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Cafaro A, Schietroma I, Sernicola L, Belli R, Campagna M, Mancini F, Farcomeni S, Pavone-Cossut MR, Borsetti A, Monini P, Ensoli B. Role of HIV-1 Tat Protein Interactions with Host Receptors in HIV Infection and Pathogenesis. Int J Mol Sci 2024; 25:1704. [PMID: 38338977 PMCID: PMC10855115 DOI: 10.3390/ijms25031704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Each time the virus starts a new round of expression/replication, even under effective antiretroviral therapy (ART), the transactivator of viral transcription Tat is one of the first HIV-1 protein to be produced, as it is strictly required for HIV replication and spreading. At this stage, most of the Tat protein exits infected cells, accumulates in the extracellular matrix and exerts profound effects on both the virus and neighbor cells, mostly of the innate and adaptive immune systems. Through these effects, extracellular Tat contributes to the acquisition of infection, spreading and progression to AIDS in untreated patients, or to non-AIDS co-morbidities in ART-treated individuals, who experience inflammation and immune activation despite virus suppression. Here, we review the role of extracellular Tat in both the virus life cycle and on cells of the innate and adaptive immune system, and we provide epidemiological and experimental evidence of the importance of targeting Tat to block residual HIV expression and replication. Finally, we briefly review vaccine studies showing that a therapeutic Tat vaccine intensifies ART, while its inclusion in a preventative vaccine may blunt escape from neutralizing antibodies and block early events in HIV acquisition.
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Affiliation(s)
- Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, 00161 Rome, Italy; (I.S.); (L.S.); (R.B.); (M.C.); (F.M.); (S.F.); (M.R.P.-C.); (A.B.); (P.M.)
| | | | | | | | | | | | | | | | | | | | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, 00161 Rome, Italy; (I.S.); (L.S.); (R.B.); (M.C.); (F.M.); (S.F.); (M.R.P.-C.); (A.B.); (P.M.)
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Cafaro A, Ensoli B. HIV-1 therapeutic vaccines in clinical development to intensify or replace antiretroviral therapy: the promising results of the Tat vaccine. Expert Rev Vaccines 2022; 21:1243-1253. [PMID: 35695268 DOI: 10.1080/14760584.2022.2089119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Upon the introduction of the combination antiretroviral therapy (cART), HIV infection has become a chronic disease. However, cART is unable to eradicate the virus and fails to restore the CD4 counts in about 30% of the treated individuals. Furthermore, treatment is life-long, and it does not protect from morbidities typically observed in the elderly. Therapeutic vaccines represent the most cost-effective intervention to intensify or replace cART. AREAS COVERED Here, we briefly discuss the obstacles to the development and evaluation of the efficacy of therapeutic vaccines and review recent approaches evaluated in clinical trials. EXPERT OPINION Although vaccines were generally safe and immunogenic, evidence of efficacy was negligible or marginal in most trials. A notable exception is the therapeutic Tat vaccine approach showing promising results of cART intensification, with CD4 T-cell increase and proviral load reduction beyond those afforded by cART alone. Rationale and evidence in support of choosing Tat as the vaccine target are thoroughly discussed.
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Affiliation(s)
- Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore Di Sanità, Rome, Italy
| | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore Di Sanità, Rome, Italy
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Ensoli B, Moretti S, Borsetti A, Maggiorella MT, Buttò S, Picconi O, Tripiciano A, Sgadari C, Monini P, Cafaro A. New insights into pathogenesis point to HIV-1 Tat as a key vaccine target. Arch Virol 2021; 166:2955-2974. [PMID: 34390393 PMCID: PMC8363864 DOI: 10.1007/s00705-021-05158-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/09/2021] [Indexed: 02/07/2023]
Abstract
Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in recent years advanced to efficacy trials with mostly unsatisfactory results. Next, we discuss a novel and somewhat contrarian approach based on biological and epidemiological evidence, which led us to choose the HIV protein Tat for the development of preventive and therapeutic HIV vaccines. Toward this goal, we review here the role of Tat in the virus life cycle as well as experimental and epidemiological evidence supporting its key role in the natural history of HIV infection and comorbidities. We then discuss the preclinical and clinical development of a Tat therapeutic vaccine, which, by improving the functionality and homeostasis of the immune system and by reducing the viral reservoir in virologically suppressed vaccinees, helps to establish key determinants for intensification of combination antiretroviral therapy (cART) and a functional cure. Future developments and potential applications of the Tat therapeutic vaccine are also discussed, as well as the rationale for its use in preventative strategies. We hope this contribution will lead to a reconsideration of the current paradigms for the development of HIV/AIDS vaccines, with a focus on targeting of viral proteins with key roles in HIV pathogenesis.
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Affiliation(s)
- Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | - Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Alessandra Borsetti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Maria Teresa Maggiorella
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Stefano Buttò
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Antonella Tripiciano
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
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Use of a Novel Peptide Welding Technology Platform for the Development of B- and T-Cell Epitope-Based Vaccines. Vaccines (Basel) 2021; 9:vaccines9050526. [PMID: 34069535 PMCID: PMC8160815 DOI: 10.3390/vaccines9050526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/29/2021] [Accepted: 05/14/2021] [Indexed: 12/23/2022] Open
Abstract
Peptide vaccines incorporating B- and T-cell epitopes have shown promise in the context of various cancers and infections. These vaccines are relatively simple to manufacture, but more immunogenic formulations are considered a priority. We developed tetrabranched derivatives for this purpose based on a novel peptide welding technology (PWT). PWTs provide molecular scaffolds for the efficient synthesis of ultrapure peptide dendrimers, which allow the delivery of multiple ligands within a single macromolecular structure. Peptide vaccines incorporating T-cell epitopes derived from melanoma and B-cell epitopes derived from human immunodeficiency virus, synthesized using this approach, elicited primary immune responses in vitro and in vivo. Subcutaneous administration of the B-cell epitope-based vaccines also elicited more potent humoral responses than subcutaneous administration of the corresponding peptides alone. Highly immunogenic peptide epitope-based vaccines can therefore be generated quickly and easily using a novel PWT.
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Khojasteh NF, Fekri M, Shabani SH, Milani A, Baesi K, Bolhassani A. Evaluation of HIV-1 Regulatory and Structural Proteins as Antigen Candidate in Mice and Humans. Curr HIV Res 2021; 19:225-237. [PMID: 33243125 DOI: 10.2174/1570162x18999201125212131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/25/2020] [Accepted: 10/27/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND The diagnosis of HIV infection is important among different groups. Moreover, combination antiretroviral therapy is used to treat HIV-1, but it cannot eradicate the infection. Thus, the development of therapeutic vaccines, along with antiretroviral therapy, is recommended. This study evaluates the values of four HIV proteins as antigen candidates in therapeutic vaccine design as well as a possible diagnostic marker for HIV infection in humans. METHODS In this study, the HIV-1 Tat and Rev regulatory proteins and structural Gp120 and p24 proteins were generated in E. coli expression system. Their immunogenicity was evaluated in BALB/ c mice using homologous and heterologous prime/boost strategies. Moreover, the detection of anti- HIV IgG antibodies against these recombinant proteins was assessed in untreated (Naïve/ HIV-infected), treated, and drug-resistant patients compared to the healthy (control) group as a possible diagnostic marker for HIV infection. RESULTS In humans, our results showed that among HIV-1 proteins, anti-Gp120 antibody was not detected in treated individuals compared to the healthy (control) group. The levels of anti-Gp120 antibody were significantly different between the treated group and Naïve as well as drug-resistant subjects. Moreover, the level of anti-p24 antibody was significantly lower in the treated group than the Naive group. In mice, the results of immunization indicated that the Rev antigen could significantly induce IgG2a, IgG2b, and IFN-γ secretion aimed at Th1 response as well as Granzyme B generation as CTL activity in comparison with other antigens. Furthermore, the heterologous DNA prime/ protein boost regimen was more potent than the homologous regimen for stimulation of cellular immunity. CONCLUSION Briefly, the levels of both anti-Gp120 and anti-p24 antibodies can be considered for the diagnosis of the HIV-infected individuals in different groups compared to the healthy group. Moreover, among four recombinant proteins, Rev elicited Th1 cellular immunity and CTL activity in mice as an antigen candidate in therapeutic vaccine development.
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Affiliation(s)
| | - Mehrshad Fekri
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | | | - Alireza Milani
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Kazem Baesi
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Azam Bolhassani
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
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Tripiciano A, Picconi O, Moretti S, Sgadari C, Cafaro A, Francavilla V, Arancio A, Paniccia G, Campagna M, Pavone-Cossut MR, Sighinolfi L, Latini A, Mercurio VS, Pietro MD, Castelli F, Saracino A, Mussini C, Perri GD, Galli M, Nozza S, Ensoli F, Monini P, Ensoli B. Anti-Tat immunity defines CD4 + T-cell dynamics in people living with HIV on long-term cART. EBioMedicine 2021; 66:103306. [PMID: 33839064 PMCID: PMC8105504 DOI: 10.1016/j.ebiom.2021.103306] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Low-level HIV viremia originating from virus reactivation in HIV reservoirs is often present in cART treated individuals and represents a persisting source of immune stimulation associated with sub-optimal recovery of CD4+ T cells. The HIV-1 Tat protein is released in the extracellular milieu and activates immune cells and latent HIV, leading to virus production and release. However, the relation of anti-Tat immunity with residual viremia, persistent immune activation and CD4+ T-cell dynamics has not yet been defined. METHODS Volunteers enrolled in a 3-year longitudinal observational study were stratified by residual viremia, Tat serostatus and frequency of anti-Tat cellular immune responses. The impact of anti-Tat immunity on low-level viremia, persistent immune activation and CD4+ T-cell recovery was investigated by test for partitions, longitudinal regression analysis for repeated measures and generalized estimating equations. FINDINGS Anti-Tat immunity is significantly associated with higher nadir CD4+ T-cell numbers, control of low-level viremia and long-lasting CD4+ T-cell recovery, but not with decreased immune activation. In adjusted analysis, the extent of CD4+ T-cell restoration reflects the interplay among Tat immunity, residual viremia and immunological determinants including CD8+ T cells and B cells. Anti-Env immunity was not related to CD4+ T-cell recovery. INTERPRETATION Therapeutic approaches aiming at reinforcing anti-Tat immunity should be investigated to improve immune reconstitution in people living with HIV on long-term cART. TRIAL REGISTRATION ISS OBS T-002 ClinicalTrials.gov identifier: NCT01024556 FUNDING: Italian Ministry of Health, special project on the Development of a vaccine against HIV based on the Tat protein and Ricerca Corrente 2019/2020.
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Affiliation(s)
- Antonella Tripiciano
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Vittorio Francavilla
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Angela Arancio
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Giovanni Paniccia
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Massimo Campagna
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | | | - Laura Sighinolfi
- Unit of Infectious Diseases, University Hospital of Ferrara, Ferrara, Italy
| | - Alessandra Latini
- Unit of Dermatology and Sexually Transmitted Diseases, San Gallicano Institute - Istituti Fisioterapici Ospitalieri (IFO) IRCCS, Rome, Italy
| | - Vito S Mercurio
- Department of Infectious Diseases, S. Maria Goretti Hospital, Latina, Italy
| | - Massimo Di Pietro
- Unit of Infectious Diseases, S.M. Annunziata Hospital, Florence, Italy
| | - Francesco Castelli
- University Division of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili, Brescia, Italy
| | - Annalisa Saracino
- Division of Infectious Diseases, Policlinic Hospital, University of Bari, Bari, Italy
| | - Cristina Mussini
- Division of Infectious Diseases, University Policlinic of Modena, Modena, Italy
| | - Giovanni Di Perri
- Clinic of Infectious Diseases, Amedeo di Savoia University Hospital, Turin, Italy
| | - Massimo Galli
- Institute of Tropical and Infectious Diseases, L. Sacco University Hospital, Milan, Italy
| | - Silvia Nozza
- Division of Infectious Diseases, S. Raffaele University Hospital IRCCS, Milan, Italy
| | - Fabrizio Ensoli
- Pathology and Microbiology, San Gallicano Institute - (IFO) IRCCS, Rome, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy.
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HIV-1 Tat Protein Enters Dysfunctional Endothelial Cells via Integrins and Renders Them Permissive to Virus Replication. Int J Mol Sci 2020; 22:ijms22010317. [PMID: 33396807 PMCID: PMC7796023 DOI: 10.3390/ijms22010317] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/21/2020] [Accepted: 12/26/2020] [Indexed: 12/21/2022] Open
Abstract
Previous work has shown that the Tat protein of Human Immunodeficiency Virus (HIV)-1 is released by acutely infected cells in a biologically active form and enters dendritic cells upon the binding of its arginine-glycine-aspartic acid (RGD) domain to the α5β1, αvβ3, and αvβ5 integrins. The up-regulation/activation of these integrins occurs in endothelial cells exposed to inflammatory cytokines that are increased in HIV-infected individuals, leading to endothelial cell dysfunction. Here, we show that inflammatory cytokine-activated endothelial cells selectively bind and rapidly take up nano-micromolar concentrations of Tat, as determined by flow cytometry. Protein oxidation and low temperatures reduce Tat entry, suggesting a conformation- and energy-dependent process. Consistently, Tat entry is competed out by RGD-Tat peptides or integrin natural ligands, and it is blocked by anti-α5β1, -αvβ3, and -αvβ5 antibodies. Moreover, modelling–docking calculations identify a low-energy Tat-αvβ3 integrin complex in which Tat makes contacts with both the αv and β3 chains. It is noteworthy that internalized Tat induces HIV replication in inflammatory cytokine-treated, but not untreated, endothelial cells. Thus, endothelial cell dysfunction driven by inflammatory cytokines renders the vascular system a target of Tat, which makes endothelial cells permissive to HIV replication, adding a further layer of complexity to functionally cure and/or eradicate HIV infection.
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Jin H, Li D, Lin MH, Li L, Harrich D. Tat-Based Therapies as an Adjuvant for an HIV-1 Functional Cure. Viruses 2020; 12:v12040415. [PMID: 32276443 PMCID: PMC7232260 DOI: 10.3390/v12040415] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/31/2020] [Accepted: 04/04/2020] [Indexed: 12/18/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV) establishes a chronic infection that can be well controlled, but not cured, by combined antiretroviral therapy (cART). Interventions have been explored to accomplish a functional cure, meaning that a patient remains infected but HIV is undetectable in the blood, with the aim of allowing patients to live without cART. Tat, the viral transactivator of transcription protein, plays a critical role in controlling HIV transcription, latency, and viral rebound following the interruption of cART treatment. Therefore, a logical approach for controlling HIV would be to block Tat. Tackling Tat with inhibitors has been a difficult task, but some recent discoveries hold promise. Two anti-HIV proteins, Nullbasic (a mutant of Tat) and HT1 (a fusion of HEXIM1 and Tat functional domains) inhibit viral transcription by interfering with the interaction of Tat and cellular factors. Two small molecules, didehydro-cortistatin A (dCA) and triptolide, inhibit Tat by different mechanisms: dCA through direct binding and triptolide through enhanced proteasomal degradation. Finally, two Tat-based vaccines under development elicit Tat-neutralizing antibodies. These vaccines have increased the levels of CD4+ cells and reduced viral loads in HIV-infected people, suggesting that the new vaccines are therapeutic. This review summarizes recent developments of anti-Tat agents and how they could contribute to a functional cure for HIV.
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Affiliation(s)
- Hongping Jin
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia; (H.J.); (D.L.); (M.-H.L.)
| | - Dongsheng Li
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia; (H.J.); (D.L.); (M.-H.L.)
| | - Min-Hsuan Lin
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia; (H.J.); (D.L.); (M.-H.L.)
| | - Li Li
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia;
| | - David Harrich
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia; (H.J.); (D.L.); (M.-H.L.)
- Correspondence: ; Tel.: +617-3845-3679
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9
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Moretti S, Cafaro A, Tripiciano A, Picconi O, Buttò S, Ensoli F, Sgadari C, Monini P, Ensoli B. HIV therapeutic vaccines aimed at intensifying combination antiretroviral therapy. Expert Rev Vaccines 2020; 19:71-84. [PMID: 31957513 DOI: 10.1080/14760584.2020.1712199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Introduction: Although successful at suppressing HIV replication, combination antiretroviral therapy (cART) only partially restores immune functions and fails to reduce the latent HIV reservoir, thus requiring novel interventions for its intensification.Areas covered: Here are reviewed therapeutic vaccine candidates that are being developed to this goal. Among them, the Tat vaccine has been shown to promote immune restoration, including CD4+ T-cell recovery in low immunological responders, and to reduce the virus reservoirs well beyond what achieved with long-term suppressive cART.Expert opinion: The authors propose the Tat vaccine as a promising vaccine candidate for cART intensification toward HIV reservoirs depletion, functional cure, and eradication strategies, suggesting that targeting a key protein in the virus life cycle is pivotal to success.
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Affiliation(s)
- Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Stefano Buttò
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Fabrizio Ensoli
- Pathology and Microbiology, San Gallicano Dermatological Institute IRCCS, Rome, Italy
| | - Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
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Cafaro A, Tripiciano A, Picconi O, Sgadari C, Moretti S, Buttò S, Monini P, Ensoli B. Anti-Tat Immunity in HIV-1 Infection: Effects of Naturally Occurring and Vaccine-Induced Antibodies Against Tat on the Course of the Disease. Vaccines (Basel) 2019; 7:vaccines7030099. [PMID: 31454973 PMCID: PMC6789840 DOI: 10.3390/vaccines7030099] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/08/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023] Open
Abstract
HIV-1 Tat is an essential protein in the virus life cycle, which is required for virus gene expression and replication. Most Tat that is produced during infection is released extracellularly and it plays a key role in HIV pathogenesis, including residual disease upon combination antiretroviral therapy (cART). Here, we review epidemiological and experimental evidence showing that antibodies against HIV-1 Tat, infrequently occurring in natural infection, play a protective role against disease progression, and that vaccine targeting Tat can intensify cART. In fact, Tat vaccination of subjects on suppressive cART in Italy and South Africa promoted immune restoration, including CD4+ T-cell increase in low immunological responders, and a reduction of proviral DNA even after six years of cART, when both CD4+ T-cell gain and DNA decay have reached a plateau. Of note, DNA decay was predicted by the neutralization of Tat-mediated entry of Env into dendritic cells by anti-Tat antibodies, which were cross-clade binding and neutralizing. Anti-Tat cellular immunity also contributed to the DNA decay. Based on these data, we propose the Tat therapeutic vaccine as a pathogenesis-driven intervention that effectively intensifies cART and it may lead to a functional cure, providing new perspectives and opportunities also for prevention and virus eradication strategies.
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Affiliation(s)
- Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Antonella Tripiciano
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Stefano Buttò
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome 00161, Italy.
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11
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Sgadari C, Monini P, Tripiciano A, Picconi O, Casabianca A, Orlandi C, Moretti S, Francavilla V, Arancio A, Paniccia G, Campagna M, Bellino S, Meschiari M, Nozza S, Sighinolfi L, Latini A, Muscatello A, Saracino A, Di Pietro M, Galli M, Cafaro A, Magnani M, Ensoli F, Ensoli B. Continued Decay of HIV Proviral DNA Upon Vaccination With HIV-1 Tat of Subjects on Long-Term ART: An 8-Year Follow-Up Study. Front Immunol 2019; 10:233. [PMID: 30815001 PMCID: PMC6381398 DOI: 10.3389/fimmu.2019.00233] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/28/2019] [Indexed: 02/02/2023] Open
Abstract
Introduction: Tat, a key HIV virulence protein, has been targeted for the development of a therapeutic vaccine aimed at cART intensification. Results from phase II clinical trials in Italy (ISS T-002) and South Africa (ISS T-003) indicated that Tat vaccination promotes increases of CD4+ T-cells and return to immune homeostasis while reducing the virus reservoir in chronically cART-treated patients. Here we present data of 92 vaccinees (59% of total vaccinees) enrolled in the ISS T-002 8-year extended follow-up study (ISS T-002 EF-UP, ClinicalTrials.gov NCT02118168). Results: Anti-Tat antibodies (Abs) induced upon vaccination persisted for the entire follow-up in 34/92 (37%) vaccinees, particularly when all 3 Ab classes (A/G/M) were present (66% of vaccinees), as most frequently observed with Tat 30 μg regimens. CD4+ T cells increased above study-entry levels reaching a stable plateau at year 5 post-vaccination, with the highest increase (165 cells/μL) in the Tat 30 μg, 3 × regimen. CD4+ T-cell increase occurred even in subjects with CD4+ nadir ≤ 250 cells/uL and in poor immunological responders and was associated with a concomitant increase of the CD4+/CD8+ T-cell ratio, a prognostic marker of morbidity/mortality inversely related to HIV reservoir size. Proviral DNA load decreased over time, with a half-life of 2 years and an estimated 90% reduction at year 8 in the Tat 30 μg, 3 × group. In multivariate analysis the kinetic and amplitude of both CD4+ T-cell increase and proviral DNA reduction were fastest and highest in subjects with all 3 anti-Tat Ab classes and in the 30 μg, 3 × group, irrespective of drug regimens (NNRTI/NRTI vs. PI). HIV proviral DNA changes from baseline were inversely related to CD4+/CD8+ T-cell ratio and CD4+ T-cell changes, and directly related to the changes of CD8+ T cells. Further, HIV DNA decay kinetics were inversely related to the frequency and levels of intermittent viremia. Finally, Tat vaccination was similarly effective irrespective of the individual immunological status or HIV reservoir size at study entry. Conclusions: Tat immunization induces progressive immune restoration and reduction of virus reservoirs above levels reached with long-term cART, and may represent an optimal vaccine candidate for cART intensification toward HIV reservoirs depletion, functional cure, and eradication strategies.
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Affiliation(s)
- Cecilia Sgadari
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Paolo Monini
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Orietta Picconi
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Anna Casabianca
- Department of Biomolecular Science, University of Urbino, Urbino, Italy
| | - Chiara Orlandi
- Department of Biomolecular Science, University of Urbino, Urbino, Italy
| | - Sonia Moretti
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Angela Arancio
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Giovanni Paniccia
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Massimo Campagna
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Stefania Bellino
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Marianna Meschiari
- Division of Infectious Diseases, University Policlinic of Modena, Modena, Italy
| | - Silvia Nozza
- Division of Infectious Diseases, San Raffaele Hospital, Milan, Italy
| | - Laura Sighinolfi
- Unit of Infectious Diseases, University Hospital of Ferrara, Ferrara, Italy
| | - Alessandra Latini
- Unit of Dermatology and Sexually Transmitted Diseases, San Gallicano Dermatological Institute IRCCS, Rome, Italy
| | - Antonio Muscatello
- Infectious Diseases Unit, IRCCS Ca' Granda Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
| | - Annalisa Saracino
- Division of Infectious Diseases, University of Bari, Policlinic Hospital, Bari, Italy
| | - Massimo Di Pietro
- Unit of Infectious Diseases, Santa Maria Annunziata Hospital, Florence, Italy
| | - Massimo Galli
- Institute of Tropical and Infectious Diseases, L. Sacco Hospital, University of Milan, Milan, Italy
| | - Aurelio Cafaro
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
| | - Mauro Magnani
- Department of Biomolecular Science, University of Urbino, Urbino, Italy
| | - Fabrizio Ensoli
- Pathology and Microbiology, San Gallicano Dermatological Institute IRCCS, Rome, Italy
| | - Barbara Ensoli
- National HIV/AIDS Research Center, Istituto Superiore di Sanità, Rome, Italy
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Cafaro A, Sgadari C, Picconi O, Tripiciano A, Moretti S, Francavilla V, Pavone Cossut MR, Buttò S, Cozzone G, Ensoli F, Monini P, Ensoli B. "cART intensification by the HIV-1 Tat B clade vaccine: progress to phase III efficacy studies". Expert Rev Vaccines 2017; 17:115-126. [PMID: 29243498 DOI: 10.1080/14760584.2018.1418666] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION In spite of its success at suppressing HIV replication, combination antiretroviral therapy (cART) only partially reduces immune dysregulation and loss of immune functions. These cART-unmet needs appear to be due to persistent virus replication and cell-to-cell transmission in reservoirs, and are causes of increased patients' morbidity and mortality. Up to now, therapeutic interventions aimed at cART-intensification by attacking the virus reservoir have failed. AREAS COVERED We briefly review the rationale and clinical development of Tat therapeutic vaccine in cART-treated subjects in Italy and South Africa (SA). Vaccination with clade-B Tat induced cross-clade neutralizing antibodies, immune restoration, including CD4+ T cell increase particularly in low immunological responders, and reduction of proviral DNA. Phase III efficacy trials in SA are planned both in adult and pediatric populations. EXPERT COMMENTARY We propose the Tat therapeutic vaccine as a pathogenesis-driven intervention that effectively intensifies cART and may lead to a functional cure and provide new perspectives for prevention and virus eradication strategies.
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Affiliation(s)
- Aurelio Cafaro
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Cecilia Sgadari
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Orietta Picconi
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Antonella Tripiciano
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Sonia Moretti
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Vittorio Francavilla
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | | | - Stefano Buttò
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | | | - Fabrizio Ensoli
- b Laboratory of Clinical Pathology and Microbiology, San Gallicano Institute , Istituti Fisioterapici Ospitalieri , Rome , Italy
| | - Paolo Monini
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
| | - Barbara Ensoli
- a National HIV/AIDS Research Center , Istituto Superiore di Sanità , Rome , Italy
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Wijesundara DK, Ranasinghe C, Grubor-Bauk B, Gowans EJ. Emerging Targets for Developing T Cell-Mediated Vaccines for Human Immunodeficiency Virus (HIV)-1. Front Microbiol 2017; 8:2091. [PMID: 29118747 PMCID: PMC5660999 DOI: 10.3389/fmicb.2017.02091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/11/2017] [Indexed: 11/13/2022] Open
Abstract
Human immunodeficiency virus (HIV)-1 has infected >75 million individuals globally, and, according to the UN, is responsible for ~2.1 million new infections and 1.1 million deaths each year. Currently, there are ~37 million individuals with HIV infection and the epidemic has already resulted in 35 million deaths. Despite the advances of anti-retroviral therapy (ART), a cost-effective vaccine remains the best long-term solution to end the HIV-1 epidemic especially given that the vast majority of infected individuals live in poor socio-economic regions of the world such as Sub-Saharan Africa which limits their accessibility to ART. The modest efficacy of the RV144 Thai trial provides hope that a vaccine for HIV-1 is possible, but as markers for sterilizing immunity are unknown, the design of an effective vaccine is empirical, although broadly cross-reactive neutralizing antibodies (bNAb) that can neutralize various quasispecies of HIV-1 are considered crucial. Since HIV-1 transmission often occurs at the genito-rectal mucosa and is cell-associated, there is a need to develop vaccines that can elicit CD8+ T cell immunity with the capacity to kill virus infected cells at the genito-rectal mucosa and the gut. Here we discuss the recent progress made in developing T cell-mediated vaccines for HIV-1 and emphasize the need to elicit mucosal tissue-resident memory CD8+ T (CD8+ Trm) cells. CD8+ Trm cells will likely form a robust front-line defense against HIV-1 and eliminate transmitter/founder virus-infected cells which are responsible for propagating HIV-1 infections following transmission in vast majority of cases.
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Affiliation(s)
- Danushka K Wijesundara
- Virology Laboratory, Basil Hetzel Institute for Translational Medicine, Discipline of Surgery, University of Adelaide, Adelaide, SA, Australia
| | - Charani Ranasinghe
- Molecular Mucosal Vaccine Immunology Group, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Branka Grubor-Bauk
- Virology Laboratory, Basil Hetzel Institute for Translational Medicine, Discipline of Surgery, University of Adelaide, Adelaide, SA, Australia
| | - Eric J Gowans
- Virology Laboratory, Basil Hetzel Institute for Translational Medicine, Discipline of Surgery, University of Adelaide, Adelaide, SA, Australia
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14
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PKC-δ isoform plays a crucial role in Tat-TLR4 signalling pathway to activate NF-κB and CXCL8 production. Sci Rep 2017; 7:2384. [PMID: 28539656 PMCID: PMC5443767 DOI: 10.1038/s41598-017-02468-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022] Open
Abstract
HIV-1 Tat protein induces the production of CXCL8 chemokine in a TLR4/MD2 and PKC dependent manner. The objective of this study was to understand whether these two pathways were distinct or constituted a single common pathway, and to determine the nature of the PKC isoforms involved and their interrelation with the activation of NF-κB and CXCL8 gene product expression. Here, we show that Tat-induced CXCL8 production is essentially dependent on the activation of PKC delta isoform, as shown a) by the capacity of PKC delta dominant negative (DN), and Rottlerin, a selective PKC delta pharmacological inhibitor, to inhibit Tat-induced CXCL8 production and b) by the ability of the constitutively active (CAT) isoform of PKC delta to induce CXCL8 production in a HEK cell line in the absence of Tat stimulation. The finding that comparable amounts of CXCL8 were produced following stimulation with either Tat protein, PKC-delta CAT transfection, or both, argue for the implication of one common pathway where PKC delta is activated downstream of TLR4 recruitment and leads to the activation of NF-κB. Altogether, our results underline the crucial role of PKC delta isoform in activating gene expression of CXCL8, a cytokine largely implicated in the physiopathology of HIV-1 infection.
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15
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Leal L, Lucero C, Gatell JM, Gallart T, Plana M, García F. New challenges in therapeutic vaccines against HIV infection. Expert Rev Vaccines 2017; 16:587-600. [PMID: 28431490 DOI: 10.1080/14760584.2017.1322513] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION There is a growing interest in developing curative strategies for HIV infection. Therapeutic vaccines are one of the most promising approaches. We will review the current knowledge and the new challenges in this research field. Areas covered: PubMed and ClinicalTrial.gov databases were searched to review the progress and prospects for clinical development of immunotherapies aimed to cure HIV infection. Dendritic cells (DC)-based vaccines have yielded the best results in the field. However, major immune-virologic barriers may hamper current vaccine strategies. We will focus on some new challenges as the antigen presentation by DCs, CTL escape mutations, B cell follicle sanctuary, host immune environment (inflammation, immune activation, tolerance), latent reservoir and the lack of surrogate markers of response. Finally, we will review the rationale for designing new therapeutic vaccine candidates to be used alone or in combination with other strategies to improve their effectiveness. Expert commentary: In the next future, the combination of DCs targeting candidates, inserts to redirect responses to unmutated parts of the virus, adjuvants to redirect responses to sanctuaries or improve the balance between activation/tolerance (IL-15, anti-PD1 antibodies) and latency reversing agents could be necessary to finally achieve the remission of HIV-1 infection.
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Affiliation(s)
- Lorna Leal
- a Infectious Diseases Unit, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
| | - Constanza Lucero
- a Infectious Diseases Unit, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
| | - Josep M Gatell
- a Infectious Diseases Unit, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
| | - Teresa Gallart
- b Retrovirology and Viral Immunopathology Laboratories, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
| | - Montserrat Plana
- b Retrovirology and Viral Immunopathology Laboratories, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
| | - Felipe García
- a Infectious Diseases Unit, HIVACAT, Hospital Clínic, IDIBAPS , University of Barcelona , Barcelona , Spain
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16
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Ronsard L, Ganguli N, Singh VK, Mohankumar K, Rai T, Sridharan S, Pajaniradje S, Kumar B, Rai D, Chaudhuri S, Coumar MS, Ramachandran VG, Banerjea AC. Impact of Genetic Variations in HIV-1 Tat on LTR-Mediated Transcription via TAR RNA Interaction. Front Microbiol 2017; 8:706. [PMID: 28484443 PMCID: PMC5399533 DOI: 10.3389/fmicb.2017.00706] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/05/2017] [Indexed: 01/10/2023] Open
Abstract
HIV-1 evades host defense through mutations and recombination events, generating numerous variants in an infected patient. These variants with an undiminished virulence can multiply rapidly in order to progress to AIDS. One of the targets to intervene in HIV-1 replication is the trans-activator of transcription (Tat), a major regulatory protein that transactivates the long terminal repeat promoter through its interaction with trans-activation response (TAR) RNA. In this study, HIV-1 infected patients (n = 120) from North India revealed Ser46Phe (20%) and Ser61Arg (2%) mutations in the Tat variants with a strong interaction toward TAR leading to enhanced transactivation activities. Molecular dynamics simulation data verified that the variants with this mutation had a higher binding affinity for TAR than both the wild-type Tat and other variants that lacked Ser46Phe and Ser61Arg. Other mutations in Tat conferred varying affinities for TAR interaction leading to differential transactivation abilities. This is the first report from North India with a clinical validation of CD4 counts to demonstrate the influence of Tat genetic variations affecting the stability of Tat and its interaction with TAR. This study highlights the co-evolution pattern of Tat and predominant nucleotides for Tat activity, facilitating the identification of genetic determinants for the attenuation of viral gene expression.
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Affiliation(s)
- Larance Ronsard
- Laboratory of Virology, National Institute of ImmunologyDelhi, India.,Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur HospitalDelhi, India
| | - Nilanjana Ganguli
- Laboratory of Virology, National Institute of ImmunologyDelhi, India
| | - Vivek K Singh
- Centre for Bioinformatics, School of Life Sciences, Pondicherry UniversityPondicherry, India
| | - Kumaravel Mohankumar
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India.,Department of Veterinary Physiology and Pharmacology, Texas A&M University, College StationTX, USA
| | - Tripti Rai
- Department of Gastroenterology and Human Nutrition, All India Institute of Medical SciencesDelhi, India
| | - Subhashree Sridharan
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India.,Department of Symptom Research, The University of Texas MD Anderson Cancer Center, HoustonTX, USA
| | - Sankar Pajaniradje
- Department of Biochemistry and Molecular Biology, Pondicherry UniversityPondicherry, India
| | - Binod Kumar
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, ChicagoIL, USA
| | - Devesh Rai
- Department of Microbiology, All India Institute of Medical SciencesDelhi, India
| | - Suhnrita Chaudhuri
- Department of Neurological Surgery, Northwestern University, ChicagoIL, USA
| | - Mohane S Coumar
- Centre for Bioinformatics, School of Life Sciences, Pondicherry UniversityPondicherry, India
| | | | - Akhil C Banerjea
- Laboratory of Virology, National Institute of ImmunologyDelhi, India
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Wahid B, Ali A, Idrees M, Rafique S. Immunotherapeutic strategies for sexually transmitted viral infections: HIV, HSV and HPV. Cell Immunol 2016; 310:1-13. [PMID: 27514252 PMCID: PMC7124316 DOI: 10.1016/j.cellimm.2016.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 07/22/2016] [Accepted: 08/02/2016] [Indexed: 12/24/2022]
Abstract
More than 1 million sexually transmitted infections (STIs) are acquired each day globally. Etiotropic drugs cannot effectively control infectious diseases therefore, there is a dire need to explore alternative strategies especially those based on the regulation of immune system. The review discusses all rational approaches to develop better understanding towards immunotherapeutic strategies based on modulation of immune system in an attempt to curb the elevating risk of infectious diseases such as HIV, HPV and HSV because of their high prevalence. Development of monoclonal antibodies, vaccines and several other immune based treatments are promising alternative strategies that are offering new opportunities to eradicate pathogens.
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Affiliation(s)
- Braira Wahid
- Centre for Applied Molecular Biology, 87-West Canal Bank Road, Thokar Niaz Baig, University of the Punjab, Lahore, Pakistan.
| | - Amjad Ali
- Centre for Applied Molecular Biology, 87-West Canal Bank Road, Thokar Niaz Baig, University of the Punjab, Lahore, Pakistan.
| | - Muhammad Idrees
- Centre for Applied Molecular Biology, 87-West Canal Bank Road, Thokar Niaz Baig, University of the Punjab, Lahore, Pakistan; Vice Chancellor Hazara University Mansehra, Pakistan.
| | - Shazia Rafique
- Centre for Applied Molecular Biology, 87-West Canal Bank Road, Thokar Niaz Baig, University of the Punjab, Lahore, Pakistan.
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Tomusange K, Wijesundara D, Gummow J, Wesselingh S, Suhrbier A, Gowans EJ, Grubor-Bauk B. Mucosal vaccination with a live recombinant rhinovirus followed by intradermal DNA administration elicits potent and protective HIV-specific immune responses. Sci Rep 2016; 6:36658. [PMID: 27853256 PMCID: PMC5113119 DOI: 10.1038/srep36658] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/18/2016] [Indexed: 01/30/2023] Open
Abstract
Mucosal immunity is deemed crucial to control sexual transmission of human immunodeficiency virus (HIV). Herein we report the efficacy of a mucosal HIV vaccine strategy comprising intranasal (IN) vaccination with a cocktail of live recombinant human rhinoviruses (HRVs) encoding overlapping fragments of HIV Gag and full length Tat (rHRV-Gag/Tat) followed by intradermal (ID) vaccination with DNA vaccines encoding HIV Gag and Tat (pVAX-Gag-Tat). This heterologous prime-boost strategy will be referred to hereafter as rHRV-DNA. As a control, IN vaccination with wild type (wt)-HRV-A1 followed by a single ID dose of pVAX (wt-HRV-A1/pVAX vaccination) was included. rHRV-DNA vaccination elicited superior multi-functional CD8+T cell responses in lymphocytes harvested from mesenteric lymph nodes and spleens, and higher titres of Tat-specific antibodies in blood and vaginal lavages, and reduced the viral load more effectively after challenge with EcoHIV, a murine HIV challenge model, in peritoneal macrophages, splenocytes and blood compared compared with wt-HRV-A1/pVAX vaccination or administration of 3 ID doses of pVAX-Gag-Tat (3X pVAX-Gag-Tat vaccination). These data provide the first evidence that a rHRV-DNA vaccination regimen can induce HIV-specific immune responses in the gut, vaginal mucosa and systemically, and supports further testing of this regimen in the development of an effective mucosally-targeted HIV-1 vaccine.
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Affiliation(s)
- Khamis Tomusange
- Virology Laboratory, Basil Hetzel Institute, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia
| | - Danushka Wijesundara
- Virology Laboratory, Basil Hetzel Institute, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia
| | - Jason Gummow
- Virology Laboratory, Basil Hetzel Institute, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia
| | - Steve Wesselingh
- South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Andreas Suhrbier
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Eric J Gowans
- Virology Laboratory, Basil Hetzel Institute, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia
| | - Branka Grubor-Bauk
- Virology Laboratory, Basil Hetzel Institute, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia
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Molecular and Genetic Characterization of HIV-1 Tat Exon-1 Gene from Cameroon Shows Conserved Tat HLA-Binding Epitopes: Functional Implications. Viruses 2016; 8:v8070196. [PMID: 27438849 PMCID: PMC4974531 DOI: 10.3390/v8070196] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/24/2016] [Accepted: 07/12/2016] [Indexed: 12/26/2022] Open
Abstract
HIV-1 Tat plays a critical role in viral transactivation. Subtype-B Tat has potential use as a therapeutic vaccine. However, viral genetic diversity and population genetics would significantly impact the efficacy of such a vaccine. Over 70% of the 37-million HIV-infected individuals are in sub-Saharan Africa (SSA) and harbor non-subtype-B HIV-1. Using specimens from 100 HIV-infected Cameroonians, we analyzed the sequences of HIV-1 Tat exon-1, its functional domains, post-translational modifications (PTMs), and human leukocyte antigens (HLA)-binding epitopes. Molecular phylogeny revealed a high genetic diversity with nine subtypes, CRF22_01A1/CRF01_AE, and negative selection in all subtypes. Amino acid mutations in Tat functional domains included N24K (44%), N29K (58%), and N40K (30%) in CRF02_AG, and N24K in all G subtypes. Motifs and phosphorylation analyses showed conserved amidation, N-myristoylation, casein kinase-2 (CK2), serine and threonine phosphorylation sites. Analysis of HLA allelic frequencies showed that epitopes for HLAs A*0205, B*5301, Cw*0401, Cw*0602, and Cw*0702 were conserved in 58%-100% of samples, with B*5301 epitopes having binding affinity scores > 100 in all subtypes. This is the first report of N-myristoylation, amidation, and CK2 sites in Tat; these PTMs and mutations could affect Tat function. HLA epitopes identified could be useful for designing Tat-based vaccines for highly diverse HIV-1 populations, as in SSA.
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