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Suvieri C, Mondanelli G, Orabona C, Pallotta MT, Panfili E, Rossini S, Volpi C, Belladonna ML. Sensing of an HIV-1-Derived Single-Stranded RNA-Oligonucleotide Induces Arginase 1-Mediated Tolerance. Cells 2024; 13:1088. [PMID: 38994942 PMCID: PMC11240372 DOI: 10.3390/cells13131088] [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: 05/09/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/13/2024] Open
Abstract
Small synthetic oligodeoxynucleotides (ODNs) can mimic microbial nucleic acids by interacting with receptor systems and promoting immunostimulatory activities. Nevertheless, some ODNs can act differently on the plasmacytoid dendritic cell (pDC) subset, shaping their immunoregulatory properties and rendering them suitable immunotherapeutic tools in several clinical settings for treating overwhelming immune responses. We designed HIV-1-derived, DNA- and RNA-based oligonucleotides (gag, pol, and U5 regions) and assessed their activity in conferring a tolerogenic phenotype to pDCs in skin test experiments. RNA-but not DNA-oligonucleotides are capable of inducing tolerogenic features in pDCs. Interestingly, sensing the HIV-1-derived single-stranded RNA-gag oligonucleotide (RNA-gag) requires both TLR3 and TLR7 and the engagement of the TRIF adaptor molecule. Moreover, the induction of a suppressive phenotype in pDCs by RNA-gag is contingent upon the induction and activation of the immunosuppressive enzyme Arginase 1. Thus, our data suggest that sensing of the synthetic RNA-gag oligonucleotide in pDCs can induce a suppressive phenotype in pDCs, a property rendering RNA-gag a potential tool for therapeutic strategies in allergies and autoimmune diseases.
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Pawar P, Gokavi J, Wakhare S, Bagul R, Ghule U, Khan I, Ganu V, Mukherjee A, Shete A, Rao A, Saxena V. MiR-155 Negatively Regulates Anti-Viral Innate Responses among HIV-Infected Progressors. Viruses 2023; 15:2206. [PMID: 38005883 PMCID: PMC10675553 DOI: 10.3390/v15112206] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 11/26/2023] Open
Abstract
HIV infection impairs host immunity, leading to progressive disease. An anti-retroviral treatment efficiently controls viremia but cannot completely restore the immune dysfunction in HIV-infected individuals. Both host and viral factors determine the rate of disease progression. Among the host factors, innate immunity plays a critical role; however, the mechanism(s) associated with dysfunctional innate responses are poorly understood among HIV disease progressors, which was investigated here. The gene expression profiles of TLRs and innate cytokines in HIV-infected (LTNPs and progressors) and HIV-uninfected individuals were examined. Since the progressors showed a dysregulated TLR-mediated innate response, we investigated the role of TLR agonists in restoring the innate functions of the progressors. The stimulation of PBMCs with TLR3 agonist-poly:(I:C), TLR7 agonist-GS-9620 and TLR9 agonist-ODN 2216 resulted in an increased expression of IFN-α, IFN-β and IL-6. Interestingly, the expression of IFITM3, BST-2, IFITM-3, IFI-16 was also increased upon stimulation with TLR3 and TLR7 agonists, respectively. To further understand the molecular mechanism involved, the role of miR-155 was explored. Increased miR-155 expression was noted among the progressors. MiR-155 inhibition upregulated the expression of TLR3, NF-κB, IRF-3, TNF-α and the APOBEC-3G, IFITM-3, IFI-16 and BST-2 genes in the PBMCs of the progressors. To conclude, miR-155 negatively regulates TLR-mediated cytokines as wel l as the expression of host restriction factors, which play an important role in mounting anti-HIV responses; hence, targeting miR-155 might be helpful in devising strategic approaches towards alleviating HIV disease progression.
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Affiliation(s)
- Puja Pawar
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
| | - Jyotsna Gokavi
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
| | - Shilpa Wakhare
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
| | - Rajani Bagul
- Division of Clinical Sciences, ICMR-National AIDS Research Institute, Pune 411026, India; (R.B.); (U.G.); (A.R.)
| | - Ujjwala Ghule
- Division of Clinical Sciences, ICMR-National AIDS Research Institute, Pune 411026, India; (R.B.); (U.G.); (A.R.)
| | - Ishrat Khan
- Division of Virology, ICMR-National AIDS Research Institute, Pune 411026, India; (I.K.); (A.M.)
| | - Varada Ganu
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
| | - Anupam Mukherjee
- Division of Virology, ICMR-National AIDS Research Institute, Pune 411026, India; (I.K.); (A.M.)
| | - Ashwini Shete
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
| | - Amrita Rao
- Division of Clinical Sciences, ICMR-National AIDS Research Institute, Pune 411026, India; (R.B.); (U.G.); (A.R.)
| | - Vandana Saxena
- Division of Immunology and Serology, ICMR-National AIDS Research Institute, Pune 411026, India; (P.P.); (J.G.); (S.W.); (V.G.); (A.S.)
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Nagendla NK, Subrahanyam SB, Konda S, Mudiam MKR. Development of liquid chromatography-triple quadrupole mass spectrometric method for the quantitative determination of a novel adjuvant, Imidazoquinoline gallamide in aluminum hydroxide gel-Imidazoquinoline gallamide and COVAXIN. J Sep Sci 2023; 46:e2300380. [PMID: 37609812 DOI: 10.1002/jssc.202300380] [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: 06/02/2023] [Revised: 08/05/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023]
Abstract
Imidazoquinoline gallamide is a toll-like receptor 7/8 agonist, belongs to the imidazoquinoline class, has the potential to activate antigen-presenting cells, and enhances immune response, primarily Th1 response. The COVAXIN is a whole virion inactivated Coronavirus disease 2019 vaccine formulated with this novel adjuvant called, aluminum hydroxide gel Imidazoquinoline gallamide, wherein, Imidazoquinoline gallamide is chemisorbed onto aluminum hydroxide gel. Herein, an analytical method based on liquid chromatography-tandem mass spectrometry was developed to identify and quantify Imidazoquinoline gallamide in aluminum hydroxide gel Imidazoquinoline gallamide and COVAXIN. The multiple reaction monitoring transitions were optimized for Imidazoquinoline gallamide quantification are [M+H]+ ions with 512.24→343.19 m/z (quantifier ion) and 512.24→360.22 m/z (qualifier ion). The developed method was validated as per the international conference on harmonization quality2 revison1 guidelines. The method was linear in the range of 0.025-10 µg/mL with a coefficient of determination of 0.9985 and the limit of quantification is 0.025 µg/mL. The accuracy was in the range of 82-121 % and intra- and inter-day precision was less than 7.1% and 5.39%, respectively. The expanded uncertainty results are 9.2% for Imidazoquinoline gallamide in the sample. The validated method was successfully applied to evaluate Imidazoquinoline gallamide concentration in every batch of COVAXIN.
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Affiliation(s)
- Narendra Kumar Nagendla
- Analytical and Structural Chemistry Department, CSIR-Indian Institute of Chemical Technology, Hyderabad, India
- Department of Analytical and Structural Chemistry, Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Seetha Bala Subrahanyam
- Analytical and Structural Chemistry Department, CSIR-Indian Institute of Chemical Technology, Hyderabad, India
- Department of Analytical and Structural Chemistry, Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Satyanand Konda
- Analytical and Structural Chemistry Department, CSIR-Indian Institute of Chemical Technology, Hyderabad, India
- Department of Analytical and Structural Chemistry, Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Mohana Krishna Reddy Mudiam
- Analytical and Structural Chemistry Department, CSIR-Indian Institute of Chemical Technology, Hyderabad, India
- Department of Analytical and Structural Chemistry, Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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Vlaming KE, van Wijnbergen K, Kaptein TM, Nijhuis M, Kootstra NJ, de Bree GJ, Geijtenbeek TB. Crosstalk between TLR8 and RIG-I-like receptors enhances antiviral immune responses. Front Med (Lausanne) 2023; 10:1146457. [PMID: 37261119 PMCID: PMC10227620 DOI: 10.3389/fmed.2023.1146457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/12/2023] [Indexed: 06/02/2023] Open
Abstract
Background Toll-like receptor (TLR) agonists have been investigated due to their potential dual effects as latency reverting agents and immune modulatory compounds in people living with HIV (PLWH). Here, we investigated whether co-stimulation of TLR7/8 agonists with RIG-I-like receptor (RLR) agonists enhances antiviral immunity. Methods Peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (DCs) were incubated with TLR and RLR-agonists for 24 h and innate and adaptive immune responses were determined (maturation markers, cytokines in supernatant, ISG expression). Results Both TLR7 and TLR8 agonists induced pro-inflammatory cytokines in DCs as well as PBMCs. TLR8 agonists were more potent in inducing cytokine responses and had a stronger effect on DC-induced immunity. Notably, while all compounds induced IL-12p70, co-stimulation with TLR8 agonists and RLR agonist polyI: C induced significantly higher levels of IL-12p70 in PBMCs. Moreover, crosstalk between TLR8 and RLR agonists induced a strong type I Interferon (IFN) response as different antiviral IFN-stimulated genes were upregulated by the combination compared to the agonists alone. Conclusion Our data strongly suggest that TLR crosstalk with RLRs leads to strong antiviral immunity as shown by induction of IL-12 and type I IFN responses in contrast to TLRs alone. Thus, co-stimulation of TLRs and RLRs might be a powerful strategy to induce reactivation of latent reservoir as well as antiviral immunity that eliminates the reactivated cells.
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Affiliation(s)
- Killian E. Vlaming
- Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Kelly van Wijnbergen
- Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Tanja M. Kaptein
- Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Monique Nijhuis
- Translational Virology, Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Neeltje J. Kootstra
- Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Godelieve J. de Bree
- Department of Internal Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Teunis B. Geijtenbeek
- Department of Experimental Immunology, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
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Jimenez-Leon MR, Gasca-Capote C, Tarancon-Diez L, Dominguez-Molina B, Lopez-Verdugo M, Ritraj R, Gallego I, Alvarez-Rios AI, Vitalle J, Bachiller S, Camacho-Sojo MI, Perez-Gomez A, Espinosa N, Roca-Oporto C, Rafii-El-Idrissi Benhnia M, Gutierrez-Valencia A, Lopez-Cortes LF, Ruiz-Mateos E. Toll-like receptor agonists enhance HIV-specific T cell response mediated by plasmacytoid dendritic cells in diverse HIV-1 disease progression phenotypes. EBioMedicine 2023; 91:104549. [PMID: 37018973 PMCID: PMC10106920 DOI: 10.1016/j.ebiom.2023.104549] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND Plasmacytoid dendritic cells (pDCs) sense viral and bacterial products through Toll-like receptor (TLR)-7 and -9 and translate this sensing into Interferon-α (IFN-α) production and T-cell activation. The understanding of the mechanisms involved in pDCs stimulation may contribute to HIV-cure immunotherapeutic strategies. The objective of the present study was to characterize the immunomodulatory effects of TLR agonist stimulations in several HIV-1 disease progression phenotypes and in non HIV-1 infected donors. METHODS pDCs, CD4 and CD8 T-cells were isolated from 450 ml of whole blood from non HIV-1 infected donors, immune responders (IR), immune non responders (INR), viremic (VIR) and elite controller (EC) participants. pDCs were stimulated overnight with AT-2, CpG-A, CpG-C and GS-9620 or no stimuli. After that, pDCs were co-cultured with autologous CD4 or CD8 T-cells and with/without HIV-1 (Gag peptide pool) or SEB (Staphylococcal Enterotoxin B). Cytokine array, gene expression and deep immunophenotyping were assayed. FINDINGS pDCs showed an increase of activation markers levels, interferon related genes, HIV-1 restriction factors and cytokines levels after TLR stimulation in the different HIV-disease progression phenotypes. This pDC activation was prominent with CpG-C and GS-9620 and induced an increase of HIV-specific T-cell response even in VIR and INR comparable with EC. This HIV-1 specific T-cell response was associated with the upregulation of HIV-1 restriction factors and IFN-α production by pDC. INTERPRETATION These results shed light on the mechanisms associated with TLR-specific pDCs stimulation associated with the induction of a T-cell mediated antiviral response which is essential for HIV-1 eradication strategies. FUNDING This work was supported by Gilead fellowship program, the Instituto de Salud Carlos III (Fondo Europeo de Desarrollo Regional, FEDER, "a way to make Europe") and the Red Temática de Investigación Cooperativa en SIDA and by the Spanish National Research Council (CSIC).
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TIRAP, TRAM, and Toll-Like Receptors: The Untold Story. Mediators Inflamm 2023; 2023:2899271. [PMID: 36926280 PMCID: PMC10014160 DOI: 10.1155/2023/2899271] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 03/09/2023] Open
Abstract
Toll-like receptors (TLRs) are the most studied receptors among the pattern recognition receptors (PRRs). They act as microbial sensors, playing major roles in the regulation of the innate immune system. TLRs mediate their cellular functions through the activation of MyD88-dependent or MyD88-independent signaling pathways. Myd88, or myeloid differentiation primary response 88, is a cytosolic adaptor protein essential for the induction of proinflammatory cytokines by all TLRs except TLR3. While the crucial role of Myd88 is well described, the contribution of other adaptors in mediating TLR signaling and function has been underestimated. In this review, we highlight important results demonstrating that TIRAP and TRAM adaptors are also required for full signaling activity and responses induced by most TLRs.
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Morodomi Y, Kanaji S, Sullivan BM, Zarpellon A, Orje JN, Won E, Shapiro R, Yang XL, Ruf W, Schimmel P, Ruggeri ZM, Kanaji T. Inflammatory platelet production stimulated by tyrosyl-tRNA synthetase mimicking viral infection. Proc Natl Acad Sci U S A 2022; 119:e2212659119. [PMID: 36409883 PMCID: PMC9860251 DOI: 10.1073/pnas.2212659119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/20/2022] [Indexed: 11/22/2022] Open
Abstract
Platelets play a role not only in hemostasis and thrombosis, but also in inflammation and innate immunity. We previously reported that an activated form of tyrosyl-tRNA synthetase (YRSACT) has an extratranslational activity that enhances megakaryopoiesis and platelet production in mice. Here, we report that YRSACT mimics inflammatory stress inducing a unique megakaryocyte (MK) population with stem cell (Sca1) and myeloid (F4/80) markers through a mechanism dependent on Toll-like receptor (TLR) activation and type I interferon (IFN-I) signaling. This mimicry of inflammatory stress by YRSACT was studied in mice infected by lymphocytic choriomeningitis virus (LCMV). Using Sca1/EGFP transgenic mice, we demonstrated that IFN-I induced by YRSACT or LCMV infection suppressed normal hematopoiesis while activating an alternative pathway of thrombopoiesis. Platelets of inflammatory origin (Sca1/EGFP+) were a relevant proportion of those circulating during recovery from thrombocytopenia. Analysis of these "inflammatory" MKs and platelets suggested their origin in myeloid/MK-biased hematopoietic stem cells (HSCs) that bypassed the classical MK-erythroid progenitor (MEP) pathway to replenish platelets and promote recovery from thrombocytopenia. Notably, inflammatory platelets displayed enhanced agonist-induced activation and procoagulant activities. Moreover, myeloid/MK-biased progenitors and MKs were mobilized from the bone marrow, as evidenced by their presence in the lung microvasculature within fibrin-containing microthrombi. Our results define the function of YRSACT in platelet generation and contribute to elucidate platelet alterations in number and function during viral infection.
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Affiliation(s)
- Yosuke Morodomi
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
| | - Sachiko Kanaji
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
| | - Brian M. Sullivan
- Viral-Immunobiology Laboratory, Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA92037
| | | | - Jennifer N. Orje
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- MERU-VasImmune, Inc., San Diego, CA92121
| | - Eric Won
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- Department of Hematology and Oncology, University of California, San Diego, CA92093
- Rady Children’s Hospital, San Diego, CA92123
| | - Ryan Shapiro
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
| | - Xiang-Lei Yang
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
| | - Wolfram Ruf
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University, 55128Germany
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA92037
| | - Paul Schimmel
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
| | - Zaverio M. Ruggeri
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- MERU-VasImmune, Inc., San Diego, CA92121
| | - Taisuke Kanaji
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA92037
- The Scripps Laboratories for tRNA Synthetase Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA92037
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Martínez-Espinoza I, Guerrero-Plata A. The Relevance of TLR8 in Viral Infections. Pathogens 2022; 11:pathogens11020134. [PMID: 35215078 PMCID: PMC8877508 DOI: 10.3390/pathogens11020134] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
Abstract
Toll-like receptors (TLRs) are the largest pattern recognition receptors responsible for activating the innate and adaptive immune response against viruses through the release of inflammatory cytokines and antiviral mediators. Viruses are recognized by several TLRs, including TLR8, which is known to bind ssRNA structures. However, the similarities between TLR8 and TLR7 have obscured the distinctive characteristics of TLR8 activation and its importance in the immune system. Here we discuss the activation and regulation of TLR8 by viruses and its importance in therapeutical options such as vaccine adjuvants and antiviral stimulators.
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Wei M, Huang X, Bian C, Sun J, Ji H. ATF6-DGAT pathway is involved in TLR7-induced innate immune response in Ctenopharyngodon idellus kidney cells. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 124:104197. [PMID: 34228994 DOI: 10.1016/j.dci.2021.104197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/01/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
DGAT1 and DGAT2 are two acyl-CoA:diacylglycerol O-acyltransferase (DGAT) enzymes that catalyze the final step in triglyceride (TG) synthesis. TGs are the primary constituents of lipid droplets (LDs). Although it has been demonstrated that LDs modulate immune and inflammatory responses in CIK cells, little is known about whether DGAT1 and DGAT2 involve in this process. Firstly, grass carp DGAT2 was isolated and characterized, encoding 361 amino acids, and all DGAT2 proteins in genomic structures are conserved in vertebrates. Then, using TLR7 agonist, we induced LDs accumulation in CIK cells. Only DGAT1b and DGAT2 were upregulated in forming TLR7 agonist induced-LDs. Next, we utilized small-molecule inhibitors of DGAT1 and DGAT2. The results indicated that DGAT1 inactivation attenuated TG content and the relative expressions of IFNα3, NF-κB, IL-1β, and TNFα genes, whereas DGAT2 inhibition decreased TG content and the relative expressions of MyD88, IRF7, IFNα3, NF-κB, IL-1β, and TNFα genes, implying that DGAT1-generated LDs and DGAT2-generated LDs contribute to TLR7-induced immune response via different signaling pathways. Finally, inhibiting ATF6 effectively decreased DGAT-generated LDs accumulation and the expression of TLR7 signaling-related genes induced by TLR7 agonist, implying that ATF6 UPR pathway may mediate the role of DGAT-generated LDs in TLR7 signaling. Overall, we demonstrate that DGAT1 and DGAT2-catalyzed TAG synthesis may generate different LDs to provide distinct signaling platforms for innate TLR7 signaling.
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Affiliation(s)
- Mingkui Wei
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Xiaocheng Huang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Chenchen Bian
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Jian Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
| | - Hong Ji
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
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10
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Meng FZ, Liu JB, Wang X, Wang P, Hu WH, Hou W, Ho WZ. TLR7 Activation of Macrophages by Imiquimod Inhibits HIV Infection through Modulation of Viral Entry Cellular Factors. BIOLOGY 2021; 10:661. [PMID: 34356516 PMCID: PMC8301371 DOI: 10.3390/biology10070661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 01/15/2023]
Abstract
The Toll-like receptor (TLR) 7 is a viral sensor for detecting single-stranded ribonucleic acid (ssRNA), the activation of which can induce intracellular innate immunity against viral infections. Imiquimod, a synthetic ligand for TLR7, has been successfully used for the topical treatment of genital/perianal warts in immunocompetent individuals. We studied the effect of imiquimod on the human immunodeficiency virus (HIV) infection of primary human macrophages and demonstrated that the treatment of cells with imiquimod effectively inhibited infection with multiple strains (Bal, YU2, and Jago) of HIV. This anti-HIV activity of imiquimod was the most potent when macrophages were treated prior to infection. Infection of macrophages with pseudotyped HIV NL4-3-ΔEnv-eGFP-Bal showed that imiquimod could block the viral entry. Further mechanistic studies revealed that while imiquimod had little effect on the interferons (IFNs) expression, its treatment of macrophages resulted in the increased production of the CC chemokines (human macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1β, and upon activation regulated normal T cells expressed and secreted (RANTES)), the natural ligands of HIV entry co-receptor CCR5, and decreased the expression of CD4 and CCR5. The addition of the antibodies against the CC chemokines to macrophage cultures could block imiquimod-mediated HIV inhibition. These findings provide experimental evidence to support the notion that TLR7 participates in the intracellular immunity against HIV in macrophages, suggesting the further clinical evaluation of imiquimod for its additional benefit of treating genital/perianal warts in people infected with HIV.
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Affiliation(s)
- Feng-Zhen Meng
- School of Basic Medical Sciences, Wuhan University, Wuhan 430000, China;
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
| | - Jin-Biao Liu
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
| | - Xu Wang
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
| | - Peng Wang
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
| | - Wen-Hui Hu
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
| | - Wei Hou
- School of Basic Medical Sciences, Wuhan University, Wuhan 430000, China;
| | - Wen-Zhe Ho
- Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; (J.-B.L.); (X.W.); (P.W.); (W.-H.H.)
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11
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Yadav S, Verma V, Singh Dhanda R, Yadav M. Insights into the toll-like receptors in sexually transmitted infections. Scand J Immunol 2020; 93:e12954. [PMID: 32762084 DOI: 10.1111/sji.12954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 07/10/2020] [Accepted: 08/01/2020] [Indexed: 12/12/2022]
Abstract
Toll-like receptors (TLRs) are like soldiers of an innate immune system, which protects vital biological processes against invading pathogens. TLR signalling pathways help in the removal of pathogens and mediate well-established inflammatory processes. However, these processes may also aid in the development or augmentation of an infection or an autoimmune disease. Recent studies have delineated TLR polymorphism's role in the loss of function, making hosts more resistant or vulnerable to the development of an infection. In this review, we have discussed the association of TLRs with sexually transmitted infections (STIs), especially to the pathogen-specific ligands. We have also assessed the impact on TLR downstream signalling and the maintenance of cellular homeostasis during immune responses. Besides, we have discussed the role of TLRs single nucleotide polymorphisms in various STIs. Since TLRs are known to play a part in defence mechanisms and in aiding infections therefore, a thorough understanding of TLRs structure and molecular mechanisms is required to explain how they can influence the outcome of an STI. Such a strategy may lead to the development of novel and useful immunotherapeutic approaches to control pathogen progression and prevent transmission.
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Affiliation(s)
- Sonal Yadav
- Dr. B. R. Ambedkar Center for Biomedical Research (ACBR), University of Delhi, Delhi, India
| | - Vivek Verma
- Dr. B. R. Ambedkar Center for Biomedical Research (ACBR), University of Delhi, Delhi, India
| | | | - Manisha Yadav
- Dr. B. R. Ambedkar Center for Biomedical Research (ACBR), University of Delhi, Delhi, India.,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
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Nguyen H, Gazy N, Venketaraman V. A Role of Intracellular Toll-Like Receptors (3, 7, and 9) in Response to Mycobacterium tuberculosis and Co-Infection with HIV. Int J Mol Sci 2020; 21:E6148. [PMID: 32858917 PMCID: PMC7503332 DOI: 10.3390/ijms21176148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a highly infectious acid-fast bacillus and is known to cause tuberculosis (TB) in humans. It is a leading cause of death from a sole infectious agent, with an estimated 1.5 million deaths yearly worldwide, and up to one third of the world's population has been infected with TB. The virulence and susceptibility of Mtb are further amplified in the presence of Human Immunodeficiency Virus (HIV). Coinfection with Mtb and HIV forms a lethal combination. Previous studies had demonstrated the synergistic effects of Mtb and HIV, with one disease accelerating the disease progression of the other through multiple mechanisms, including the modulation of the immune response to these two pathogens. The response of the endosomal pattern recognition receptors to these two pathogens, specifically toll-like receptors (TLR)-3, -7, and -9, has not been elucidated, with some studies producing mixed results. This article seeks to review the roles of TLR-3, -7, and -9 in response to Mtb infection, as well as Mtb-HIV-coinfection via Toll-interleukin 1 receptor (TIR) domain-containing adaptor inducing INF-β (TRIF)-dependent and myeloid differentiation factor 88 (MyD88)-dependent pathways.
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Affiliation(s)
- Huy Nguyen
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766-1854, USA
| | - Nicky Gazy
- Beaumont Health System, 5450 Fort St, Trenton, MI 48183, USA
| | - Vishwanath Venketaraman
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766-1854, USA
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Patinote C, Karroum NB, Moarbess G, Cirnat N, Kassab I, Bonnet PA, Deleuze-Masquéfa C. Agonist and antagonist ligands of toll-like receptors 7 and 8: Ingenious tools for therapeutic purposes. Eur J Med Chem 2020; 193:112238. [PMID: 32203790 PMCID: PMC7173040 DOI: 10.1016/j.ejmech.2020.112238] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/17/2022]
Abstract
The discovery of the TLRs family and more precisely its functions opened a variety of gates to modulate immunological host responses. TLRs 7/8 are located in the endosomal compartment and activate a specific signaling pathway in a MyD88-dependant manner. According to their involvement into various autoimmune, inflammatory and malignant diseases, researchers have designed diverse TLRs 7/8 ligands able to boost or block the inherent signal transduction. These modulators are often small synthetic compounds and most act as agonists and to a much lesser extent as antagonists. Some of them have reached preclinical and clinical trials, and only one has been approved by the FDA and EMA, imiquimod. The key to the success of these modulators probably lies in their combination with other therapies as recently demonstrated. We gather in this review more than 360 scientific publications, reviews and patents, relating the extensive work carried out by researchers on the design of TLRs 7/8 modulators, which are classified firstly by their biological activities (agonist or antagonist) and then by their chemical structures, which total syntheses are not discussed here. This review also reports about 90 clinical cases, thereby showing the biological interest of these modulators in multiple pathologies.
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Affiliation(s)
- Cindy Patinote
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France.
| | - Nour Bou Karroum
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France; Tumorigenèse et Pharmacologie Antitumorale, Lebanese University, EDST, BP 90656, Fanar Jdeideh, Lebanon
| | - Georges Moarbess
- Tumorigenèse et Pharmacologie Antitumorale, Lebanese University, EDST, BP 90656, Fanar Jdeideh, Lebanon
| | - Natalina Cirnat
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Issam Kassab
- Tumorigenèse et Pharmacologie Antitumorale, Lebanese University, EDST, BP 90656, Fanar Jdeideh, Lebanon
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Friedel–Crafts chemistry 56*. Unprecedented construction of functionalized polycyclic quinolines via Friedel–Crafts cycliacylation and Beckmann rearrangement. Chem Heterocycl Compd (N Y) 2019. [DOI: 10.1007/s10593-019-02509-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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Giacomelli A, de Rose S, Rusconi S. Clinical pharmacology in HIV cure research - what impact have we seen? Expert Rev Clin Pharmacol 2019; 12:17-29. [PMID: 30570410 DOI: 10.1080/17512433.2019.1561272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: Combined antiretroviral therapy (cART) has transformed an inexorably fatal disease into a chronic pathology, shifting the focus of research from the control of viral replication to the possibility of HIV cure. Areas covered: The present review assesses the principal pharmacological strategies that have been tested for an HIV cure starting from the in vitro proof of concept and the potential rationale of their in vivo applicability. We evaluated the possible pharmacological procedures employed during the early-stage HIV infection and the possibility of cART-free remission. We then analyzed the shock and kill approach from the single compounds in vitro mechanism of action, to the in vivo application of single or combined actions. Finally, we briefly considered the novel immunological branch through the discovery and development of broadly neutralizing antibodies in regard to the current and future in vivo therapeutic strategies aiming to verify the clinical applicability of these compounds. Expert opinion: Despite an incredible effort in HIV research cure, the likelihood of completely eradicating HIV is unreachable within our current knowledge. A better understanding of the mechanism of viral latency and the full characterization of HIV reservoir are crucial for the discovery of new therapeutic targets and novel pharmacological entities.
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Affiliation(s)
- Andrea Giacomelli
- a Infectious Diseases Unit, DIBIC Luigi Sacco , University of Milan , Milan , Italy
| | - Sonia de Rose
- a Infectious Diseases Unit, DIBIC Luigi Sacco , University of Milan , Milan , Italy
| | - Stefano Rusconi
- a Infectious Diseases Unit, DIBIC Luigi Sacco , University of Milan , Milan , Italy
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Du K, Liu J, Broering R, Zhang X, Yang D, Dittmer U, Lu M. Recent advances in the discovery and development of TLR ligands as novel therapeutics for chronic HBV and HIV infections. Expert Opin Drug Discov 2018; 13:661-670. [PMID: 29772941 DOI: 10.1080/17460441.2018.1473372] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Toll-like receptor (TLR) ligands remain as promising antiviral drug candidates for the treatment of chronic viral infections. Basic research on the mechanisms of antiviral activity of TLR ligands in preclinical animal models and clinical testing of drug candidates have been carried out in recent years. Areas covered: This review provides an overview of the preclinical and clinical testing of TLR ligands in two major viral infections: hepatitis B virus (HBV) and human immunodeficiency virus (HIV). Recent results have further demonstrated the potent antiviral activity of various TLR ligands . A TLR7 agonist is in clinical trials for the treatment of chronic HBV infection while a HBV vaccine using a TLR9 ligand as an adjuvant has proven to be superior to conventional HBV vaccines and has been approved for clinical use. Generally, TLR activation may achieve viral control mainly by promoting adaptive immunity to viral proteins. Expert opinion: Recent research in this field indicates that TLR ligands could be developed as clinically effective drugs if the obstacles concerning toxicity and application routes are overcome. TLR-mediated promotion of adaptive immunity is a major issue for future studies and will determine the future development of TLR ligands as drugs for immunomodulation.
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Affiliation(s)
- Keye Du
- a Department of Infectious Disease , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Jia Liu
- a Department of Infectious Disease , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Ruth Broering
- b Department of Gastroenterology and Hepatology , University Hospital Essen, University of Duisburg-Essen , Essen , Germany
| | - Xiaoyong Zhang
- c Hepatology Unit and Department of Infectious Diseases , Nanfang Hospital, Southern Medical University , Guangzhou , China
| | - Dongliang Yang
- a Department of Infectious Disease , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Ulf Dittmer
- d Institute of Virology , University Hospital Essen, University of Duisburg-Essen , Essen , Germany
| | - Mengji Lu
- d Institute of Virology , University Hospital Essen, University of Duisburg-Essen , Essen , Germany
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TLR7 Agonists Display Potent Antiviral Effects against Norovirus Infection via Innate Stimulation. Antimicrob Agents Chemother 2018. [PMID: 29530841 DOI: 10.1128/aac.02417-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Norovirus infections are a significant health and economic burden globally, accounting for hundreds of millions of cases of acute gastroenteritis every year. In the absence of an approved norovirus vaccine, there is an urgent need to develop antivirals to treat chronic infections and provide prophylactic therapy to limit viral spread during epidemics and pandemics. Toll-like receptor (TLR) agonists have been explored widely for their antiviral potential, and several are progressing through clinical trials for the treatment of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) and as adjuvants for norovirus viruslike particle (VLP) vaccines. However, norovirus therapies in development are largely direct-acting antivirals (DAAs) with fewer compounds that target the host. Our aim was to assess the antiviral potential of TLR7 agonist immunomodulators on norovirus infection using the murine norovirus (MNV) and human Norwalk replicon models. TLR7 agonists R-848, Gardiquimod, GS-9620, R-837, and loxoribine were screened using a plaque reduction assay, and each displayed inhibition of MNV replication (50% effective concentrations [EC50s], 23.5 nM, 134.4 nM, 0.59 μM, 1.5 μM, and 79.4 μM, respectively). RNA sequencing of TLR7-stimulated cells revealed a predominant upregulation of innate immune response genes and interferon (IFN)-stimulated genes (ISGs) that are known to drive an antiviral state. Furthermore, the combination of R-848 and the nucleoside analogue (NA) 2'C-methylcytidine elicited a synergistic antiviral effect against MNV, demonstrating that combinational therapy of host modulators and DAAs might be used to reduce drug cytotoxicity. In summary, we have identified that TLR7 agonists display potent inhibition of norovirus replication and are a therapeutic option to combat norovirus infections.
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Toll-Like Receptor 7 Agonist GS-9620 Induces HIV Expression and HIV-Specific Immunity in Cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy. J Virol 2017; 91:JVI.02166-16. [PMID: 28179531 PMCID: PMC5375698 DOI: 10.1128/jvi.02166-16] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/20/2017] [Indexed: 02/07/2023] Open
Abstract
Antiretroviral therapy can suppress HIV replication to undetectable levels but does not eliminate latent HIV, thus necessitating lifelong therapy. Recent efforts to target this persistent reservoir have focused on inducing the expression of latent HIV so that infected cells may be recognized and eliminated by the immune system. Toll-like receptor (TLR) activation stimulates antiviral immunity and has been shown to induce HIV from latently infected cells. Activation of TLR7 leads to the production of several stimulatory cytokines, including type I interferons (IFNs). In this study, we show that the selective TLR7 agonist GS-9620 induced HIV in peripheral blood mononuclear cells (PBMCs) from HIV-infected individuals on suppressive antiretroviral therapy. GS-9620 increased extracellular HIV RNA 1.5- to 2-fold through a mechanism that required type I IFN signaling. GS-9620 also activated HIV-specific T cells and enhanced antibody-mediated clearance of HIV-infected cells. Activation by GS-9620 in combination with HIV peptide stimulation increased CD8 T cell degranulation, production of intracellular cytokines, and cytolytic activity. T cell activation was again dependent on type I IFNs produced by plasmacytoid dendritic cells. GS-9620 induced phagocytic cell maturation and improved effector-mediated killing of HIV-infected CD4 T cells by the HIV envelope-specific broadly neutralizing antibody PGT121. Collectively, these data show that GS-9620 can activate HIV production and improve the effector functions that target latently infected cells. GS-9620 may effectively complement orthogonal therapies designed to stimulate antiviral immunity, such as therapeutic vaccines or broadly neutralizing antibodies. Clinical studies are under way to determine if GS-9620 can target HIV reservoirs. IMPORTANCE Though antiretroviral therapies effectively suppress viral replication, they do not eliminate integrated proviral DNA. This stable intermediate of viral infection is persistently maintained in reservoirs of latently infected cells. Consequently, lifelong therapy is required to maintain viral suppression. Ultimately, new therapies that specifically target and eliminate the latent HIV reservoir are needed. Toll-like receptor agonists are potent enhancers of innate antiviral immunity that can also improve the adaptive immune response. Here, we show that a highly selective TLR7 agonist, GS-9620, activated HIV from peripheral blood mononuclear cells isolated from HIV-infected individuals with suppressed infection. GS-9620 also improved immune effector functions that specifically targeted HIV-infected cells. Previously published studies on the compound in other chronic viral infections show that it can effectively induce immune activation at safe and tolerable clinical doses. Together, the results of these studies suggest that GS-9620 may be useful for treating HIV-infected individuals on suppressive antiretroviral therapy.
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TLR7 Agonist GS-9620 Is a Potent Inhibitor of Acute HIV-1 Infection in Human Peripheral Blood Mononuclear Cells. Antimicrob Agents Chemother 2016; 61:AAC.01369-16. [PMID: 27799218 PMCID: PMC5192112 DOI: 10.1128/aac.01369-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/19/2016] [Indexed: 02/06/2023] Open
Abstract
GS-9620 is a potent and selective oral Toll-like receptor 7 (TLR7) agonist that directly activates plasmacytoid dendritic cells (pDCs). GS-9620 suppressed hepatitis B virus (HBV) in animal models of chronic infection and transiently activated HIV expression ex vivo in latently infected peripheral blood mononuclear cells (PBMCs) from virally suppressed patients. Currently, GS-9620 is under clinical evaluation for treating chronic HBV infection and for reducing latent reservoirs in virally suppressed HIV-infected patients. Here, we investigated the in vitro anti-HIV-1 activity of GS-9620. GS-9620 potently inhibited viral replication in PBMCs, particularly when it was added 24 to 48 h prior to HIV infection (50% effective concentration = 27 nM). Depletion of pDCs but not other immune cell subsets from PBMC cultures suppressed GS-9620 antiviral activity. Although GS-9620 was inactive against HIV in purified CD4+ T cells and macrophages, HIV replication was potently inhibited by conditioned medium derived from GS-9620-treated pDC cultures when added to CD4+ T cells prior to infection. This suggests that GS-9620-mediated stimulation of PBMCs induced the production of a soluble factor(s) inhibiting HIV replication in trans. GS-9620-treated PBMCs primarily showed increased production of interferon alpha (IFN-α), and cotreatment with IFN-α-blocking antibodies reversed the HIV-1-inhibitory effect of GS-9620. Additional studies demonstrated that GS-9620 inhibited a postentry event in HIV replication at a step coincident with or prior to reverse transcription. The simultaneous activation of HIV-1 expression and inhibition of HIV-1 replication are important considerations for the clinical evaluation of GS-9620 since these antiviral effects may help restrict potential local HIV spread upon in vivo latency reversal.
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Hofmann H, Vanwalscappel B, Bloch N, Landau NR. TLR7/8 agonist induces a post-entry SAMHD1-independent block to HIV-1 infection of monocytes. Retrovirology 2016; 13:83. [PMID: 27905985 PMCID: PMC5131500 DOI: 10.1186/s12977-016-0316-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 11/15/2016] [Indexed: 12/03/2022] Open
Abstract
Background Monocytes, the primary myeloid cell-type in peripheral blood, are resistant to HIV-1 infection as a result of the lentiviral restriction factor SAMHD1. Toll-like receptors recognize microbial pathogen components, inducing the expression of antiviral host proteins and proinflammatory cytokines. TLR agonists that mimic microbial ligands have been found to have activity against HIV-1 in macrophages. The induction of restriction factors in monocytes by TLR agonist activation has not been well studied. To analyze restriction factor induction by TLR activation in monocytes, we used the imidazoquinoline TLR7/8 agonist R848 and infected with HIV-1 reporter virus that contained packaged viral accessory protein Vpx, which allows the virus to escape SAMHD1-mediated restriction. Results R848 prevented the replication of Vpx-containing HIV-1 and HIV-2 in peripheral blood mononuclear cells and monocytes. The block was post-entry but prior to reverse transcription of the viral genomic RNA. The restriction was associated with destabilization of the genomic RNA molecules of the in-coming virus particle. R848 treatment of activated T cells did not protect them from infection but treated monocytes produced high levels of proinflammatory cytokines, including type-I IFN that protected bystander activated T cells from infection. Conclusion The activation of TLR7/8 induces two independent restrictions to HIV-1 replication in monocytes: a cell-intrinsic block that acts post-entry to prevent reverse transcription; and a cell-extrinsic block, in which monocytes produce high levels of proinflammatory cytokines (primarily type-I IFN) that protects bystander monocytes and T lymphocytes. The cell-intrinsic block may result from the induction of a novel restriction factor, which can be termed Lv5 and acts by destabilizing the in-coming viral genomic RNA, either by the induction of a host ribonuclease or by disrupting the viral capsid. TLR agonists are being developed for therapeutic use to diminish the size of the latent provirus reservoir in HIV-1 infected individuals. Such drugs may both induce latent provirus expression and restrict virus replication during treatment. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0316-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Henning Hofmann
- Department of Microbiology, NYU School of Medicine, New York, NY, USA.,Department of HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | | | - Nicolin Bloch
- Department of Microbiology, NYU School of Medicine, New York, NY, USA
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Donninelli G, Gessani S, Del Cornò M. Interplay between HIV-1 and Toll-like receptors in human myeloid cells: friend or foe in HIV-1 pathogenesis? J Leukoc Biol 2015; 99:97-105. [PMID: 26307548 DOI: 10.1189/jlb.4vmr0415-160r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/23/2015] [Indexed: 12/22/2022] Open
Abstract
The Toll-like receptors are the first line of the host response to pathogens, representing an essential component of the innate and adaptive immune response. They recognize different pathogens and trigger responses directed at eliminating the invader and at developing immunologic long-term memory, ultimately affecting viral pathogenesis. In viral infections, sensing of nucleic acids and/or viral structural proteins generally induces a protective immune response. Thus, it is not surprising that many viruses have developed strategies to evade or counteract signaling through the Toll-like receptor pathways, to survive the host defense machinery and ensure propagation. Thus, Toll-like receptor engagement can also be part of viral pathogenic mechanisms. Evidence for a direct interaction of Toll-like receptors with human immunodeficiency virus type 1 (HIV-1) structures has started to be achieved, and alterations of their expression and function have been described in HIV-1-positive subjects. Furthermore, Toll-like receptor triggering by bacterial and viral ligands have been described to modulate HIV-1 replication and host response, leading to protective or detrimental effects. This review covers major advances in the field of HIV-1 interplay with Toll-like receptors, focusing on human myeloid cells (e.g., monocytes/macrophages and dendritic cells). The role of this interaction in the dysregulation of myeloid cell function and in dictating aspects of the multifaceted pathogenesis of acquired immunodeficiency syndrome will be discussed.
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Affiliation(s)
- Gloria Donninelli
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Sandra Gessani
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Manuela Del Cornò
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
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Buitendijk M, Eszterhas SK, Howell AL. Toll-like receptor agonists are potent inhibitors of human immunodeficiency virus-type 1 replication in peripheral blood mononuclear cells. AIDS Res Hum Retroviruses 2014; 30:457-67. [PMID: 24328502 DOI: 10.1089/aid.2013.0199] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Innate immune responses to microbial pathogens are initiated following the binding of ligand to specific pattern recognition receptors. Each pattern recognition receptor, which includes members of the Toll-like receptor (TLR) family, is specific for a particular type of pathogen associated molecular pattern ensuring that the organism can respond rapidly to a wide range of pathogens including bacteria, viruses, and fungi. We studied the extent to which agonists to endosomal TLR could induce anti-HIV-1 activity in peripheral blood mononuclear cells (PBMCs). When agonists to TLR3, TLR7, TLR8 and TLR9 were added prior to infection with HIV-1, they significantly reduced infection of peripheral blood mononuclear cells. Interestingly, agonists to TLR8 and TLR9 were highly effective at blocking HIV replication even when added as late as 48 h or 72 h, respectively, after HIV-1 infection, indicating that the anti-viral effect was durable and long lasting. Analysis of the induction of anti-viral genes after agonist activation of TLR indicated that all of the agonists induced expression of the type I interferons and interferon stimulated genes, although to variable levels that depended on the agonist used. Interestingly, only the agonist to TLR9, ODN2395 DNA, induced expression of type II interferon and the anti-HIV proteins Apobec3G and SAMHD1. By blocking TLR activity using an inhibitor to the MyD88 adaptor protein, we demonstrated that, at least for TLR8 and TLR9, the anti-HIV activity was not entirely mediated by TLR activation, but likely by the activation of additional anti-viral sensors in HIV target cells. These findings suggest that agonists to the endosomal TLR function to induce expression of anti-HIV molecules by both TLR-mediated and non-TLR-mediated mechanisms. Moreover, the non-TLR-mediated mechanisms induced by these agonists could potentially be exploited to block HIV-1 replication in recently HIV-exposed individuals.
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Affiliation(s)
- Maarten Buitendijk
- Department of Veterans Affairs, Veterans Health Administration, Biomedical Laboratory Research and Development, White River Junction, Vermont
- Department of Physiology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Susan K. Eszterhas
- Department of Veterans Affairs, Veterans Health Administration, Biomedical Laboratory Research and Development, White River Junction, Vermont
- Department of Microbiology/Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Alexandra L. Howell
- Department of Veterans Affairs, Veterans Health Administration, Biomedical Laboratory Research and Development, White River Junction, Vermont
- Department of Microbiology/Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
- Department of Medicine, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
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Victoria S, Temerozo JR, Gobbo L, Pimenta-Inada HK, Bou-Habib DC. Activation of Toll-like receptor 2 increases macrophage resistance to HIV-1 infection. Immunobiology 2013; 218:1529-36. [PMID: 23891328 DOI: 10.1016/j.imbio.2013.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 05/20/2013] [Accepted: 06/05/2013] [Indexed: 10/26/2022]
Abstract
Patients infected with HIV-1, the etiological agent of AIDS, have increased intestinal permeability, which allows for the passage of microbial products, including Toll-like receptor (TLR) ligands, into circulation. The exposure of HIV-1-infected cells to certain TLR agonists affects viral replication, but studies associating viral production with the activation of TLR2 in HIV-1-infected cells are rare and controversial. Here, we report that the TLR2 ligands Zymosan and Pam3CSK4 potently inhibit HIV-1 replication in acutely infected monocyte-derived macrophages and the exposure to TLR2 ligands prior to infection renders macrophages refractory to HIV-1 production. Macrophage treatment with Pam3CSK4 did not change the cellular expression of the HIV-1 entry receptors CD4 and CCR5. Both TLR2 ligands increased the macrophage production of β-chemokines and IL-10, and the blockage of these soluble factors prevented the inhibitory effect of TLR2 activation on HIV-1 replication. Our findings show that the direct engagement of TLR2 in HIV-1-infected macrophages increase cellular resistance to HIV-1 infection, and that controlling HIV-1 replication with agonists for TLR2 might have implications for the development of antiretroviral therapies.
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Affiliation(s)
- Sabina Victoria
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Av. Brasil 4365, Manguinhos - 21040-360, Rio de Janeiro, RJ, Brazil
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