - José F Vega
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Yuejin Li
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Ping He
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Katja Klein
- Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada
| | - Jamie F S Mann
- Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada
| | - Wei Jiang
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Eric J Arts
- Department of Molecular Biology and Microbiology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada
| | - Yong Gao
- Department of Molecular Biology and Microbiology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada.
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12
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Infection of rhesus macaques with a pool of simian immunodeficiency virus with the envelope genes from acute HIV-1 infections. AIDS Res Ther 2016; 13:41. [PMID: 27906032 PMCID: PMC5124249 DOI: 10.1186/s12981-016-0125-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/16/2016] [Indexed: 01/29/2023] Open
Abstract
Background New simian–human immunodeficiency chimeric viruses with an HIV-1 env (SHIVenv) are critical for studies on HIV pathogenesis, vaccine development, and microbicide testing. Macaques are typically exposed to single CCR5-using SHIVenv which in most instances does not reflect the conditions during acute/early HIV infection (AHI) in humans. Instead of individual and serial testing new SHIV constructs, a pool of SHIVenv_B derived from 16 acute HIV-1 infections were constructed using a novel yeast-based SHIV cloning approach and then used to infect macaques. Results Even though none of the 16 SHIVenvs contained the recently reported mutations in env genes that could significantly enhance their binding affinity to RhCD4, one SHIVenv (i.e. SHIVenv_B3-PRB926) established infection in macaques exposed to this pool. AHI SHIVenv_B viruses as well as their HIVenv_B counterparts were analyzed for viral protein content, function, and fitness to identify possible difference between SHIVenv_B3-PRB926 and the other 15 SHIVenvs in the pool. All of the constructs produced SHIV or HIV chimeric with wild type levels of capsid (p27 and p24) content, reverse transcriptase (RT) activity, and expressed envelope glycoproteins that could bind to cell receptors CD4/CCR5 and mediate virus entry. HIV-1env_B chimeric viruses were propagated in susceptible cell lines but the 16 SHIVenv_B variants showed only limited replication in macaque peripheral blood mononuclear cells (PBMCs) and 174×CEM.CCR5 cell line. AHI chimeric viruses including HIVenv_B3 showed only minor variations in cell entry efficiency and kinetics as well as replicative fitness in human PBMCs. Reduced number of N-link glycosylation sites and slightly greater CCR5 affinity/avidity was the only distinguishing feature of env_B3 versus other AHI env’s in the pool, a feature also observed in the HIV establishing new infections in humans. Conclusion Despite the inability to propagate in primary cells and cell lines, a pool of 16 SHIVenv viruses could establish infection but only one virus, SHIVenv_B3 was isolated in the macaque and then shown to repeatedly infected macaques. This SHIVenv_B3 virus did not show any distinct phenotypic property from the other 15 SHIVenv viruses but did have the fewest N-linked glycosylation sites. Electronic supplementary material The online version of this article (doi:10.1186/s12981-016-0125-8) contains supplementary material, which is available to authorized users.
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13
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Venner CM, Nankya I, Kyeyune F, Demers K, Kwok C, Chen PL, Rwambuya S, Munjoma M, Chipato T, Byamugisha J, Van Der Pol B, Mugyenyi P, Salata RA, Morrison CS, Arts EJ. Infecting HIV-1 Subtype Predicts Disease Progression in Women of Sub-Saharan Africa. EBioMedicine 2016; 13:305-314. [PMID: 27751765 PMCID: PMC5264310 DOI: 10.1016/j.ebiom.2016.10.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/06/2016] [Accepted: 10/09/2016] [Indexed: 12/22/2022] Open
Abstract
INTRODUCTION Long-term natural history cohorts of HIV-1 in the absence of treatment provide the best measure of virulence by different viral subtypes. METHODS Newly HIV infected Ugandan and Zimbabwean women (N=303) were recruited and monitored for clinical, social, behavioral, immunological and viral parameters for 3 to 9.5years. RESULTS Ugandan and Zimbabwean women infected with HIV-1 subtype C had 2.5-fold slower rates of CD4 T-cell declines and higher frequencies of long-term non-progression than those infected with subtype A or D (GEE model, P<0.001), a difference not associated with any other clinical parameters. Relative replicative fitness and entry efficiency of HIV-1 variants directly correlated with virulence in the patients, subtype D>A>C (P<0.001, ANOVA). DISCUSSION HIV-1 subtype C was less virulent than either A or D in humans; the latter being the most virulent. Longer periods of asymptomatic HIV-1 subtype C could explain the continued expansion and dominance of subtype C in the global epidemic.
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Affiliation(s)
- Colin M Venner
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Immaculate Nankya
- Joint Clinical Research Centre, Kampala, Uganda; Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | | - Korey Demers
- Joint Clinical Research Centre, Kampala, Uganda; Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Cynthia Kwok
- Family Health International 360, Durham, NC, USA
| | | | - Sandra Rwambuya
- Joint Clinical Research Centre, Kampala, Uganda; Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Marshall Munjoma
- Department of Obstetrics and Gynaecology, University of Zimbabwe, Harare, Zimbabwe
| | - Tsungai Chipato
- Department of Obstetrics and Gynaecology, University of Zimbabwe, Harare, Zimbabwe
| | | | - Barbara Van Der Pol
- Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, USA
| | | | - Robert A Salata
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | | - Eric J Arts
- Department of Microbiology and Immunology, Western University, London, ON, Canada; Joint Clinical Research Centre, Kampala, Uganda; Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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14
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Asmal M, Lane S, Tian M, Nickel G, Venner C, Dirk B, Dikeakos J, Luedemann C, Mach L, Balachandran H, Buzby A, Rao S, Letvin N, Gao Y, Arts EJ. Pathogenic infection of Rhesus macaques by an evolving SIV-HIV derived from CCR5-using envelope genes of acute HIV-1 infections. Virology 2016; 499:298-312. [PMID: 27723488 DOI: 10.1016/j.virol.2016.09.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/15/2016] [Accepted: 09/22/2016] [Indexed: 12/31/2022]
Abstract
For studies on vaccines and therapies for HIV disease, SIV-HIV chimeric viruses harboring the HIV-1 env gene (SHIVenv) remain the best virus in non-human primate models. However, there are still very few SHIVenv viruses that can cause AIDS in non-CD8-depleted animals. In the present study, a recently created CCR5-using SHIVenv_B3 virus with env gene derived from acute/early HIV-1 infections (AHI) successfully established pathogenic infection in macaques. Through a series of investigations on the evolution, mutational profile, and phenotype of the virus and the resultant humoral immune response in infected rhesus macaques, we found that the E32K mutation in the Env C1 domain was associated with macaque pathogenesis, and that the electrostatic interactions in Env may favor E32K at the gp120 N terminus and "lock" the binding to heptad repeat 1 of gp41 in the trimer and produce a SHIVenv with increased fitness and pathogenesis during macaque infections.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Viral/immunology
- Disease Models, Animal
- Evolution, Molecular
- Gene Products, env/chemistry
- Gene Products, env/genetics
- Gene Products, env/immunology
- HIV Envelope Protein gp120/chemistry
- HIV Envelope Protein gp120/genetics
- HIV Envelope Protein gp120/immunology
- HIV Infections/genetics
- HIV Infections/immunology
- HIV Infections/virology
- HIV-1/classification
- HIV-1/genetics
- HIV-1/immunology
- HIV-1/pathogenicity
- Humans
- Immunity, Humoral
- Macaca mulatta
- Molecular Sequence Data
- Mutation, Missense
- Phylogeny
- Receptors, CCR5/genetics
- Receptors, CCR5/immunology
- Receptors, Virus/genetics
- Receptors, Virus/immunology
- Sequence Alignment
- Simian Immunodeficiency Virus/classification
- Simian Immunodeficiency Virus/genetics
- Simian Immunodeficiency Virus/immunology
- Simian Immunodeficiency Virus/pathogenicity
- Virulence
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Affiliation(s)
- Mohammed Asmal
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Sophie Lane
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Meijuan Tian
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Gabrielle Nickel
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Colin Venner
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Brennan Dirk
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Jimmy Dikeakos
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Corinne Luedemann
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Linh Mach
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Harikrishnan Balachandran
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Adam Buzby
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Srinivas Rao
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Norman Letvin
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yong Gao
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Eric J Arts
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.
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15
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Nankya IL, Tebit DM, Abraha A, Kyeyune F, Gibson R, Jegede O, Nickel G, Arts EJ. Defining the fitness of HIV-1 isolates with dual/mixed co-receptor usage. AIDS Res Ther 2015; 12:34. [PMID: 26435727 PMCID: PMC4592561 DOI: 10.1186/s12981-015-0066-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 07/28/2015] [Indexed: 02/08/2023] Open
Abstract
Background CCR5-using (r5) HIV-1 predominates during asymptomatic disease followed by occasional emergence of CXCR4-using (x4) or dual tropic (r5x4) virus. We examined the contribution of the x4 and r5 components to replicative fitness of HIV-1 isolates. Methods Dual tropic r5x4 viruses were predicted from average HIV-1 env sequences of two primary subtype C HIV-1 isolates (C19 and C27) and from two patient plasma samples (B12 and B19). Chimeric Env viruses with an NL4-3 backbone were constructed from the B12 and B19 env sequences. To determine replicative fitness, these primary and chimeric dual tropic HIV-1 were then competed against HIV-1 reference isolates in U87.CD4 cells expressing CXCR4 or CCR5 or in PBMCs ± entry inhibitors. Contribution of the x4 and r5 clones within the quasispecies of these chimeric or primary HIV-1 isolates were then compared to the frequency of x4, r5, and dual tropic clones within the quasispecies as predicted by phenotypic assays, clonal sequencing, and 454 deep sequencing. Results In the primary HIV-1 isolates (C19 and C27), subtype C dual tropic clones dominated over x4 clones while pure r5 clones were absent. In two subtype B chimeric viruses (B12 and B19), r5 clones were >100-fold more abundant than x4 or r5/x4 clones. The dual tropic C19 and C27 HIV-1 isolates outcompeted r5 primary HIV-1 isolates, B2 and C3 in PBMCs. When AMD3100 was added or when only U87.CD4.CCR5 cells were used, the B2 and C3 reference viruses now out-competed the r5 component of the dual tropic C19 and C27. In contrast, the same replicative fitness was observed with dualtropic B12 and B19 HIV-1 isolates relative to x4 HIV-1 A8 and E6 or the r5 B2 and C3 viruses, even when the r5 or x4 component was inhibited by maraviroc (or AMD3100) or in U87.CD4.CXCR4 (or CCR5) cells. Conclusions In the dual tropic HIV-1 isolates, the x4 replicative fitness is higher than r5 clones but the x4 or x4/r5 clones are typically at low frequency in the intrapatient virus population. Ex vivo HIV propagation promotes outgrowth of the x4 clones and provides an over-estimate of x4 dominance in replicative fitness within dual tropic viruses. Electronic supplementary material The online version of this article (doi:10.1186/s12981-015-0066-7) contains supplementary material, which is available to authorized users.
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16
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Bagaya BS, Vega JF, Tian M, Nickel GC, Li Y, Krebs KC, Arts EJ, Gao Y. Functional bottlenecks for generation of HIV-1 intersubtype Env recombinants. Retrovirology 2015; 12:44. [PMID: 25997955 PMCID: PMC4445978 DOI: 10.1186/s12977-015-0170-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/02/2015] [Indexed: 11/13/2022] Open
Abstract
Background Intersubtype recombination is a powerful driving force for HIV evolution, impacting both HIV-1 diversity within an infected individual and within the global epidemic. This study examines if viral protein function/fitness is the major constraint shaping selection of recombination hotspots in replication-competent HIV-1 progeny. A better understanding of the interplay between viral protein structure-function and recombination may provide insights into both vaccine design and drug development. Results In vitro HIV-1 dual infections were used to recombine subtypes A and D isolates and examine breakpoints in the Env glycoproteins. The entire env genes of 21 A/D recombinants with breakpoints in gp120 were non-functional when cloned into the laboratory strain, NL4-3. Likewise, cloning of A/D gp120 coding regions also produced dead viruses with non-functional Envs. 4/9 replication-competent viruses with functional Env’s were obtained when just the V1-V5 regions of these same A/D recombinants (i.e. same A/D breakpoints as above) were cloned into NL4-3. Conclusion These findings on functional A/D Env recombinants combined with structural models of Env suggest a conserved interplay between the C1 domain with C5 domain of gp120 and extracellular domain of gp41. Models also reveal a co-evolution within C1, C5, and ecto-gp41 domains which might explain the paucity of intersubtype recombination in the gp120 V1-V5 regions, despite their hypervariability. At least HIV-1 A/D intersubtype recombination in gp120 may result in a C1 from one subtype incompatible with a C5/gp41 from another subtype.
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Affiliation(s)
- Bernard S Bagaya
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
| | - José F Vega
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
| | - Meijuan Tian
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada.
| | - Gabrielle C Nickel
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
| | - Yuejin Li
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
| | - Kendall C Krebs
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
| | - Eric J Arts
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada.
| | - Yong Gao
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA. .,Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA.
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17
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Rausch JW, Tian M, Li Y, Angelova L, Bagaya BS, Krebs KC, Qian F, Zhu C, Arts EJ, Le Grice SFJ, Gao Y. SiRNA-induced mutation in HIV-1 polypurine tract region and its influence on viral fitness. PLoS One 2015; 10:e0122953. [PMID: 25860884 PMCID: PMC4393142 DOI: 10.1371/journal.pone.0122953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/16/2015] [Indexed: 02/06/2023] Open
Abstract
Converting single-stranded viral RNA into double stranded DNA for integration is an essential step in HIV-1 replication. Initial polymerization of minus-strand DNA is primed from a host derived tRNA, whereas subsequent plus-strand synthesis requires viral primers derived from the 3' and central polypurine tracts (3' and cPPTs). The 5' and 3' termini of these conserved RNA sequence elements are precisely cleaved by RT-associated RNase H to generate specific primers that are used to initiate plus-strand DNA synthesis. In this study, siRNA wad used to produce a replicative HIV-1 variant contained G(-1)A and T(-16)A substitutions within/adjacent to the 3'PPT sequence. Introducing either or both mutations into the 3'PPT region or only the G(-1)A substitution in the cPPT region of NL4-3 produced infectious virus with decreased fitness relative to the wild-type virus. In contrast, introducing the T(-16)A or both mutations into the cPPT rendered the virus(es) incapable of replication, most likely due to the F185L integrase mutation produced by this nucleotide substitution. Finally, the effects of G(-1)A and T(-16)A mutations on cleavage of the 3'PPT were examined using an in vitro RNase H cleavage assay. Substrate containing both mutations was mis-cleaved to a greater extent than either wild-type substrate or substrate containing the T(-16)A mutation alone, which is consistent with the observed effects of the equivalent nucleotide substitutions on the replication fitness of NL4-3 virus. In conclusion, siRNA targeting of the HIV-1 3'PPT region can substantially suppress virus replication, and this selective pressure can be used to generate infectious virus containing mutations within or near the HIV-1 PPT. Moreover, in-depth analysis of the resistance mutations demonstrates that although virus containing a G(-1)A mutation within the 3'PPT is capable of replication, this nucleotide substitution shifts the 3'-terminal cleavage site in the 3'PPT by one nucleotide (nt) and significantly reduces viral fitness.
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Affiliation(s)
- Jason W. Rausch
- HIV Drug Resistance Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Meijuan Tian
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Yuejin Li
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Lora Angelova
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Bernard S. Bagaya
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kendall C. Krebs
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Feng Qian
- Suzhou Fifth People’s Hospital, Suzhou, Jiangsu, China
| | - Chuanwu Zhu
- Suzhou Fifth People’s Hospital, Suzhou, Jiangsu, China
| | - Eric J. Arts
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Stuart F. J. Le Grice
- HIV Drug Resistance Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Yong Gao
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
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18
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Etemad B, Ghulam-Smith M, Gonzalez O, White LF, Sagar M. Single genome amplification and standard bulk PCR yield HIV-1 envelope products with similar genotypic and phenotypic characteristics. J Virol Methods 2015; 214:46-53. [PMID: 25681527 DOI: 10.1016/j.jviromet.2015.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 01/25/2015] [Indexed: 11/19/2022]
Abstract
Recent studies suggest that single genome amplification (SGA) as compared to standard bulk PCR and virus stocks from 293T transfection versus short term passage in peripheral blood mononuclear cells (PBMC) yield a less biased representation of HIV-1 envelope characteristics. In 9 different subjects, genetic diversity, divergence, and population structure were not significantly different among SGA or bulk PCR amplified envelope V1-V3 segments. In these subjects, 293T transfection derived virus stocks with SGA or bulk PCR amplified envelopes have similar infectivity, replication kinetics, co-receptor usage, and neutralization susceptibility. While PBMC passage as compared to the 293T derived virus stocks had similar co-receptor usage, PBMC viruses were less neutralization susceptible to some specific antibodies. Our results suggest that the method of envelope sequence amplification, either SGA or bulk PCR, does not have a significant impact on the genotypic and phenotypic properties of the virus envelope quasispecies.
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Affiliation(s)
- Behzad Etemad
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | | | - Oscar Gonzalez
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Laura F White
- Boston University School of Public Health, Boston, MA, USA
| | - Manish Sagar
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
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19
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Etemad B, Gonzalez OA, White L, Laeyendecker O, Kirk GD, Mehta S, Sagar M. Characterization of HIV-1 envelopes in acutely and chronically infected injection drug users. Retrovirology 2014; 11:106. [PMID: 25430652 PMCID: PMC4253609 DOI: 10.1186/s12977-014-0106-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 11/08/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Mucosally acquired human immunodeficiency virus type 1 (HIV-1) infection results from a limited number of variants, and these infecting strains potentially have unique properties, such as increased susceptibility to entry blockers, relative interferon-alpha (IFN-α) resistance, and replication differences in some primary cells. There is no data about the phenotypic properties of HIV-1 envelope variants found early after acquisition among subjects infected through injection drug use (IDU). For the first time, we compared the characteristics of virus envelopes among injection drug users sampled prior to seroconversion (HIV RNA+/Ab-), within 1 year (early), and more than 2 years (chronic) after estimated acquisition. RESULTS Virus envelopes from 7 HIV RNA+/Ab- subjects possessed lower genetic diversity and divergence compared to 7 unrelated individuals sampled during the chronic phase of disease. Replication competent recombinant viruses incorporating the HIV RNA+/Ab- as compared to the chronic phase envelopes were significantly more sensitive to a CCR5 receptor inhibitor and IFN-α and showed a statistical trend toward greater sensitivity to a fusion blocker. The early as compared to chronic infection envelopes also demonstrated a statistical trend or significantly greater sensitivity to CCR5 and fusion inhibitor and IFN- α. The HIV RNA+/Ab- as compared to chronic envelope viruses replicated to a lower extent in mature monocyte derived dendritic cells - CD4+ T cell co-cultures, but there were no significant replication differences in other primary cells among the viruses with envelopes from the 3 different stages of infection. CONCLUSIONS Similar to mucosal acquisition, HIV-1 envelope quasispecies present in injection drug users prior to seroconversion have unique phenotypic properties compared to those circulating during the chronic phase of disease.
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Affiliation(s)
- Behzad Etemad
- Boston University School of Medicine, Boston, MA, USA.
| | | | - Laura White
- Boston University School of Public Health, Boston, MA, USA.
| | - Oliver Laeyendecker
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Gregory D Kirk
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Shruti Mehta
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Manish Sagar
- Boston University School of Medicine, Boston, MA, USA.
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Claiborne DT, Prince JL, Hunter E. A restriction enzyme based cloning method to assess the in vitro replication capacity of HIV-1 subtype C Gag-MJ4 chimeric viruses. J Vis Exp 2014:51506. [PMID: 25225725 PMCID: PMC4364379 DOI: 10.3791/51506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The protective effect of many HLA class I alleles on HIV-1 pathogenesis and disease progression is, in part, attributed to their ability to target conserved portions of the HIV-1 genome that escape with difficulty. Sequence changes attributed to cellular immune pressure arise across the genome during infection, and if found within conserved regions of the genome such as Gag, can affect the ability of the virus to replicate in vitro. Transmission of HLA-linked polymorphisms in Gag to HLA-mismatched recipients has been associated with reduced set point viral loads. We hypothesized this may be due to a reduced replication capacity of the virus. Here we present a novel method for assessing the in vitro replication of HIV-1 as influenced by the gag gene isolated from acute time points from subtype C infected Zambians. This method uses restriction enzyme based cloning to insert the gag gene into a common subtype C HIV-1 proviral backbone, MJ4. This makes it more appropriate to the study of subtype C sequences than previous recombination based methods that have assessed the in vitro replication of chronically derived gag-pro sequences. Nevertheless, the protocol could be readily modified for studies of viruses from other subtypes. Moreover, this protocol details a robust and reproducible method for assessing the replication capacity of the Gag-MJ4 chimeric viruses on a CEM-based T cell line. This method was utilized for the study of Gag-MJ4 chimeric viruses derived from 149 subtype C acutely infected Zambians, and has allowed for the identification of residues in Gag that affect replication. More importantly, the implementation of this technique has facilitated a deeper understanding of how viral replication defines parameters of early HIV-1 pathogenesis such as set point viral load and longitudinal CD4+ T cell decline.
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Affiliation(s)
- Daniel T Claiborne
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University
| | - Jessica L Prince
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University
| | - Eric Hunter
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University; Department of Pathology and Laboratory Medicine, Emory University;
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Contribution of human immunodeficiency virus type 1 minority variants to reduced drug susceptibility in patients on an integrase strand transfer inhibitor-based therapy. PLoS One 2014; 9:e104512. [PMID: 25110880 PMCID: PMC4128663 DOI: 10.1371/journal.pone.0104512] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/09/2014] [Indexed: 12/13/2022] Open
Abstract
The role of HIV-1 minority variants on transmission, pathogenesis, and virologic failure to antiretroviral regimens has been explored; however, most studies of low-level HIV-1 drug-resistant variants have focused in single target regions. Here we used a novel HIV-1 genotypic assay based on deep sequencing, DEEPGEN (Gibson et al 2014 Antimicrob Agents Chemother 58∶2167) to simultaneously analyze the presence of minority variants carrying mutations associated with reduced susceptibility to protease (PR), reverse transcriptase (RT), and integrase strand transfer integrase inhibitors (INSTIs), as well as HIV-1 coreceptor tropism. gag-p2/NCp7/p1/p6/pol-PR/RT/INT and env/C2V3 PCR products were obtained from twelve heavily treatment-experienced patients experiencing virologic failure while participating in a 48-week dose-ranging study of elvitegravir (GS-US-183-0105). Deep sequencing results were compared with (i) virological response to treatment, (ii) genotyping based on population sequencing, (iii) phenotyping data using PhenoSense and VIRALARTS, and (iv) HIV-1 coreceptor tropism based on the phenotypic test VERITROP. Most patients failed the antiretroviral regimen with numerous pre-existing mutations in the PR and RT, and additionally newly acquired INSTI-resistance mutations as determined by population sequencing (mean 9.4, 5.3, and 1.4 PI- RTI-, and INSTI-resistance mutations, respectively). Interestingly, since DEEPGEN allows the accurate detection of amino acid substitutions at frequencies as low as 1% of the population, a series of additional drug resistance mutations were detected by deep sequencing (mean 2.5, 1.5, and 0.9, respectively). The presence of these low-abundance HIV-1 variants was associated with drug susceptibility, replicative fitness, and coreceptor tropism determined using sensitive phenotypic assays, enhancing the overall burden of resistance to all four antiretroviral drug classes. Further longitudinal studies based on deep sequencing tests will help to clarify (i) the potential impact of minority HIV-1 drug resistant variants in response to antiretroviral therapy and (ii) the importance of the detection of HIV minority variants in the clinical practice.
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Early infection HIV-1 envelope V1-V2 genotypes do not enhance binding or replication in cells expressing high levels of α4β7 integrin. J Acquir Immune Defic Syndr 2014; 64:249-53. [PMID: 23797693 DOI: 10.1097/qai.0b013e3182a06ddd] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been postulated that HIV-1 envelope properties, such as shorter and less-glycosylated V1-V2 loops commonly observed among non-subtype B early-transmitted viruses, promote utilization of the gut homing integrin α4β7. This property potentially confers an advantage to some HIV-1 variants early after acquisition. We found that replication-competent recombinant viruses incorporating HIV-1 subtype A compact and less-glycosylated early versus chronic phase V1-V2 loops demonstrated no significant difference in binding to α4β7 high CD8⁺ T cells or replication in α4β7 high CD4⁺ T cells. Integrin α4β7 usage does not select for shorter less-glycosylated envelopes during transmission.
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Pérez-Olmeda M, Alcami J. Determination of HIV tropism and its use in the clinical practice. Expert Rev Anti Infect Ther 2014; 11:1291-302. [DOI: 10.1586/14787210.2013.852469] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Pena-Cruz V, Etemad B, Chatziandreou N, Nyein PH, Stock S, Reynolds SJ, Laeyendecker O, Gray RH, Serwadda D, Lee SJ, Quinn TC, Sagar M. HIV-1 envelope replication and α4β7 utilization among newly infected subjects and their corresponding heterosexual partners. Retrovirology 2013; 10:162. [PMID: 24369910 PMCID: PMC3883469 DOI: 10.1186/1742-4690-10-162] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/10/2013] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Previous studies suggest that active selection limits the number of HIV-1 variants acquired by a newly infected individual from the diverse variants circulating in the transmitting partner. We compared HIV-1 envelopes from 9 newly infected subjects and their linked transmitting partner to explore potential mechanisms for selection. RESULTS Recipient virus envelopes had significant genotypic differences compared to those present in the transmitting partner. Recombinant viruses incorporating pools of recipient and transmitter envelopes showed no significant difference in their sensitivity to receptor and fusion inhibitors, suggesting they had relatively similar entry capacity in the presence of low CD4 and CCR5 levels. Aggregate results in primary cells from up to 4 different blood or skin donors showed that viruses with envelopes from the transmitting partner as compared to recipient envelopes replicated more efficiently in CD4+ T cells, monocyte derived dendritic cell (MDDC) - CD4+ T cell co-cultures, Langerhans cells (LCs) - CD4+ T cell co-cultures and CD4+ T cells expressing high levels of the gut homing receptor, α4β7, and demonstrated greater binding to α4β7 high / CD8+ T cells. These transmitter versus recipient envelope virus phenotypic differences, however, were not always consistent among the primary cells from all the different blood or skin donation volunteers. CONCLUSION Although genotypically unique variants are present in newly infected individuals compared to the diverse swarm circulating in the chronically infected transmitting partner, replication in potential early target cells and receptor utilization either do not completely dictate this genetic selection, or these potential transmission phenotypes are lost very soon after HIV-1 acquisition.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Manish Sagar
- Department of Medicine, Division of Infectious Diseases, Boston University, Boston, MA, USA.
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Purcell DFJ, Elliott JH, Ross AL, Frater J. Towards an HIV cure: science and debate from the International AIDS Society 2013 symposium. Retrovirology 2013; 10:134. [PMID: 24224983 PMCID: PMC3828479 DOI: 10.1186/1742-4690-10-134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 11/04/2013] [Indexed: 11/25/2022] Open
Abstract
The International AIDS Society convened the multi-stakeholder “Towards an HIV Cure” symposium in Kuala Lumpur, Malaysia in 2013 to address the significant research challenges posed by the search for a cure for HIV infection. Current antiretroviral regimens select for a small reservoir of cells that harbour latent HIV provirus, produce few or no HIV virions, and resist detection or clearance by host immunity. The symposium examined basic molecular science and animal model data, and emerging and ongoing clinical trial results to prioritise strategies and determine the viral and immune responses that could lead to HIV remission without ART. Here we review the presentations that scrutinized the molecular mechanisms controlling virus expression from proviral DNA, and the intrinsic cellular restriction and immune mechanisms preventing viral production. Insights from the basic science have translated into new therapeutic strategies seeking HIV remission without ongoing therapy, and much interest was focused on these ongoing trials. We also summarise the emerging ethical issues and patient expectations as concepts move into the clinic.
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Affiliation(s)
- Damian F J Purcell
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, VIC 3010, Australia.
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26
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Chamanian M, Purzycka KJ, Wille PT, Ha JS, McDonald D, Gao Y, Le Grice SFJ, Arts EJ. A cis-acting element in retroviral genomic RNA links Gag-Pol ribosomal frameshifting to selective viral RNA encapsidation. Cell Host Microbe 2013; 13:181-92. [PMID: 23414758 DOI: 10.1016/j.chom.2013.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 11/06/2012] [Accepted: 01/09/2013] [Indexed: 12/18/2022]
Abstract
During retroviral RNA encapsidation, two full-length genomic (g) RNAs are selectively incorporated into assembling virions. Packaging involves a cis-acting packaging element (Ψ) within the 5' untranslated region of unspliced HIV-1 RNA genome. However, the mechanism(s) that selects and limits gRNAs for packaging remains uncertain. Using a dual complementation system involving bipartite HIV-1 gRNA, we observed that gRNA packaging is additionally dependent on a cis-acting RNA element, the genomic RNA packaging enhancer (GRPE), found within the gag p1-p6 domain and overlapping the Gag-Pol ribosomal frameshift signal. Deleting or disrupting the two conserved GRPE stem loops diminished gRNA packaging and infectivity >50-fold, while deleting gag sequences between Ψ and GRPE had no effect. Downregulating the translation termination factor eRF1 produces defective virus particles containing 20 times more gRNA. Thus, only the HIV-1 RNAs employed for Gag-Pol translation may be specifically selected for encapsidation, possibly explaining the limitation of two gRNAs per virion.
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Affiliation(s)
- Mastooreh Chamanian
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106, USA
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27
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Resistance mutations outside the integrase coding region have an effect on human immunodeficiency virus replicative fitness but do not affect its susceptibility to integrase strand transfer inhibitors. PLoS One 2013; 8:e65631. [PMID: 23776513 PMCID: PMC3679210 DOI: 10.1371/journal.pone.0065631] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/25/2013] [Indexed: 11/19/2022] Open
Abstract
Most studies describing phenotypic resistance to integrase strand transfer inhibitors have analyzed viruses carrying only patient-derived HIV-1 integrase genes (INT-recombinant viruses). However, to date, many of the patients on INSTI-based treatment regimes, such as raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG) are infected with multidrug-resistant HIV-1 strains. Here we analyzed the effect of drug resistance mutations in Gag (p2/NCp7/p1/p6), protease (PR), reverse transcriptase (RT), and integrase (IN) coding regions on susceptibility to INSTIs and viral replicative fitness using a novel HIV-1 phenotyping assay. Initial characterization based on site-directed mutant INSTI-resistant viruses confirmed the effect of a series of INSTI mutations on reduced susceptibility to EVG and RAL and viral replicative fitness (0.6% to 99% relative to the HIV-1NL4-3 control). Two sets of recombinant viruses containing a 3,428-bp gag-p2/NCp7/p1/p6/pol-PR/RT/IN (p2-INT) or a 1,088 bp integrase (INT) patient-derived fragment were constructed from plasma samples obtained from 27 virologic failure patients participating in a 48-week dose-ranging study of elvitegravir, GS-US-183-0105. A strong correlation was observed when susceptibility to EVG and RAL was assayed using p2-INT- vs. INT-recombinant viruses (Pearson coefficient correlation 0.869 and 0.918, P<0.0001 for EVG and RAL, respectively), demonstrating that mutations in the protease and RT have limited effect on susceptibility to these INSTIs. On the other hand, the replicative fitness of viruses harboring drug resistance mutations in PR, RT, and IN was generally impaired compared to viruses carrying only INSTI-resistance mutations. Thus, in the absence of drug pressure, drug resistance mutations in the PR and RT contribute to decrease the replicative fitness of the virus already impaired by mutations in the integrase. The use of recombinant viruses containing most or all HIV-1 regions targeted by antiretroviral drugs might be essential to understand the collective effect of epistatic interactions in multidrug-resistant viruses.
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28
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Multifaceted mechanisms of HIV inhibition and resistance to CCR5 inhibitors PSC-RANTES and Maraviroc. Antimicrob Agents Chemother 2013; 57:2640-50. [PMID: 23529732 DOI: 10.1128/aac.02511-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small-molecule CCR5 antagonists, such as maraviroc (MVC), likely block HIV-1 through an allosteric, noncompetitive inhibition mechanism, whereas inhibition by agonists such as PSC-RANTES is less defined and may involve receptor removal by cell surface downregulation, competitive inhibition by occluding the HIV-1 envelope binding, and/or allosteric effects by altering CCR5 conformation. We explored the inhibitory mechanisms of maraviroc and PSC-RANTES by employing pairs of virus clones with differential sensitivities to these inhibitors. Intrinsic PSC-RANTES-resistant virus (YA versus RT) or those selected in PSC-RANTES treated macaques (M584 versus P3-4) only displayed resistance in multiple-cycle assays or with a CCR5 mutant that cannot be downregulated. In single-cycle assays, these HIV-1 clones displayed equal sensitivity to PSC-RANTES inhibition, suggesting effective receptor downregulation. Prolonged PSC-RANTES exposure resulted in desensitization of the receptor to internalization such that increasing virus concentration (substrate) could saturate the receptors and overcome PSC-RANTES inhibition. In contrast, resistance to MVC was observed with the MVC-resistant HIV-1 (R3 versus S2) in both multiple- and single-cycle assays and with altered virus concentrations, which is indicative of allosteric inhibition. MVC could also mediate inhibition and possibly resistance through competitive mechanisms.
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29
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Sensitive cell-based assay for determination of human immunodeficiency virus type 1 coreceptor tropism. J Clin Microbiol 2013; 51:1517-27. [PMID: 23486708 DOI: 10.1128/jcm.00092-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CCR5 antagonists are a powerful new class of antiretroviral drugs that require a companion assay to evaluate the presence of CXCR4-tropic (non-R5) viruses prior to use in human immunodeficiency virus (HIV)-infected individuals. In this study, we have developed, characterized, verified, and prevalidated a novel phenotypic test to determine HIV-1 coreceptor tropism (VERITROP) based on a sensitive cell-to-cell fusion assay. A proprietary vector was constructed containing a near-full-length HIV-1 genome with the yeast uracil biosynthesis (URA3) gene replacing the HIV-1 env coding sequence. Patient-derived HIV-1 PCR products were introduced by homologous recombination using an innovative yeast-based cloning strategy. The env-expressing vectors were then used in a cell-to-cell fusion assay to determine the presence of R5 and/or non-R5 HIV-1 variants within the viral population. Results were compared with (i) the original version of Trofile (Monogram Biosciences, San Francisco, CA), (ii) population sequencing, and (iii) 454 pyrosequencing, with the genotypic data analyzed using several bioinformatics tools, i.e., the 11/24/25 rule, Geno2Pheno (2% to 5.75%, 3.5%, or 10% false-positive rate [FPR]), and webPSSM. VERITROP consistently detected minority non-R5 variants from clinical specimens, with an analytical sensitivity of 0.3%, with viral loads of ≥1,000 copies/ml, and from B and non-B subtypes. In a pilot study, a 73.7% (56/76) concordance was observed with the original Trofile assay, with 19 of the 20 discordant results corresponding to non-R5 variants detected using VERITROP and not by the original Trofile assay. The degree of concordance of VERITROP and Trofile with population and deep sequencing results depended on the algorithm used to determine HIV-1 coreceptor tropism. Overall, VERITROP showed better concordance with deep sequencing/Geno2Pheno at a 0.3% detection threshold (67%), whereas Trofile matched better with population sequencing (79%). However, 454 sequencing using Geno2Pheno at a 10% FPR and 0.3% threshold and VERITROP more accurately predicted the success of a maraviroc-based regimen. In conclusion, VERITROP may promote the development of new HIV coreceptor antagonists and aid in the treatment and management of HIV-infected individuals prior to and/or during treatment with this class of drugs.
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Chatziandreou N, Arauz AB, Freitas I, Nyein PH, Fenton G, Mehta SH, Kirk GD, Sagar M. Sensitivity changes over the course of infection increases the likelihood of resistance against fusion but not CCR5 receptor blockers. AIDS Res Hum Retroviruses 2012; 28:1584-93. [PMID: 22650962 DOI: 10.1089/aid.2011.0319] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As HIV-1 evolves over the course of infection, resistance against antiretrovirals may arise in the absence of drug pressure, especially against receptor and fusion blockers because of the extensive changes observed in the envelope glycoprotein. Here we show that viruses from the chronic phase of disease are significantly less sensitive to CCR5 receptor and fusion blockers compared to early infection variants. Differences in susceptibility to CCR5 antagonists were observed in spite of no demonstrable CXCR4 receptor utilization. No significant sensitivity differences were observed to another entry blocker, soluble CD4, or to reverse transcriptase, protease, or integrase inhibitors. Chronic as compared to early phase variants demonstrated greater replication when passaged in the presence of subinhibitory concentrations of fusion but not CCR5 receptor inhibitors. Fusion antagonist resistance, however, emerged from only one chronic phase virus culture. Because sensitivity to receptor and fusion antagonists is correlated with receptor affinity and fusion capacity, respectively, changes that occur in the envelope glycoprotein over the course of infection confer greater ability to use the CCR5 receptor and increased fusion ability. Our in vitro passage studies suggest that these evolving phenotypes increase the likelihood of resistance against fusion but not CCR5 receptor blockers.
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Affiliation(s)
| | | | - Ines Freitas
- Brigham and Women's Hospital, Boston, Massachusetts
| | | | | | - Shruti H. Mehta
- Johns Hopkins University School of Medicine, Baltimore, Maryland
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Gregory D. Kirk
- Johns Hopkins University School of Medicine, Baltimore, Maryland
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Manish Sagar
- Brigham and Women's Hospital, Boston, Massachusetts
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HIV-1 resistance to maraviroc conferred by a CD4 binding site mutation in the envelope glycoprotein gp120. J Virol 2012; 87:923-34. [PMID: 23135713 DOI: 10.1128/jvi.01863-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Maraviroc (MVC) is a CCR5 antagonist that inhibits HIV-1 entry by binding to the coreceptor and inducing structural alterations in the extracellular loops. In this study, we isolated MVC-resistant variants from an HIV-1 primary isolate that arose after 21 weeks of tissue culture passage in the presence of inhibitor. gp120 sequences from passage control and MVC-resistant cultures were cloned into NL4-3 via yeast-based recombination followed by sequencing and drug susceptibility testing. Using 140 clones, three mutations were linked to MVC resistance, but none appeared in the V3 loop as was the case with previous HIV-1 strains resistant to CCR5 antagonists. Rather, resistance was dependent upon a single mutation in the C4 region of gp120. Chimeric clones bearing this N425K mutation replicated at high MVC concentrations and displayed significant shifts in 50% inhibitory concentrations (IC(50)s), characteristic of resistance to all other antiretroviral drugs but not typical of MVC resistance. Previous reports on MVC resistance describe an ability to use a drug-bound form of the receptor, leading to reduction in maximal drug inhibition. In contrast, our structural models on K425 gp120 suggest that this resistant mutation impacts CD4 interactions and highlights a novel pathway for MVC resistance.
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Mucosal tissue tropism and dissemination of HIV-1 subtype B acute envelope-expressing chimeric virus. J Virol 2012; 87:890-9. [PMID: 23135721 DOI: 10.1128/jvi.02216-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) transmission results from infection with one or a small number of variants from the donor quasispecies. Transmitted/founder (T/F) viruses have recently been identified from acutely infected patients, but the way in which they interact with primary targets of HIV-1 infection is poorly understood. We have conducted a biological characterization of a panel of subtype B T/F acute and chronic envelope (Env)-expressing chimeric virus in primary human target cells and mucosal tissues. Both acute and chronic Envs preferentially replicated in peripheral blood mononuclear cells (PBMC) and a CD4 T-cell line compared to monocyte-derived macrophages, or dendritic cells (DC). In a model of trans infection from monocyte-derived dendritic cells to T cells, chimeric virus from acute Envs achieved significantly lower titers compared to chronic Envs. Challenge of primary human mucosal tissues revealed significantly higher levels of replication in chronic Env-expressing virus in rectal tissue compared to cervical and penile tissues and enhanced replication in tonsillar tissue relative to acute Envs. In agreement with data from the DC to T-cell trans infection assay, chronic Env-chimeric virus pools were transmitted more efficiently by migratory cells from cervical and penile tissues to CD4(+) T cells than individual acute Env chimeras. These data indicate that virus with HIV-1 Envs of transmitted acute infections preferentially replicate in T cells rather than macrophages or dendritic cells and are less efficiently transmitted from antigen-presenting cells to CD4 T cells than chronic Envs. Such properties together with chemokine (C-C motif) receptor 5 (CCR5) use may confer an advantage for transmission.
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Novel method for simultaneous quantification of phenotypic resistance to maturation, protease, reverse transcriptase, and integrase HIV inhibitors based on 3'Gag(p2/p7/p1/p6)/PR/RT/INT-recombinant viruses: a useful tool in the multitarget era of antiretroviral therapy. Antimicrob Agents Chemother 2011; 55:3729-42. [PMID: 21628544 DOI: 10.1128/aac.00396-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Twenty-six antiretroviral drugs (ARVs), targeting five different steps in the life cycle of the human immunodeficiency virus type 1 (HIV-1), have been approved for the treatment of HIV-1 infection. Accordingly, HIV-1 phenotypic assays based on common cloning technology currently employ three, or possibly four, different recombinant viruses. Here, we describe a system to assess HIV-1 resistance to all drugs targeting the three viral enzymes as well as viral assembly using a single patient-derived, chimeric virus. Patient-derived p2-INT (gag-p2/NCp7/p1/p6/pol-PR/RT/IN) products were PCR amplified as a single fragment (3,428 bp) or two overlapping fragments (1,657 bp and 2,002 bp) and then recombined into a vector containing a near-full-length HIV-1 genome with the Saccharomyces cerevisiae uracil biosynthesis gene (URA3) replacing the 3,428 bp p2-INT segment (Dudley et al., Biotechniques 46:458-467, 2009). P2-INT-recombinant viruses were employed in drug susceptibility assays to test the activity of protease (PI), nucleoside/nucleotide reverse transcriptase (NRTI), nonnucleoside reverse transcriptase (NNRTI), and integrase strand-transfer (INSTI) inhibitors. Using a single standardized test (ViralARTS HIV), this new technology permits the rapid and automated quantification of phenotypic resistance for all known and candidate antiretroviral drugs targeting all viral enzymes (PR, RT, including polymerase and RNase H activities, and IN), some of the current and potential assembly inhibitors, and any drug targeting Pol or Gag precursor cleavage sites (relevant for PI and maturation inhibitors) This novel assay may be instrumental (i) in the development and clinical assessment of novel ARV drugs and (ii) to monitor patients failing prior complex treatment regimens.
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Lalonde MS, Lobritz MA, Ratcliff A, Chamanian M, Athanassiou Z, Tyagi M, Wong J, Robinson JA, Karn J, Varani G, Arts EJ. Inhibition of both HIV-1 reverse transcription and gene expression by a cyclic peptide that binds the Tat-transactivating response element (TAR) RNA. PLoS Pathog 2011; 7:e1002038. [PMID: 21625572 PMCID: PMC3098202 DOI: 10.1371/journal.ppat.1002038] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 03/04/2011] [Indexed: 11/18/2022] Open
Abstract
The RNA response element TAR plays a critical role in HIV replication by
providing a binding site for the recruitment of the viral transactivator protein
Tat. Using a structure-guided approach, we have developed a series of
conformationally-constrained cyclic peptides that act as structural mimics of
the Tat RNA binding region and block Tat-TAR interactions at nanomolar
concentrations in vitro. Here we show that these compounds
block Tat-dependent transcription in cell-free systems and in cell-based
reporter assays. The compounds are also cell permeable, have low toxicity, and
inhibit replication of diverse HIV-1 strains, including both CXCR4-tropic and
CCR5-tropic primary HIV-1 isolates of the divergent subtypes A, B, C, D and
CRF01_AE. In human peripheral blood mononuclear cells, the cyclic peptidomimetic
L50 exhibited an IC50 ∼250 nM. Surprisingly, inhibition of
LTR-driven HIV-1 transcription could not account for the full antiviral
activity. Timed drug-addition experiments revealed that L-50 has a bi-phasic
inhibition curve with the first phase occurring after HIV-1 entry into the host
cell and during the initiation of HIV-1 reverse transcription. The second phase
coincides with inhibition of HIV-1 transcription. Reconstituted reverse
transcription assays confirm that HIV-1 (−) strand strong stop DNA
synthesis is blocked by L50-TAR RNA interactions in-vitro.
These findings are consistent with genetic evidence that TAR plays critical
roles both during reverse transcription and during HIV gene expression. Our
results suggest that antiviral drugs targeting TAR RNA might be highly effective
due to a dual inhibitory mechanism. The HIV-1 transactivator protein (Tat), together with the elongation factor
P-TEFb binds to an HIV-1 RNA secondary structure in the 5′-UTRs of nascent
viral mRNAs (TAR) and promotes transcription elongation. This process has been
an attractive target for drug development but previous inhibitors that bind
either Tat or TAR have been plagued by poor inhibition of virus replication,
limited cell penetration, and off-target effects. In this article, we describe a
series of rationally designed cyclic peptides that block Tat-TAR interactions.
L50, the most potent of these compounds, inhibits a wide range of HIV-1 strains
from around the world. Remarkably, L50 inhibits two distinct steps in the HIV-1
lifecycle. As expected, L50 inhibits Tat-dependent HIV-1 transcription, but the
majority of its anti-HIV activity is due to a block in reverse transcription,
i.e. synthesis of the proviral DNA from the RNA genome. L50 inhibition of
reverse transcription reveals an important role for TAR RNA during reverse
transcription as well as providing one of first examples of a drug with a dual
mechanism of action.
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Affiliation(s)
- Matthew S. Lalonde
- Department of Biochemistry, Case Western
Reserve University, Cleveland, Ohio, United States of America
| | - Michael A. Lobritz
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - Annette Ratcliff
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - Mastooreh Chamanian
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - Zafiria Athanassiou
- Department of Chemistry and Department of
Biochemistry, University of Washington, Seattle, Washington, United States of
America
| | - Mudit Tyagi
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - Julian Wong
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - John A. Robinson
- Department of Chemistry, University of Zurich,
Zurich, Switzerland
| | - Jonathan Karn
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
| | - Gabriele Varani
- Department of Chemistry and Department of
Biochemistry, University of Washington, Seattle, Washington, United States of
America
| | - Eric J. Arts
- Department of Molecular Biology and
Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of
America
- Division of Infectious Diseases, Department of
Medicine, Case Western Reserve University, Cleveland, Ohio, United States of
America
- * E-mail:
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35
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Selhorst P, Vazquez AC, Terrazas-Aranda K, Michiels J, Vereecken K, Heyndrickx L, Weber J, Quiñones-Mateu ME, Ariën KK, Vanham G. Human immunodeficiency virus type 1 resistance or cross-resistance to nonnucleoside reverse transcriptase inhibitors currently under development as microbicides. Antimicrob Agents Chemother 2011; 55:1403-13. [PMID: 21282453 PMCID: PMC3067143 DOI: 10.1128/aac.01426-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 11/29/2010] [Accepted: 01/19/2011] [Indexed: 11/20/2022] Open
Abstract
Microbicides based on nonnucleoside reverse transcriptase inhibitors (NNRTIs) are currently being developed to protect women from HIV acquisition through sexual contact. However, the large-scale introduction of these products raises two major concerns. First, when these microbicides are used by undiagnosed HIV-positive women, they could potentially select for viral resistance, which may compromise subsequent therapeutic options. Second, NNRTI-based microbicides that are inactive against NNRTI-resistant strains might promote the selective transmission of these viruses. In order to address these concerns, drug resistance was selected in vitro by the serial passage of three viral isolates from subtypes B and C and CRF02_AG (a circulating recombinant form) in activated peripheral blood mononuclear cells (PBMCs) under conditions of increasing concentrations of three NNRTIs (i.e., TMC120, UC781, and MIV-160) that are currently being developed as candidate microbicides. TMC120 and MIV-160 displayed a high genetic barrier to resistance development, whereas resistance to UC781 emerged rapidly, similarly to efavirenz and nevirapine. Phenotypically, the selected viruses appeared to be highly cross-resistant to current first-line therapeutic NNRTIs (i.e., delavirdine, nevirapine, and efavirenz), although they retained some susceptibility to the more recently developed NNRTIs lersivirine and etravirine. The ability of UC781, TMC120, and MIV-160 to inhibit the in vitro-selected NNRTI-resistant viruses was also limited, although residual activity could be observed for the candidate microbicide NNRTI MIV-170. Interestingly, only four p2/p7/p1/p6/PR/RT/INT recombinant NNRTI-resistant viruses (i.e., TMC120-resistant VI829, EFV-resistant VI829, MIV-160-resistant VI829, and EFV-resistant MP568) showed impairments in replicative fitness. Overall, these in vitro analyses demonstrate that due to potential cross-resistance, the large-scale introduction of single-NNRTI-based microbicides should be considered with caution.
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Affiliation(s)
- Philippe Selhorst
- Department of Microbiology, Virology Unit, Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerp, Belgium.
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