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Martins SA, Santos J, Silva RDM, Rosa C, Cabo Verde S, Correia JDG, Melo R. How promising are HIV-1-based virus-like particles for medical applications. Front Cell Infect Microbiol 2022; 12:997875. [PMID: 36275021 PMCID: PMC9585283 DOI: 10.3389/fcimb.2022.997875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/23/2022] [Indexed: 11/26/2022] Open
Abstract
New approaches aimed at identifying patient-specific drug targets and addressing unmet clinical needs in the framework of precision medicine are a strong motivation for researchers worldwide. As scientists learn more about proteins that drive known diseases, they are better able to design promising therapeutic approaches to target those proteins. The field of nanotechnology has been extensively explored in the past years, and nanoparticles (NPs) have emerged as promising systems for target-specific delivery of drugs. Virus-like particles (VLPs) arise as auspicious NPs due to their intrinsic properties. The lack of viral genetic material and the inability to replicate, together with tropism conservation and antigenicity characteristic of the native virus prompted extensive interest in their use as vaccines or as delivery systems for therapeutic and/or imaging agents. Owing to its simplicity and non-complex structure, one of the viruses currently under study for the construction of VLPs is the human immunodeficiency virus type 1 (HIV-1). Typically, HIV-1-based VLPs are used for antibody discovery, vaccines, diagnostic reagent development and protein-based assays. This review will be centered on the use of HIV-1-based VLPs and their potential biomedical applications.
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Affiliation(s)
- Sofia A. Martins
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Joana Santos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Rúben D. M. Silva
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Cátia Rosa
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Sandra Cabo Verde
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
- Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - João D. G. Correia
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
- Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
- *Correspondence: João D. G. Correia, ; Rita Melo,
| | - Rita Melo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
- *Correspondence: João D. G. Correia, ; Rita Melo,
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Ta TM, Malik S, Anderson EM, Jones AD, Perchik J, Freylikh M, Sardo L, Klase ZA, Izumi T. Insights Into Persistent HIV-1 Infection and Functional Cure: Novel Capabilities and Strategies. Front Microbiol 2022; 13:862270. [PMID: 35572626 PMCID: PMC9093714 DOI: 10.3389/fmicb.2022.862270] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 02/21/2022] [Indexed: 12/23/2022] Open
Abstract
Although HIV-1 replication can be efficiently suppressed to undetectable levels in peripheral blood by combination antiretroviral therapy (cART), lifelong medication is still required in people living with HIV (PLWH). Life expectancies have been extended by cART, but age-related comorbidities have increased which are associated with heavy physiological and economic burdens on PLWH. The obstacle to a functional HIV cure can be ascribed to the formation of latent reservoir establishment at the time of acute infection that persists during cART. Recent studies suggest that some HIV reservoirs are established in the early acute stages of HIV infection within multiple immune cells that are gradually shaped by various host and viral mechanisms and may undergo clonal expansion. Early cART initiation has been shown to reduce the reservoir size in HIV-infected individuals. Memory CD4+ T cell subsets are regarded as the predominant cellular compartment of the HIV reservoir, but monocytes and derivative macrophages or dendritic cells also play a role in the persistent virus infection. HIV latency is regulated at multiple molecular levels in transcriptional and post-transcriptional processes. Epigenetic regulation of the proviral promoter can profoundly regulate the viral transcription. In addition, transcriptional elongation, RNA splicing, and nuclear export pathways are also involved in maintaining HIV latency. Although most proviruses contain large internal deletions, some defective proviruses may induce immune activation by expressing viral proteins or producing replication-defective viral-like particles. In this review article, we discuss the state of the art on mechanisms of virus persistence in the periphery and tissue and summarize interdisciplinary approaches toward a functional HIV cure, including novel capabilities and strategies to measure and eliminate the infected reservoirs and induce immune control.
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Affiliation(s)
- Tram M. Ta
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Sajjaf Malik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Elizabeth M. Anderson
- Office of the Assistant Secretary for Health, Region 3, U.S. Department of Health and Human Services, Washington, DC, United States
| | - Amber D. Jones
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Jocelyn Perchik
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Maryann Freylikh
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States
| | - Luca Sardo
- Department of Infectious Disease and Vaccines, Merck & Co., Inc., Kenilworth, NJ, United States
| | - Zackary A. Klase
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Neuroimmunology and CNS Therapeutics, Institute of Molecular Medicine and Infectious Diseases, Drexel University of Medicine, Philadelphia, PA, United States
| | - Taisuke Izumi
- Department of Biological Sciences, Misher College of Arts and Sciences, University of the Sciences in Philadelphia, Philadelphia, PA, United States,*Correspondence: Taisuke Izumi,
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Potent Induction of Envelope-Specific Antibody Responses by Virus-Like Particle (VLP) Immunogens Based on HIV-1 Envelopes from Patients with Early Broadly Neutralizing Responses. J Virol 2021; 96:e0134321. [PMID: 34668778 PMCID: PMC8754226 DOI: 10.1128/jvi.01343-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Longitudinal studies in HIV-1-infected individuals have indicated that 2 to 3 years of infection are required to develop broadly neutralizing antibodies. However, we have previously identified individuals with broadly neutralizing activity (bNA) in early HIV-1 infection, indicating that a vaccine may be capable of bNA induction after short periods of antigen exposure. Here, we describe 5 HIV-1 envelope sequences from individuals who have developed bNA within the first 100 days of infection (early neutralizers) and selected two of them to design immunogens based on HIV-1-Gag virus-like particles (VLPs). These VLPs were homogeneous and incorporated the corresponding envelopes (7 to 9 μg of gp120 in 1010 VLPs). Both envelopes (Envs) bound to well-characterized broadly neutralizing antibodies (bNAbs), including trimer-specific antibodies (PGT145, VRC01, and 35022). For immunogenicity testing, we immunized rabbits with the Env-VLPs or with the corresponding stabilized soluble envelope trimers. A short immunization protocol (105 days) was used to recapitulate the early nAb induction observed after HIV-1 infection in these two individuals. All VLP and trimeric envelope immunogens induced a comparably strong anti-gp120 response despite having immunized rabbits with 30 times less gp120 in the case of the Env-VLPs. In addition, animals immunized with VLP-formulated Envs induced antibodies that cross-recognized the corresponding soluble stabilized trimer and vice versa, even though no neutralizing activity was observed. Nevertheless, our data may provide a new platform of immunogens, based on HIV-1 envelopes from patients with early broadly neutralizing responses, with the potential to generate protective immune responses using vaccination protocols similar to those used in classical preventive vaccines. IMPORTANCE It is generally accepted that an effective HIV-1 vaccine should be able to induce broad-spectrum neutralizing antibodies. Since most of these antibodies require long periods of somatic maturation in vivo, several groups are developing immunogens, based on the HIV envelope protein, that require complex and lengthy immunization protocols that would be difficult to implement in the general population. Here, we show that rabbits immunized with new envelopes (VLP formulated) from two individuals who demonstrated broadly neutralizing activity very early after infection induced specific HIV-1 antibodies after a short immunization protocol. This evidence provides the basis for generating protective immune responses with classic vaccination protocols with vaccine prototypes based on HIV envelope sequences from individuals who have developed early broadly neutralizing responses.
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Sarca AD, Sardo L, Fukuda H, Matsui H, Shirakawa K, Horikawa K, Takaori-Kondo A, Izumi T. FRET-Based Detection and Quantification of HIV-1 Virion Maturation. Front Microbiol 2021; 12:647452. [PMID: 33767685 PMCID: PMC7985248 DOI: 10.3389/fmicb.2021.647452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 01/18/2021] [Indexed: 01/27/2023] Open
Abstract
HIV-1 infectivity is achieved through virion maturation. Virus particles undergo structural changes via cleavage of the Gag polyprotein mediated by the viral protease, causing the transition from an uninfectious to an infectious status. The majority of proviruses in people living with HIV-1 treated with combination antiretroviral therapy are defective with large internal deletions. Defective proviral DNA frequently preserves intact sequences capable of expressing viral structural proteins to form virus-like particles whose maturation status is an important factor for chronic antigen-mediated immune stimulation and inflammation. Thus, novel methods to study the maturation capability of defective virus particles are needed to characterize their immunogenicity. To build a quantitative tool to study virion maturation in vitro, we developed a novel single virion visualization technique based on fluorescence resonance energy transfer (FRET). We inserted an optimized intramolecular CFP-YPF FRET donor-acceptor pair bridged with an HIV-1 protease cleavage sequence between the Gag MA-CA domains. This system allowed us to microscopically distinguish mature and immature virions via their FRET signal when the FRET donor and acceptor proteins were separated by the viral protease during maturation. We found that approximately 80% of the FRET labeled virus particles were mature with equivalent infectivity to wild type. The proportion of immature virions was increased by treatment of virus producer cells with a protease inhibitor in a dose-dependent manner, which corresponded to a relative decrease in infectivity. Potential areas of application for this tool are assessing maturation efficiency in different cell type settings of intact or deficient proviral DNA integrated cells. We believe that this FRET-based single-virion imaging platform will facilitate estimating the impact on the immune system of both extracellular intact and defective viruses by quantifying the Gag maturation status.
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Affiliation(s)
- Anamaria D Sarca
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Luca Sardo
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Hirofumi Fukuda
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Matsui
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kotaro Shirakawa
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kazuki Horikawa
- Department of Optical Imaging, Advanced Research Promotion Center, Tokushima University, Tokushima, Japan
| | - Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Taisuke Izumi
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Gonelli CA, Khoury G, Center RJ, Purcell DFJ. HIV-1-based Virus-like Particles that Morphologically Resemble Mature, Infectious HIV-1 Virions. Viruses 2019; 11:v11060507. [PMID: 31159488 PMCID: PMC6630479 DOI: 10.3390/v11060507] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/23/2019] [Accepted: 05/29/2019] [Indexed: 01/04/2023] Open
Abstract
A prophylactic vaccine eliciting both broad neutralizing antibodies (bNAbs) to the HIV-1 envelope glycoprotein (Env) and strong T cell responses would be optimal for preventing HIV-1 transmissions. Replication incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present authentic-structured, virion-associated Env to elicit bNAbs, and also stimulate T cell responses. Here, we optimize our DNA vaccine plasmids as VLP expression vectors for efficient Env incorporation and budding. The original vector that was used in human trials inefficiently produced VLPs, but maximized safety by inactivating RNA genome packaging, enzyme functions that are required for integration into the host genome, and deleting accessory proteins Vif, Vpr, and Nef. These original DNA vaccine vectors generated VLPs with incomplete protease-mediated cleavage of Gag and were irregularly sized. Mutations to restore function within the defective genes revealed that several of the reverse transcriptase (RT) deletions mediated this immature phenotype. Here, we made efficient budding, protease-processed, and mature-form VLPs that resembled infectious virions by introducing alternative mutations that completely removed the RT domain, but preserved most other safety mutations. These VLPs, either expressed from DNA vectors in vivo or purified after expression in vitro, are potentially useful immunogens that can be used to elicit antibody responses that target Env on fully infectious HIV-1 virions.
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Affiliation(s)
- Christopher A Gonelli
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
| | - Georges Khoury
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
| | - Rob J Center
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
- Viral Entry and Vaccines Laboratory, Disease Elimination, Burnet Institute, Melbourne, Victoria 3004, Australia.
| | - Damian F J Purcell
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria 3000, Australia.
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Beltran-Pavez C, Ferreira CB, Merino-Mansilla A, Fabra-Garcia A, Casadella M, Noguera-Julian M, Paredes R, Olvera A, Haro I, Brander C, Garcia F, Gatell JM, Yuste E, Sanchez-Merino V. Guiding the humoral response against HIV-1 toward a MPER adjacent region by immunization with a VLP-formulated antibody-selected envelope variant. PLoS One 2018; 13:e0208345. [PMID: 30566493 PMCID: PMC6300218 DOI: 10.1371/journal.pone.0208345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/15/2018] [Indexed: 12/15/2022] Open
Abstract
Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions.
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Affiliation(s)
- Carolina Beltran-Pavez
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
| | - Carolina B. Ferreira
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
| | - Alberto Merino-Mansilla
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
| | - Amanda Fabra-Garcia
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
| | - Maria Casadella
- HIVACAT, Barcelona, Spain
- IrsiCaixa AIDS Research Institute, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Marc Noguera-Julian
- HIVACAT, Barcelona, Spain
- IrsiCaixa AIDS Research Institute, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
- Universitat de Vic-Universitat Central de Catalunya (UVic-UCC), Vic, Spain
| | - Roger Paredes
- HIVACAT, Barcelona, Spain
- IrsiCaixa AIDS Research Institute, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
- Universitat de Vic-Universitat Central de Catalunya (UVic-UCC), Vic, Spain
| | - Alex Olvera
- HIVACAT, Barcelona, Spain
- IrsiCaixa AIDS Research Institute, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Isabel Haro
- Unit of Synthesis and Biomedical Applications of Peptides, IQAC-CSIC, Barcelona, Spain
| | - Christian Brander
- HIVACAT, Barcelona, Spain
- IrsiCaixa AIDS Research Institute, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
- Universitat de Vic-Universitat Central de Catalunya (UVic-UCC), Vic, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Felipe Garcia
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
- Infectious Diseases Unit, Hospital Clinic, Barcelona, Spain
| | - Jose M. Gatell
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
- Infectious Diseases Unit, Hospital Clinic, Barcelona, Spain
| | - Eloisa Yuste
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
| | - Victor Sanchez-Merino
- AIDS Research Unit, Institut d’Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain
- HIVACAT, Barcelona, Spain
- * E-mail:
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Gohda J, Ma Y, Huang Y, Zhang Y, Gu L, Han Y, Li T, Gao B, Gao GF, Inoue JI, Iwamoto A, Ishida T. HIV-1 replicates in human osteoclasts and enhances their differentiation in vitro. Retrovirology 2015; 12:12. [PMID: 25809599 PMCID: PMC4340110 DOI: 10.1186/s12977-015-0139-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 01/14/2015] [Indexed: 11/10/2022] Open
Abstract
Background HIV-1 infected patients frequently have osteolytic bone disease, which is caused by the dysregulation of the bone remodeling system that involves the interaction between osteoblasts and osteoclasts, but the relationship between osteolytic disease and HIV-1 infection remains unclear. In this study we tested whether HIV-1 infection of osteoclasts affects their differentiation. Results We prepared human osteoclasts from CD14+ monocytes and examined them for their susceptibility to HIV-1. Furthermore, we investigated the effect of HIV-1 infection on osteoclast differentiation. CD14-derived osteoclasts were shown to express CD4, CCR5, and CXCR4 each at the similar level to that shown with macrophages. R5-tropic HIV-1 and X4-tropic HIV-1 were found to infect CD14-derived osteoclasts and replicate in them. Furthermore, HIV-1 infection induced formation of larger osteoclastst, enhanced the expression of mRNAs for three osteoclast specific marker molecules (tartrate-resistant acid phosphatase, cathepsin K, and the calcitonin receptor), and up-regulated osteoclast bone resorption activity. Conclusions Our results suggest that osteoclasts serve as a novel target for HIV-1 infection, which may enhance the osteoclast differentiation contributing to the development of osteolytic disease in HIV-1-infected patients.
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Azizi A, Aidoo F, Gisonni-Lex L, McNeil B. Determination of HSV-1 UL5 and UL29 gene copy numbers in an HSV complementing Vero cell line. J Biotechnol 2013; 168:382-7. [DOI: 10.1016/j.jbiotec.2013.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/27/2013] [Accepted: 10/02/2013] [Indexed: 11/16/2022]
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Coiras M, Montes M, Montanuy I, López-Huertas MR, Mateos E, Le Sommer C, Garcia-Blanco MA, Hernández-Munain C, Alcamí J, Suñé C. Transcription elongation regulator 1 (TCERG1) regulates competent RNA polymerase II-mediated elongation of HIV-1 transcription and facilitates efficient viral replication. Retrovirology 2013; 10:124. [PMID: 24165037 PMCID: PMC3874760 DOI: 10.1186/1742-4690-10-124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 10/18/2013] [Indexed: 12/30/2022] Open
Abstract
Background Control of RNA polymerase II (RNAPII) release from pausing has been proposed as a checkpoint mechanism to ensure optimal RNAPII activity, especially in large, highly regulated genes. HIV-1 gene expression is highly regulated at the level of elongation, which includes transcriptional pausing that is mediated by both viral and cellular factors. Here, we present evidence for a specific role of the elongation-related factor TCERG1 in regulating the extent of HIV-1 elongation and viral replication in vivo. Results We show that TCERG1 depletion diminishes the basal and viral Tat-activated transcription from the HIV-1 LTR. In support of a role for an elongation mechanism in the transcriptional control of HIV-1, we found that TCERG1 modifies the levels of pre-mRNAs generated at distal regions of HIV-1. Most importantly, TCERG1 directly affects the elongation rate of RNAPII transcription in vivo. Furthermore, our data demonstrate that TCERG1 regulates HIV-1 transcription by increasing the rate of RNAPII elongation through the phosphorylation of serine 2 within the carboxyl-terminal domain (CTD) of RNAPII and suggest a mechanism for the involvement of TCERG1 in relieving pausing. Finally, we show that TCERG1 is required for HIV-1 replication. Conclusions Our study reveals that TCERG1 regulates HIV-1 transcriptional elongation by increasing the elongation rate of RNAPII and phosphorylation of Ser 2 within the CTD. Based on our data, we propose a general mechanism for TCERG1 acting on genes that are regulated at the level of elongation by increasing the rate of RNAPII transcription through the phosphorylation of Ser2. In the case of HIV-1, our evidence provides the basis for further investigation of TCERG1 as a potential therapeutic target for the inhibition of HIV-1 replication
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Carlos Suñé
- Department of Molecular Biology, Instituto de Parasitología y Biomedicina "López Neyra" (IPBLN-CSIC), Armilla, Granada 18016, Spain.
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Guardo AC, Álvarez-Fernández C, Arberas H, García-Pérez J, García F, Bargalló ME, Maleno MJ, Gatell JM, Mothe B, Alcami J, Sánchez-Palomino S, Plana M. Use of RT-defective HIV virions: new tool to evaluate specific response in chronic asymptomatic HIV-infected individuals. PLoS One 2013; 8:e58927. [PMID: 23516578 PMCID: PMC3597525 DOI: 10.1371/journal.pone.0058927] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/08/2013] [Indexed: 01/14/2023] Open
Abstract
Background Generation of new reagents that can be used to screen or monitor HIV-1-specific responses constituted an interesting field in the development of HIV vaccines to improve their efficacy. Methods We have evaluated the specific T cell response against different types of NL4-3 virions (including NL4-3 aldrithiol-2 treated, NL4-3/ΔRT and R5 envelopes: NL4-3/ΔRT/ΔEnv[AC10] and NL4-3/ΔRT/ΔEnv[Bal]) and against pools of overlapping peptides (15 mer) encompassing the HIV-1 Gag and Nef regions. Cryopreserved PBMC from a subset of 69 chronic asymptomatic HIV positive individuals have been employed using different techniques including IFN-γ ELISPOT assay, surface activation markers and intracellular cytokine staining (ICS) by flow cytometry. Results The differential response obtained against NL4-3 aldrithiol-2 treated and NL4-3/ΔRT virions (25% vs 55%, respectively) allow us to divide the population in three groups: “full-responders” (positive response against both viral particles), “partial-responders” (positive response only against NL4-3/ΔRT virions) and “non-responders” (negative responses). There was no difference between X4 and R5 envelopes. The magnitude of the total responses was higher against NL4-3/ΔRT and was positively correlated with gender and inverse correlated with viral load. On the contrary CD4+ T cell count was not associated with this response. In any case responses to the viruses tended to be lower in magnitude than those detected by the overlapping peptides tested. Finally we have found an increased frequency of HLA-B27 allele (23% vs 9%) and a significant reduction in some activation markers (CD69 and CD38) on T cells surface in responders vs non-responders individuals. Conclusions In summary these virions could be considered as alternative and useful reagents for screening HIV-1-specific T cell responses in HIV exposed uninfected people, HIV infected patients and to assess immunogenicity of new prototypes both in vitro and in vaccine trials, by a feasible, simply, effective and low cost assay.
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Affiliation(s)
- Alberto Crespo Guardo
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - Carmen Álvarez-Fernández
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - Hodei Arberas
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - Javier García-Pérez
- AIDS Immunopathology Unit. National Center of Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Felipe García
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
- Infectious Diseases Unit, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Manuel Enric Bargalló
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - María José Maleno
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - José María Gatell
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
- Infectious Diseases Unit, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Beatriz Mothe
- Institut de Recerca de la SIDA IrsiCaixa – HIVACAT, Hospital Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - José Alcami
- AIDS Immunopathology Unit. National Center of Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Sonsoles Sánchez-Palomino
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
| | - Montserrat Plana
- Retrovirology and Viral Immunopathology Laboratory, Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain
- Catalan Program for HIV Vaccine Development (HIVACAT), Barcelona, Spain
- * E-mail:
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