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Mori L, Valente ST. Cure and Long-Term Remission Strategies. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2407:391-428. [PMID: 34985678 DOI: 10.1007/978-1-0716-1871-4_26] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The majority of virally suppressed individuals will experience rapid viral rebound upon antiretroviral therapy (ART) interruption, providing a strong rationale for the development of cure strategies. Moreover, despite ART virological control, HIV infection is still associated with chronic immune activation, inflammation, comorbidities, and accelerated aging. These effects are believed to be due, in part, to low-grade persistent transcription and trickling production of viral proteins from the pool of latent proviruses constituting the viral reservoir. In recent years there has been an increasing interest in developing what has been termed a functional cure for HIV. This approach entails the long-term, durable control of viral expression in the absence of therapy, preventing disease progression and transmission, despite the presence of detectable integrated proviruses. One such strategy, the block-and-lock approach for a functional cure, proposes the epigenetic silencing of proviral expression, locking the virus in a profound latent state, from which reactivation is very unlikely. The proof-of-concept for this approach was demonstrated with the use of a specific small molecule targeting HIV transcription. Here we review the principles behind the block-and-lock approach and some of the additional strategies proposed to silence HIV expression.
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Affiliation(s)
- Luisa Mori
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA
| | - Susana T Valente
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, FL, USA.
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Esmail H, Riou C, Bruyn ED, Lai RPJ, Harley YXR, Meintjes G, Wilkinson KA, Wilkinson RJ. The Immune Response to Mycobacterium tuberculosis in HIV-1-Coinfected Persons. Annu Rev Immunol 2018; 36:603-638. [PMID: 29490165 DOI: 10.1146/annurev-immunol-042617-053420] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Globally, about 36.7 million people were living with HIV infection at the end of 2015. The most frequent infection co-occurring with HIV-1 is Mycobacterium tuberculosis-374,000 deaths per annum are attributable to HIV-tuberculosis, 75% of those occurring in Africa. HIV-1 infection increases the risk of tuberculosis by a factor of up to 26 and alters its clinical presentation, complicates diagnosis and treatment, and worsens outcome. Although HIV-1-induced depletion of CD4+ T cells underlies all these effects, more widespread immune deficits also contribute to susceptibility and pathogenesis. These defects present a challenge to understand and ameliorate, but also an opportunity to learn and optimize mechanisms that normally protect people against tuberculosis. The most effective means to prevent and ameliorate tuberculosis in HIV-1-infected people is antiretroviral therapy, but this may be complicated by pathological immune deterioration that in turn requires more effective host-directed anti-inflammatory therapies to be derived.
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Affiliation(s)
- Hanif Esmail
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa; .,Department of Medicine, Imperial College London, London W2 1PG, United Kingdom.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Catherine Riou
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa;
| | - Elsa du Bruyn
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa;
| | | | - Yolande X R Harley
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa;
| | - Graeme Meintjes
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa;
| | - Katalin A Wilkinson
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa; .,The Francis Crick Institute, London NW1 2AT, United Kingdom
| | - Robert J Wilkinson
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, Cape Town 7925, Republic of South Africa; .,Department of Medicine, Imperial College London, London W2 1PG, United Kingdom.,The Francis Crick Institute, London NW1 2AT, United Kingdom
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Medina-Moreno S, Dowling TC, Zapata JC, Le NM, Sausville E, Bryant J, Redfield RR, Heredia A. Targeting of CDK9 with indirubin 3'-monoxime safely and durably reduces HIV viremia in chronically infected humanized mice. PLoS One 2017; 12:e0183425. [PMID: 28817720 PMCID: PMC5560554 DOI: 10.1371/journal.pone.0183425] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 08/03/2017] [Indexed: 12/12/2022] Open
Abstract
Successful propagation of HIV in the human host requires entry into a permissive cell, reverse transcription of viral RNA, integration into the human genome, transcription of the integrated provirus, and assembly/release of new virus particles. Currently, there are antiretrovirals against each of these viral steps, except for provirus transcription. An inhibitor of HIV transcription could both increase potency of treatment and suppress drug-resistant strains. Cellular cyclin-dependent kinase 9 (CDK9) serves as a cofactor for the HIV Tat protein and is required for effective transcription of the provirus. Previous studies have shown that the CDK9 inhibitor Indirubin 3’-monoxime (IM) inhibits HIV transcription in vitro and in short-term in vivo studies of HIV acute infection in humanized mice (PBMC-NSG model), suggesting a therapeutic potential. The objective of this study is to evaluate the toxicity, pharmacokinetics and long-term antiviral activity of IM during chronic HIV infection in humanized mice (HSC-NSG model). We show that IM concentrations above EC50 values are rapidly achieved and sustained for > 3 h in plasma, and that non-toxic concentrations durably reduce HIV RNA levels. In addition, IM enhanced the antiviral activity of antiretrovirals from the reverse transcriptase, protease and integrase inhibitor classes in in vitro infectivity assays. In summary, IM may enhance current antiretroviral treatments and could help achieve a “functional cure” in HIV patients by preventing expression of proviruses.
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Affiliation(s)
- Sandra Medina-Moreno
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Thomas C. Dowling
- Department of Pharmaceutical Sciences, Ferris State University, Grand Rapids, Michigan, United States of America
| | - Juan C. Zapata
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Nhut M. Le
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Edward Sausville
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Joseph Bryant
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Robert R. Redfield
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Alonso Heredia
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Abstract
The modulation of tuberculosis (TB)-induced immunopathology caused by human immunodeficiency virus (HIV)-1 coinfection remains incompletely understood but underlies the change seen in the natural history, presentation, and prognosis of TB in such patients. The deleterious combination of these two pathogens has been dubbed a "deadly syndemic," with each favoring the replication of the other and thereby contributing to accelerated disease morbidity and mortality. HIV-1 is the best-recognized risk factor for the development of active TB and accounts for 13% of cases globally. The advent of combination antiretroviral therapy (ART) has considerably mitigated this risk. Rapid roll-out of ART globally and the recent recommendation by the World Health Organization (WHO) to initiate ART for everyone living with HIV at any CD4 cell count should lead to further reductions in HIV-1-associated TB incidence because susceptibility to TB is inversely proportional to CD4 count. However, it is important to note that even after successful ART, patients with HIV-1 are still at increased risk for TB. Indeed, in settings of high TB incidence, the occurrence of TB often remains the first presentation of, and thereby the entry into, HIV care. As advantageous as ART-induced immune recovery is, it may also give rise to immunopathology, especially in the lower-CD4-count strata in the form of the immune reconstitution inflammatory syndrome. TB-immune reconstitution inflammatory syndrome will continue to impact the HIV-TB syndemic.
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Abstract
Immunology is a central theme when it comes to tuberculosis (TB). The outcome of human infection with Mycobacterium tuberculosis is dependent on the ability of the immune response to clear or contain the infection. In cases where this fails, the bacterium replicates, disseminates within the host, and elicits a pathologic inflammatory response, and disease ensues. Clinical presentation of TB disease is remarkably heterogeneous, and the disease phenotype is largely dependent on host immune status. Onward transmission of M. tuberculosis to new susceptible hosts is thought to depend on an excessive inflammatory response causing a breakdown of the lung matrix and formation of lung cavities. But this varies in cases of underlying immunological dysfunction: for example, HIV-1 infection is associated with less cavitation, while diabetes mellitus comorbidity is associated with increased cavitation and risk of transmission. In compliance with the central theme of immunology in tuberculosis, we rely on detection of an adaptive immune response, in the form of interferon-gamma release assays or tuberculin skin tests, to diagnose infection with M. tuberculosis. Here we review the immunology of TB in the human host, focusing on cellular and humoral adaptive immunity as well as key features of innate immune responses and the underlying immunological dysfunction which associates with human TB risk factors. Our review is restricted to human immunology, and we highlight distinctions from the immunological dogma originating from animal models of TB, which pervade the field.
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Abstract
Antiretroviral therapy (ART) potently suppresses HIV-1 replication, but the virus persists in quiescent infected CD4(+)T cells as a latent integrated provirus, and patients must indefinitely remain on therapy. If ART is terminated, these integrated proviruses can reactivate, driving new rounds of infection. A functional cure for HIV requires eliminating low-level ongoing viral replication that persists in certain tissue sanctuaries and preventing viral reactivation. The HIV Tat protein plays an essential role in HIV transcription by recruiting the kinase activity of the P-TEFb complex to the viral mRNA's stem-bulge-loop structure, TAR, activating transcriptional elongation. Because the Tat-mediated transactivation cascade is critical for robust HIV replication, the Tat/TAR/P-TEFb complex is one of the most attractive targets for drug development. Importantly, compounds that interfere with transcription could impair viral reactivation, low-level ongoing replication, and replenishment of the latent reservoir, thereby reducing the size of the latent reservoir pool. Here, we discuss the potential importance of transcriptional inhibitors in the treatment of latent HIV-1 disease and review recent findings on targeting Tat, TAR, and P-TEFb individually or as part of a complex. Finally, we discuss the impact of extracellular Tat in HIV-associated neurocognitive disorders and cancers.
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Toossi Z, Liu S, Wu M, Mayanja-Kizza H, Hirsch CS. Short communication: circulating plasma HIV-1 viral protein R in dual HIV-1/tuberculosis infection. AIDS Res Hum Retroviruses 2014; 30:644-7. [PMID: 24798102 DOI: 10.1089/aid.2013.0269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Circulating free HIV-1 viral protein R (Vpr) is found in up to one third of subjects with HIV-1 infection. Free Vpr presumably shares some of the immunopathogenic effects of cell-associated Vpr. Here we assessed Vpr in plasma and pleural fluid from HIV/tuberculosis (TB) dually infected subjects with pleural TB and from plasma of patients with pulmonary HIV/TB. Vpr was assessed by western blot analysis. In plasma from HIV/TB subjects with pulmonary TB free Vpr could be detected in 47%. Only one subject, among 26 tested, with HIV monoinfection showed plasma Vpr activity. The majority (87.5%) of patients with pleural HIV/TB demonstrated free Vpr reactivity in their plasma. However, no Vpr activity was found in autologous pleural fluid samples from pleural HIV/TB patients. Standard (s) Vpr reactivity was reduced markedly by the addition of sVpr to pleural fluid from HIV-uninfected subjects. A high incidence of plasma Vpr reactivity in HIV/TB patients implies heightened processing and release of this HIV-1 accessory protein during HIV/TB coinfection. The contribution of free Vpr to HIV-1 immunopathogenesis during HIV/TB needs to be studied.
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Affiliation(s)
- Zahra Toossi
- Case Western Reserve University, Cleveland, Ohio
- Veterans Affairs Medical Center, Cleveland, Ohio
| | - Shigou Liu
- Case Western Reserve University, Cleveland, Ohio
| | - Mianda Wu
- Case Western Reserve University, Cleveland, Ohio
| | - Harriet Mayanja-Kizza
- Case Western Reserve University, Cleveland, Ohio
- Makerere University, Kampala, Uganda
- Joint Clinical Research Center, Kampala, Uganda
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Heredia A, Natesan S, Le NM, Medina-Moreno S, Zapata JC, Reitz M, Bryant J, Redfield RR. Indirubin 3'-monoxime, from a Chinese traditional herbal formula, suppresses viremia in humanized mice infected with multidrug-resistant HIV. AIDS Res Hum Retroviruses 2014; 30:403-6. [PMID: 24401082 DOI: 10.1089/aid.2013.0249] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Alonso Heredia
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Senthilkumar Natesan
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Nhut M. Le
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Sandra Medina-Moreno
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Juan C. Zapata
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marvin Reitz
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Joseph Bryant
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert R. Redfield
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
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Clark KB. Biotic activity of Ca(2+)-modulating non-traditional antimicrobial and -viral agents. Front Microbiol 2013; 4:381. [PMID: 24376441 PMCID: PMC3859912 DOI: 10.3389/fmicb.2013.00381] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 11/24/2013] [Indexed: 01/23/2023] Open
Affiliation(s)
- Kevin B Clark
- Research and Development Service, Veterans Affairs Greater Los Angeles Healthcare System Los Angeles, CA, USA
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Deffur A, Mulder NJ, Wilkinson RJ. Co-infection with Mycobacterium tuberculosis and human immunodeficiency virus: an overview and motivation for systems approaches. Pathog Dis 2013; 69:101-13. [PMID: 23821533 DOI: 10.1111/2049-632x.12060] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022] Open
Abstract
Tuberculosis is a devastating disease that accounts for a high proportion of infectious disease morbidity and mortality worldwide. HIV-1 co-infection exacerbates tuberculosis. Enhanced understanding of the host-pathogen relationship in HIV-1 and Mycobacterium tuberculosis co-infection is required. While reductionist approaches have yielded many valuable insights into disease pathogenesis, systems approaches are required that develop data-driven models able to predict emergent properties of this complex co-infection system in order to develop novel therapeutic approaches and to improve diagnostics. Here, we provide a pathogenesis-focused overview of HIV-TB co-infection followed by an introduction to systems approaches and concrete examples of how such approaches are useful.
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Affiliation(s)
- Armin Deffur
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa; Department of Medicine, University of Cape Town, Cape Town, South Africa
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O'Garra A, Redford PS, McNab FW, Bloom CI, Wilkinson RJ, Berry MPR. The immune response in tuberculosis. Annu Rev Immunol 2013; 31:475-527. [PMID: 23516984 DOI: 10.1146/annurev-immunol-032712-095939] [Citation(s) in RCA: 889] [Impact Index Per Article: 80.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
There are 9 million cases of active tuberculosis reported annually; however, an estimated one-third of the world's population is infected with Mycobacterium tuberculosis and remains asymptomatic. Of these latent individuals, only 5-10% will develop active tuberculosis disease in their lifetime. CD4(+) T cells, as well as the cytokines IL-12, IFN-γ, and TNF, are critical in the control of Mycobacterium tuberculosis infection, but the host factors that determine why some individuals are protected from infection while others go on to develop disease are unclear. Genetic factors of the host and of the pathogen itself may be associated with an increased risk of patients developing active tuberculosis. This review aims to summarize what we know about the immune response in tuberculosis, in human disease, and in a range of experimental models, all of which are essential to advancing our mechanistic knowledge base of the host-pathogen interactions that influence disease outcome.
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Affiliation(s)
- Anne O'Garra
- Division of Immunoregulation, MRC National Institute for Medical Research, London NW7 1AA, UK.
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Abstract
TB causes 1.4 million deaths annually. HIV-1 infection is the strongest risk factor for TB. The characteristic immunological effect of HIV is on CD4 cell count. However, the risk of TB is elevated in HIV-1 infected individuals even in the first few years after HIV acquisition and also after CD4 cell counts are restored with antiretroviral therapy. In this review, we examine features of the immune response to TB and how this is affected by HIV-1 infection and vice versa. We discuss how the immunology of HIV-TB coinfection impacts on the clinical presentation and diagnosis of TB, and how antiretroviral therapy affects the immune response to TB, including the development of TB immune reconstitution inflammatory syndrome. We highlight important areas of uncertainty and future research needs.
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Affiliation(s)
- Naomi F Walker
- Infectious Diseases & Immunity, Imperial College London, W12 0NN, UK
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Diseases & Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Graeme Meintjes
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Diseases & Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
- Department of Medicine, Norfolk Place, Imperial College London, W2 1PG, UK
| | - Robert J Wilkinson
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Diseases & Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
- Department of Medicine, Norfolk Place, Imperial College London, W2 1PG, UK
- MRC National Institute for Medical Research, London, NW7 1AA, UK
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Strategies to Block HIV Transcription: Focus on Small Molecule Tat Inhibitors. BIOLOGY 2012; 1:668-97. [PMID: 24832514 PMCID: PMC4009808 DOI: 10.3390/biology1030668] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/06/2012] [Accepted: 11/07/2012] [Indexed: 01/29/2023]
Abstract
After entry into the target cell, the human immunodeficiency virus type I (HIV) integrates into the host genome and becomes a proviral eukaryotic transcriptional unit. Transcriptional regulation of provirus gene expression is critical for HIV replication. Basal transcription from the integrated HIV promoter is very low in the absence of the HIV transactivator of transcription (Tat) protein and is solely dependent on cellular transcription factors. The 5' terminal region (+1 to +59) of all HIV mRNAs forms an identical stem-bulge-loop structure called the Transactivation Responsive (TAR) element. Once Tat is made, it binds to TAR and drastically activates transcription from the HIV LTR promoter. Mutations in either the Tat protein or TAR sequence usually affect HIV replication, indicating a strong requirement for their conservation. The necessity of the Tat-mediated transactivation cascade for robust HIV replication renders Tat one of the most desirable targets for transcriptional therapy against HIV replication. Screening based on inhibition of the Tat-TAR interaction has identified a number of potential compounds, but none of them are currently used as therapeutics, partly because these agents are not easily delivered for an efficient therapy, emphasizing the need for small molecule compounds. Here we will give an overview of the different strategies used to inhibit HIV transcription and review the current repertoire of small molecular weight compounds that target HIV transcription.
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