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Malik JA, Kaur G, Agrewala JN. Revolutionizing medicine with toll-like receptors: A path to strengthening cellular immunity. Int J Biol Macromol 2023; 253:127252. [PMID: 37802429 DOI: 10.1016/j.ijbiomac.2023.127252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 10/01/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
Toll-like receptors play a vital role in cell-mediated immunity, which is crucial for the immune system's defense against pathogens and maintenance of homeostasis. The interaction between toll-like-receptor response and cell-mediated immunity is complex and essential for effectively eliminating pathogens and maintaining immune surveillance. In addition to pathogen recognition, toll-like receptors serve as adjuvants in vaccines, as molecular sensors, and recognize specific patterns associated with pathogens and danger signals. Incorporating toll-like receptor ligands into vaccines can enhance the immune response to antigens, making them potent adjuvants. Furthermore, they bridge the innate and adaptive immune systems and improve antigen-presenting cells' capacity to process and present antigens to T cells. The intricate signaling pathways and cross-talk between toll-like-receptor and T cell receptor (TCR) signaling emphasize their pivotal role in orchestrating effective immune responses against pathogens, thus facilitating the development of innovative vaccine strategies. This article provides an overview of the current understanding of toll-like receptor response and explores their potential clinical applications. By unraveling the complex mechanisms of toll-like-receptor signaling, we can gain novel insights into immune responses and potentially develop innovative therapeutic approaches. Ongoing investigations into the toll-like-receptor response hold promise in the future in enhancing our ability to combat infections, design effective vaccines, and improve clinical outcomes.
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Affiliation(s)
- Jonaid Ahmad Malik
- Immunology Laboratory, Department of Biomedical Engineering, Indian Institute of Technology, Ropar, Punjab 140001, India
| | - Gurpreet Kaur
- Immunology Laboratory, Department of Biomedical Engineering, Indian Institute of Technology, Ropar, Punjab 140001, India; Department of Biotechnology, Chandigarh Group of Colleges, Landran, Mohali, Punjab 140055, India
| | - Javed N Agrewala
- Immunology Laboratory, Department of Biomedical Engineering, Indian Institute of Technology, Ropar, Punjab 140001, India.
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Abstract
The innate immune system is critical for inducing durable and protective T cell responses to infection and has been increasingly recognized as a target for cancer immunotherapy. In this review, we present a framework wherein distinct innate immune signaling pathways activate five key dendritic cell activities that are important for T cell-mediated immunity. We discuss molecular pathways that can agonize these activities and highlight that no single pathway can agonize all activities needed for durable immunity. The immunological distinctions between innate immunotherapy administration to the tumor microenvironment versus administration via vaccination are examined, with particular focus on the strategies that enhance dendritic cell migration, interferon expression, and interleukin-1 family cytokine production. In this context, we argue for the importance of appreciating necessity vs. sufficiency when considering the impact of innate immune signaling in inflammation and protective immunity and offer a conceptual guideline for the development of efficacious cancer immunotherapies.
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Affiliation(s)
- Longyue L Cao
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA, USA
| | - Jonathan C Kagan
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA, USA.
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Wang X, Qiu W, Liu H, He M, He W, Li Z, Wu Z, Xu X, Chen P. The inducible secreting TLR5 agonist, CBLB502, enhances the anti-tumor activity of CAR133-NK92 cells in colorectal cancer. Cancer Biol Med 2023; 20:j.issn.2095-3941.2023.0033. [PMID: 37731205 PMCID: PMC10546094 DOI: 10.20892/j.issn.2095-3941.2023.0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 07/17/2023] [Indexed: 09/22/2023] Open
Abstract
OBJECTIVE CAR-T/NK cells have had limited success in the treatment of solid tumors, such as colorectal cancer (CRC), in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative relapse after the initial response. This barrier might be overcome by enhancing the recruitment and durability of endogenous immune cells. METHODS Immunohistochemistry and flow cytometry were used to assess the expression of CD133 antigen in tissue microarrays and cell lines, respectively. Retroviral vector transduction was used to generate CBLB502-secreting CAR133-NK92 cells (CAR133-i502-NK92). The tumor killing capacity of CAR133-NK92 cells in vitro and in vivo were quantified via LDH release, the RTCA assay, and the degranulation test, as well as measuring tumor bioluminescence signal intensity in mice xenografts. RESULTS We engineered CAR133-i502-NK92 cells and demonstrated that those cells displayed enhanced proliferation (9.0 × 104 cells vs. 7.0 × 104 cells) and specific anti-tumor activities in vitro and in a xenogeneic mouse model, and were well-tolerated. Notably, CBLB502 secreted by CAR133-i502-NK92 cells effectively activated endogenous immune cells. Furthermore, in hCD133+/hCD133- mixed cancer xenograft models, CAR133-i502-NK92 cells suppressed cancer growth better than the counterparts (n = 5, P = 0.0297). Greater T-cell infiltration was associated with greater anti-tumor potency (P < 0.0001). CONCLUSIONS Armed with a CBLB502 TLR5 agonist, CAR133-NK92 cells were shown to be capable of specifically eliminating CD133-positive colon cancer cells in a CAR133-dependent manner and indirectly eradicating CD133-negative colon cancer cells in a CBLB502-specific endogenous immune response manner. This study describes a novel technique for optimizing CAR-T/NK cells for the treatment of antigenically-diverse solid tumors.
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Affiliation(s)
- Xiaohui Wang
- College of Biotechnology, Southwest University, Chongqing 400715, China
- Department of Stem Cell & Regenerative Medicine, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Wei Qiu
- Department of Dermatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325035, China
| | - Haoyu Liu
- College of Biotechnology, Southwest University, Chongqing 400715, China
| | - Min He
- Department of Stem Cell & Regenerative Medicine, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Wei He
- College of Biotechnology, Southwest University, Chongqing 400715, China
| | - Zhan Li
- Department of Stem Cell & Regenerative Medicine, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Zhiqiang Wu
- Department of Biotherapeutics, The First Medical Center, Chinese PLA General Hospital, Beijing 100038, China
| | - Xiang Xu
- Department of Stem Cell & Regenerative Medicine, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Ping Chen
- College of Biotechnology, Southwest University, Chongqing 400715, China
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5
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Abstract
Immunotherapy continues to be in the spotlight of oncology therapy research in the past few years and has been proven to be a promising option to modulate one's innate and adaptive immune systems for cancer treatment. However, the poor delivery efficiency of immune agents, potential off-target toxicity, and nonimmunogenic tumors significantly limit its effectiveness and extensive application. Recently, emerging biomaterial-based drug carriers, including but not limited to immune cells and bacteria, are expected to be potential candidates to break the dilemma of immunotherapy, with their excellent natures of intrinsic tumor tropism and immunomodulatory activity. More than that, the tiny vesicles and physiological components derived from them have similar functions with their source cells due to the inheritance of various surface signal molecules and proteins. Herein, we presented representative examples about the latest advances of biomaterial-based delivery systems employed in cancer immunotherapy, including immune cells, bacteria, and their derivatives. Simultaneously, opportunities and challenges of immune cells and bacteria-based carriers are discussed to provide reference for their future application in cancer immunotherapy.
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Affiliation(s)
- Jingwen Jiang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
| | - Yanjuan Huang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
| | - Zishan Zeng
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
| | - Chunshun Zhao
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
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6
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Yang Y, Li H, Fotopoulou C, Cunnea P, Zhao X. Toll-like receptor-targeted anti-tumor therapies: Advances and challenges. Front Immunol 2022; 13:1049340. [PMID: 36479129 PMCID: PMC9721395 DOI: 10.3389/fimmu.2022.1049340] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors, originally discovered to stimulate innate immune reactions against microbial infection. TLRs also play essential roles in bridging the innate and adaptive immune system, playing multiple roles in inflammation, autoimmune diseases, and cancer. Thanks to the immune stimulatory potential of TLRs, TLR-targeted strategies in cancer treatment have proved to be able to regulate the tumor microenvironment towards tumoricidal phenotypes. Quantities of pre-clinical studies and clinical trials using TLR-targeted strategies in treating cancer have been initiated, with some drugs already becoming part of standard care. Here we review the structure, ligand, signaling pathways, and expression of TLRs; we then provide an overview of the pre-clinical studies and an updated clinical trial watch targeting each TLR in cancer treatment; and finally, we discuss the challenges and prospects of TLR-targeted therapy.
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Affiliation(s)
- Yang Yang
- Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, China
| | - Hongyi Li
- Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, China
| | - Christina Fotopoulou
- Division of Cancer, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Paula Cunnea
- Division of Cancer, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Xia Zhao
- Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Department of Gynecology and Obstetrics, West China Second Hospital, Sichuan University, Chengdu, China
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7
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Peng Y, Wang Y, Wang M, Lan J, Chen Y. Therapeutic applications of toll-like receptors (TLRs) agonists in AML. Clin Transl Oncol 2022. [PMID: 35962918 DOI: 10.1007/s12094-022-02917-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/27/2022] [Indexed: 10/15/2022]
Abstract
Acute myeloid leukemia (AML) is an aggressive type of blood cancer affecting bone marrow (BM). In AML, hematopoietic precursors are arrested in the early stages of development and are defined as the presence of ≥ 20% blasts (leukemia cells) in the BM. Toll-like receptors (TLR) are major groups of pattern recognition receptors expressed by almost all innate immune cells that enable them to detect a wide range of pathogen-associated molecular patterns and damage-associated molecular patterns to prime immune responses toward adaptive immunity. Because TLRs are commonly expressed on transformed immune system cells (ranging from blasts to memory cells), they can be a potential option for developing efficient clinical alternatives in hematologic tumors. This is because several in vitro and in vivo investigations have demonstrated that TLR signaling increased the immunogenicity of AML cells, making them more vulnerable to T cell-mediated invasion. This study aimed to review the current knowledge in this field and provide some insight into the therapeutic potentials of TLRs in AML.
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8
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Alekseenko IV, Pleshkan VV, Kuzmich AI, Kondratieva SA, Sverdlov ED. Gene-Immune Therapy of Cancer: Approaches and Problems. RUSS J GENET+ 2022. [DOI: 10.1134/s1022795422040020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Sartorius R, Trovato M, Manco R, D'Apice L, De Berardinis P. Exploiting viral sensing mediated by Toll-like receptors to design innovative vaccines. NPJ Vaccines 2021; 6:127. [PMID: 34711839 PMCID: PMC8553822 DOI: 10.1038/s41541-021-00391-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/01/2021] [Indexed: 12/12/2022] Open
Abstract
Toll-like receptors (TLRs) are transmembrane proteins belonging to the family of pattern-recognition receptors. They function as sensors of invading pathogens through recognition of pathogen-associated molecular patterns. After their engagement by microbial ligands, TLRs trigger downstream signaling pathways that culminate into transcriptional upregulation of genes involved in immune defense. Here we provide an updated overview on members of the TLR family and we focus on their role in antiviral response. Understanding of innate sensing and signaling of viruses triggered by these receptors would provide useful knowledge to prompt the development of vaccines able to elicit effective and long-lasting immune responses. We describe the mechanisms developed by viral pathogens to escape from immune surveillance mediated by TLRs and finally discuss how TLR/virus interplay might be exploited to guide the design of innovative vaccine platforms.
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Affiliation(s)
- Rossella Sartorius
- Institute of Biochemistry and Cell Biology, C.N.R., Via Pietro Castellino 111, 80131, Naples, Italy.
| | - Maria Trovato
- Institute of Biochemistry and Cell Biology, C.N.R., Via Pietro Castellino 111, 80131, Naples, Italy
| | - Roberta Manco
- Institute of Biochemistry and Cell Biology, C.N.R., Via Pietro Castellino 111, 80131, Naples, Italy
| | - Luciana D'Apice
- Institute of Biochemistry and Cell Biology, C.N.R., Via Pietro Castellino 111, 80131, Naples, Italy.
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Shi T, Jiang J, Gao M, Ma R, Chen X, Zhang R, Xu J, Wang W, Xu S, Liu X, Zheng H, Wang C, Li L, Li R. Editing flagellin derivatives for exploration of potent radioprotective agents. Eur J Pharmacol 2021; 907:174259. [PMID: 34153338 DOI: 10.1016/j.ejphar.2021.174259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/01/2021] [Accepted: 06/11/2021] [Indexed: 11/30/2022]
Abstract
Exploration of medical radiation countermeasures (MRCs) has great implications in protection of mammals from radiation damages. While flagellin has been recently reported to show radioprotective effects, the relationships between flagellin structure and radioprotective activity are rarely explored. Herein, we deliberately edited the amino acid sequence of flagellin in its binding domain with toll-like receptor 5 (TLR5) for exploration of potent flagellin derivatives (Fds). An in vitro screening paradigm was developed to examine the radioprotective effects of six engineered Fds. Notably, mutation of 103 threonine on flagellin into asparagine resulted in a potent MRC candidate (Fd-T103N) displaying 1.28-fold increment of interactions with TLR5. Fd-T103N was able to further activate NF-κB pathway, induce immune protective cytokine (e.g. G-CSF) release, and significantly ameliorate γ-irradiation induced cell death. The protection effects of Fd-T103N were further validated in mice exposed to 10 Gy γ-irradiations. Compared to parent flagellin, Fd-T103N treatment showed higher G-CSF release in mouse blood, lower intestine damages, and 13% increments of mouse survival rates. In short, the established predictive paradigm could greatly reduce the labor-, time- and animal-costs in exploration of MRC candidates. Fd-T103N is a promising candidate of investigational new drug for radioprotection.
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Affiliation(s)
- Tong Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Jun Jiang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Meng Gao
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Ronglin Ma
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Xuejun Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Ruihua Zhang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Jianfu Xu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Weili Wang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Shujuan Xu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Xi Liu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Huizhen Zheng
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Chen Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Liqin Li
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Ruibin Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, Jiangsu, China.
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11
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Pahlavanneshan S, Sayadmanesh A, Ebrahimiyan H, Basiri M. Toll-Like Receptor-Based Strategies for Cancer Immunotherapy. J Immunol Res 2021; 2021:9912188. [PMID: 34124272 PMCID: PMC8166496 DOI: 10.1155/2021/9912188] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/28/2021] [Accepted: 05/09/2021] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are expressed and play multiple functional roles in a variety of immune cell types involved in tumor immunity. There are plenty of data on the pharmacological targeting of TLR signaling using agonist molecules that boost the antitumor immune response. A recent body of research has also demonstrated promising strategies for improving the cell-based immunotherapy methods by inducing TLR signaling. These strategies include systemic administration of TLR antagonist along with immune cell transfer and also genetic engineering of the immune cells using TLR signaling components to improve the function of genetically engineered immune cells such as chimeric antigen receptor-modified T cells. Here, we explore the current status of the cancer immunotherapy approaches based on manipulation of TLR signaling to provide a perspective of the underlying rationales and potential clinical applications. Altogether, reviewed publications suggest that TLRs make a potential target for the immunotherapy of cancer.
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Affiliation(s)
- Saghar Pahlavanneshan
- Functional Neurosurgery Research Center, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Sayadmanesh
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Hamidreza Ebrahimiyan
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Mohsen Basiri
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
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12
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Mett V, Kurnasov OV, Bespalov IA, Molodtsov I, Brackett CM, Burdelya LG, Purmal AA, Gleiberman AS, Toshkov IA, Burkhart CA, Kogan YN, Andrianova EL, Gudkov AV, Osterman AL. A deimmunized and pharmacologically optimized Toll-like receptor 5 agonist for therapeutic applications. Commun Biol 2021; 4:466. [PMID: 33846531 PMCID: PMC8041767 DOI: 10.1038/s42003-021-01978-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/11/2021] [Indexed: 12/21/2022] Open
Abstract
The Toll-like receptor 5 (TLR5) agonist entolimod, a derivative of Salmonella flagellin, has therapeutic potential for several indications including radioprotection and cancer immunotherapy. However, in Phase 1 human studies, entolimod induced a rapid neutralizing immune response, presumably due to immune memory from prior exposure to flagellated enterobacteria. To enable multi-dose applications, we used structure-guided reengineering to develop a next-generation, substantially deimmunized entolimod variant, GP532. GP532 induces TLR5-dependent NF-κB activation like entolimod but is smaller and has mutations eliminating an inflammasome-activating domain and key B- and T-cell epitopes. GP532 is resistant to human entolimod-neutralizing antibodies and shows reduced de novo immunogenicity. GP532 also has improved bioavailability, a stronger effect on key cytokine biomarkers, and a longer-lasting effect on NF-κB. Like entolimod, GP532 demonstrated potent prophylactic and therapeutic efficacy in mouse models of radiation-induced death and tissue damage. These results establish GP532 as an optimized TLR5 agonist suitable for multi-dose therapies and for patients with high titers of preexisting flagellin-neutralizing antibodies.
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Affiliation(s)
| | - Oleg V Kurnasov
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | | | - Ivan Molodtsov
- Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
| | | | | | | | | | | | | | | | | | - Andrei V Gudkov
- Genome Protection, Inc., Buffalo, NY, USA. .,Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.
| | - Andrei L Osterman
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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Zhou Z, Qi J, Yang D, Yang MS, Jeong H, Lim CW, Kim JW, Kim B. Exogenous activation of toll-like receptor 5 signaling mitigates acetaminophen-induced hepatotoxicity in mice. Toxicol Lett 2021; 342:58-72. [PMID: 33571619 DOI: 10.1016/j.toxlet.2021.01.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 01/06/2021] [Accepted: 01/28/2021] [Indexed: 02/06/2023]
Abstract
Acetaminophen (APAP) poisoning is the most common cause of drug-induced acute liver injury (ALI). Our results showed that toll-like receptor 5 (TLR5) was abundantly expressed in hepatocytes and dramatically downregulated in the toxic mouse livers. Hence, we herein investigated the role of TLR5 signaling after APAP overdose. Mice were intraperitoneally (i.p.) injected with APAP to induce ALI, and then injected with flagellin at one hour after APAP administration. Flagellin attenuated APAP-induced ALI based on decreased histopathologic lesions, serum biochemical, oxidative stress, and inflammation. Furthermore, the protective effects of flagellin were abolished by TH1020 (a TLR5 antagonist) treatment. These results suggest that flagellin exerted protective effects on ALI via TLR5 activation. Mechanistically, flagellin injection promoted the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus in hepatocytes. Consistent with the in vivo results, flagellin increased the activation of Nrf2 in hepatocytes, resulting in decreased APAP toxicity. ML385, a selective inhibitor of Nrf2, abolished the flagellin-mediated hepatoprotective effects in damaged livers and hepatocytes. Additionally, the flagellin-induced Nrf2 translocation was dependent upon the activation of TLR5-JNK/p38 pathways. These findings suggest that TLR5 signaling-induced Nrf2 activation, at least partially, contributed to the protection against APAP-induced ALI by flagellin treatment.
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Affiliation(s)
- Zixiong Zhou
- Department of Pathology, School of Basic Medical Sciences, Fujian Medical University, No. 1, Xuefu North Road, University Town, Fuzhou, 350122, Fujian, China
| | - Jing Qi
- Department of Pathology, School of Basic Medical Sciences, Fujian Medical University, No. 1, Xuefu North Road, University Town, Fuzhou, 350122, Fujian, China
| | - Daram Yang
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea
| | - Myeon-Sik Yang
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea
| | - Hyuneui Jeong
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea
| | - Chae Woong Lim
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea
| | - Jong-Won Kim
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea; Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Bumseok Kim
- Biosafety Research Institute and Laboratory of Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do, 54596, Republic of Korea.
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14
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Luchner M, Reinke S, Milicic A. TLR Agonists as Vaccine Adjuvants Targeting Cancer and Infectious Diseases. Pharmaceutics 2021; 13:142. [PMID: 33499143 PMCID: PMC7911620 DOI: 10.3390/pharmaceutics13020142] [Citation(s) in RCA: 114] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/16/2021] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Modern vaccines have largely shifted from using whole, killed or attenuated pathogens to being based on subunit components. Since this diminishes immunogenicity, vaccine adjuvants that enhance the immune response to purified antigens are critically needed. Further advantages of adjuvants include dose sparing, increased vaccine efficacy in immunocompromised individuals and the potential to protect against highly variable pathogens by broadening the immune response. Due to their ability to link the innate with the adaptive immune response, Toll-like receptor (TLR) agonists are highly promising as adjuvants in vaccines against life-threatening and complex diseases such as cancer, AIDS and malaria. TLRs are transmembrane receptors, which are predominantly expressed by innate immune cells. They can be classified into cell surface (TLR1, TLR2, TLR4, TLR5, TLR6) and intracellular TLRs (TLR3, TLR7, TLR8, TLR9), expressed on endosomal membranes. Besides a transmembrane domain, each TLR possesses a leucine-rich repeat (LRR) segment that mediates PAMP/DAMP recognition and a TIR domain that delivers the downstream signal transduction and initiates an inflammatory response. Thus, TLRs are excellent targets for adjuvants to provide a "danger" signal to induce an effective immune response that leads to long-lasting protection. The present review will elaborate on applications of TLR ligands as vaccine adjuvants and immunotherapeutic agents, with a focus on clinically relevant adjuvants.
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Affiliation(s)
- Marina Luchner
- Department of Biochemistry, Magdalen College Oxford, University of Oxford, Oxford OX1 4AU, UK;
| | - Sören Reinke
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK;
| | - Anita Milicic
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK;
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15
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Abstract
Gastric cancer (GC) is one of the most common cancers in the world, and the incidence of gastric cancer in Asia appears to increase in recent years. Although there is a lot of improvement in treatment approaches, the prognosis of GC is poor. So it is urgent to search for a novel and more effective treatment to improve the survival rate of patients. Both innate immunity and adaptive immunity are important in cancer. In the innate immune system, pattern recognition receptors (PRRs) activate immune responses by recognizing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Toll-like receptors (TLRs) are a class of pattern recognition receptors (PRRs). Many studies have reported that TLRs are involved in the occurrence, development, and treatment of GC. Therefore, TLRs are potential targets for immunotherapy to gastric cancer. However, gastric cancer is a heterogeneous disorder, and TLRs function in GC is complex. TLRs agonists can be potentially used not only as therapeutic agents to treat gastric cancer but also as adjuvants in conjunction with other immunotherapies. They might provide a promising new target for GC treatment. In the review, we sort out the mechanism of TLRs involved in tumor immunity and summarize the current progress in TLRs-based therapeutic approaches and other immunotherapies in the treatment of GC.
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Affiliation(s)
- Lin Cui
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Xiuqing Wang
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Dekai Zhang
- Center for Infectious and Inflammatory Diseases, Texas A&M University, Houston, TX, United States
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16
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Narayanankutty A, Sasidharan A, Job JT. Targeting Toll like Receptors in Cancer: Role of TLR Natural and Synthetic Modulators. Curr Pharm Des 2020; 26:5040-5053. [DOI: 10.2174/1381612826666200720235058] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 06/19/2020] [Indexed: 02/08/2023]
Abstract
Background:
Toll like receptors (TLRs) are a group of transmembrane receptors belonging to the
broad class pattern recognition receptors (PRR), involved in recognition of Pathogen Associated Molecular Patterns
(PAMPs) thereby inducing an immune response. Apart from these exogenous PAMPs, numerous endogenous
PAMPs are also ligands for various TLRs thereby activating the TLR dependent immune response, subsequently
leading to the onset of an inflammatory response. Prolonged activation of TLR by these endogenous
PAMPs leads to chronic inflammatory insults to the body and which in turn alters the proliferative patterns of the
cells, which ultimately leads to the development of cancer.
Objectives:
The present review aims to provide a detailed outline of the differential roles of various TLRs in
cancer and the possible use of them as a therapeutic target.
Methods:
Data were collected from PubMed/Sciencedirect/Web of Science database and sorted; the latest literature
on TLRs was incorporated in the review.
Results:
Among the different TLRs, few are reported to be anti-neoplastic, which controls the cell growth and
multiplication in response to the endogenous signals. On the contrary, numerous studies have reported the procarcinogenic
potentials of TLRs. Hence, TLRs have emerged as a potential target for the prevention and treatment
of various types of cancers. Several molecules, such as monoclonal antibodies, small molecule inhibitors and
natural products have shown promising anticancer potential by effectively modulating the TLR signalling.
Conclusion:
Toll-like receptors play vital roles in the process of carcinogenesis, hence TLR targeting is a promising
approach for cancer prevention.
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Affiliation(s)
- Arunaksharan Narayanankutty
- Division of Cell and Molecular Biology, PG and Research Department of Zoology, St. Joseph’s College (Autonomous), Devagiri, Calicut, Kerala-673 008, India
| | | | - Joice T. Job
- Division of Cell and Molecular Biology, PG and Research Department of Zoology, St. Joseph’s College (Autonomous), Devagiri, Calicut, Kerala-673 008, India
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17
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Bai L, Li W, Zheng W, Xu D, Chen N, Cui J. Promising targets based on pattern recognition receptors for cancer immunotherapy. Pharmacol Res 2020; 159:105017. [DOI: 10.1016/j.phrs.2020.105017] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023]
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18
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Eremina NV, Kazey VI, Mishugin SV, Leonenkov RV, Pushkar DY, Mett VL, Gudkov AV. First-in-human study of anticancer immunotherapy drug candidate mobilan: safety, pharmacokinetics and pharmacodynamics in prostate cancer patients. Oncotarget 2020; 11:1273-1288. [PMID: 32292576 PMCID: PMC7147088 DOI: 10.18632/oncotarget.27549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 03/14/2020] [Indexed: 12/31/2022] Open
Abstract
Toll-like receptor 5 (TLR5) controls endogenous immune responses to pathogens and is a promising target for pharmacological stimulation of anti-tumor immunity. Mobilan is an innovative gene therapy agent consisting of a non-replicating bicistronic adenovirus directing constitutive expression of human Toll-like receptor 5 (TLR5) and the secreted flagellin-based TLR5 agonist, 502s. In mice, Mobilan injection into prostate tumors resulted in autocrine TLR5 signaling, immune system activation, and suppression of tumor growth and metastasis. Here we report a first-in-human placebo-controlled clinical study of Mobilan aimed at evaluating safety, tolerability, pharmacokinetics and pharmacodynamics of a single intra-prostate injection of Mobilan in early stage prostate cancer patients. Mobilan was safe and well-tolerated at all tested doses; thus, the maximum tolerated dose was not identified. Injection of Mobilan induced signs of self-resolving inflammation not present in placebo-injected patients, including transient elevation of PSA and cytokine (G-CSF, IL-6) levels, and increased lymphoid infiltration in prostate tissue. The highest dose of Mobilan (1011 viral particles) produced the best combination of safety and pharmacodynamic effects. Therefore, Mobilan is well-tolerated and induces the expected pharmacodynamic response in humans. These results support further clinical development of Mobilan as a novel immunotherapy for prostate cancer.
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Affiliation(s)
| | | | - Sergey V Mishugin
- D.D. Pletnev Municipal Clinical Hospital, Moscow Department of Healthcare, Moscow, Russian Federation
| | - Roman V Leonenkov
- St. Petersburg Clinical Research and Practical Center for Specialized Oncological Medical Care, St. Petersburg, Russian Federation
| | - Dmitry Y Pushkar
- S.I. Spasokukotsky Municipal Clinical Hospital, Moscow Department of Healthcare, Moscow, Russian Federation
| | | | - Andrei V Gudkov
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
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19
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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20
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Javaid N, Yasmeen F, Choi S. Toll-Like Receptors and Relevant Emerging Therapeutics with Reference to Delivery Methods. Pharmaceutics 2019; 11:E441. [PMID: 31480568 DOI: 10.3390/pharmaceutics11090441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/24/2019] [Accepted: 08/28/2019] [Indexed: 02/06/2023] Open
Abstract
The built-in innate immunity in the human body combats various diseases and their causative agents. One of the components of this system is Toll-like receptors (TLRs), which recognize structurally conserved molecules derived from microbes and/or endogenous molecules. Nonetheless, under certain conditions, these TLRs become hypofunctional or hyperfunctional, thus leading to a disease-like condition because their normal activity is compromised. In this regard, various small-molecule drugs and recombinant therapeutic proteins have been developed to treat the relevant diseases, such as rheumatoid arthritis, psoriatic arthritis, Crohn’s disease, systemic lupus erythematosus, and allergy. Some drugs for these diseases have been clinically approved; however, their efficacy can be enhanced by conventional or targeted drug delivery systems. Certain delivery vehicles such as liposomes, hydrogels, nanoparticles, dendrimers, or cyclodextrins can be employed to enhance the targeted drug delivery. This review summarizes the TLR signaling pathway, associated diseases and their treatments, and the ways to efficiently deliver the drugs to a target site.
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21
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Ayala‐Cuellar AP, Cho J, Choi K. Toll‐like receptors: A pathway alluding to cancer control. J Cell Physiol 2019; 234:21707-21715. [DOI: 10.1002/jcp.28879] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Ana Patricia Ayala‐Cuellar
- Laboratory of Biochemistry and Immunology, College of Veterinary Medicine Chungbuk National University Cheongju Chungbuk Republic of Korea
| | - Jaejin Cho
- Department of Dental Regenerative Biotechnology Seoul National University Seoul Republic of Korea
| | - Kyung‐Chul Choi
- Laboratory of Biochemistry and Immunology, College of Veterinary Medicine Chungbuk National University Cheongju Chungbuk Republic of Korea
- Institute of Life Science and Bio‐Engineering, TheraCell Bio & Science Cheongju Chungbuk Republic of Korea
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22
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Aleynick M, Svensson-Arvelund J, Flowers CR, Marabelle A, Brody JD. Pathogen Molecular Pattern Receptor Agonists: Treating Cancer by Mimicking Infection. Clin Cancer Res 2019; 25:6283-6294. [DOI: 10.1158/1078-0432.ccr-18-1800] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/08/2019] [Accepted: 05/16/2019] [Indexed: 11/16/2022]
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23
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Abstract
Toll-like receptors (TLRs) are associated with tumor growth and immunosuppression, as well as apoptosis and immune system activation. TLRs can activate apoptosis and innate and adaptive immunity pathways, which can be pharmacologically targeted for the development of anticancer oncotherapies. Several studies and clinical trials indicate that TLR agonists are promising adjuvants or elements of novel therapies, particularly when used in conjunction with chemotherapy or radiotherapy. An increasing number of studies suggest that the activation of TLRs in various cancer types is related to oncotherapy; however, before this finding can be applied to clinical practice, additional studies are required. Research suggests that TLR agonists may have potential applications in cancer therapy; nevertheless, because TLR signaling can also promote tumorigenesis, a critical and comprehensive evaluation of TLR action is warranted. This review focuses on recent studies that have assessed the strengths and weaknesses of utilizing TLR agonists as potential anticancer agents.
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Affiliation(s)
- Caiqi Liu
- Department of Gastroenterology, Second Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Ci Han
- Department of Critical Care Medicine, Third Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Jinfeng Liu
- Department of Pain, Second Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
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24
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Anwar MA, Shah M, Kim J, Choi S. Recent clinical trends in Toll-like receptor targeting therapeutics. Med Res Rev 2018; 39:1053-1090. [PMID: 30450666 PMCID: PMC6587958 DOI: 10.1002/med.21553] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 10/18/2018] [Accepted: 10/21/2018] [Indexed: 12/13/2022]
Abstract
Toll‐like receptors (TLRs) are germline‐encoded receptors that are central to innate and adaptive immune responses. Owing to their vital role in inflammation, TLRs are rational targets in clinics; thus, many ligands and biologics have been reported to overcome the progression of various inflammatory and malignant conditions and support the immune system. For each TLR, at least one, and often many, drug formulations are being evaluated. Ligands reported as stand‐alone drugs may also be reported based on their use in combinatorial therapeutics as adjuvants. Despite their profound efficacy in TLR‐modulation in preclinical studies, multiple drugs have been terminated at different stages of clinical trials. Here, TLR modulating drugs that have been evaluated in clinical trials are discussed, along with their mode of action, suggestive failure reasons, and ways to improve the clinical outcomes. This review presents recent advances in TLR‐targeting drugs and provides directions for more successful immune system manipulation.
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Affiliation(s)
- Muhammad Ayaz Anwar
- Department of Molecular Science and Technology, Ajou University, Suwon, Korea
| | - Masaud Shah
- Department of Molecular Science and Technology, Ajou University, Suwon, Korea
| | | | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, Korea
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25
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Affiliation(s)
| | - Alf Lamprecht
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, D-53121 Bonn, Germany
- PEPITE EA4267, Univ. Bourgonge Franch-Comte, 25030 Besançon, France
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26
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Il Kim M, Lee C, Park J, Jeon BY, Hong M. Crystal structure of Bacillus cereus flagellin and structure-guided fusion-protein designs. Sci Rep 2018; 8:5814. [PMID: 29643437 PMCID: PMC5895748 DOI: 10.1038/s41598-018-24254-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/23/2018] [Indexed: 12/16/2022] Open
Abstract
Flagellin is a major component of the flagellar filament. Flagellin also functions as a specific ligand that stimulates innate immunity through direct interaction with Toll-like receptor 5 (TLR5) in the host. Because flagellin activates the immune response, it has been of interest to develop as a vaccine adjuvant in subunit vaccines or antigen fusion vaccines. Despite the widespread application of flagellin fusion in preventing infectious diseases, flagellin-antigen fusion designs have never been biophysically and structurally characterized. Moreover, flagellin from Salmonella species has been used extensively despite containing hypervariable regions not required for TLR5 that can cause an unexpected immune response. In this study, flagellin from Bacillus cereus (BcFlg) was identified as the smallest flagellin molecule containing only the conserved TLR5-activating D0 and D1 domains. The crystal structure of BcFlg was determined to provide a scheme for fusion designs. Through homology-based modeling and comparative structural analyses, diverse fusion strategies were proposed. Moreover, cellular and biophysical analysis of an array of fusion constructs indicated that insertion fusion at BcFlg residues 178–180 does not interfere with the protein stability or TLR5-stimulating capacity of flagellin, suggesting its usefulness in the development and optimization of flagellin fusion vaccines.
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Affiliation(s)
- Meong Il Kim
- Division of Biological Science and Technology, Yonsei University, Wonju, 26493, Republic of Korea
| | - Choongdeok Lee
- Division of Biological Science and Technology, Yonsei University, Wonju, 26493, Republic of Korea
| | - Jaewan Park
- Division of Biological Science and Technology, Yonsei University, Wonju, 26493, Republic of Korea
| | - Bo-Young Jeon
- Department of Biomedical Laboratory Science, Yonsei University, Wonju, 26493, Republic of Korea
| | - Minsun Hong
- Division of Biological Science and Technology, Yonsei University, Wonju, 26493, Republic of Korea.
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