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Phetsouphanh C, Phalora P, Hackstein CP, Thornhill J, Munier CML, Meyerowitz J, Murray L, VanVuuren C, Goedhals D, Drexhage L, Russell RA, Sattentau QJ, Mak JYW, Fairlie DP, Fidler S, Kelleher AD, Frater J, Klenerman P. Human MAIT cells respond to and suppress HIV-1. eLife 2021; 10:e50324. [PMID: 34951583 PMCID: PMC8752121 DOI: 10.7554/elife.50324] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 12/23/2021] [Indexed: 11/13/2022] Open
Abstract
Human MAIT cells sit at the interface between innate and adaptive immunity, are polyfunctional and are capable of killing pathogen infected cells via recognition of the Class IB molecule MR1. MAIT cells have recently been shown to possess an antiviral protective role in vivo and we therefore sought to explore this in relation to HIV-1 infection. There was marked activation of MAIT cells in vivo in HIV-1-infected individuals, which decreased following ART. Stimulation of THP1 monocytes with R5 tropic HIVBAL potently activated MAIT cells in vitro. This activation was dependent on IL-12 and IL-18 but was independent of the TCR. Upon activation, MAIT cells were able to upregulate granzyme B, IFNγ and HIV-1 restriction factors CCL3, 4, and 5. Restriction factors produced by MAIT cells inhibited HIV-1 infection of primary PBMCs and immortalized target cells in vitro. These data reveal MAIT cells to be an additional T cell population responding to HIV-1, with a potentially important role in controlling viral replication at mucosal sites.
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Affiliation(s)
- Chansavath Phetsouphanh
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
- The Kirby Institute, University of New South WalesSydneyAustralia
| | - Prabhjeet Phalora
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
| | | | | | | | - Jodi Meyerowitz
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
| | - Lyle Murray
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
| | | | - Dominique Goedhals
- Division of Virology, University of the Free State/National Health Laboratory ServiceFree StateSouth Africa
| | - Linnea Drexhage
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
| | - Rebecca A Russell
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
| | - Quentin J Sattentau
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
| | - Jeffrey YW Mak
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
| | - David P Fairlie
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of QueenslandBrisbaneAustralia
| | | | | | - John Frater
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of OxfordOxfordUnited Kingdom
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Toll-Like Receptor (TLR) Signaling Enables Cyclic GMP-AMP Synthase (cGAS) Sensing of HIV-1 Infection in Macrophages. mBio 2021; 12:e0281721. [PMID: 34844429 PMCID: PMC8630538 DOI: 10.1128/mbio.02817-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
HIV-1 replicates in cells that express a wide array of innate immune sensors and may do so simultaneously with other pathogens. How a coexisting innate immune stimulus influences the outcome of HIV-1 sensing, however, remains poorly understood. Here, we demonstrate that the activation of a second signaling pathway enables a cyclic GMP-AMP synthase (cGAS)-dependent type I interferon (IFN-I) response to HIV-1 infection. We used RNA sequencing to determine that HIV-1 alone induced few or no signs of an IFN-I response in THP-1 cells. In contrast, when supplemented with suboptimal levels of bacterial lipopolysaccharide (LPS), HIV-1 infection triggered the production of elevated levels of IFN-I and significant upregulation of interferon-stimulated genes. LPS-mediated enhancement of IFN-I production upon HIV-1 infection, which was observed in primary macrophages, was lost by blocking reverse transcription and with a hyperstable capsid, pointing to viral DNA being an essential immunostimulatory molecule. LPS also synergistically enhanced IFN-I production by cyclic GMP-AMP (cGAMP), a second messenger of cGAS. These observations suggest that the DNA sensor cGAS is responsible for a type I IFN response to HIV-1 in concert with LPS receptor Toll-like receptor 4 (TLR4). Small amounts of a TLR2 agonist also cooperate with HIV-1 to induce type I IFN production. These results demonstrate how subtle immunomodulatory activity renders HIV-1 capable of eliciting an IFN-I response through positive cross talk between cGAS and TLR sensing pathways.
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SERINC5 Can Enhance Proinflammatory Cytokine Production by Primary Human Myeloid Cells in Response to Challenge with HIV-1 Particles. J Virol 2021; 95:JVI.02372-20. [PMID: 33597208 DOI: 10.1128/jvi.02372-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/02/2021] [Indexed: 11/20/2022] Open
Abstract
HIV-1 has to overcome physical barriers posed by host cell restriction factors (RFs) for efficient replication. Some RFs, including Trim5α and tetherin, trigger antiviral signaling in addition to directly impairing HIV replication. SERINC5 (S5) is an RF that is incorporated into HIV-1 particles to potently impair their infectivity and is efficiently antagonized by the viral pathogenesis factor Nef. Since effects of S5 on HIV-1 infectivity were mostly studied in reporter cell lines, we analyzed the effects of S5 during infection of primary HIV-1 target cells. In activated CD4+ T lymphocytes, virion incorporation of S5 only moderately impaired virion infectivity and was not associated with altered innate immune recognition. In contrast, in monocyte-derived macrophages, S5 virion incorporation potentiated the production of proinflammatory cytokines with very potent but donor-dependent effects on virion infectivity. Nef counteracted effects of S5 on both cytokine production and virion infectivity. Similar S5-induced cytokine production was observed in immature monocyte-derived dendritic cells. Notably, S5-mediated enhancement of cytokine production was not linked to the efficacy of productive infection and could be overcome by using vesicular stomatitis virus glycoprotein (VSV-G) but not infectivity restriction-insensitive HIV-1 Env for cell entry. Moreover, inhibiting entry of S5-negative HIV-1 ΔNef particles increased proinflammatory cytokine production comparably to virion incorporation of S5. Together, these results describe the sensitization of noninfectious HIV-1 particles to proinflammatory cytokine production by myeloid target cells as an additional and Nef-sensitive activity of S5. Moreover, the study reveals important cell-type and donor-dependent differences in the sensitivity of HIV target cells for antiviral effects of S5.IMPORTANCE SERINC5 (S5) is a host cell restriction factor (RF) that impairs the infectivity of HIV-1 particles in target cell lines. To assess the potential physiological relevance of this restriction, we assessed the effects of S5 on HIV-1 infection of relevant primary human target cells. We found that effects of S5 on infection of CD4+ T lymphocytes were negligible. In myeloid target cells, however, virion incorporation of S5 potently suppressed infectivity and promoted innate immune recognition of HIV-1 particles characterized by proinflammatory cytokine production. Both effects were not observed in cells of all donors analyzed, were exerted independently of one another, and were counteracted by the HIV-1 pathogenesis factor Nef. These results identify the sensitization of HIV-1 particles for innate immune recognition by myeloid target cells as a novel activity of S5 and emphasize the need to study RF function in the context of primary target cells and taking donor variabilities into account.
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Herdoiza Padilla E, Crauwels P, Bergner T, Wiederspohn N, Förstner S, Rinas R, Ruf A, Kleemann M, Handrick R, Tuckermann J, Otte K, Walther P, Riedel CU. mir-124-5p Regulates Phagocytosis of Human Macrophages by Targeting the Actin Cytoskeleton via the ARP2/3 Complex. Front Immunol 2019; 10:2210. [PMID: 31636629 PMCID: PMC6787173 DOI: 10.3389/fimmu.2019.02210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/02/2019] [Indexed: 01/20/2023] Open
Abstract
Phagocytosis is a cellular process crucial for recognition and removal of apoptotic cells and foreign particles, subsequently initiating appropriate immune responses. The process of phagocytosis is highly complex and involves major rearrangements of the cytoskeleton. Due to its complexity and importance for tissue homoeostasis and immune responses, it is tightly regulated. Over the last decade, microRNAs (miRNAs) have emerged as important regulators of biological pathways including the immune response by fine-tuning expression of gene regulatory networks. In order to identify miRNAs implicated in the regulation of phagocytosis, a systematic screening of all currently known, human miRNAs was performed using THP-1 macrophage-like cells and serum-opsonized latex beads. Of the total of 2,566 miRNAs analyzed, several led to significant changes in phagocytosis. Among these, we validated miR-124-5p as a novel regulator of phagocytosis. Transfection with miR-124-5p mimics reduced the number of phagocytic cells as well as the phagocytic activity of phorbol-12-myristate-13-acetate (PMA)-activated THP-1 cells and ex vivo differentiated primary human macrophages. In silico analysis suggested that miR-124-5p targets genes involved in regulation of the actin cytoskeleton. Transcriptional analyses revealed that expression of genes encoding for several subunits of the ARP2/3 complex, a crucial regulator of actin polymerization, is reduced upon transfection of cells with miR-124-5p. Further in silico analyses identified potential binding motifs for miR-124-5p in the mRNAs of these genes. Luciferase reporter assays using these binding motifs indicate that at least two of the genes (ARPC3 and ARPC4) are direct targets of miR-124-5p. Moreover, ARPC3 and ARPC4 protein levels were significantly reduced following miR-124-5p transfection. Collectively, the presented results suggest that miR-124-5p regulates phagocytosis in human macrophages by directly targeting expression of components of the ARP2/3 complex.
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Affiliation(s)
| | - Peter Crauwels
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Tim Bergner
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Nicole Wiederspohn
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Sabrina Förstner
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Rebecca Rinas
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Anna Ruf
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Michael Kleemann
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Biberach, Germany
| | - René Handrick
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Biberach, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Kerstin Otte
- Institute of Applied Biotechnology, University of Applied Sciences Biberach, Biberach, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Christian U Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
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Kinetics of Early Innate Immune Activation during HIV-1 Infection of Humanized Mice. J Virol 2019; 93:JVI.02123-18. [PMID: 30867315 PMCID: PMC6532090 DOI: 10.1128/jvi.02123-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 03/01/2019] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection is associated with aberrant immune activation; however, most model systems for HIV-1 have been used during established infection. Here, we utilize ultrasensitive HIV-1 quantification to delineate early events during the eclipse, burst, and chronic phases of HIV-1 infection in humanized mice. We show that very early in infection, HIV-1 suppresses peripheral type I interferon (IFN) and interferon-stimulated gene (ISG) responses, including the HIV-1 restriction factor IFI44. At the peak of innate immune activation, prior to CD4 T cell loss, HIV-1 infection differentially affects peripheral and lymphoid Toll-like receptor (TLR) expression profiles in T cells and macrophages. This results in a trend toward an altered activation of nuclear factor κB (NF-κB), TANK-binding kinase 1 (TBK1), and interferon regulatory factor 3 (IRF3). The subsequent type I and III IFN responses result in preferential induction of peripheral ISG responses. Following this initial innate immune activation, peripheral expression of the HIV-1 restriction factor SAM domain- and HD domain-containing protein 1 (SAMHD1) returns to levels below those observed in uninfected mice, suggesting that HIV-1 interferes with their basal expression. However, peripheral cells still retain their responsiveness to exogenous type I IFN, whereas splenic cells show a reduction in select ISGs in response to IFN. This demonstrates the highly dynamic nature of very early HIV-1 infection and suggests that blocks to the induction of HIV-1 restriction factors contribute to the establishment of viral persistence.IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) infection is restricted to humans and some nonhuman primates (e.g., chimpanzee and gorilla). Alternative model systems based on simian immunodeficiency virus (SIV) infection of macaques are available but do not recapitulate all aspects of HIV-1 infection and disease. Humanized mice, which contain a human immune system, can be used to study HIV-1, but only limited information on early events and immune responses is available to date. Here, we describe very early immune responses to HIV-1 and demonstrate a suppression of cell-intrinsic innate immunity. Furthermore, we show that HIV-1 infection interacts differently with innate immune responses in blood and lymphoid organs.
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Rodrigues V, Ruffin N, San-Roman M, Benaroch P. Myeloid Cell Interaction with HIV: A Complex Relationship. Front Immunol 2017; 8:1698. [PMID: 29250073 PMCID: PMC5714857 DOI: 10.3389/fimmu.2017.01698] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/17/2017] [Indexed: 12/19/2022] Open
Abstract
Cells of the myeloid lineage, particularly macrophages, serve as primary hosts for HIV in vivo, along with CD4 T lymphocytes. Macrophages are present in virtually every tissue of the organism, including locations with negligible T cell colonization, such as the brain, where HIV-mediated inflammation may lead to pathological sequelae. Moreover, infected macrophages are present in multiple other tissues. Recent evidence obtained in humanized mice and macaque models highlighted the capacity of macrophages to sustain HIV replication in vivo in the absence of T cells. Combined with the known resistance of the macrophage to the cytopathic effects of HIV infection, such data bring a renewed interest in this cell type both as a vehicle for viral spread as well as a viral reservoir. While our understanding of key processes of HIV infection of macrophages is far from complete, recent years have nevertheless brought important insight into the uniqueness of the macrophage infection. Productive infection of macrophages by HIV can occur by different routes including from phagocytosis of infected T cells. In macrophages, HIV assembles and buds into a peculiar plasma membrane-connected compartment that preexists to the infection. While the function of such compartment remains elusive, it supposedly allows for the persistence of infectious viral particles over extended periods of time and may play a role on viral transmission. As cells of the innate immune system, macrophages have the capacity to detect and respond to viral components. Recent data suggest that such sensing may occur at multiple steps of the viral cycle and impact subsequent viral spread. We aim to provide an overview of the HIV-macrophage interaction along the multiple stages of the viral life cycle, extending when pertinent such observations to additional myeloid cell types such as dendritic cells or blood monocytes.
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Affiliation(s)
- Vasco Rodrigues
- Institut Curie, PSL Research University, INSERM U932, Paris, France
| | - Nicolas Ruffin
- Institut Curie, PSL Research University, INSERM U932, Paris, France
| | - Mabel San-Roman
- Institut Curie, PSL Research University, UMR3216, Paris, France
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Sensing of HIV-1 Entry Triggers a Type I Interferon Response in Human Primary Macrophages. J Virol 2017; 91:JVI.00147-17. [PMID: 28490595 DOI: 10.1128/jvi.00147-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/05/2017] [Indexed: 12/23/2022] Open
Abstract
Along with CD4+ T lymphocytes, macrophages are a major cellular source of HIV-1 replication and a potential viral reservoir. Following entry and reverse transcription in macrophages, cloaking of the viral cDNA by the HIV-1 capsid limits its cytosolic detection, enabling efficient replication. However, whether incoming HIV-1 particles are sensed by macrophages prior to reverse transcription remains unclear. Here, we show that HIV-1 triggers a broad expression of interferon (IFN)-stimulated genes (ISG) in monocyte-derived macrophages within a few hours after infection. This response does not require viral reverse transcription or the presence of HIV-1 RNA within particles, but viral fusion is essential. This response is elicited by viruses carrying different envelope proteins and thus different receptors to proceed for viral entry. Expression of ISG in response to viral entry requires TBK1 activity and type I IFNs signaling. Remarkably, the ISG response is transient but affects subsequent viral spread. Together, our results shed light on an early step of HIV-1 sensing by macrophages at the level of entry, which confers an early protection through type I IFN signaling and has potential implications in controlling the infection.IMPORTANCE HIV infection is restricted to T lymphocytes and macrophages. HIV-1-infected macrophages are found in many tissues of infected patients, even under antiretroviral therapy, and are considered a viral reservoir. How HIV-1 is detected and what type of responses are elicited upon sensing remain in great part elusive. The kinetics and localization of the production of cytokines such as interferons in response to HIV is of critical importance to understanding how the infection and the immune response are established. Our study provides evidence that macrophages can detect HIV-1 as soon as it enters the cell. Interestingly, this sensing is independent of the presence of viral nucleic acids within the particles but requires their fusion with the macrophages. This triggers a low interferon response, which activates an antiviral program protecting cells against further viral challenge and thus potentially limiting the spread of the infection.
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Silvin A, Manel N. Innate immune sensing of HIV infection. Curr Opin Immunol 2015; 32:54-60. [PMID: 25617674 DOI: 10.1016/j.coi.2014.12.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/01/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023]
Abstract
The ability to sense infections is primordial to preserve organisms. Immune cells express pathogen sensors that induct innate and adaptive immune responses. Understanding how HIV-1 infection defeats these responses in most individuals remains an outstanding challenge. Since HIV-1 targets immune cells, innate immune sensors are remarkably positioned at the nexus of viral replication and immunity. Here, we discuss recent studies that have revealed innate sensing mechanisms of HIV-1 infection in plasmacytoid dendritic cells, monocyte-derived dendritic cells, monocyte-derived macrophages, and CD4+ T cells. These studies help understand how HIV-1 avoids antiviral innate immune sensors and how it induces pathogenic processes. Ultimately, this may contribute to therapy and vaccines.
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Affiliation(s)
- Aymeric Silvin
- Institut Curie, 12 rue Lhomond, 75005 Paris, France; INSERM U932, 12 rue Lhomond, 75005 Paris, France
| | - Nicolas Manel
- Institut Curie, 12 rue Lhomond, 75005 Paris, France; INSERM U932, 12 rue Lhomond, 75005 Paris, France.
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Sabbatucci M, Covino DA, Purificato C, Mallano A, Federico M, Lu J, Rinaldi AO, Pellegrini M, Bona R, Michelini Z, Cara A, Vella S, Gessani S, Andreotti M, Fantuzzi L. Endogenous CCL2 neutralization restricts HIV-1 replication in primary human macrophages by inhibiting viral DNA accumulation. Retrovirology 2015; 12:4. [PMID: 25608886 PMCID: PMC4314729 DOI: 10.1186/s12977-014-0132-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 12/19/2014] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Macrophages are key targets of HIV-1 infection. We have previously described that the expression of CC chemokine ligand 2 (CCL2) increases during monocyte differentiation to macrophages and it is further up-modulated by HIV-1 exposure. Moreover, CCL2 acts as an autocrine factor that promotes viral replication in infected macrophages. In this study, we dissected the molecular mechanisms by which CCL2 neutralization inhibits HIV-1 replication in monocyte-derived macrophages (MDM), and the potential involvement of the innate restriction factors protein sterile alpha motif (SAM) histidine/aspartic acid (HD) domain containing 1 (SAMHD1) and apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3 (APOBEC3) family members. RESULTS CCL2 neutralization potently reduced the number of p24 Gag+ cells during the course of either productive or single cycle infection with HIV-1. In contrast, CCL2 blocking did not modify entry of HIV-1 based Virus Like Particles, thus demonstrating that the restriction involves post-entry steps of the viral life cycle. Notably, the accumulation of viral DNA, both total, integrated and 2-LTR circles, was strongly impaired by neutralization of CCL2. Looking for correlates of HIV-1 DNA accumulation inhibition, we found that the antiviral effect of CCL2 neutralization was independent of the modulation of SAMHD1 expression or function. Conversely, a strong and selective induction of APOBEC3A expression, to levels comparable to those of freshly isolated monocytes, was associated with the inhibition of HIV-1 replication mediated by CCL2 blocking. Interestingly, the CCL2 neutralization mediated increase of APOBEC3A expression was type I IFN independent. Moreover, the transcriptome analysis of the effect of CCL2 blocking on global gene expression revealed that the neutralization of this chemokine resulted in the upmodulation of additional genes involved in the defence response to viruses. CONCLUSIONS Neutralization of endogenous CCL2 determines a profound restriction of HIV-1 replication in primary MDM affecting post-entry steps of the viral life cycle with a mechanism independent of SAMHD1. In addition, CCL2 blocking is associated with induction of APOBEC3A expression, thus unravelling a novel mechanism which might contribute to regulate the expression of innate intracellular viral antagonists in vivo. Thus, our study may potentially lead to the development of new therapeutic strategies for enhancing innate cellular defences against HIV-1 and protecting macrophages from infection.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Laura Fantuzzi
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
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SAMHD1 specifically affects the antiviral potency of thymidine analog HIV reverse transcriptase inhibitors. Antimicrob Agents Chemother 2014; 58:4804-13. [PMID: 24913159 DOI: 10.1128/aac.03145-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sterile alpha motif and histidine-aspartic domain-containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate (dNTP) triphosphohydrolase recently recognized as an antiviral factor that acts by depleting dNTP availability for viral reverse transcriptase (RT). SAMHD1 restriction is counteracted by the human immunodeficiency virus type 2 (HIV-2) accessory protein Vpx, which targets SAMHD1 for proteosomal degradation, resulting in an increased availability of dNTPs and consequently enhanced viral replication. Nucleoside reverse transcriptase inhibitors (NRTI), one of the most common agents used in antiretroviral therapy, compete with intracellular dNTPs as the substrate for viral RT. Consequently, SAMHD1 activity may be influencing NRTI efficacy in inhibiting viral replication. Here, a panel of different RT inhibitors was analyzed for their different antiviral efficacy depending on SAMHD1. Antiviral potency was measured for all the inhibitors in transformed cell lines and primary monocyte-derived macrophages and CD4(+) T cells infected with HIV-1 with or without Vpx. No changes in sensitivity to non-NRTI or the integrase inhibitor raltegravir were observed, but for NRTI, sensitivity significantly changed only in the case of the thymidine analogs (AZT and d4T). The addition of exogenous thymidine mimicked the change in viral sensitivity observed after Vpx-mediated SAMHD1 degradation, pointing toward a differential effect of SAMHD1 activity on thymidine. Accordingly, sensitivity to AZT was also reduced in CD4(+) T cells infected with HIV-2 compared to infection with the HIV-2ΔVpx strain. In conclusion, reduction of SAMHD1 levels significantly decreases HIV sensitivity to thymidine but not other nucleotide RT analog inhibitors in both macrophages and lymphocytes.
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Taya K, Nakayama EE, Shioda T. Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages. PLoS One 2014; 9:e90969. [PMID: 24599229 PMCID: PMC3944824 DOI: 10.1371/journal.pone.0090969] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 02/05/2014] [Indexed: 11/19/2022] Open
Abstract
Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.
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Affiliation(s)
- Kahoru Taya
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Emi E. Nakayama
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- * E-mail:
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Abstract
More than 34 million people in the world are living with HIV/AIDS. Each year there are nearly three million new HIV infections and nearly two million AIDS-related deaths. In the face of these staggering statistics, there is a vocal group of individuals who deny reality and claim that HIV is harmless or may not even exist at all. Mirroring the AIDS pandemic itself, AIDS denialism is a threat to public health. AIDS denialism propagates the views of a few rogue scientists through press releases, social media, and a significant presence on the Internet. AIDS Denialists aim to undermine HIV testing, prevention, and treatment. Most tragic has been the adoption of AIDS Denialist views by public officials, perhaps none more infamous than former President of South Africa Thabo Mbeki. This article examines the psychology of AIDS denialism, focusing on its emergence from the earliest days of AIDS and its grounding in conspiracy thinking and medical mistrust. The article also describes the tactics and rhetoric of AIDS denialism and those who are most vulnerable to AIDS Denialist claims. Recommendations are offered for countering AIDS denialism by exposing its fake experts and baseless claims.
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Affiliation(s)
- Seth C. Kalichman
- Department of Psychology, University of Connecticut, Storrs, CT, USA
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13
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Neu C, Sedlag A, Bayer C, Förster S, Crauwels P, Niess JH, van Zandbergen G, Frascaroli G, Riedel CU. CD14-dependent monocyte isolation enhances phagocytosis of listeria monocytogenes by proinflammatory, GM-CSF-derived macrophages. PLoS One 2013; 8:e66898. [PMID: 23776701 PMCID: PMC3679097 DOI: 10.1371/journal.pone.0066898] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 01/28/2023] Open
Abstract
Macrophages are an important line of defence against invading pathogens. Human macrophages derived by different methods were tested for their suitability as models to investigate Listeria monocytogenes (Lm) infection and compared to macrophage-like THP-1 cells. Human primary monocytes were isolated by either positive or negative immunomagnetic selection and differentiated in the presence of granulocyte macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF) into pro- or anti-inflammatory macrophages, respectively. Regardless of the isolation method, GM-CSF-derived macrophages (GM-Mφ) stained positive for CD206 and M-CSF-derived macrophages (M-Mφ) for CD163. THP-1 cells did not express CD206 or CD163 following incubation with PMA, M- or GM-CSF alone or in combination. Upon infection with Lm, all primary macrophages showed good survival at high multiplicities of infection whereas viability of THP-1 was severely reduced even at lower bacterial numbers. M-Mφ generally showed high phagocytosis of Lm. Strikingly, phagocytosis of Lm by GM-Mφ was markedly influenced by the method used for isolation of monocytes. GM-Mφ derived from negatively isolated monocytes showed low phagocytosis of Lm whereas GM-Mφ generated from positively selected monocytes displayed high phagocytosis of Lm. Moreover, incubation with CD14 antibody was sufficient to enhance phagocytosis of Lm by GM-Mφ generated from negatively isolated monocytes. By contrast, non-specific phagocytosis of latex beads by GM-Mφ was not influenced by treatment with CD14 antibody. Furthermore, phagocytosis of Lactococcus lactis, Escherichia coli, human cytomegalovirus and the protozoan parasite Leishmania major by GM-Mφ was not enhanced upon treatment with CD14 antibody indicating that this effect is specific for Lm. Based on these observations, we propose macrophages derived by ex vivo differentiation of negatively selected human primary monocytes as the most suitable model to study Lm infection of macrophages.
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Affiliation(s)
- Caroline Neu
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Anne Sedlag
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Carina Bayer
- Institute of Virology, University Medical Center Ulm, Ulm, Germany
| | - Sabine Förster
- Division of Immunology, Paul-Ehrlich-Institute, Federal Institute for Vaccines and Biomedicines, Langen, Germany
| | - Peter Crauwels
- Division of Immunology, Paul-Ehrlich-Institute, Federal Institute for Vaccines and Biomedicines, Langen, Germany
| | - Jan-Hendrik Niess
- Department of Visceral Medicine and Surgery, Inselspital, Bern, Switzerland
| | - Ger van Zandbergen
- Division of Immunology, Paul-Ehrlich-Institute, Federal Institute for Vaccines and Biomedicines, Langen, Germany
| | - Giada Frascaroli
- Institute of Virology, University Medical Center Ulm, Ulm, Germany
| | - Christian U. Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
- * E-mail:
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