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Chakraborty S, Ye J, Wang H, Sun M, Zhang Y, Sang X, Zhuang Z. Application of toll-like receptors (TLRs) and their agonists in cancer vaccines and immunotherapy. Front Immunol 2023; 14:1227833. [PMID: 37936697 PMCID: PMC10626551 DOI: 10.3389/fimmu.2023.1227833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) expressed in various immune cell types and perform multiple purposes and duties involved in the induction of innate and adaptive immunity. Their capability to propagate immunity makes them attractive targets for the expansion of numerous immunotherapeutic approaches targeting cancer. These immunotherapeutic strategies include using TLR ligands/agonists as monotherapy or combined therapeutic strategies. Several TLR agonists have demonstrated significant efficacy in advanced clinical trials. In recent years, multiple reports established the applicability of TLR agonists as adjuvants to chemotherapeutic drugs, radiation, and immunotherapies, including cancer vaccines. Cancer vaccines are a relatively novel approach in the field of cancer immunotherapy and are currently under extensive evaluation for treating different cancers. In the present review, we tried to deliver an inclusive discussion of the significant TLR agonists and discussed their application and challenges to their incorporation into cancer immunotherapy approaches, particularly highlighting the usage of TLR agonists as functional adjuvants to cancer vaccines. Finally, we present the translational potential of rWTC-MBTA vaccination [irradiated whole tumor cells (rWTC) pulsed with phagocytic agonists Mannan-BAM, TLR ligands, and anti-CD40 agonisticAntibody], an autologous cancer vaccine leveraging membrane-bound Mannan-BAM, and the immune-inducing prowess of TLR agonists as a probable immunotherapy in multiple cancer types.
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Affiliation(s)
- Samik Chakraborty
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
- NE1 Inc., New York, NY, United States
| | - Juan Ye
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Herui Wang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Mitchell Sun
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Yaping Zhang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Xueyu Sang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Zhengping Zhuang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
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2
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Toll-like Receptor Response to Hepatitis C Virus Infection: A Recent Overview. Int J Mol Sci 2022; 23:ijms23105475. [PMID: 35628287 PMCID: PMC9141274 DOI: 10.3390/ijms23105475] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 02/05/2023] Open
Abstract
Hepatitis C virus (HCV) infection remains a major global health burden, causing chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Toll-like receptors (TLRs) are evolutionarily conserved pattern recognition receptors that detect pathogen-associated molecular patterns and activate downstream signaling to induce proinflammatory cytokine and chemokine production. An increasing number of studies have suggested the importance of TLR responses in the outcome of HCV infection. However, the exact role of innate immune responses, including TLR response, in controlling chronic HCV infection remains to be established. A proper understanding of the TLR response in HCV infection is essential for devising new therapeutic approaches against HCV infection. In this review, we discuss the progress made in our understanding of the host innate immune response to HCV infection, with a particular focus on the TLR response. In addition, we discuss the mechanisms adopted by HCV to avoid immune surveillance mediated by TLRs.
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Gao Y, Nepal N, Jin SZ. Toll-like receptors and hepatitis C virus infection. Hepatobiliary Pancreat Dis Int 2021; 20:521-529. [PMID: 34419367 DOI: 10.1016/j.hbpd.2021.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 07/26/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hepatitis C virus (HCV) infection is a worldwide issue. However, the current treatment for hepatitis C has many shortcomings. Toll-like receptors (TLRs) are pattern recognition receptors involved in HCV infection, and an increasing number of studies are focusing on the role of TLRs in the progression of hepatitis C. DATA SOURCES We performed a PubMed search up to January 2021 with the following keywords: hepatitis C, toll-like receptors, interferons, inflammation, and immune evasion. We also used terms such as single-nucleotide polymorphisms (SNPs), susceptibility, fibrosis, cirrhosis, direct-acting antiviral agents, agonists, and antagonists to supplement the query results. We reviewed relevant publications analyzing the correlation between hepatitis C and TLRs and the role of TLRs in HCV infection. RESULTS TLRs 1-4 and 6-9 are involved in the process of HCV infection. When the host is exposed to the HCV, TLRs, as important participants in HCV immune evasion, trigger innate immunity to remove the virus and also promote inflammation and liver fibrosis. TLR gene SNPs affect hepatitis C susceptibility, treatment, and prognosis. The contribution of each TLR to HCV is different. Drugs targeting various TLRs are developed and validated, and TLRs can synergize with classic hepatitis C drugs, including interferon and direct-acting antiviral agents, constituting a new direction for the treatment of hepatitis C. CONCLUSIONS TLRs are important receptors in HCV infection. Different TLRs induce different mechanisms of virus clearance and inflammatory response. Although TLR-related antiviral therapy strategies exist, more studies are needed to explore the clinical application of TLR-related drugs.
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Affiliation(s)
- Yang Gao
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Narayan Nepal
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Shi-Zhu Jin
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China.
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Hennessy C, McKernan DP. Anti-Viral Pattern Recognition Receptors as Therapeutic Targets. Cells 2021; 10:cells10092258. [PMID: 34571909 PMCID: PMC8466445 DOI: 10.3390/cells10092258] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/11/2022] Open
Abstract
Pattern recognition receptors (PRRs) play a central role in the inflammation that ensues following microbial infection by their recognition of molecular patterns present in invading microorganisms but also following tissue damage by recognising molecules released during disease states. Such receptors are expressed in a variety of cells and in various compartments of these cells. PRR binding of molecular patterns results in an intracellular signalling cascade and the eventual activation of transcription factors and the release of cytokines, chemokines, and vasoactive molecules. PRRs and their accessory molecules are subject to tight regulation in these cells so as to not overreact or react in unnecessary circumstances. They are also key to reacting to infection and in stimulating the immune system when needed. Therefore, targeting PRRs offers a potential therapeutic approach for chronic inflammatory disease, infections and as vaccine adjuvants. In this review, the current knowledge on anti-viral PRRs and their signalling pathways is reviewed. Finally, compounds that target PRRs and that have been tested in clinical trials for chronic infections and as adjuvants in vaccine trials are discussed.
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5
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Maghraby AS. Immunomodulatory Responses Of Toll Like Receptors Against 2019nCoV. RUSSIAN OPEN MEDICAL JOURNAL 2021. [DOI: 10.15275/rusomj.2021.0202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The present review discusses the immune signals via toll like receptors (TLRs) against 2019nCoV. We researched using different database, up to June 18th, 2020. All the included articles were published in English language. The outcome of this review, that some TLRs agonists or antagonists are progressed as drugs to combat and down regulating TLRs immune signals respectively. TLRs 3 and 4 recognized 2019nCoV spike protein through immune and molecular signals that leading to immune stimulation of pro-inflammatory cytokines and even the immune fever. While the TLRs7 and 8 recognized single-stranded ribonucleic acids (ssRNAs) leading to elevation of the tumour necrosis factor α (TNF-α), interleukin (IL)-6 and -12 levels. TLRs agonists or antagonists utilized as immunotherapeutic targets against 2019nCoV via TLRs signals. Chloroquine and hydroxychloroquine; the approval compounds for 2019nCoV therapy can be inhibiting the class II major histocompatibility complex molecules expression and antigen presentation and even immune suppressions of the pro-inflammatory cytokines profile.
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Grippo JF, Folitar I, Passe S, Jiang Q, Rodriguez I, Fettner SH, Calleja E. Safety, tolerability, pharmacokinetics, and pharmacodynamics of a TLR7 agonist prodrug RO6870868 in healthy volunteers. Clin Transl Sci 2021; 14:1524-1534. [PMID: 33742764 PMCID: PMC8301559 DOI: 10.1111/cts.13016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 12/13/2022] Open
Abstract
RO6870868 is an oral prodrug of the toll‐like receptor 7 (TLR7) specific agonist, RO6871765. TLR7 agonists augment host immune activity and are in development to treat hepatitis B infection. We evaluated the safety, tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of RO6870868 in a first‐in‐human, phase I, randomized, single ascending oral dose study in 60 healthy volunteers at 6 dose levels (200–2000 mg). Single oral doses were generally well‐tolerated with a predictable safety profile associated with dose‐dependent increases in systemic interferon. No serious adverse events (AEs) were reported and no subject withdrew from the study due to an AE. No clinically significant changes were observed in vital signs, electrocardiograms, or laboratory parameters. Following oral RO6870868 doses, plasma RO6871765 concentrations increased rapidly, exhibiting mean terminal half‐life ranging 2–6 h across all cohorts, with area under the plasma concentration versus time curve extrapolated to infinity (AUC0‐∞) increasing proportionally with dose. A pattern of dose and time‐dependent PD activity was demonstrated consistent with engagement of the TLR7 system. Single RO6870868 doses activated components of the TLR innate immune system in a dose‐dependent manner with adequate safety and tolerability. Single‐dose data in healthy volunteers are useful to evaluate safety, PK, and PD activity of TLR7 agonists and help to guide dose and regimen selection for further trials in patients with chronic hepatitis B.
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Affiliation(s)
| | | | - Sharon Passe
- Roche Innovation Center, New York, New York, USA
| | - Qiudi Jiang
- Roche Innovation Center Shanghai, Shanghai, China
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Keshavarz A, Pourbagheri-Sigaroodi A, Zafari P, Bagheri N, Ghaffari SH, Bashash D. Toll-like receptors (TLRs) in cancer; with an extensive focus on TLR agonists and antagonists. IUBMB Life 2020; 73:10-25. [PMID: 33217774 DOI: 10.1002/iub.2412] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/01/2020] [Accepted: 11/01/2020] [Indexed: 12/19/2022]
Abstract
At the forefront of the battle against pathogens or any endogenously released molecules, toll-like receptors (TLRs) play an important role as the most noble pattern recognition receptors. The ability of these receptors in distinguishing "self" and "non-self" antigens is a cornerstone in the innate immunity system; however, misregulation links inflammatory responses to the development of human cancers. It has been known for some time that aberrant expression and regulation of TLRs not only endows cancer cells an opportunity to escape from the immune system but also supports them through enhancing proliferation and angiogenesis. Over the past decades, cancer research studies have witnessed a number of preclinical and clinical breakthroughs in the field of TLR modulators and some of the agents have exceptionally performed well in advanced clinical trials. In the present review, we have provided a comprehensive review of different TLR agonists and antagonists and discuss their limitations, toxicities, and challenges to outline their future incorporation in cancer treatment strategies.
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Affiliation(s)
- Ali Keshavarz
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parisa Zafari
- Department of Immunology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Nader Bagheri
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Seyed H Ghaffari
- Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Wang Y, Yang H, Li H, Zhao S, Zeng Y, Zhang P, Lin X, Sun X, Wang L, Fu G, Gao Y, Wang P, Gao D. Development of a novel TLR8 agonist for cancer immunotherapy. MOLECULAR BIOMEDICINE 2020; 1:6. [PMID: 35006413 PMCID: PMC8607422 DOI: 10.1186/s43556-020-00007-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/14/2020] [Indexed: 01/12/2023] Open
Abstract
Toll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. Several TLRs are being pursued as cancer drug targets. We discovered a novel, highly potent and selective small molecule TLR8 agonist DN052. DN052 exhibited strong in vitro cellular activity with EC50 at 6.7 nM and was highly selective for TLR8 over other TLRs including TLR4, 7 and 9. DN052 displayed excellent in vitro ADMET and in vivo PK profiles. DN052 potently inhibited tumor growth as a single agent. Moreover, combination of DN052 with the immune checkpoint inhibitor, selected targeted therapeutics or chemotherapeutic drugs further enhanced efficacy of single agents. Mechanistically, treatment with DN052 resulted in strong induction of pro-inflammatory cytokines in ex vivo human PBMC assay and in vivo monkey study. GLP toxicity studies in rats and monkeys demonstrated favorable safety profile. This led to the advancement of DN052 into phase 1 clinical trials.
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Affiliation(s)
- Yuxun Wang
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China.
| | - Heping Yang
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Huanping Li
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Shuda Zhao
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Yikun Zeng
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Panpan Zhang
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Xiaoqin Lin
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Xiaoxiang Sun
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Longsheng Wang
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Guangliang Fu
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Yaqiao Gao
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Pei Wang
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
| | - Daxin Gao
- Shanghai Denovo Pharmatech Co., Ltd., 576 Libing Road, Shanghai Zhangjiang High-Tech Park, Pudong New District, Shanghai, 201203, China
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Flórez-Álvarez L, Ruiz-Perez L, Taborda N, Hernandez JC. Toll-like receptors as a therapeutic target in cancer, infections and inflammatory diseases. Immunotherapy 2020; 12:311-322. [PMID: 32237938 DOI: 10.2217/imt-2019-0096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Toll-like receptors (TLRs) are widely expressed pattern recognition receptors that bind to conserved molecular patterns expressed by pathogens and damaged cells. After recognition, activated TLRs induce the expression of various proinflammatory and antiviral molecules. Thus, TLRs are potential targets for treatment strategies aimed at boosting the adaptive immune response to vaccines, controlling infections, enhancing immune responses during tumor treatment and attenuating immune responses in inflammatory disorders. This Special Report examines the potential of TLRs as targets for the treatment of cancer, infections and inflammatory diseases. Here, we make a particular emphasis on molecules capable of modulating TLRs and their therapeutic applications.
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Affiliation(s)
- Lizdany Flórez-Álvarez
- Infettare, Facultad de Medicina, Universidad Cooperativa de Colombia, Medellín, Colombia.,Grupo Inmunovirologia, Facultad de Medicina, Universidad de Antioquia, UdeA; Calle 70 No. 52-21, Medellín, Colombia
| | - Lanie Ruiz-Perez
- School of Pharmacy & Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth WA 6845, Australia
| | - Natalia Taborda
- Grupo Inmunovirologia, Facultad de Medicina, Universidad de Antioquia, UdeA; Calle 70 No. 52-21, Medellín, Colombia.,Grupo de Investigaciones Biomédicas Uniremington, Programa de Medicina, Facultad de Ciencias de la Salud, Corporación Universitaria Remington, Medellín, Colombia
| | - Juan C Hernandez
- Infettare, Facultad de Medicina, Universidad Cooperativa de Colombia, Medellín, Colombia
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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: 68] [Impact Index Per Article: 17.0] [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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McKernan DP. Pattern recognition receptors as potential drug targets in inflammatory disorders. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 119:65-109. [PMID: 31997773 DOI: 10.1016/bs.apcsb.2019.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pattern recognition receptors (PRRs) are a key part of the innate immune system, the body's first line of defense against infection and tissue damage. This superfamily of receptors including Toll-like receptors (TLRs), NOD-like receptors (NLRs), C-type lectin-like receptors (CLRs) and RIG-like receptors (RLRs) are responsible for initiation of the inflammatory response by their recognition of molecular patterns present in invading microorganisms (such as bacteria, viruses or fungi) during infection or in molecules released following tissue damage during acute or chronic disease states (such as sepsis or arthritis). These receptors are widely expressed and located on the cell surface, in intracellular compartments or in the cytoplasm can detect a single or subset of molecules including lipoproteins, carbohydrates or nucleic acids. In response, they initiate an intracellular signaling cascade that culminates in the synthesis and release of cytokines, chemokines and vasoactive molecules. These steps are necessary to maintain tissue homeostasis and remove potentially dangerous pathogens. However, during extreme or acute responses or during chronic disease, this can be damaging and even lead to death. Therefore, it is thought that targeting such receptors may offer a therapeutic approach in chronic inflammatory diseases or in cases of acute infection leading to sepsis. Herein, the current knowledge on the molecular biology of PRRs is reviewed along with their association with inflammatory and infectious diseases. Finally, the testing of therapeutic compounds and their future merit as targets is discussed.
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12
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Macedo AB, Novis CL, Bosque A. Targeting Cellular and Tissue HIV Reservoirs With Toll-Like Receptor Agonists. Front Immunol 2019; 10:2450. [PMID: 31681325 PMCID: PMC6804373 DOI: 10.3389/fimmu.2019.02450] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 10/01/2019] [Indexed: 01/04/2023] Open
Abstract
The elimination of both cellular and tissue latent reservoirs is a challenge toward a successful HIV cure. "Shock and Kill" are among the therapeutic strategies that have been more extensively studied to target these reservoirs. These strategies are aimed toward the reactivation of the latent reservoir using a latency-reversal agent (LRA) with the subsequent killing of the reactivated cell either by the cytotoxic arm of the immune system, including NK and CD8 T cells, or by viral cytopathic mechanisms. Numerous LRAs are currently being investigated in vitro, ex vivo as well as in vivo for their ability to reactivate and reduce latent reservoirs. Among those, several toll-like receptor (TLR) agonists have been shown to reactivate latent HIV. In humans, there are 10 TLRs that recognize different pathogen-associated molecular patterns. TLRs are present in several cell types, including CD4 T cells, the cell compartment that harbors the majority of the latent reservoir. Besides their ability to reactivate latent HIV, TLR agonists also increase immune activation and promote an antiviral response. These combined properties make TLR agonists unique among the different LRAs characterized to date. Additionally, some of these agonists have shown promise toward finding an HIV cure in animal models. When in combination with broadly neutralizing antibodies, TLR-7 agonists have shown to impact the SIV latent reservoir and delay viral rebound. Moreover, there are FDA-approved TLR agonists that are currently being investigated for cancer therapy and other diseases. All these has prompted clinical trials using TLR agonists either alone or in combination toward HIV eradication approaches. In this review, we provide an extensive characterization of the state-of-the-art of the use of TLR agonists toward HIV eradication strategies and the mechanism behind how TLR agonists target both cellular and tissue HIV reservoirs.
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Affiliation(s)
- Amanda B. Macedo
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington, DC, United States
| | - Camille L. Novis
- Department of Pathology, Division of Microbiology and Immunology, The University of Utah, Salt Lake City, UT, United States
| | - Alberto Bosque
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington, DC, United States
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Arora S, Ahmad S, Irshad R, Goyal Y, Rafat S, Siddiqui N, Dev K, Husain M, Ali S, Mohan A, Syed MA. TLRs in pulmonary diseases. Life Sci 2019; 233:116671. [PMID: 31336122 PMCID: PMC7094289 DOI: 10.1016/j.lfs.2019.116671] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/16/2019] [Accepted: 07/19/2019] [Indexed: 12/21/2022]
Abstract
Toll-like receptors (TLRs) comprise a clan of proteins involved in identification and triggering a suitable response against pathogenic attacks. As lung is steadily exposed to multiple infectious agents, antigens and host-derived danger signals, the inhabiting stromal and myeloid cells of the lung express an aggregate of TLRs which perceive the endogenously derived damage-associated molecular patterns (DAMPs) along with pathogen associated molecular patterns (PAMPs) and trigger the TLR-associated signalling events involved in host defence. Thus, they form an imperative component of host defence activation in case of microbial infections as well as non-infectious pulmonary disorders such as interstitial lung disease, acute lung injury and airways disease, such as COPD and asthma. They also play an equally important role in lung cancer. Targeting the TLR signalling network would pave ways to the design of more reliable and effective vaccines against infectious agents and control deadly infections, desensitize allergens and reduce inflammation. Moreover, TLR agonists may act as adjuvants by increasing the efficiency of cancer vaccines, thereby contributing their role in treatment of lung cancer too. Overall, TLRs present a compelling and expeditiously bolstered area of research and addressing their signalling events would be of significant use in pulmonary diseases.
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Affiliation(s)
- Shweta Arora
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Shaniya Ahmad
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Rasha Irshad
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Yamini Goyal
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Sahar Rafat
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Neha Siddiqui
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Kapil Dev
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Mohammad Husain
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
| | - Shakir Ali
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
| | - Anant Mohan
- Department of Pulmonary Medicine, AIIMS, New Delhi, India.
| | - Mansoor Ali Syed
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, India.
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14
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Ashraf MU, Iman K, Khalid MF, Salman HM, Shafi T, Rafi M, Javaid N, Hussain R, Ahmad F, Shahzad-Ul-Hussan S, Mirza S, Shafiq M, Afzal S, Hamera S, Anwar S, Qazi R, Idrees M, Qureshi SA, Chaudhary SU. Evolution of efficacious pangenotypic hepatitis C virus therapies. Med Res Rev 2018; 39:1091-1136. [PMID: 30506705 DOI: 10.1002/med.21554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.
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Affiliation(s)
- Muhammad Usman Ashraf
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Kanzal Iman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Farhan Khalid
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Hafiz Muhammad Salman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Talha Shafi
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Momal Rafi
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | - Nida Javaid
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Rashid Hussain
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Fayyaz Ahmad
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | | | - Shaper Mirza
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Shafiq
- Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Samia Afzal
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sadia Hamera
- Department of Plant Genetics, Institute of Life Sciences, University of Rostock, Germany
| | - Saima Anwar
- Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Romena Qazi
- Department of Pathology, Shaukat Khanum Memorial Cancer Hospital & Research Centre, Lahore, Pakistan
| | - Muhammad Idrees
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.,Hazara University, Mansehra, Pakistan
| | - Sohail A Qureshi
- Institute of Integrative Biosciences, CECOS-University of Information Technology and Emerging Sciences, Peshawar, Pakistan
| | - Safee Ullah Chaudhary
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
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15
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Feng S, Gao L, Han X, Hu T, Hu Y, Liu H, Thomas AW, Yan Z, Yang S, Young JAT, Yun H, Zhu W, Shen HC. Discovery of Small Molecule Therapeutics for Treatment of Chronic HBV Infection. ACS Infect Dis 2018; 4:257-277. [PMID: 29369612 DOI: 10.1021/acsinfecdis.7b00144] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The chronic infection of hepatitis B virus (HBV) inflicts 250 million people worldwide representing a major public health threat. A significant subpopulation of patients eventually develop cirrhosis and hepatocellular carcinoma (HCC). Unfortunately, none of the current standard therapies for chronic hepatitis B (CHB) result in a satisfactory clinical cure rate. Driven by a highly unmet medical need, multiple pharmaceutical companies and research institutions have been engaged in drug discovery and development to improve the CHB functional cure rate, defined by sustainable viral suppression and HBsAg clearance after a finite treatment. This Review summarizes the recent advances in the discovery and development of novel anti-HBV small molecules. It is believed that an improved CHB functional cure rate may be accomplished via the combination of molecules with distinct MoAs. Thus, certain molecules may evolve into key components of a suitable combination therapy leading to superior outcome of clinical efficacy in the future.
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Affiliation(s)
- Song Feng
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Lu Gao
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Xingchun Han
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Taishan Hu
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Yimin Hu
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Haixia Liu
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Andrew W. Thomas
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Zhipeng Yan
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Song Yang
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - John A. T. Young
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Hongying Yun
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Wei Zhu
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
| | - Hong C. Shen
- Roche Innovation Center Shanghai, Roche Pharma Research & Early Development, Building 5, 720 Cailun Road, Shanghai, 201203, China
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16
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Sacchi A, Tumino N, Turchi F, Refolo G, Fimia G, Ciccosanti F, Montalbano M, Lionetti R, Taibi C, D'Offizi G, Casetti R, Bordoni V, Cimini E, Martini F, Agrati C. Dendritic cells activation is associated with sustained virological response to telaprevir treatment of HCV-infected patients. Clin Immunol 2017; 183:82-90. [PMID: 28736275 DOI: 10.1016/j.clim.2017.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 06/28/2017] [Accepted: 07/19/2017] [Indexed: 11/16/2022]
Abstract
First anti-HCV treatments, that include protease inhibitors in conjunction with IFN-α and Ribavirin, increase the sustained virological response (SVR) up to 80% in patients infected with HCV genotype 1. The effects of triple therapies on dendritic cell (DC) compartment have not been investigated. In this study we evaluated the effect of telaprevir-based triple therapy on DC phenotype and function, and their possible association with treatment outcome. HCV+ patients eligible for telaprevir-based therapy were enrolled, and circulating DC frequency, phenotype, and function were evaluated by flow-cytometry. The antiviral activity of plasmacytoid DC was also tested. In SVR patients, myeloid DC frequency transiently decreased, and returned to baseline level when telaprevir was stopped. Moreover, an up-regulation of CD80 and CD86 on mDC was observed in SVR patients as well as an improvement of IFN-α production by plasmacytoid DC, able to inhibit in vitro HCV replication.
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Affiliation(s)
- Alessandra Sacchi
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy.
| | - Nicola Tumino
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Federica Turchi
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Giulia Refolo
- Cellular Biology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - GianMaria Fimia
- Cellular Biology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Fabiola Ciccosanti
- Cellular Biology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Marzia Montalbano
- Clinical Division, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Raffaella Lionetti
- Clinical Division, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Chiara Taibi
- Clinical Division, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Gianpiero D'Offizi
- Clinical Division, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Rita Casetti
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Veronica Bordoni
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Eleonora Cimini
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Federico Martini
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
| | - Chiara Agrati
- Cellular Immunology Laboratory, "Lazzaro Spallanzani" National Institute for Infectious Diseases, IRCCS, Rome, Italy
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17
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Pei Y, Wang C, Yan SF, Liu G. Past, Current, and Future Developments of Therapeutic Agents for Treatment of Chronic Hepatitis B Virus Infection. J Med Chem 2017; 60:6461-6479. [PMID: 28383274 DOI: 10.1021/acs.jmedchem.6b01442] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
For decades, treatment of hepatitis B virus (HBV) infection has been relying on interferon (IFN)-based therapies and nucleoside/nucleotide analogues (NAs) that selectively target the viral polymerase reverse transcriptase (RT) domain and thereby disrupt HBV viral DNA synthesis. We have summarized here the key steps in the HBV viral life cycle, which could potentially be targeted by novel anti-HBV therapeutics. A wide range of next-generation direct antiviral agents (DAAs) with distinct mechanisms of actions are discussed, including entry inhibitors, transcription inhibitors, nucleoside/nucleotide analogues, inhibitors of viral ribonuclease H (RNase H), modulators of viral capsid assembly, inhibitors of HBV surface antigen (HBsAg) secretion, RNA interference (RNAi) gene silencers, antisense oligonucleotides (ASOs), and natural products. Compounds that exert their antiviral activities mainly through host factors and immunomodulation, such as host targeting agents (HTAs), programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors, and Toll-like receptor (TLR) agonists, are also discussed. In this Perspective, we hope to provide an overview, albeit by no means being comprehensive, for the recent development of novel therapeutic agents for the treatment of chronic HBV infection, which not only are able to sustainably suppress viral DNA but also aim to achieve functional cure warranted by HBsAg loss and ultimately lead to virus eradication and cure of hepatitis B.
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Affiliation(s)
- Yameng Pei
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
| | - Chunting Wang
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
| | - S Frank Yan
- Molecular Design and Chemical Biology, Roche Pharma Research and Early Development, Roche Innovation Center Shanghai , Shanghai 201203, China
| | - Gang Liu
- School of Pharmaceutical Sciences, Tsinghua University , Beijing 100084, China
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18
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Wu TYH. Strategies for designing synthetic immune agonists. Immunology 2016; 148:315-25. [PMID: 27213842 DOI: 10.1111/imm.12622] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/04/2016] [Accepted: 05/18/2016] [Indexed: 12/16/2022] Open
Abstract
Enhancing the immune system is a validated strategy to combat infectious disease, cancer and allergy. Nevertheless, the development of immune adjuvants has been hampered by safety concerns. Agents that can stimulate the immune system often bear structural similarities with pathogen-associated molecular patterns found in bacteria or viruses and are recognized by pattern recognition receptors (PRRs). Activation of these PRRs results in the immediate release of inflammatory cytokines, up-regulation of co-stimulatory molecules, and recruitment of innate immune cells. The distribution and duration of these early inflammatory events are crucial in the development of antigen-specific adaptive immunity in the forms of antibody and/or T cells capable of searching for and destroying the infectious pathogens or cancer cells. However, systemic activation of these PRRs is often poorly tolerated. Hence, different strategies have been employed to modify or deliver immune agonists in an attempt to control the early innate receptor activation through temporal or spatial restriction. These approaches include physicochemical manipulation, covalent conjugation, formulation and conditional activation/deactivation. This review will describe recent examples of discovery and optimization of synthetic immune agonists towards clinical application.
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19
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Zhang Y, El-Far M, Dupuy FP, Abdel-Hakeem MS, He Z, Procopio FA, Shi Y, Haddad EK, Ancuta P, Sekaly RP, Said EA. HCV RNA Activates APCs via TLR7/TLR8 While Virus Selectively Stimulates Macrophages Without Inducing Antiviral Responses. Sci Rep 2016; 6:29447. [PMID: 27385120 PMCID: PMC4935957 DOI: 10.1038/srep29447] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/20/2016] [Indexed: 02/08/2023] Open
Abstract
The innate and adaptive immune systems fail to control HCV infection in the majority of infected individuals. HCV is an ssRNA virus, which suggests a role for Toll-like receptors (TLRs) 7 and 8 in initiating the anti-viral response. Here we demonstrate that HCV genomic RNA harbours specific sequences that initiate an anti-HCV immune response through TLR7 and TLR8 in various antigen presenting cells. Conversely, HCV particles are detected by macrophages, but not by monocytes and DCs, through a TLR7/8 dependent mechanism; this leads to chloroquine sensitive production of pro-inflammatory cytokines including IL-1β, while the antiviral type I Interferon response is not triggered in these cells. Antibodies to DC-SIGN, a c-type lectin selectively expressed by macrophages but not pDCs or mDCs, block the production of cytokines. Novel anti-HCV vaccination strategies should target the induction of TLR7/8 stimulation in APCs in order to establish potent immune responses against HCV.
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Affiliation(s)
- Yuwei Zhang
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA
| | - Mohamed El-Far
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Franck P Dupuy
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA.,Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Mohamed S Abdel-Hakeem
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Kasr El-Aini, Cairo 11562, Egypt
| | - Zhong He
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA
| | - Francesco Andrea Procopio
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA
| | - Yu Shi
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA
| | - Elias K Haddad
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA
| | - Petronela Ancuta
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Rafick-Pierre Sekaly
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, Florida 3498, USA.,Case Western Reserve University, Cleveland, Ohio, USA
| | - Elias A Said
- Centre de recherche du centre Hospitalier de l'Université de Montréal (CRCHUM), Hôpital Saint-Luc, Québec H2X 0A9, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Québec H3T 1J4, Canada.,Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, the Sultanate of Oman
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20
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Lebold KM, Jacoby DB, Drake MG. Toll-Like Receptor 7-Targeted Therapy in Respiratory Disease. Transfus Med Hemother 2016; 43:114-9. [PMID: 27226793 DOI: 10.1159/000445324] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/09/2016] [Indexed: 01/01/2023] Open
Abstract
Allergic asthma and allergic rhinitis are inflammatory diseases of the respiratory tract characterized by an excessive type-2 T helper cell (Th2) immune response. Toll-like receptor 7 (TLR7) is a single-stranded viral RNA receptor expressed in the airway that initiates a Th1 immune response and has garnered interest as a novel therapeutic target for treatment of allergic airway diseases. In animal models, synthetic TLR7 agonists reduce airway hyperreactivity, eosinophilic inflammation, and airway remodeling while decreasing Th2-associated cytokines. Furthermore, activation of TLR7 rapidly relaxes airway smooth muscle via production of nitric oxide. Thus, TLR7 has dual bronchodilator and anti-inflammatory effects. Two TLR7 ligands with promising pharmacologic profiles have entered clinical trials for the treatment of allergic rhinitis. Moreover, TLR7 agonists are potential antiviral therapies against respiratory viruses. TLR7 agonists enhance influenza vaccine efficacy and also reduce viral titers when given during an active airway infection. In this review, we examine the current data supporting TLR7 as a therapeutic target in allergic airway diseases.
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Affiliation(s)
- Katie M Lebold
- Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, OR, USA
| | - David B Jacoby
- Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Matthew G Drake
- Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, OR, USA
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21
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Fung J, Lai CL, Seto WK, Yuen MF. Emerging drugs for the treatment of hepatitis B. Expert Opin Emerg Drugs 2016; 21:183-93. [DOI: 10.1517/14728214.2016.1162155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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22
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Shah M, Anwar MA, Kim JH, Choi S. Advances in Antiviral Therapies Targeting Toll-like Receptors. Expert Opin Investig Drugs 2016; 25:437-53. [DOI: 10.1517/13543784.2016.1154040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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23
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Host-Targeting Agents to Prevent and Cure Hepatitis C Virus Infection. Viruses 2015; 7:5659-85. [PMID: 26540069 PMCID: PMC4664971 DOI: 10.3390/v7112898] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 09/25/2015] [Accepted: 10/19/2015] [Indexed: 12/13/2022] Open
Abstract
Chronic hepatitis C virus (HCV) infection is a major cause of liver cirrhosis and hepatocellular carcinoma (HCC) which are leading indications of liver transplantation (LT). To date, there is no vaccine to prevent HCV infection and LT is invariably followed by infection of the liver graft. Within the past years, direct-acting antivirals (DAAs) have had a major impact on the management of chronic hepatitis C, which has become a curable disease in the majority of DAA-treated patients. In contrast to DAAs that target viral proteins, host-targeting agents (HTAs) interfere with cellular factors involved in the viral life cycle. By acting through a complementary mechanism of action and by exhibiting a generally higher barrier to resistance, HTAs offer a prospective option to prevent and treat viral resistance. Indeed, given their complementary mechanism of action, HTAs and DAAs can act in a synergistic manner to reduce viral loads. This review summarizes the different classes of HTAs against HCV infection that are in preclinical or clinical development and highlights their potential to prevent HCV infection, e.g., following LT, and to tailor combination treatments to cure chronic HCV infection.
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24
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Therapeutic vaccines in treating chronic hepatitis B: the end of the beginning or the beginning of the end? Med Microbiol Immunol 2014; 204:121-9. [DOI: 10.1007/s00430-014-0381-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 09/15/2014] [Indexed: 12/13/2022]
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25
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Eyre NS, Helbig KJ, Beard MR. Current and future targets of antiviral therapy in the hepatitis C virus life cycle. Future Virol 2014. [DOI: 10.2217/fvl.14.83] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
ABSTRACT Advances in our understanding of the hepatitis C virus (HCV) life cycle have enabled the development of numerous clinically advanced direct-acting antivirals. Indeed, the recent approval of first-generation direct-acting antivirals that target the viral NS3–4A protease and NS5B RNA-dependent RNA polymerase brings closer the possibility of universally efficacious and well-tolerated antiviral therapies for this insidious infection. However, the complexities of comorbidities, unforeseen side effects or drug–drug interactions, viral diversity, the high mutation rate of HCV RNA replication and the elegant and constantly evolving mechanisms employed by HCV to evade host and therapeutically implemented antiviral strategies remain as significant obstacles to this goal. Here, we review advances in our understanding of the HCV life cycle and associated opportunities for antiviral therapy.
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Affiliation(s)
- Nicholas S Eyre
- School of Molecular & Biomedical Science, The University of Adelaide & Centre for Cancer Biology, SA Pathology, Adelaide, South Australia, Australia
| | - Karla J Helbig
- School of Molecular & Biomedical Science, The University of Adelaide & Centre for Cancer Biology, SA Pathology, Adelaide, South Australia, Australia
| | - Michael R Beard
- School of Molecular & Biomedical Science, The University of Adelaide & Centre for Cancer Biology, SA Pathology, Adelaide, South Australia, Australia
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26
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Patel MC, Shirey KA, Pletneva LM, Boukhvalova MS, Garzino-Demo A, Vogel SN, Blanco JC. Novel drugs targeting Toll-like receptors for antiviral therapy. Future Virol 2014; 9:811-829. [PMID: 25620999 DOI: 10.2217/fvl.14.70] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Toll-like receptors (TLRs) are sentinel receptors of the host innate immune system that recognize conserved 'pathogen-associated molecular patterns' of invading microbes, including viruses. The activation of TLRs establishes antiviral innate immune responses and coordinates the development of long-lasting adaptive immunity in order to control viral pathogenesis. However, microbe-induced damage to host tissues may release 'danger-associated molecular patterns' that also activate TLRs, leading to an overexuberant inflammatory response and, ultimately, to tissue damage. Thus, TLRs have proven to be promising targets as therapeutics for the treatment of viral infections that result in inflammatory damage or as adjuvants in order to enhance the efficacy of vaccines. Here, we explore recent advances in TLR biology with a focus on novel drugs that target TLRs (agonists and antagonists) for antiviral therapy.
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Affiliation(s)
- Mira C Patel
- Department of Microbiology & Immunology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Kari Ann Shirey
- Department of Microbiology & Immunology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | | | | | - Alfredo Garzino-Demo
- Department of Microbiology & Immunology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA ; Institute of Human Virology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Stefanie N Vogel
- Department of Microbiology & Immunology, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
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27
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Lawitz E, Gruener D, Marbury T, Hill J, Webster L, Hassman D, Nguyen AH, Pflanz S, Mogalian E, Gaggar A, Massetto B, Subramanian GM, McHutchison JG, Jacobson IM, Freilich B, Rodriguez-Torres M. Safety, pharmacokinetics and pharmacodynamics of the oral toll-like receptor 7 agonist GS-9620 in treatment-naive patients with chronic hepatitis C. Antivir Ther 2014; 20:699-708. [PMID: 25105516 DOI: 10.3851/imp2845] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND GS-9620 is a potent oral agonist of toll-like receptor 7, a key modulator of the innate immune response. In healthy volunteers, low doses of GS-9620 (2, 4 and 6 mg) induced significant expression of peripheral interferon-stimulated-gene (ISG) mRNA in the absence of detectable serum interferon-α and systemic adverse events (AEs). We evaluated the safety, pharmacokinetics and pharmacodynamics of GS-9620 in treatment-naive patients chronically infected with HCV genotype 1. METHODS In this double-blind, placebo-controlled study, 51 patients were randomized 5:1 (active:placebo) to receive either a single dose or two once-weekly doses of GS-9620 at four dose levels (0.3, 1, 2 and 4 mg) or placebo. Pharmacodynamic assessments included peripheral ISG15 mRNA expression, serum interferon-α and interferon-γ-inducible protein (IP)-10 levels and HCV RNA quantification. RESULTS GS-9620 was well-tolerated at all doses. Most AEs were mild or moderate in severity. GS-9620 exhibited dose-linear pharmacokinetics with a median half-life in plasma of 18 h. Transient, dose-dependent ISG15 induction was observed at 1, 2 and 4 mg, with peak mean fold change within 48 h followed by a decline to baseline levels within 7 days of dosing. Serum interferon-α induction post-baseline was detected in 16.7% (8/48) of patients. No clinically significant reductions in HCV RNA were observed. CONCLUSIONS GS-9620 was safe, well-tolerated and biologically active in patients with HCV infection. Induction of ISG15 occurred in the absence of detectable serum interferon-α or systemic AEs in most patients, supporting a pre-systemic mechanism of action. ClinicalTrials.gov identifier: NCT01591668.
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Affiliation(s)
- Eric Lawitz
- Texas Liver Institute, University of Texas Health Science Center, San Antonio, TX, USA.
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Hou J, Groothuismink ZMA, Koning L, Roomer R, van IJcken WFJ, Kreefft K, Liu BS, Janssen HLA, de Knegt RJ, Boonstra A. Analysis of the transcriptome and immune function of monocytes during IFNα-based therapy in chronic HCV revealed induction of TLR7 responsiveness. Antiviral Res 2014; 109:116-24. [PMID: 25014880 DOI: 10.1016/j.antiviral.2014.06.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/10/2014] [Accepted: 06/30/2014] [Indexed: 01/17/2023]
Abstract
Although in vitro studies have been performed to dissect the mechanism of action of IFNα, detailed in vivo studies on the long-term effects of IFNα on monocytes have not been performed. Here we examined peripheral blood from 14 chronic HCV patients at baseline and 12 weeks after start of IFNα-based therapy. Monocytes were phenotyped by flow-cytometry and their function evaluated upon TLR stimulation and assessed by multiplex cytokine assays. During therapy of HCV patients, monocytes displayed a hyperactive state as evidenced by increased TLR-induced pro-inflammatory cytokine levels, as well as enhanced CD69 and CD83 mRNA and protein expression. Moreover, monocytes from 8 patients at baseline and 12 weeks after start of IFNα-based therapy were transcriptomically profiled by high throughput RNA-sequencing. Detailed RNA-seq analysis of monocytes showed significant ISG mRNA induction during therapy. Importantly, IFNα-based therapy activated TLR7 signaling pathways, as demonstrated by up-regulated expression of TLR7, MyD88, and IRF7 mRNA, whereas other TLR family members as well as CD1c, CLEC4C, and CLEC9A were not induced. The induction of TLR7 responsiveness of monocytes by IFNα in vivo in HCV patients is relevant for the development of TLR7 agonists that are currently under development as a promising immunotherapeutic compounds to treat chronic viral hepatitis.
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Affiliation(s)
- Jun Hou
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Zwier M A Groothuismink
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Ludi Koning
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Robert Roomer
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | | | - Kim Kreefft
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Bi-Sheng Liu
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Harry L A Janssen
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands; Liver Clinic University Health Network, Division of Gastroenterology, University of Toronto, Canada
| | - Robert J de Knegt
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Andre Boonstra
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center Rotterdam, The Netherlands.
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Ireton RC, Gale M. Pushing to a cure by harnessing innate immunity against hepatitis C virus. Antiviral Res 2014; 108:156-64. [PMID: 24907428 DOI: 10.1016/j.antiviral.2014.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/08/2014] [Accepted: 05/23/2014] [Indexed: 02/08/2023]
Abstract
Hepatitis C virus (HCV) causes 350,000 deaths and infects at least 3million people worldwide every year. Currently no vaccine has been developed. Direct-acting antiviral (DAA) drugs with high efficacy for suppressing HCV infection have recently been introduced into the clinic. While DAAs initially required combination therapy with type-1 interferon (IFN) administration for full efficacy and to avoid viral resistance to treatment, new DAA combinations show promise as an IFN-free regimen. However, IFN-free DAA therapy is in its infancy, still to be proven and today is cost-prohibitive for the patient. A major goal in HCV therapy to remove or replace IFN with DAAs or an alternative therapeutic to render virologic response with continued virus sensitivity to DAAs, thus facilitating a cure for infection. Recent advances in our understanding of innate immune responses to HCV have identified new therapeutic targets to combat HCV infection. We discuss how the targeting of innate immune response factors can be harnessed with DAAs to produce new generations of DAA-based HCV therapeutics. This article forms part of a symposium in Antiviral Research on "Hepatitis C: next steps toward global eradication."
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Affiliation(s)
- Reneé C Ireton
- Center for the Study of Innate Immunity to Hepatitis C Virus, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, United States.
| | - Michael Gale
- Center for the Study of Innate Immunity to Hepatitis C Virus, Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, United States.
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30
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Funk E, Kottilil S, Gilliam B, Talwani R. Tickling the TLR7 to cure viral hepatitis. J Transl Med 2014; 12:129. [PMID: 24884741 PMCID: PMC4039542 DOI: 10.1186/1479-5876-12-129] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 04/16/2014] [Indexed: 01/01/2023] Open
Abstract
Chronic hepatitis B and C are the leading causes of liver disease and liver transplantation worldwide. Ability to mount an effective immune response against both HBV and HCV is associated with spontaneous clearance of both infections, while an inability to do so leads to chronicity of both infections. To mount an effective immune response, both innate and adaptive immune responses must work in tandem. Hence, developing protective immunity to hepatitis viruses is an important goal in order to reduce the global burden of these two infections and prevent development of long-term complications. In this regard, the initial interactions between the pathogen and immune system are pivotal in determining the effectiveness of immune response and subsequent elimination of pathogens. Toll-like receptors (TLRs) are important regulators of innate and adaptive immune responses to various pathogens and are often involved in initiating and augmenting effective antiviral immunity. Immune-based therapeutic strategies that specifically induce type I interferon responses are associated with functional cure for both chronic HBV and HCV infections. Precisely, TLR7 stimulation mediates an endogenous type I interferon response, which is critical in development of a broad, effective and protective immunity against hepatitis viruses. This review focuses on anti-viral strategies that involve targeting TLR7 that may lead to development of protective immunity and eradication of hepatitis B.
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Affiliation(s)
- Emily Funk
- Critical Care Medicine Department, Clinical Research Center, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shyam Kottilil
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bruce Gilliam
- Institute of Human Virology at the University of Maryland School of Medicine, 725 West Lombard St. N151, Baltimore, MD 21201, USA
| | - Rohit Talwani
- Institute of Human Virology at the University of Maryland School of Medicine, 725 West Lombard St. N151, Baltimore, MD 21201, USA
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31
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Hussein WM, Liu TY, Skwarczynski M, Toth I. Toll-like receptor agonists: a patent review (2011 - 2013). Expert Opin Ther Pat 2014; 24:453-70. [PMID: 24456079 DOI: 10.1517/13543776.2014.880691] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Toll-like receptors (TLRs) are a crucial part of the innate immunity and present the first line of defense against pathogens. In humans, there are ten TLRs, with TLR3, 7, 8 and 9 located in intracellular vesicles and the remaining expressed on the cell surface. These transmembrane protein receptors recognize a wide range of pathogen components. A large number of TLR agonists, either derived from pathogen components or modified synthetic molecules, were developed and investigated for their ability to stimulate an immune response. AREAS COVERED This review includes an updated summary (2011 - 2013) of TLR agonists that have been published in patent applications and/or progressed to clinical studies, with an emphasis on their chemical structure, immune response, prophylactic and therapeutic outcomes. EXPERT OPINION A number of factors have contributed to the design and development of TLR agonists such as solving the crystal structures of TLR bound to their ligands, improvements in our understanding of the signaling pathway activated after TLR stimulation and the identification of the native ligands of all human TLRs. Some of the TLR agonists have been approved for human use by the FDA while others have reached clinical studies in Phases I, II and III. Generally, immunotherapy based on TLR agonists is very promising for the prevention and/or treatment of several disorders including cancer, allergy and microbial infections. However, many TLR agonists were withdrawn from further studies as they either lacked efficacy or caused serious side effects.
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Affiliation(s)
- Waleed M Hussein
- The University of Queensland, School of Chemistry and Molecular Biosciences , St. Lucia, Brisbane, Qld 4072 , Australia
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32
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Savva A, Roger T. Targeting toll-like receptors: promising therapeutic strategies for the management of sepsis-associated pathology and infectious diseases. Front Immunol 2013; 4:387. [PMID: 24302927 PMCID: PMC3831162 DOI: 10.3389/fimmu.2013.00387] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 11/05/2013] [Indexed: 01/04/2023] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. TLRs are also triggered by danger signals released by injured or stressed cells during sepsis. Here we focus on studies developing TLR agonists and antagonists for the treatment of infectious diseases and sepsis. Positioned at the cell surface, TLR4 is essential for sensing lipopolysaccharide of Gram-negative bacteria, TLR2 is involved in the recognition of a large panel of microbial ligands, while TLR5 recognizes flagellin. Endosomal TLR3, TLR7, TLR8, TLR9 are specialized in the sensing of nucleic acids produced notably during viral infections. TLR4 and TLR2 are favorite targets for developing anti-sepsis drugs, and antagonistic compounds have shown efficient protection from septic shock in pre-clinical models. Results from clinical trials evaluating anti-TLR4 and anti-TLR2 approaches are presented, discussing the challenges of study design in sepsis and future exploitation of these agents in infectious diseases. We also report results from studies suggesting that the TLR5 agonist flagellin may protect from infections of the gastrointestinal tract and that agonists of endosomal TLRs are very promising for treating chronic viral infections. Altogether, TLR-targeted therapies have a strong potential for prevention and intervention in infectious diseases, notably sepsis.
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Affiliation(s)
- Athina Savva
- Infectious Diseases Service, Department of Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne , Lausanne , Switzerland
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33
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Helbig ET, Opitz B, Sander LE. Adjuvant immunotherapies as a novel approach to bacterial infections. Immunotherapy 2013; 5:365-81. [PMID: 23557420 DOI: 10.2217/imt.13.17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The rapid emergence of multidrug-resistant pathogens, especially Gram-negative bacteria and mycobacteria, represents one of the major medical challenges of the 21st century. The gradual loss of effective classical antibiotics for many bacterial pathogens, combined with an increasing population density and mobility, urgently calls for the development of novel treatments. Here, we discuss the potential of adjuvant immunotherapies to selectively stimulate protective immune responses as a treatment option for bacterial infections. In order to elicit appropriate immune responses and to avoid unwanted inflammatory tissue damage, it is essential to identify ligands and receptor pathways that specifically control protective responses at the site of infection. We summarize existing data and discuss suitable candidate targets for future immunotherapies of infectious diseases.
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Affiliation(s)
- Elisa T Helbig
- Department of Infectious Diseases & Pulmonary Medicine, Charité University Hospital, Augustenburger Platz 1, 13353 Berlin, Germany
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34
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Roethle PA, McFadden RM, Yang H, Hrvatin P, Hui H, Graupe M, Gallagher B, Chao J, Hesselgesser J, Duatschek P, Zheng J, Lu B, Tumas DB, Perry J, Halcomb RL. Identification and Optimization of Pteridinone Toll-like Receptor 7 (TLR7) Agonists for the Oral Treatment of Viral Hepatitis. J Med Chem 2013; 56:7324-33. [DOI: 10.1021/jm400815m] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Paul A. Roethle
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Ryan M. McFadden
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Hong Yang
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Paul Hrvatin
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Hon Hui
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Michael Graupe
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Brian Gallagher
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Jessica Chao
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Joseph Hesselgesser
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Paul Duatschek
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Jim Zheng
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Bing Lu
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Daniel B. Tumas
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Jason Perry
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Randall L. Halcomb
- Departments of †Medicinal Chemistry, ‡Clinical Virology, §Drug Metabolism, ∥Biology, and ⊥Structural Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
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35
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Zoulim F, Luangsay S, Durantel D. Targeting innate immunity: a new step in the development of combination therapy for chronic hepatitis B. Gastroenterology 2013; 144:1342-4. [PMID: 23710602 DOI: 10.1053/j.gastro.2013.04.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Lanford RE, Guerra B, Chavez D, Giavedoni L, Hodara VL, Brasky KM, Fosdick A, Frey CR, Zheng J, Wolfgang G, Halcomb RL, Tumas DB. GS-9620, an oral agonist of Toll-like receptor-7, induces prolonged suppression of hepatitis B virus in chronically infected chimpanzees. Gastroenterology 2013; 144:1508-17, 1517.e1-10. [PMID: 23415804 PMCID: PMC3691056 DOI: 10.1053/j.gastro.2013.02.003] [Citation(s) in RCA: 304] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 01/12/2013] [Accepted: 02/06/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Direct-acting antiviral agents suppress hepatitis B virus (HBV) load, but they require life-long use. Stimulation of the innate immune system could increase its ability to control the virus and have long-lasting effects after a finite regimen. We investigated the effects of immune activation with GS-9620--a potent and selective orally active small molecule agonist of Toll-like receptor 7--in chimpanzees with chronic HBV infection. METHODS GS-9620 was administered to chimpanzees every other day (3 times each week) for 4 weeks at 1 mg/kg and, after a 1-week rest, for 4 weeks at 2 mg/kg. We measured viral load in plasma and liver samples, the pharmacokinetics of GS-9620, and the following pharmacodynamics parameters: interferon-stimulated gene expression, cytokine and chemokine levels, lymphocyte and natural killer cell activation, and viral antigen expression. Clinical pathology parameters were monitored to determine the safety and tolerability of GS-9620. RESULTS Short-term oral administration of GS-9620 provided long-term suppression of serum and liver HBV DNA. The mean maximum reduction of viral DNA was 2.2 logs, which occurred within 1 week of the end of GS-9620 administration; reductions of >1 log persisted for months. Serum levels of HBV surface antigen and HBV e antigen, and numbers of HBV antigen-positive hepatocytes, were reduced as hepatocyte apoptosis increased. GS-9620 administration induced production of interferon-α and other cytokines and chemokines, and activated interferon-stimulated genes, natural killer cells, and lymphocyte subsets. CONCLUSIONS The small molecule GS-9620 activates Toll-like receptor 7 signaling in immune cells of chimpanzees to induce clearance of HBV-infected cells. This reagent might be developed for treatment of patients with chronic HBV infection.
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Affiliation(s)
- Robert E Lanford
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas 78227, USA.
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Doyle JS, Aspinall E, Liew D, Thompson AJ, Hellard ME. Current and emerging antiviral treatments for hepatitis C infection. Br J Clin Pharmacol 2013; 75:931-43. [PMID: 22882367 PMCID: PMC3612710 DOI: 10.1111/j.1365-2125.2012.04419.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 08/07/2012] [Indexed: 12/21/2022] Open
Abstract
Newly licensed direct acting antivirals for hepatitis C virus HCV are able to cure up to 75% of patients chronically infected with genotype-1 infection, which is the predominant HCV strain in Europe and North America. Emerging antiviral therapies promise further increases in virological response, as well as improved tolerability, reduced duration of therapy, and will potentially eliminate the need for interferon use. This review highlights the main therapeutic agents used in current standard of care, including telaprevir and boceprevir. It goes on to evaluate the mechanisms of emerging drugs, their stage of development and response rates seen in research to date. Finally, it projects into the not too distant future to consider treatment strategies involving combinations of agents and interferon-free therapies, and in which patients they might prove most successful.
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Affiliation(s)
- Joseph S Doyle
- Centre for Population Health, Burnet Institute, Melbourne, Victoria, Australia.
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38
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Es-Saad S, Tremblay N, Baril M, Lamarre D. Regulators of innate immunity as novel targets for panviral therapeutics. Curr Opin Virol 2012; 2:622-8. [PMID: 23017246 PMCID: PMC7102864 DOI: 10.1016/j.coviro.2012.08.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 08/30/2012] [Indexed: 12/21/2022]
Abstract
Interferons (IFNs) have long been used as an immunomodulatory therapy for a large array of acute and chronic viral infections. However, IFN therapies have been plagued by severe side effects. The discovery of pathogen recognition receptors (PRR) rejuvenated the interest for immunomodulatory therapies. The successes obtained with Toll-like receptor (TLR) agonists in activating immune cells and as adjuvant for prophylactic vaccines against different viruses paved the way to targeted immunomodulatory therapy. Better characterization of pathogen-induced immune disorders and newly discovered regulators of innate immunity have now the potential to specifically withdraw prevailing subversion mechanisms and to transform antiviral treatments by introducing panviral therapeutics with less adverse effects than IFN therapies.
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Affiliation(s)
- Salwa Es-Saad
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Montréal, Québec, Canada
| | - Nicolas Tremblay
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Montréal, Québec, Canada
| | - Martin Baril
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Montréal, Québec, Canada
| | - Daniel Lamarre
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Montréal, Québec, Canada
- Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
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Abstract
The immune response in patients chronically infected with HCV plays a unique role during the infection because of its potential to contribute not only to viral clearance and, in some cases, protective immunity, but also to liver injury. A detailed understanding of the immunological mechanisms involved in persistence to HCV is essential to fully appreciate the complexity of the disease. In recent years, enormous progress has been made to characterize the dysfunctional natural killer cells and T cells during the chronic phase of infection. This information is important to further optimize treatment strategies based on the strengthening antiviral and immunomodulatory activities in patients chronically infected with HCV.
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Affiliation(s)
- Michelle Spaan
- Liver Unit, Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
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40
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Koga-Yamakawa E, Dovedi SJ, Murata M, Matsui H, Leishman AJ, Bell J, Ferguson D, Heaton SP, Oki T, Tomizawa H, Bahl A, Takaku H, Wilkinson RW, Harada H. Intratracheal and oral administration of SM-276001: a selective TLR7 agonist, leads to antitumor efficacy in primary and metastatic models of cancer. Int J Cancer 2012; 132:580-90. [PMID: 22733292 DOI: 10.1002/ijc.27691] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/18/2012] [Accepted: 05/30/2012] [Indexed: 11/09/2022]
Abstract
Topical TLR7 agonists such as imiquimod are highly effective for the treatment of dermatological malignancies; however, their efficacy in the treatment of nondermatological tumors has been less successful. We report that oral administration of the novel TLR7-selective small molecule agonist; SM-276001, leads to the induction of an inflammatory cytokine and chemokine milieu and to the activation of a diverse population of immune effector cells including T and B lymphocytes, NK and NKT cells. Oral administration of SM-276001 leads to the induction of IFNα, TNFα and IL-12p40 and a reduction in tumor burden in the Balb/c syngeneic Renca and CT26 models. Using the OV2944-HM-1 model of ovarian cancer which spontaneously metastasizes to the lungs following subcutaneous implantation, we evaluated the efficacy of intratracheal and oral administration of SM-276001 in an adjuvant setting following surgical resection of the primary tumor. We show that both oral and intratracheal TLR7 therapy can reduce the frequency of pulmonary metastasis, and metastasis to the axillary lymph nodes. These results demonstrate that SM-276001 is a potent selective TLR7 agonist that can induce antitumor immune responses when dosed either intratracheally or orally.
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Affiliation(s)
- Erina Koga-Yamakawa
- Pharmacology Research Laboratories, Drug Research Division, Dainippon Sumitomo Pharma, 3-1-98, Kasugade Naka, Konohana-ku, Osaka, Japan.
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41
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Connolly DJ, O'Neill LAJ. New developments in Toll-like receptor targeted therapeutics. Curr Opin Pharmacol 2012; 12:510-8. [PMID: 22748800 DOI: 10.1016/j.coph.2012.06.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Accepted: 06/06/2012] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLRs) play a crucial role in host defence and inflammation. Given that a significant amount of evidence implicates TLRs in the pathogenesis of immune diseases and cancer, and their activation occurs early in the inflammatory cascade, they are attractive targets for novel therapeutic agents. Potential therapeutics include TLR-targeted antibodies, small molecules and nucleic acid based drugs. Agonists are being tested in vaccines against hepatitis C and influenza as well as in allergic rhinitis and certain cancers. Antagonists are being tested in ischemia/reperfusion injury, systemic lupus erythematosus and psoriasis. The prospect of targeting TLRs in multiple pathologies continues to hold much promise.
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Affiliation(s)
- Dympna J Connolly
- Trinity Biomedical Sciences Institute, School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Ireland
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Abstract
Despite the availability of effective combination antiretroviral therapy (cART), liver disease is one of the leading causes of morbidity and mortality in Human Immunodeficiency Virus (HIV)-infected individuals, specifically, in the presence of viral hepatitis coinfection. HIV, a single stranded RNA virus, can bind to and activate both Toll-like receptor (TLR)7 and TLR8 in circulating blood mononuclear cells, but little is known about the effect of HIV on TLRs expressed in the liver. HIV can directly infect cells of the liver and HIV-mediated depletion of CD4+ T-cells in the gastrointestinal tract (GI tract) results in increased circulating lipopolysaccharide (LPS), both of which may impact on TLR signaling in the liver and subsequent liver disease progression. The potential direct and indirect effects of HIV on TLR signaling in the liver will be explored in this paper.
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Boonstra A, Liu BS, Groothuismink ZMA, Bergmann JF, de Bruijne J, Hotho DM, Hansen BE, van Vliet AA, van de Wetering de Rooij J, Fletcher SP, Bauman LA, Rahimy M, Appleman JR, Freddo JL, Reesink HW, de Knegt RJ, Janssen HLA. Potent immune activation in chronic hepatitis C patients upon administration of an oral inducer of endogenous interferons that acts via Toll-like receptor 7. Antivir Ther 2011; 17:657-67. [PMID: 22301364 DOI: 10.3851/imp2023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND ANA773, an oral prodrug of a small-molecule Toll-like receptor (TLR)7 agonist, induces a dose-related decrease in serum HCV RNA levels in chronic hepatitis C patients. METHODS The prodrug ANA773 was administered to healthy individuals and chronic hepatitis C patients. At different time points during the course of treatment, modulation of the phenotype and function of peripheral leukocytes were evaluated to determine the role of distinct immune cells on the clinical outcome of therapy. RESULTS Early after administration of the TLR7 agonist, a mild transient reduction of the number of lymphocytes was observed in both healthy individuals and chronic hepatitis C patients. Moreover, repeated administration of ANA773 resulted in transiently reduced numbers of myeloid and plasmacytoid dendritic cells (DC) in blood. Interestingly, reduced plasmacytoid DC numbers as well as increased serum interferon (IFN)-α and IFN-γ inducible protein (IP)-10 levels were observed only in virological responders (≥1 log(10) IU/ml reduction of HCV RNA levels upon ANA773 treatment), but were absent in virological non-responders. In vitro stimulation of peripheral blood mononuclear cells from virological responders showed a high frequency of IFN-α-producing plasmacytoid DC upon stimulation in vitro with ANA773, whereas no IFN-α was induced in non-responders. CONCLUSIONS These findings indicate that the viral load decline in chronic hepatitis C patients treated with the TLR7 agonist ANA773 is likely due to intrinsic differences in the induction of endogenous IFNs and IFN-stimulated gene products (IFN-α and IP-10) upon TLR7 ligation.
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Affiliation(s)
- Andre Boonstra
- Department of Gastroenterology and Hepatology, Erasmus Medical Center University Hospital, Rotterdam, the Netherlands.
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Jansen PLM, De Bruijne J. Controlled-release interferon alpha 2b, a new member of the interferon family for the treatment of chronic hepatitis C. Expert Opin Investig Drugs 2011; 21:111-8. [PMID: 22126968 DOI: 10.1517/13543784.2012.640671] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Combination therapy with pegylated interferon alpha (Peg-interferon) and ribavirin is currently the cornerstone of antiviral therapy for chronic hepatitis C. Monotherapy with Peg-interferon still is important for the treatment of chronic hepatitis B. With the advent of new therapies, protease inhibitors for chronic hepatitis C and nucleotide inhibitors for chronic hepatitis B, there remains a need for interferon-based therapies. The side effects of Peg-interferon are a main disadvantage and represent a stumbling block for many patients to enter and continue therapy. AREAS COVERED In this review, the authors will discuss controlled-release interferon alpha 2b (CR2b) (Locteron®, Biolex Therapeutics, Pittsboro, NC, USA), a new slow-release interferon alpha 2b preparation for the treatment of chronic viral hepatitis. Other alternative interferons will also be discussed. EXPERT OPINION CR2b is a slow-release microsphere preparation for the administration of plant-derived recombinant human interferon alpha 2b. Compared with Peg-interferon, treatment with CR2b shows less flu-like reactions and less depression, and is at least as effective as conventional Peg-interferon-based therapy in patients with chronic hepatitis C. CR2b has the added advantage of biweekly instead of once weekly administration. CR2b appears to cause more neutropenia than Peg-interferon alpha 2b. This may be due to higher trough serum levels of CR2b at the end of a dosing interval. The bone marrow effects of CR2b closely resemble those published for the registered Peg-interferon alpha 2a. CR2b appears to have at least comparable efficacy with fewer side effects than current registered Peg-interferons.
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Affiliation(s)
- Peter L M Jansen
- Academic Medical Center, Department of Gastroenterology and Hepatology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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