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Distinct roles but cooperative effect of TLR3/9 agonists and PD-1 blockade in converting the immunotolerant microenvironment of irreversible electroporation-ablated tumors. Cell Mol Immunol 2021; 18:2632-2647. [PMID: 34782757 PMCID: PMC8633376 DOI: 10.1038/s41423-021-00796-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 09/05/2021] [Accepted: 09/30/2021] [Indexed: 01/16/2023] Open
Abstract
Irreversible electroporation (IRE) is a new cancer ablation technology, but methods to improve IRE-induced therapeutic immunity are only beginning to be investigated. We developed a mouse model bearing large primary (300 mm3) and medium distant (100 mm3) EG7 lymphomas engineered to express ovalbumin (OVA) as a nominal tumor antigen. We established experimental protocols including IRE alone and IRE combined with Toll-like receptor (TLR)3/9 agonists (poly I:C/CpG) (IRE + pIC/CpG), PD-1 blockade (IRE + PD-1 blockade), or both (IRE + Combo) to investigate therapeutic effects on primary and distant EG7 tumors and conversion-promoting effects on the immunotolerant tumor microenvironment (TME). We demonstrated that IRE alone simulated very weak OVA-specific CD8+ T cell responses and did not inhibit primary tumor growth. IRE + pIC/CpG synergistically stimulated more efficient OVA-specific CD8+ T cell responses and primary tumor growth inhibition than IRE + PD-1 blockade. IRE + pIC/CpG played a major role in the modulation of immune cell profiles but a minor role in the downregulation of PD-L1 expression in the TME and vice versa for IRE + PD-1 blockade. IRE + Combo cooperatively induced potent OVA-specific CD8+ T cell immunity and rescued exhausted intratumoral CD8+ T cells, leading to eradication of not only primary tumors but also untreated concomitant distant tumors and lung metastases. IRE + Combo efficiently modulated immune cell profiles, as evidenced by reductions in immunotolerant type-2 (M2) macrophages, myeloid-derived suppressor-cells, plasmacytoid dendritic cells, and regulatory T cells and by increases in immunogenic M1 macrophages, CD169+ macrophages, type-1 conventional dendritic cells, and CD8+ T cells, leading to conversion of immunotolerance in not only primary TMEs but also untreated distant TMEs. IRE + Combo also showed effective therapeutic effects in two breast cancer models. Therefore, our results suggest that IRE + Combo is a promising strategy to improve IRE ablation therapy in cancer.
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2
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Nam J, Son S, Park KS, Moon JJ. Photothermal therapy combined with neoantigen cancer vaccination for effective immunotherapy against large established tumors and distant metastasis. ADVANCED THERAPEUTICS 2021; 4:2100093. [PMID: 34485685 PMCID: PMC8412374 DOI: 10.1002/adtp.202100093] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Indexed: 12/12/2022]
Abstract
Photothermal therapy (PTT) and neoantigen cancer vaccine each offers minimally invasive and highly specific cancer therapy; however, they are not effective against large established tumors due to physical and biological barriers that attenuate thermal ablation and abolish anti-tumor immunity. Here, we designed and performed comparative study using small (~ 50 mm3) and large (> 100 mm3) tumors to examine how tumor size affects the therapeutic efficiency of PTT and neoantigen cancer vaccine. We show that spiky gold nanoparticle (SGNP)-based PTT and synergistic dual adjuvant-based neoantigen cancer vaccine can efficiently regress small tumors as a single agent, but not large tumors due to limited internal heating and immunosuppressive tumor microenvironment (TME). We report that PTT sensitizes tumors to neoantigen cancer vaccination by destroying and compromising the TME via thermally induced cellular and molecular damage, while neoantigen cancer vaccine reverts local immune suppression induced by PTT and shapes residual TME in favor of anti-tumor immunity. The combination therapy efficiently eradicated large local tumors and also exerted strong abscopal effect against pre-established distant tumors with robust systemic anti-tumor immunity. Thus, PTT combined with neoantigen cancer vaccine is a promising nano-immunotherapy for personalized therapy of advanced cancer.
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Affiliation(s)
- Jutaek Nam
- Department of Pharmaceutical Sciences, Biointerfaces Institute, University of Michigan
| | - Sejin Son
- Department of Pharmaceutical Sciences, Biointerfaces Institute, University of Michigan
| | - Kyung Soo Park
- Department of Biomedical Engineering, Biointerfaces Institute, University of Michigan
| | - James J Moon
- Department of Pharmaceutical Sciences, Department of Biomedical Engineering, Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48108, USA
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3
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Abstract
CpG Oligonucleotides (ODN) are immunomodulatory synthetic oligonucleotides specifically designed to stimulate Toll-like receptor 9. TLR9 is expressed on human plasmacytoid dendritic cells and B cells and triggers an innate immune response characterized by the production of Th1 and pro-inflammatory cytokines. This chapter reviews recent progress in understanding the mechanism of action of CpG ODN and provides an overview of human clinical trial results using CpG ODN to improve vaccines for the prevention/treatment of cancer, allergy, and infectious disease.
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Affiliation(s)
| | | | - Dennis M Klinman
- National Cancer Institute, NIH, Frederick, MD, USA.
- Leitman Klinman Consulting, Potomac, MD, USA.
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4
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Lisk C, Yuen R, Kuniholm J, Antos D, Reiser ML, Wetzler LM. Toll-Like Receptor Ligand Based Adjuvant, PorB, Increases Antigen Deposition on Germinal Center Follicular Dendritic Cells While Enhancing the Follicular Dendritic Cells Network. Front Immunol 2020; 11:1254. [PMID: 32636846 PMCID: PMC7318107 DOI: 10.3389/fimmu.2020.01254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/18/2020] [Indexed: 01/01/2023] Open
Abstract
Vaccines are arguably one of the greatest advancements in modern medicine. Subunit vaccines comprise the majority of current preparations and consist of two main components-antigen and adjuvant. The antigen is a small molecule against which the vaccine induces an immune response to provide protection via the immunostimulatory ability of the adjuvant. Our laboratory has investigated the adjuvant properties of Toll-like receptor (TLR) ligand-based adjuvants, especially the outer membrane protein from Neisseria mengingitidis, PorB. In this current study we used PorB, along with CpG, an intracellular TLR9 agonist, and a non-TLR adjuvant, aluminum salts (Alum), to further investigate cellular mechanisms of adjuvanticity, focusing on the fate of intact antigen in the germinal center and association with follicular dendritic cells (FDCs). FDCs are located in the B cell light zone of the germinal center and are imperative for affinity maturation. They are stromal cells that retain whole intact antigen allowing recognition by the B cell receptor of the germinal center B cells. Our studies demonstrate that TLR ligands, but not Alum, increase the FDC network, while PorB and Alum increased colocalization of FDC and the model soluble antigen, ovalbumin (OVA). As PorB is the only adjuvant tested that induces both a higher number of FDCs and increased deposition of antigen on FDCs, it has the greatest ability to increase FDC-antigen interaction, essential for induction of B cell affinity maturation. These studies demonstrate a further mechanism and potential superiority of PorB as an adjuvant and its influence on antibody production.
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Affiliation(s)
- Christina Lisk
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center, Boston, MA, United States
| | - Rachel Yuen
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States
| | - Jeff Kuniholm
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States
| | - Danielle Antos
- Department of Microbiology and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | | | - Lee M Wetzler
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center, Boston, MA, United States.,Department of Microbiology, Boston University School of Medicine, Boston, MA, United States
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Troy A, Esparza-Gonzalez SC, Bartek A, Creissen E, Izzo L, Izzo AA. Pulmonary mucosal immunity mediated through CpG provides adequate protection against pulmonary Mycobacterium tuberculosis infection in the mouse model. A role for type I interferon. Tuberculosis (Edinb) 2020; 123:101949. [PMID: 32741537 DOI: 10.1016/j.tube.2020.101949] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/28/2022]
Abstract
Toll-Like Receptor (TLR) 9 stimulation is required for induction of potent immune responses against pathogen invasion. The use of unmethylated CpG as adjuvants in vaccines provides an excellent means of stimulating adaptive immunity. Our data demonstrate that CpG-C provided prolonged immune responses in the mouse model of tuberculosis when formulated with liposomes and the Mycobacterium tuberculosis antigen ESAT-6. A reduction in the mycobacterial burden was best achieved when administered as an intranasal vaccine and was dependent on type I interferon (IFN). There was a significant difference between CpG-C inoculated wild type and IFN-αR1-/- mice, indicating that type I IFN plays a role in the immune response following CpG-C inoculation. Further analysis showed that early NK cell presence was not an absolute requirement, although elevated IFN-γ levels were detected in the lungs of mice within 48 h. The reduction in mycobacterial burden was MyD88-independent as CpG-C inoculated MyD88-/- mice showed comparable mycobacterial burdens to wild type mice with no detriment due to the lack of MyD88. Together our data show that pulmonary stimulation of TLR9 bearing antigen presenting cells resulted in the induction of protective immunity against M. tuberculosis infection that was dependent on type I IFN signaling.
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Affiliation(s)
- Amber Troy
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
| | - Sandra C Esparza-Gonzalez
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
| | - Alicia Bartek
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
| | - Elizabeth Creissen
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
| | - Linda Izzo
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA
| | - Angelo A Izzo
- Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA.
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6
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Enhancement of immunomodulative effect of lactic acid bacteria on plasmacytoid dendritic cells with sucrose palmitate. Sci Rep 2018; 8:3147. [PMID: 29453437 PMCID: PMC5816640 DOI: 10.1038/s41598-018-21527-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 02/06/2018] [Indexed: 11/08/2022] Open
Abstract
Plasmacytoid dendritic cells (pDCs) play a key role in the immune response against viruses. In addition, recent research has suggested that pDCs possess direct and indirect tumoricidal activities. We previously found that a lactic acid bacteria strain, Lactococcus lactis JCM 5805 (LC-Plasma), stimulated pDCs and prevented viral infection in mouse and human studies. Meanwhile, emulsifiers have recently been highlighted as candidate adjuvants for some viral vaccines and cancer immunotherapies. In this study, we discovered some specific emulsifiers, mainly consisting of sucrose fatty acid esters, that drastically enhance the potency of LC-Plasma to activate pDCs in vitro. The emulsifiers promoted the efficient uptake of LC-Plasma by pDCs and the ratio of pDCs that took up LC-Plasma correlated with the activity of pDCs. In addition, an in vivo study showed that oral treatment with LC-Plasma mixed with an emulsifier induced a higher expression of genes related to anti-viral immunity in the lung compared to treatment with LC-Plasma alone. Both LC-Plasma and the emulsifiers used in this study have been confirmed to be safe for human use. Therefore, LC-Plasma mixed with an emulsifier might be a useful tool for certain anti-cancer and anti-viral therapies.
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Nam J, Son S, Moon JJ. Adjuvant-Loaded Spiky Gold Nanoparticles for Activation of Innate Immune Cells. Cell Mol Bioeng 2017; 10:341-355. [PMID: 29270238 DOI: 10.1007/s12195-017-0505-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Gold nanoparticles are versatile carriers for delivery of biomacromolecules. Here, we have developed spiky gold nanoparticles (SGNPs) that can efficiently deliver immunostimulatory agents. OBJECTIVES Our goal was to develop a platform technology for co-delivery of multiple adjuvant molecules for synergistic stimulation and maturation of innate immune cells. METHODS SGNPs were synthesized by a seed-mediated, surfactant-free synthesis method and incorporated with polyinosinic-polycytidylic acid (pIC) and DNA oligonucleotide containing unmethylated CpG motif (CpG) by an electrostatic layer-by-layer approach. Adjuvant-loaded SGNP nano-complexes were examined for their biophysical and biochemical properties and studied for immune activation using bone marrow-derived dendritic cells (BMDCs). RESULTS We have synthesized SGNPs with branched nano-spikes layered with pIC and/or CpG. Adjuvant-loaded SGNP nano-complexes promoted cellular uptake of the adjuvants. Importantly, we achieved spatio-temporal control over co-delivery of pIC and CpG via SGNPs, which produced synergistic enhancement in cytokine release (IL-6, TNF-α) and upregulation of co-stimulatory markers (CD40, CD80, CD86) in BMDCs, compared with pIC, CpG, or their admixtures. CONCLUSION SGNPs serve as a versatile delivery platform that allows flexible and on-demand cargo fabrication for strong activation of innate immune cells.
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Affiliation(s)
- Jutaek Nam
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sejin Son
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - James J Moon
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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8
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Bayyurt B, Tincer G, Almacioglu K, Alpdundar E, Gursel M, Gursel I. Encapsulation of two different TLR ligands into liposomes confer protective immunity and prevent tumor development. J Control Release 2017; 247:134-144. [PMID: 28069554 DOI: 10.1016/j.jconrel.2017.01.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/30/2016] [Accepted: 01/04/2017] [Indexed: 11/16/2022]
Abstract
Nucleic acid-based Toll-like receptor (TLR) ligands are promising adjuvants and immunotherapeutic agents. Combination of TLR ligands potentiates immune response by providing synergistic immune activity via triggering different signaling pathways and may impact antigen dependent T-cell immune memory. However, their short circulation time due to nuclease attack hampers their clinical performance. Liposomes offer inclusion of protein and nucleic acid-based drugs with high encapsulation efficiency and drug loading. Furthermore, they protect cargo from enzymatic cleavage while providing stability, and enhancing biological activity. Herein, we aimed to develop a liposomal carrier system co-encapsulating TLR3 (polyinosinic-polycytidylic acid; poly(I:C)) and TLR9 (oligodeoxynucleotides (ODN) expressing unmethylated CpG motifs; CpG ODN) ligands as immunoadjuvants together with protein antigen. To demonstrate that this depot system not only induce synergistic innate immune activation but also boost antigen-dependent immune response, we analyzed the potency of dual ligand encapsulated liposomes in long-term cancer protection assay. Data revealed that CpG ODN and poly(I:C) co-encapsulation significantly enhanced cytokine production from spleen cells. Activation and maturation of dendritic cells as well as bactericidal potency of macrophages along with internalization capacity of ligands were elevated upon incubation with liposomes co-encapsulating CpG ODN and poly(I:C). Immunization with co-encapsulated liposomes induced OVA-specific Th1-biased immunity which persisted for eight months post-booster injection. Subsequent challenge with OVA-expressing tumor cell line, E.G7, demonstrated that mice immunized with liposomes co-encapsulating dual ligands had significantly slower tumor progression. Tumor clearance was dependent on OVA-specific cytotoxic memory T-cells. These results suggest that liposomes co-encapsulating TLR3 and TLR9 ligands and a specific cancer antigen could be developed as a preventive cancer vaccine.
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Affiliation(s)
- Banu Bayyurt
- Thorlab. Therapeutic ODN Research Lab, Department of Molecular Biology and Genetics, Bilkent University, Bilkent, 06800, Ankara, Turkey
| | - Gizem Tincer
- Thorlab. Therapeutic ODN Research Lab, Department of Molecular Biology and Genetics, Bilkent University, Bilkent, 06800, Ankara, Turkey
| | - Kubra Almacioglu
- Thorlab. Therapeutic ODN Research Lab, Department of Molecular Biology and Genetics, Bilkent University, Bilkent, 06800, Ankara, Turkey
| | - Esin Alpdundar
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Mayda Gursel
- Department of Biological Sciences, Middle East Technical University, 06800, Ankara, Turkey
| | - Ihsan Gursel
- Thorlab. Therapeutic ODN Research Lab, Department of Molecular Biology and Genetics, Bilkent University, Bilkent, 06800, Ankara, Turkey.
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9
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Sommariva M, Le Noci V, Storti C, Bianchi F, Tagliabue E, Balsari A, Sfondrini L. Activation of NK cell cytotoxicity by aerosolized CpG-ODN/poly(I:C) against lung melanoma metastases is mediated by alveolar macrophages. Cell Immunol 2017; 313:52-58. [PMID: 28089340 DOI: 10.1016/j.cellimm.2017.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 12/31/2022]
Abstract
Controversies remain about NK cells direct responsiveness to Toll-like receptor (TLR) agonists or dependence on macrophages. In a melanoma lung metastasis model, aerosolized TLR9 and TLR3 agonists have been reported to induce antitumor immunity through NK cells activation. In the current study, we demonstrated that in vitro TLR9/TLR3 stimulation induced IFN-γ secretion by NK cells, but an increase in their cytotoxicity was detected only after NK cells co-culture with in vitro TLR9/TLR3 agonists pretreated alveolar macrophages. Alveolar macrophages from melanoma lung metastases-bearing mice, treated with aerosolized TLR agonists, also promoted NK cell cytotoxicity. Activated NK cells from lungs of melanoma metastases-bearing mice that were given aerosolized TLR9/TLR3 agonists were able to polarize naive alveolar macrophages toward a M1-like phenotype. Our results demonstrate that activation of NK cells in the lung after TLR engagement is mediated by alveolar macrophages and that activated NK cells shape macrophage behavior.
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Affiliation(s)
- Michele Sommariva
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy.
| | - Valentino Le Noci
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy.
| | - Chiara Storti
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy.
| | - Francesca Bianchi
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy.
| | - Elda Tagliabue
- Molecular Targets Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, 20133 Milan, Italy.
| | - Andrea Balsari
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy; Molecular Targets Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, 20133 Milan, Italy.
| | - Lucia Sfondrini
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Magiagalli 31, 20133 Milan, Italy.
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10
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Changes in expression of genes involved in antitumor immunity in mice vaccinated with tumor vaccine composed of irradiated syngeneic tumor cells and CpG oligodeoxynucleotides. Mol Immunol 2016; 79:1-13. [PMID: 27677155 DOI: 10.1016/j.molimm.2016.09.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/16/2016] [Accepted: 09/21/2016] [Indexed: 01/17/2023]
Abstract
In our previous studies, it has been demonstrated that in more than 80% of mice long-lasting antitumor immunity has been established following intraperitoneal (i.p.) vaccination with tumor vaccine composed of irradiated syngeneic tumor cells and CpG ODNs class C. The aim of this study was, therefore, to investigate molecular mechanisms through which this vaccine triggers the immunity and to define genes particularly involved in this process. Changes in gene expression were followed in mononuclear cells isolated from peritoneal lavages, spleens and bone marrow samples. The expression of 84 genes significant for T-cell and B-cell activation as well as genes engaged in activation of macrophages, NK cells and DCs was determined using the RT2- Profiler PCR array. It has been observed that this tumor vaccine induces the up-regulation of genes involved in activation, proliferation and survival of memory T-cells (Cd8a, Cd8b1, Prlr, Was, Cxcl12, Il12, Sftpd, Tnfrsf13c, Il15, Il18), and prevents the activation of genes involved in generation of Treg and induction of immune tolerance (Sit1, Sla2, Cd1d1, Pdcd1lg2, Pawr, Socs5, Il27, Il4). We may conclude based on results of gene expression analysis, that tumor vaccine fine-tunes the proportion of cytotoxic to regulatory lymphocytes having an important impact on the induction and maintenance of memory cells in bone marrow.
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11
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Liu Q, Ding JL. The molecular mechanisms of TLR-signaling cooperation in cytokine regulation. Immunol Cell Biol 2016; 94:538-42. [PMID: 26860369 DOI: 10.1038/icb.2016.18] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 02/02/2016] [Accepted: 02/07/2016] [Indexed: 12/19/2022]
Abstract
Innate immune cells recognize pathogens through pattern recognition receptors (PRRs), and activation of PRRs induces downstream signaling pathways to mount appropriate immune responses. Pathogens usually carry multiple ligands, which can simultaneously activate multiple PRRs. The cooperation of multiple PRRs and consequential crosstalk between their downstream pathways could enhance cytokine expression, which is required for effective immune responses. On the other hand, immune over-activation could also harm the host if immune homeostasis is not restored. Therefore, it is important to understand the mechanisms of PRR cooperation during an infection. As the best characterized PRRs, Toll-like receptors (TLRs) have an important role in pathogen recognition, and crosstalk among TLRs is common. In this review, we provide an update on the recent findings on the mechanisms of TLR cooperation. We summarize the known mechanisms and provide a future perspective on TLR crosstalk study, with a caution against the use of multiple TLR ligands as adjuvants in therapeutic strategies.
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Affiliation(s)
- Qian Liu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Jeak Ling Ding
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
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12
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Thaiss CA, Levy M, Itav S, Elinav E. Integration of Innate Immune Signaling. Trends Immunol 2016; 37:84-101. [PMID: 26755064 DOI: 10.1016/j.it.2015.12.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022]
Abstract
The last decades of research in innate immunology have revealed a multitude of sensing receptors that evaluate the presence of microorganisms or cellular damage in tissues. In the context of a complex tissue, many such sensing events occur simultaneously. Thus, the downstream pathways need to be integrated to launch an appropriate cellular response, to tailor the magnitude of the reaction to the inciting event, and to terminate it in a manner that avoids immunopathology. Here, we provide a conceptual overview of the crosstalk between innate immune receptors in the initiation of a concerted immune reaction to microbial and endogenous triggers. We classify the known interactions into categories of communication and provide examples of their importance in pathogenic infection.
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Affiliation(s)
| | - Maayan Levy
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Shlomik Itav
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, Rehovot, Israel.
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13
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Synergistic Stimulation with Different TLR7 Ligands Modulates Gene Expression Patterns in the Human Plasmacytoid Dendritic Cell Line CAL-1. Mediators Inflamm 2015; 2015:948540. [PMID: 26770023 PMCID: PMC4684865 DOI: 10.1155/2015/948540] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 12/26/2022] Open
Abstract
Objective. TLR7 ligation in plasmacytoid dendritic cells is promising for the treatment of cancer, allergy, and infectious diseases; however, high doses of ligands are required. We hypothesized that the combination of structurally different TLR7 ligands exponentiates the resulting immune response. Methods. CAL-1 (human pDC line) cells were incubated with the TLR7-specific adenine analog CL264 and single-stranded 9.2s RNA. Protein secretion was measured by ELISA. Microarray technique was used to detect modified gene expression patterns upon synergistic stimulation, revealing underlying functional groups and networks. Cell surface binding properties were studied using FACS analysis. Results. CL264 in combination with 9.2s RNA significantly enhanced cytokine and interferon secretion to supra-additive levels. This effect was due to a stronger stimulation of already regulated genes (by monostimulation) as well as to recruitment of thus far unregulated genes. Top scoring canonical pathways referred to immune-related processes. Network analysis revealed IL-1β, IL-6, TNF, and IFN-β as major regulatory nodes, while several minor regulatory nodes were also identified. Binding of CL264 to the cell surface was enhanced by 9.2s RNA. Conclusion. Structurally different TLR7 ligands act synergistically on gene expression patterns and on the resulting inflammatory response. These data could impact future strategies optimizing TLR7-targeted drug design.
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14
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Micera A, Balzamino BO, Zazzo AD, Biamonte F, Sica G, Bonini S. Toll-Like Receptors and Tissue Remodeling: The Pro/Cons Recent Findings. J Cell Physiol 2015; 231:531-44. [DOI: 10.1002/jcp.25124] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 08/04/2015] [Indexed: 12/21/2022]
Affiliation(s)
| | | | - Antonio Di Zazzo
- Department of Ophthalmology; University Campus Bio-Medico; Rome Italy
| | - Filippo Biamonte
- Institute of Histology and Embryology; Faculty of Medicine; Catholic University of the Sacred Heart; Rome Italy
| | - Gigliola Sica
- Institute of Histology and Embryology; Faculty of Medicine; Catholic University of the Sacred Heart; Rome Italy
| | - Stefano Bonini
- Department of Ophthalmology; University Campus Bio-Medico; Rome Italy
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15
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Cross talk of the first-line defense TLRs with PI3K/Akt pathway, in preconditioning therapeutic approach. MOLECULAR AND CELLULAR THERAPIES 2015; 3:4. [PMID: 26056605 PMCID: PMC4456045 DOI: 10.1186/s40591-015-0041-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 05/19/2015] [Indexed: 01/04/2023]
Abstract
Toll-like receptor family (TLRs), pattern recognition receptors, is expressed not only on immune cells but also on non-immune cells, including cardiomyocytes, fibroblasts, and vascular endothelial cells. One main function of TLRs in the non-immune system is to regulate apoptosis. TLRs are the central mediators in hepatic, pulmonary, brain, and renal ischemic/reperfusion (I/R) injury. Up-regulation of TLRs and their ligation by either exogenous or endogenous danger signals plays critical roles in ischemia/reperfusion-induced tissue damage. Conventional TLR-NF-κB pathways are markedly activated in failing and ischemic myocardium. Recent studies have identified a cross talk between TLR activation and the PI3K/Akt pathway. The activation of TLRs is proposed to be the most potent preconditioning method after ischemia, to improve the cell survival via the mechanism involved the PI3K/Akt signaling pathway and to attenuate the subsequent TLR-NF-κB pathway stimulation. Thus, TLRs could be a great target in the new treatment approaches for myocardial I/R injury.
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Pourrajab F, Yazdi MB, Zarch MB, Zarch MB, Hekmatimoghaddam S. Cross talk of the first-line defense TLRs with PI3K/Akt pathway, in preconditioning therapeutic approach. MOLECULAR AND CELLULAR THERAPIES 2015; 3:4. [PMID: 26056605 PMCID: PMC4456045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 05/19/2015] [Indexed: 11/21/2023]
Abstract
Toll-like receptor family (TLRs), pattern recognition receptors, is expressed not only on immune cells but also on non-immune cells, including cardiomyocytes, fibroblasts, and vascular endothelial cells. One main function of TLRs in the non-immune system is to regulate apoptosis. TLRs are the central mediators in hepatic, pulmonary, brain, and renal ischemic/reperfusion (I/R) injury. Up-regulation of TLRs and their ligation by either exogenous or endogenous danger signals plays critical roles in ischemia/reperfusion-induced tissue damage. Conventional TLR-NF-κB pathways are markedly activated in failing and ischemic myocardium. Recent studies have identified a cross talk between TLR activation and the PI3K/Akt pathway. The activation of TLRs is proposed to be the most potent preconditioning method after ischemia, to improve the cell survival via the mechanism involved the PI3K/Akt signaling pathway and to attenuate the subsequent TLR-NF-κB pathway stimulation. Thus, TLRs could be a great target in the new treatment approaches for myocardial I/R injury.
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Affiliation(s)
- Fatemeh Pourrajab
- />School of Medicine, Shahid Sadoughi University of Medical Sciences, Professor Hessabi 11 BLV, Shohadaye Gomnam BLV, Yazd, Iran P.O. 8915173149
- />Department of Clinical Biochemistry and Molecular Biology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Baghi Yazdi
- />School of Medicine, Shahid Sadoughi University of Medical Sciences, Professor Hessabi 11 BLV, Shohadaye Gomnam BLV, Yazd, Iran P.O. 8915173149
| | - Mojtaba Babaei Zarch
- />School of Medicine, Shahid Sadoughi University of Medical Sciences, Professor Hessabi 11 BLV, Shohadaye Gomnam BLV, Yazd, Iran P.O. 8915173149
| | - Mohammadali Babaei Zarch
- />School of Medicine, Shahid Sadoughi University of Medical Sciences, Professor Hessabi 11 BLV, Shohadaye Gomnam BLV, Yazd, Iran P.O. 8915173149
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17
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Neeland MR, Elhay MJ, Powell DR, Rossello FJ, Meeusen ENT, de Veer MJ. Transcriptional profile in afferent lymph cells following vaccination with liposomes incorporating CpG. Immunology 2015; 144:518-529. [PMID: 25308816 DOI: 10.1111/imm.12401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/14/2014] [Accepted: 10/02/2014] [Indexed: 12/17/2022] Open
Abstract
Vaccine formulations incorporating innate immune stimulants are highly immunogenic; however, the biological signals that originate in the peripheral tissues at the site of injection and are transmitted to the local lymph node to induce immunity remain unclear. By directly cannulating the ovine afferent lymphatic vessels, we have previously shown that it takes 72 hr for mature antigen-loaded dendritic cells and monocytes to appear within afferent lymph following injection of a liposomal formulation containing the Toll-like receptor ligand CpG. In this present study, we characterize the global transcriptional signatures at this time-point in ovine afferent lymph cells as they migrate from the injection site into the lymphatics following vaccination with a liposome antigen formulation incorporating CpG. We show that at 72 hr post vaccination, liposomes alone induce no changes in gene expression and inflammatory profiles within afferent lymph; however, the incorporation of CpG drives interferon, antiviral and cytotoxic gene programmes. This study also measures the expression of key genes within individual cell types in afferent lymph. Antiviral gene signatures are most prominent in lymphocytes, which may play a significant and unexpected role in sustaining the immune response to vaccination at the site of injection. These findings provide a comprehensive analysis of the in vivo immunological pathways that connect the injection site with the local draining lymph node following vaccination.
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Affiliation(s)
- Melanie R Neeland
- Biotechnology Research Laboratories, Department of Physiology, Monash University, Clayton, Vic., Australia
| | - Martin J Elhay
- Zoetis Research and Manufacturing Australia P/L, Parkville, Vic., Australia
| | - David R Powell
- Victorian Bioinformatics Consortium, Monash University, Clayton, Vic., Australia.,Victorian Life Sciences Computation Initiative, Life Sciences Computation Centre, Carlton, Vic., Australia
| | - Fernando J Rossello
- Victorian Bioinformatics Consortium, Monash University, Clayton, Vic., Australia.,Victorian Life Sciences Computation Initiative, Life Sciences Computation Centre, Carlton, Vic., Australia
| | - Els N T Meeusen
- Biotechnology Research Laboratories, Department of Physiology, Monash University, Clayton, Vic., Australia.,Department of Microbiology, Monash University, Clayton, Vic., Australia
| | - Michael J de Veer
- Biotechnology Research Laboratories, Department of Physiology, Monash University, Clayton, Vic., Australia
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18
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Abstract
Cross-talk within the innate immune pathways is highly complex and contains many unknowns. Here, we discuss the different combinations of PAMPs, together with the sequence, order, and dosage of consecutive PAMP challenges, which determine the nature of the immune response by macrophages. The engagement of different Toll-like receptor (TLR) ligands leads to quantitatively and qualitatively unique cytokine production, showing that TLR pathway crosstalk enables the innate immune system to orchestrate immediate local and global responses. It is likely that multiple pathways are involved in the regulation of cytokine synergy, including many that have yet to be discovered.
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Affiliation(s)
- Rebecca S T Tan
- 1NUS graduate School for Integrative Science and Engineering, National University of Singapore, Singapore
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19
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Shirota H, Klinman DM. Recent progress concerning CpG DNA and its use as a vaccine adjuvant. Expert Rev Vaccines 2013; 13:299-312. [PMID: 24308579 DOI: 10.1586/14760584.2014.863715] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
CpG Oligonucleotides (ODN) are immunomodulatory synthetic oligonucleotides designed to specifically agonize Toll-like receptor 9. Here, we review recent progress in understanding the mechanism of action of CpG ODN and provide an overview of human clinical trial results using CpG ODN to improve the vaccines for cancer, allergy and infectious disease.
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20
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Islam MA, Pröll M, Hölker M, Tholen E, Tesfaye D, Looft C, Schellander K, Cinar MU. Alveolar macrophage phagocytic activity is enhanced with LPS priming, and combined stimulation of LPS and lipoteichoic acid synergistically induce pro-inflammatory cytokines in pigs. Innate Immun 2013; 19:631-43. [PMID: 23608822 DOI: 10.1177/1753425913477166] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The objective of the present study was to investigate LPS and lipoteichoic acid (LTA)-induced TLRs, associated signaling molecules and inflammatory mediators, as well as to compare their combined effect in porcine alveolar macrophages. Macrophages were incubated for 24 h with various concentrations of LPS, LTA, LPS + LTA or control. Multiple concentrations of LPS elicited marked up-regulation in mRNA for TLR2 and TLR4, CD14, MD2, MyD88, IRAK-4 and TRAF6 compared with the control. LTA had no effect on TLR4 and MD2; only higher doses up-regulated TLR2, CD14, MyD88, IRAK-4 and TRAF6 mRNA. LPS-activated cells released IL1-β, IL12-β, TNF-α, IL-6, IL-8, IFN-γ and IL-10 in a dose-dependent manner, while LTA had no effect on IL-1β, IL-6 and IFN-γ. Higher doses of LTA induced IL-12β, TNF-α, IL-8 and IL-10. Combined stimulation augmented TLR2, CD14 and MyD88 mRNA, and subsequently produced elevated levels of IL-6, TNF-α and IL-8 when compared with LPS and LTA alone. Additionally, phagocytosis of macrophages was significantly increased following low concentration of LPS treatment. Only low levels of NO (nitric oxide) were detected in the LPS group. Overall, compared with LPS, LTA was a relatively weak inducer, and co-stimulation accelerated gene and cytokine production associated with pulmonary innate immune function.
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21
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The synergy in cytokine production through MyD88-TRIF pathways is co-ordinated with ERK phosphorylation in macrophages. Immunol Cell Biol 2013; 91:377-87. [PMID: 23567895 DOI: 10.1038/icb.2013.13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although specific single Toll-like receptor (TLR) ligands are known to drive the development of Th1 or Th2 immunity, the outcome of different combinations of TLR ligands on innate immunity is not well defined. Spatiotemporal dynamics are critical in determining the specificity of the immune response, but the mechanisms underlying combinatorial TLR stimulation remain unclear. Here, we tested pairwise combinations of TLR ligands separated by different time intervals for their effect on cytokine production in macrophages. We observed that stimulation via a combination of MyD88- and TRIF-utilizing adaptors leads to a highly synergistic cytokine response. On a timescale of 4-24 h, macrophages pretreated with poly(I:C) (TLR3 ligand) are cross-primed to a second stimulation with R848 (TLR7 ligand) and vice versa, and each condition exhibits different optimal time windows of synergistic response for each cytokine. We show that the synergy resulting from combinatorial stimuli (poly(I:C) and R848 is also regulated by the order and dosage of the TLR agonists. Secondary response genes, which depend on new protein synthesis for transcription, show greater synergy than primary response genes, and such enhancement is abolished when new protein synthesis is inhibited. Synergistic cytokine production appears concordant with sustained ERK phosphorylation, suggesting that the de novo factors act via inhibition of ERK dephosphorylation, for example, by the downregulation of dual specificity phosphatase 6. Taken together, our findings illustrate a checkpoint in the innate immune system, where the synchronization of timing of both MyD88 and TRIF pathways is required for a maximal cytokine response and potential memory effect in macrophages.
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22
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Enriching pathogen transcripts from infected samples: a capture-based approach to enhanced host-pathogen RNA sequencing. Anal Biochem 2013; 438:90-6. [PMID: 23535274 DOI: 10.1016/j.ab.2013.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/06/2013] [Accepted: 03/08/2013] [Indexed: 01/22/2023]
Abstract
To fully understand the interactions of a pathogen with its host, it is necessary to analyze the RNA transcripts of both the host and pathogen throughout the course of an infection. Although this can be accomplished relatively easily on the host side, the analysis of pathogen transcripts is complicated by the overwhelming amount of host RNA isolated from an infected sample. Even with the read depth provided by second-generation sequencing, it is extremely difficult to get enough pathogen reads for an effective gene-level analysis. In this study, we describe a novel capture-based technique and device that considerably enriches for pathogen transcripts from infected samples. This versatile method can, in principle, enrich for any pathogen in any infected sample. To test the technique's efficacy, we performed time course tissue culture infections using Rift Valley fever virus and Francisella tularensis. At each time point, RNA sequencing (RNA-Seq) was performed and the results of the treated samples were compared with untreated controls. The capture of pathogen transcripts, in all cases, led to more than an order of magnitude enrichment of pathogen reads, greatly increasing the number of genes hit, the coverage of those genes, and the depth at which each transcript was sequenced.
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23
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Silva JM, Videira M, Gaspar R, Préat V, Florindo HF. Immune system targeting by biodegradable nanoparticles for cancer vaccines. J Control Release 2013; 168:179-99. [PMID: 23524187 DOI: 10.1016/j.jconrel.2013.03.010] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 03/11/2013] [Accepted: 03/14/2013] [Indexed: 01/08/2023]
Abstract
The concept of therapeutic cancer vaccines is based on the activation of the immune system against tumor cells after the presentation of tumor antigens. Nanoparticles (NPs) have shown great potential as delivery systems for cancer vaccines as they potentiate the co-delivery of tumor-associated antigens and adjuvants to dendritic cells (DCs), insuring effective activation of the immune system against tumor cells. In this review, the immunological mechanisms behind cancer vaccines, including the role of DCs in the stimulation of T lymphocytes and the use of Toll-like receptor (TLR) ligands as adjuvants will be discussed. An overview of each of the three essential components of a therapeutic cancer vaccine - antigen, adjuvant and delivery system - will be provided with special emphasis on the potential of particulate delivery systems for cancer vaccines, in particular those made of biodegradable aliphatic polyesters, such as poly(lactic-co-glycolic acid) (PLGA) and poly-ε-caprolactone (PCL). Some of the factors that can influence NP uptake by DCs, including size, surface charge, surface functionalization and route of administration, will also be considered.
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Affiliation(s)
- Joana M Silva
- iMed.UL, Research Institute for Medicines and Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, 1649-003 Lisbon, Portugal
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24
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Abstract
Serious infection and the patient's response (sepsis) is a serious health problem that, even today, is associated with a mortality rate of 30 %-50 %. The phases of severe sepsis include an early hyperinflammatory response to pathogens and a late immunosuppressed phase. Toll-like receptors (TLRs) are a family of transmembrane innate immune receptors that play a major role in both phases of sepsis. Here, their physiology and the therapeutic strategies employed to date are reviewed. Currently, there are no approved therapies targeting TLRs, but it is anticipated that in the future, the less-studied TLRs, such as TLR3, TLR7, and TLR9, will evolve therapeutic targets, perhaps predominantly with agonists, versus the usual antagonist strategies. Furthermore, accurately characterizing the stage of sepsis will be essential to directing appropriate therapeutic choices.
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Affiliation(s)
- John H Boyd
- Critical Care Research Laboratories, Heart + Lung Institute, St. Paul's Hospital, University of British Columbia, 1081 Burrard Street, Vancouver, BC, Canada, V6Z 1Y6,
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26
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Steinhagen F, Meyer C, Tross D, Gursel M, Maeda T, Klaschik S, Klinman DM. Activation of type I interferon-dependent genes characterizes the "core response" induced by CpG DNA. J Leukoc Biol 2012; 92:775-85. [PMID: 22750547 DOI: 10.1189/jlb.1011522] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Synthetic ODNs expressing CpG motifs trigger an innate immune response via TLR9. pDCs are major effectors of this response. Two structurally distinct classes of CpG ODNs have been identified that differentially activate pDCs. "K" ODNs trigger the production of TNF-α and IL-6, whereas "D" ODNs preferentially induce the secretion of IFN-α. As K and D ODNs have distinct therapeutic effects, knowledge of their shared and sequence-specific activity is of considerable importance. This work uses the CAL-1 human pDC line to analyze the effect of CpG stimulation on gene expression. Genes up-regulated by both K and D ODNs (n=92) were largely dependent on type I IFN signaling and characterized functionally by antiviral activity. K ODNs induced a short-term increase in IFN-α/β production and uniquely up-regulated genes that supported antibacterial responses. In contrast, D ODNs triggered a persistent increase in IFN-α/β production and uniquely up-regulated genes associated with metabolic functions. Thus, the core functionality of human pDCs mediated by TLR9 ligation rests on a type I IFN response that differs from the response induced by the structural elements unique to specific classes of ODNs.
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Affiliation(s)
- Folkert Steinhagen
- Laboratory of Experimental Immunology, Cancer and Inflammation Program, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
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27
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Abstract
Stimulation of toll-like receptor 9 (TLR9) by CpG-C containing oligonucleotides attenuates ischemic injury in the brain and liver. In this study, we investigate whether any of the three classes of CpG (A, B, or C) mitigate ischemia-induced cardiac dysfunction. We measured left ventricular ejection fraction (LVEF) in C57BL/6 mice using transthoracic echocardiography. Using LPS as an inflammatory stimulus, CpG-C was uniquely able to prevent cardiac dysfunction; its activity was confirmed through nuclear factor κB transcriptional activity assay in HL-1 cardiomyocytes. We went on to investigate CpG-C's efficacy and mechanism in the treatment of ischemia-reperfusion. Compared with baseline, no class of CpG significantly altered LVEF at 6 or 24 h; 40 mg/kg LPS induced a rapid, profound suppression of LVEF compared with baseline (26% ± 1.4% vs. 65% ± 1.4%), whereas pretreatment with CpG demonstrated that of the three classes, only CpG-C prevented the LPS -induced decrease in LVEF (51% ± 5.8%). In separate mice, 1-h ischemia followed by reperfusion of the left anterior descending artery resulted in a 7-day suppression of the LVEF (66% ± 5.2% at baseline; 46% ± 4.7% at day 1, and 46% ± 4.0% at day 7), whereas mice either pretreated with or begun on an infusion of CpG-C during the ischemia had no significant decline in LVEF. Gene expression microarray of CpG-C-stimulated cells revealed upregulation of the nuclear factor κB pathway inhibitors TNFAIP3, NFKBIA, TRIM30, and TNIP1. These may play a role in attenuation of cardiac inflammation. The TLR9 ligand CpG-C attenuates the acute inflammatory cardiac dysfunction induced by both LPS and ischemia-reperfusion of the left anterior descending artery.
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Identification of novel innate immune genes by transcriptional profiling of macrophages stimulated with TLR ligands. Mol Immunol 2011; 48:1886-95. [PMID: 21665277 DOI: 10.1016/j.molimm.2011.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Revised: 05/11/2011] [Accepted: 05/16/2011] [Indexed: 12/20/2022]
Abstract
Toll-like receptors (TLRs) are key receptors in innate immunity and trigger responses following interaction with pathogen-associated molecular patterns (PAMPs). TLR3, TLR4 and TLR9 recognize double stranded RNA, lipopolysaccharide (LPS) and CpG DNA, respectively. These receptors differ importantly in downstream adaptor molecules. TLR4 signals through MyD88 and TRIF; in contrast, the TLR3 pathway involves only TRIF while TLR9 signals solely through MyD88. To determine how differences in downstream signaling could influence gene expression in innate immunity, gene expression patterns were determined for the RAW264.7 macrophage cell line stimulated with LPS, poly (I:C), or CpG DNA. Gene expression profiles 6 and 24h post-stimulation were analyzed to determine genes, pathways and transcriptional networks induced. As these experiments showed, the number and extent of genes expressed varied with stimulus. LPS and poly (I:C) induced an abundant array of genes in RAW264.7 cells at 6h and 24h following treatment while CpG DNA induced many fewer. By analyzing data for networks and pathways, we prioritized differentially expressed genes with respect to those common to the three TLR ligands as well as those shared by LPS and poly (I:C) but not CpG DNA. The importance of changes in gene expression was demonstrated by experiments indicating that RNA interference-mediated inhibition of two genes identified in this analysis, PLEC1 and TPST1, reduced IL-6 production by J774A.1 and RAW264.7 macrophages stimulated with LPS. Together, these findings delineate macrophage gene response patterns induced by different PAMPs and identify new genes that have not previously been implicated in innate immunity.
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Adoptive immunotherapy combined with intratumoral TLR agonist delivery eradicates established melanoma in mice. Cancer Immunol Immunother 2011; 60:671-83. [PMID: 21327636 DOI: 10.1007/s00262-011-0984-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 01/26/2011] [Indexed: 12/17/2022]
Abstract
Toll-like receptor (TLR) agonists can trigger broad inflammatory responses that elicit rapid innate immunity and promote the activities of lymphocytes, which can potentially enhance adoptive immunotherapy in the tumor-bearing setting. In the present study, we found that Polyinosinic:Polycytidylic Acid [Poly(I:C)] and CpG oligodeoxynucleotide 1826 [CpG], agonists for TLR 3 and 9, respectively, potently activated adoptively transferred T cells against a murine model of established melanoma. Intratumoral injection of Poly(I:C) and CpG, combined with systemic transfer of activated pmel-1 T cells, specific for gp100(25-33), led to enhanced survival and eradication of 9-day established subcutaneous B16F10 melanomas in a proportion of mice. A series of survival studies in knockout mice supported a key mechanistic pathway, whereby TLR agonists acted via host cells to enhance IFN-γ production by adoptively transferred T cells. IFN-γ, in turn, enhanced the immunogenicity of the B16F10 melanoma line, leading to increased killing by adoptively transferred T cells. Thus, this combination approach counteracted tumor escape from immunotherapy via downregulation of immunogenicity. In conclusion, TLR agonists may represent advanced adjuvants within the setting of adoptive T-cell immunotherapy of cancer and hold promise as a safe means of enhancing this approach within the clinic.
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Characterization of immunostimulatory CpG-rich sequences from different Bifidobacterium species. Appl Environ Microbiol 2010; 76:2846-55. [PMID: 20208019 DOI: 10.1128/aem.01714-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The beneficial effects of Bifidobacterium are partly due to its immunostimulatory properties. These immunostimulatory properties may be linked to the presence of unmethylated CpG motifs specific to bacterial DNA, which may induce a TH1 response by activating Toll-like receptors (TLR). Using in silico analyses, PCR amplification, and dot blotting, we characterized the CpG content of various bifidobacterial strains and evaluated the immunostimulatory properties and genomic heterogeneity of these motifs in the genus. Our in silico study, based on entire genome sequences from five bifidobacterial strains, showed that Bifidobacterium genomes contain numerous CpG motifs, including 5'-purine-purine-CG-pyrimidine-pyrimidine-3' and 5'-purine-TCG-pyrimidine-pyrimidine-3' motifs, and biologically active sequences previously identified in lactic acid bacteria. We identified four CpG-rich sequences with Bifidobacterium longum NCC2705. Two sequences with a percent G+C of about 68% included 14 and 16 CpG motifs. Two sequences with a percent G+C of about 60% included 16 and 6 CpG motifs. These sequences induce the production of monocyte chemoattractant protein 1 (MCP-1) and tumor necrosis factor alpha (TNF-alpha) through a pattern of TLR9 stimulation on RAW 264.7 macrophages. No link could be established between their immunostimulatory properties, the number of CpG motifs, and percent G+C. We investigated inter- and intraspecies heterogeneity in 71 strains of various origins. These sequences were highly conserved in the genus. No link was found between the presence of the CpG-rich sequence and the origin of the strains (healthy, allergic, or preterm infants). The high frequency of CpG motifs in the DNA of Bifidobacterium may play an important role in the immunostimulatory properties of commensal or probiotic bifidobacterial strains.
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