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Javidan M, Amiri AM, Koohi N, Joudaki N, Bashirrohelleh MA, Pirsadeghi A, Biregani AF, Rashno M, Dehcheshmeh MG, Sharifat M, Khodadadi A, Mafakher L. Restoring immune balance with Tregitopes: A new approach to treating immunological disorders. Biomed Pharmacother 2024; 177:116983. [PMID: 38908205 DOI: 10.1016/j.biopha.2024.116983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 06/08/2024] [Accepted: 06/15/2024] [Indexed: 06/24/2024] Open
Abstract
The induction of immunological tolerance is a promising strategy for managing autoimmune diseases, allergies, and transplant rejection. Tregitopes, a class of peptides, have emerged as potential agents for this purpose. They activate regulatory T cells, which are pivotal in reducing inflammation and promoting tolerance, by binding to MHC II molecules and facilitating their processing and presentation to Treg cells, thereby encouraging their proliferation. Moreover, Tregitopes influence the phenotype of antigen-presenting cells by attenuating the expression of CD80, CD86, and MHC class II while enhancing ILT3, resulting in the inhibition of NF-kappa B signaling pathways. Various techniques, including in vitro and in silico methods, are applied to identify Tregitope candidates. Currently, Tregitopes play a vital role in balancing immune activation and tolerance in clinical applications such as Pompe disease, diabetes-related antigens, and the prevention of spontaneous abortions in autoimmune diseases. Similarly, Tregitopes can induce antigen-specific regulatory T cells. Their anti-inflammatory effects are significant in conditions such as autoimmune encephalomyelitis, inflammatory bowel disease, and Guillain-Barré syndrome. Additionally, Tregitopes have been leveraged to enhance vaccine design and efficacy. Recent advancements in understanding the potential benefits and drawbacks of IVIG and the discovery of the function and mechanism of Tregitopes have introduced Tregitopes as a popular option for immune system modulation. It is expected that they will bring about a significant revolution in the management and treatment of autoimmune and immunological diseases. This article is a comprehensive review of Tregitopes, concluding with the potential of these epitopes as a therapeutic avenue for immunological disorders.
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Affiliation(s)
- Moslem Javidan
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Amir Mohamad Amiri
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Narges Koohi
- Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nazanin Joudaki
- Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Ali Bashirrohelleh
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Pirsadeghi
- Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Farhadi Biregani
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Rashno
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Cellular and Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Moosa Sharifat
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Khodadadi
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Cancer, Petroleum, and Environmental Pollutants Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Ladan Mafakher
- Thalassemia & Hemoglobinopathy Research center, Health research institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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Miah SMS, Lelias S, Gutierrez AH, McAllister M, Boyle CM, Moise L, De Groot AS. A SARS-CoV-2 NSP7 homolog of a Treg epitope suppresses CD4+ and CD8+ T cell memory responses. Front Immunol 2023; 14:1290688. [PMID: 38124752 PMCID: PMC10731459 DOI: 10.3389/fimmu.2023.1290688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/03/2023] [Indexed: 12/23/2023] Open
Abstract
Pathogens escape host defenses by T-cell epitope mutation or deletion (immune escape) and by simulating the appearance of human T cell epitopes (immune camouflage). We identified a highly conserved, human-like T cell epitope in non-structural protein 7 (NSP7) of SARS-CoV-2, RNA-dependent RNA polymerase (RdRp) hetero-tetramer complex. Remarkably, this T cell epitope has significant homology to a T regulatory cell epitope (Tregitope) previously identified in the Fc region of human immunoglobulin G (IgG) (Tregitope 289). We hypothesized that the SARS-CoV-2 NSP7 epitope (NSP7-289) may induce suppressive responses by engaging and activating pre-existing regulatory T cells. We therefore compared NSP7-289 and IgG Tregitopes (289 and 289z, a shorter version of 289 that isolates the shared NSP7 epitope) in vitro. Tregitope peptides 289, 289z and NSP7-289 bound to multiple HLA-DRB1 alleles in vitro and suppressed CD4+ and CD8+ T cell memory responses. Identification and in vitro validation of SARS-CoV-2 NSP7-289 provides further evidence of immune camouflage and suggests that pathogens can use human-like epitopes to evade immune response and potentially enhance host tolerance. Further exploration of the role of cross-conserved Tregs in human immune responses to pathogens such as SARS-CoV-2 is warranted.
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Affiliation(s)
| | | | | | | | | | | | - Anne S. De Groot
- EpiVax, Inc., Providence, RI, United States
- Center for Vaccines and Immunology, University of Georgia, Athens, GA, United States
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3
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Hartwig O, Shetab Boushehri MA, Shalaby KS, Loretz B, Lamprecht A, Lehr CM. Drug delivery to the inflamed intestinal mucosa - targeting technologies and human cell culture models for better therapies of IBD. Adv Drug Deliv Rev 2021; 175:113828. [PMID: 34157320 DOI: 10.1016/j.addr.2021.113828] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/19/2022]
Abstract
Current treatment strategies for inflammatory bowel disease (IBD) seek to alleviate the undesirable symptoms of the disorder. Despite the higher specificity of newer generation therapeutics, e.g. monoclonal antibodies, adverse effects still arise from their interference with non-specific systemic immune cascades. To circumvent such undesirable effects, both conventional and newer therapeutic options can benefit from various targeting strategies. Of course, both the development and the assessment of the efficiency of such targeted delivery systems necessitate the use of suitable in vivo and in vitro models representing relevant pathophysiological manifestations of the disorder. Accordingly, the current review seeks to provide a comprehensive discussion of the available preclinical models with emphasis on human in vitro models of IBD, along with their potentials and limitations. This is followed by an elaboration on the advancements in the field of biology- and nanotechnology-based targeted drug delivery systems and the potential rooms for improvement to facilitate their clinical translation.
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Affiliation(s)
- Olga Hartwig
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), D-66123 Saarbrücken, Germany; Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
| | | | - Karim S Shalaby
- Department of Pharmaceutics, University of Bonn, D-53121 Bonn, Germany; Department of Pharmaceutics and Industrial Pharmacy, Ain Shams University, Cairo, Egypt
| | - Brigitta Loretz
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), D-66123 Saarbrücken, Germany
| | - Alf Lamprecht
- Department of Pharmaceutics, University of Bonn, D-53121 Bonn, Germany.
| | - Claus-Michael Lehr
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), D-66123 Saarbrücken, Germany; Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany.
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4
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Dembele M, Tao S, Massoud AH, Miah SMS, Lelias S, De Groot AS, Mazer BD. Tregitopes Improve Asthma by Promoting Highly Suppressive and Antigen-Specific Tregs. Front Immunol 2021; 12:634509. [PMID: 33953711 PMCID: PMC8089381 DOI: 10.3389/fimmu.2021.634509] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/26/2021] [Indexed: 01/09/2023] Open
Abstract
Tregitopes (T regulatory epitopes) are IgG-derived peptides with high affinity to major histocompatibility complex class II (MHCII), that are known to promote tolerance by activating T regulatory cell (Treg) activity. Here we characterized the effect of IgG Tregitopes in a well-established murine model of allergic asthma, demonstrating in vivo antigen-specific tolerance via adoptive transfer of Tregitope-and-allergen-activated Tregs. Asthma is a heterogeneous chronic inflammatory condition affecting the airways and impacting over 300 million individuals worldwide. Treatment is suppressive, and no current therapy addresses immune regulation in severely affected asthmatics. Although high dose intra-venous immunoglobulin (IVIg) is not commonly used in the asthma clinic setting, it has been shown to improve severe asthma in children and in adults. In our laboratory, we previously demonstrated that IVIg abrogates airway hyperresponsiveness (AHR) in a murine model of asthma and induces suppressive antigen-specific T-regulatory cells. We hypothesized that IgG-derived Tregitopes would modulate allergic airway disease by inducing highly suppressive antigen-specific Tregs capable of diminishing T effector cell responses and establishing antigen-specific tolerance. Using ovalbumin (OVA-) and ragweed-driven murine models of allergic airway disease, we characterized the immunoregulatory properties of Tregitopes and performed Treg adoptive transfer to OVA- and ragweed-allergic mice to test for allergen specificity. Treatment with Tregitopes attenuated allergen-induced airway hyperresponsiveness and lung inflammation. We demonstrated that Tregitopes induce highly suppressive allergen-specific Tregs. The tolerogenic action of IgG Tregitopes in our model is very similar to that of IVIg, so we foresee that IgG Tregitopes could potentially replace steroid-based treatment and can offer a synthetic alternative to IVIg in a range of inflammatory and allergic conditions.
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MESH Headings
- Adoptive Transfer
- Animals
- Animals, Genetically Modified
- Anti-Asthmatic Agents/pharmacology
- Antigens, Plant
- Asthma/drug therapy
- Asthma/immunology
- Asthma/metabolism
- Asthma/physiopathology
- Bronchoconstriction/drug effects
- Cells, Cultured
- Cytokines/metabolism
- Disease Models, Animal
- Epitopes, T-Lymphocyte/drug effects
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/metabolism
- Humans
- Immunoglobulin Fab Fragments/pharmacology
- Immunoglobulin Fc Fragments/pharmacology
- Inflammation Mediators/metabolism
- Lung/drug effects
- Lung/immunology
- Lung/metabolism
- Lung/physiopathology
- Lymphocyte Activation/drug effects
- Mice, Inbred C57BL
- Ovalbumin
- Plant Extracts
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- T-Lymphocytes, Regulatory/transplantation
- Mice
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Affiliation(s)
- Marieme Dembele
- The Research Institute of the McGill University Health Centre, Division of Pediatric Allergy Immunology and Dermatology, Montreal Children’s Hospital, McGill University Health Centre, Montreal, QC, Canada
| | - Shao Tao
- The Research Institute of the McGill University Health Centre, Division of Pediatric Allergy Immunology and Dermatology, Montreal Children’s Hospital, McGill University Health Centre, Montreal, QC, Canada
| | - Amir H. Massoud
- The Research Institute of the McGill University Health Centre, Division of Pediatric Allergy Immunology and Dermatology, Montreal Children’s Hospital, McGill University Health Centre, Montreal, QC, Canada
| | | | | | - Anne S. De Groot
- EpiVax, Inc., Providence, RI, United States
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Bruce D. Mazer
- The Research Institute of the McGill University Health Centre, Division of Pediatric Allergy Immunology and Dermatology, Montreal Children’s Hospital, McGill University Health Centre, Montreal, QC, Canada
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5
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De Groot AS, Rosenberg AS, Miah SMS, Skowron G, Roberts BJ, Lélias S, Terry FE, Martin WD. Identification of a potent regulatory T cell epitope in factor V that modulates CD4+ and CD8+ memory T cell responses. Clin Immunol 2021; 224:108661. [PMID: 33412295 DOI: 10.1016/j.clim.2020.108661] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023]
Abstract
Identification of T cell epitopes that are recognized by Tregs may elucidate the relative contributions of thymic Tregs and induced Tregs to control of autoimmune diseases and allergy. One such T regulatory cell epitope or 'Tregitope', derived from blood Factor V, is described here. Tregs responding to Tregitope FV621 are potent suppressors of CD4+ T effector responses to Tetanus Toxoid in an in vitro bystander suppression assay, strongly inhibit proliferation of effector CD8+ T cells, down-modulate CD86 and HLA DR on antigen-presenting cells, and enhance expression of granzyme B in Tregs. Tregitope FV621 also suppresses anti-OVA immune responses in vivo. The immunomodulatory effect of Tregitope FV621 is enhanced when conjugated to albumin, suggesting that the short half-life of Tregitope peptides can be prolonged. The in silico tools used to prospectively identify the FV Tregitope described here, when combined with in vitro /in vivo validating assays, may facilitate future Tregitope discoveries.
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Affiliation(s)
- Anne S De Groot
- EpiVax, Inc., Providence, RI, USA; Center for Vaccines and Immunology, University of Georgia, USA.
| | - Amy S Rosenberg
- Center for Drug Evaluation and Research, FDA, White Oak, MD, USA
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Faraji F, Karjoo Z, Moghaddam MV, Heidari S, Emameh RZ, Falak R. Challenges related to the immunogenicity of parenteral recombinant proteins: Underlying mechanisms and new approaches to overcome it. Int Rev Immunol 2018; 37:301-315. [PMID: 29851534 DOI: 10.1080/08830185.2018.1471139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Immune response elicited by therapeutic proteins is an important safety and efficacy issue for regulatory agencies, drug manufacturers, clinicians, and patients. Administration of therapeutic proteins can potentially induce the production of anti-drug antibodies or cell-mediated immune responses. At first, it was speculated that the immunogenicity is related to the non-human origin of these proteins. Later on, it was confirmed that the human proteins may also show immunogenicity. In this review article, we will focus on a number of factors, which play crucial roles in the human protein immunogenicity. These factors are related to the patient's status (or intrinsic properties) and molecular characteristics of the therapeutic protein's (or extrinsic properties). Furthermore, we will discuss available in silico, in vitro, and in vivo methods for the prediction of sequences, which may generate an immune response following parenteral administration of these proteins. In summary, nowadays, it is possible for drug manufacturers to evaluate the risk of immunogenicity of therapeutic proteins and implement a management plan to overcome the problems prior to proceeding to human clinical trials.
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Affiliation(s)
- Fatemeh Faraji
- a Immunology Research Center , Iran University of Medical Sciences (IUMS) , Tehran , Iran.,b Department of Immunology, School of Medicine , Iran University of Medical Sciences (IUMS) , Tehran , Iran
| | - Zahra Karjoo
- a Immunology Research Center , Iran University of Medical Sciences (IUMS) , Tehran , Iran
| | | | - Sahel Heidari
- a Immunology Research Center , Iran University of Medical Sciences (IUMS) , Tehran , Iran.,b Department of Immunology, School of Medicine , Iran University of Medical Sciences (IUMS) , Tehran , Iran
| | - Reza Zolfaghari Emameh
- c Department of Energy and Environmental Biotechnology, Division of Industrial & Environmental Biotechnology , National Institute of Genetic Engineering and Biotechnology (NIGEB) , Tehran , Iran
| | - Reza Falak
- a Immunology Research Center , Iran University of Medical Sciences (IUMS) , Tehran , Iran.,b Department of Immunology, School of Medicine , Iran University of Medical Sciences (IUMS) , Tehran , Iran
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7
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Basner-Tschakarjan E, Mingozzi F. Cell-Mediated Immunity to AAV Vectors, Evolving Concepts and Potential Solutions. Front Immunol 2014; 5:350. [PMID: 25101090 PMCID: PMC4107954 DOI: 10.3389/fimmu.2014.00350] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/08/2014] [Indexed: 11/13/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are one of the most efficient in vivo gene delivery platforms. Over the past decade, clinical trials of AAV vector-mediated gene transfer led to some of the most exciting results in the field of gene therapy and, recently, to the market approval of an AAV-based drug in Europe. With clinical development, however, it became obvious that the host immune system represents an important obstacle to successful gene transfer with AAV vectors. In this review article, we will discuss the issue of cytotoxic T cell responses directed against the AAV capsid encountered on human studies. While over the past several years the field has acquired a tremendous amount of information on the interactions of AAV vectors with the immune system, a lot of questions are still unanswered. Novel concepts are emerging, such as the relationship between the total capsid dose and the T cell-mediated clearance of transduced cells, the potential role of innate immunity in vector immunogenicity highlighted in preclinical studies, and the cross talk between regulatory and effector T cells in the determination of the outcome of gene transfer. There is still a lot to learn about immune responses in AAV gene transfer, for example, it is not well understood what are the determinants of the kinetics of activation of T cells in response to vector administration, why not all subjects develop detrimental T cell responses following gene transfer, and whether the intervention strategies currently in use to block T cell-mediated clearance of transduced cells will be safe and effective for all gene therapy indications. Results from novel preclinical models and clinical studies will help to address these points and to reach the important goal of developing safe and effective gene therapy protocols to treat human diseases.
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Affiliation(s)
| | - Federico Mingozzi
- University Pierre and Marie Curie , Paris , France ; Genethon , Evry , France
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8
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Tregitope peptides: the active pharmaceutical ingredient of IVIG? Clin Dev Immunol 2013; 2013:493138. [PMID: 24454476 PMCID: PMC3886585 DOI: 10.1155/2013/493138] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 10/17/2013] [Indexed: 11/17/2022]
Abstract
Five years ago, we reported the identification and characterization of several regulatory T-cell epitopes (now called Tregitopes) that were discovered in the heavy and light chains of IgG (De Groot et al. Blood, 2008). When added ex vivo to human PBMCs, these Tregitopes activated regulatory T cells (Tregs), increased expression of the transcription factor FoxP3, and induced IL-10 expression in CD4(+) T cells. We have now shown that coadministration of the Tregitopes in vivo, in a number of different murine models of autoimmune disease, can suppress immune responses to antigen in an antigen-specific manner, and that this response is mediated by Tregs. In addition we have shown that, although these are generally promiscuous epitopes, the activity of individual Tregitope peptides is restricted by HLA. In this brief report, we provide an overview of the effects of Tregitopes in vivo, discuss potential applications, and suggest that Tregitopes may represent one of the "active pharmaceutical ingredients" of IVIg. Tregitope applications may include any of the autoimmune diseases that are currently treated almost exclusively with intravenous immunoglobulin G (IVIG), such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Multifocal Motor Neuropathy (MMN), as well as gene therapy and allergy where Tregitopes may provide a means of inducing antigen-specific tolerance.
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Jawa V, Cousens LP, Awwad M, Wakshull E, Kropshofer H, De Groot AS. T-cell dependent immunogenicity of protein therapeutics: Preclinical assessment and mitigation. Clin Immunol 2013; 149:534-55. [PMID: 24263283 DOI: 10.1016/j.clim.2013.09.006] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/13/2013] [Accepted: 09/14/2013] [Indexed: 02/07/2023]
Abstract
Protein therapeutics hold a prominent and rapidly expanding place among medicinal products. Purified blood products, recombinant cytokines, growth factors, enzyme replacement factors, monoclonal antibodies, fusion proteins, and chimeric fusion proteins are all examples of therapeutic proteins that have been developed in the past few decades and approved for use in the treatment of human disease. Despite early belief that the fully human nature of these proteins would represent a significant advantage, adverse effects associated with immune responses to some biologic therapies have become a topic of some concern. As a result, drug developers are devising strategies to assess immune responses to protein therapeutics during both the preclinical and the clinical phases of development. While there are many factors that contribute to protein immunogenicity, T cell- (thymus-) dependent (Td) responses appear to play a critical role in the development of antibody responses to biologic therapeutics. A range of methodologies to predict and measure Td immune responses to protein drugs has been developed. This review will focus on the Td contribution to immunogenicity, summarizing current approaches for the prediction and measurement of T cell-dependent immune responses to protein biologics, discussing the advantages and limitations of these technologies, and suggesting a practical approach for assessing and mitigating Td immunogenicity.
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10
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Prabagar MG, Choi HJ, Park JY, Loh S, Kang YS. Intravenous immunoglobulin-mediated immunosuppression and the development of an IVIG substitute. Clin Exp Med 2013; 14:361-73. [PMID: 23996469 DOI: 10.1007/s10238-013-0255-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/19/2013] [Indexed: 02/07/2023]
Abstract
Immunoglobulins are glycoproteins produced by the cells of the immune system. Their primary function is to protect the body from pathogenic infection. Moreover, a concentrated polyclonal mixture of immunoglobulin G (IgG), the so-called intravenous IgG (IVIG), has been used to treat various chronic and systemic disorders of the immune system. Studies on the effects of IVIG in autoimmune disease models have revealed that IgG Fc fragments confer protection against various autoimmune diseases. The identification of this IgG Fc immunomodulatory component is important for the development of IVIG substitutes. The focus of this review is to introduce one of the Fc regulatory entities and to provide a summary of the current knowledge of the putative general mechanisms underlying IVIG activity in vivo on the basis of these Fc fragments. We also address the recent insights into several approaches for the development of IVIG substitutes.
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Affiliation(s)
- Miglena G Prabagar
- Department of Biomedical Science and Technology, SMART Institute of Advanced Biomedical Science, Institute of Functional Genomics, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701, Republic of Korea
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11
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Grant CW, Moran-Paul CM, Duclos SK, Guberski DL, Arreaza-Rubín G, Spain LM. Testing agents for prevention or reversal of type 1 diabetes in rodents. PLoS One 2013; 8:e72989. [PMID: 24023664 PMCID: PMC3758263 DOI: 10.1371/journal.pone.0072989] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/23/2013] [Indexed: 01/29/2023] Open
Abstract
We report the results of an independent laboratory's tests of novel agents to prevent or reverse type 1 diabetes (T1D) in the non-obese diabetic (NOD) mouse, BioBreeding diabetes prone (BBDP) rat, and multiple autoimmune disease prone (MAD) rat models. Methods were developed to better mimic human clinical trials, including: prescreening, randomization, blinding, and improved glycemic care of the animals. Agents were suggested by the research community in an open call for proposals, and selected for testing by an NIDDK appointed independent review panel. Agents selected for testing to prevent diabetes at later stages of progression in a rodent model were a STAT4 antagonist (DT22669), alpha1 anti-trypsin (Aralast NP), celastrol (a natural product with anti-inflammatory properties), and a Macrophage Inflammatory Factor inhibitor (ISO-092). Agents tested for reversal of established T1D in rodent models were: alpha1 anti-trypsin (Aralast NP), tolerogenic peptides (Tregitopes), and a long-acting formulation of GLP-1 (PGC-GLP-1). None of these agents were seen to prevent or reverse type 1 diabetes, while the positive control interventions were effective: anti-CD3 treatment provided disease reversal in the NOD mouse, dexamethasone prevented T1D induction in the MAD rat, and cyclosporin prevented T1D in the BBDP rat. For some tested agents, details of previous formulation, delivery, or dosing, as well as laboratory procedure, availability of reagents and experimental design, could have impacted our ability to confirm prior reports of efficacy in preclinical animal models. In addition, the testing protocols utilized here provided detection of effects in a range commonly used in placebo controlled clinical trials (for example, 50% effect size), and thus may have been underpowered to observe more limited effects. That said, we believe the results compiled here, showing good control and repeatability, confirm the feasibility of screening diverse test agents in an independent laboratory.
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Affiliation(s)
- Christian W. Grant
- Biomedical Research Models (BRM), Inc., Worcester and Springfield, Massachusetts, United States of America
| | - Catherine M. Moran-Paul
- Biomedical Research Models (BRM), Inc., Worcester and Springfield, Massachusetts, United States of America
| | - Shane K. Duclos
- Biomedical Research Models (BRM), Inc., Worcester and Springfield, Massachusetts, United States of America
| | - Dennis L. Guberski
- Biomedical Research Models (BRM), Inc., Worcester and Springfield, Massachusetts, United States of America
| | - Guillermo Arreaza-Rubín
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Lisa M. Spain
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, Maryland, United States of America
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12
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Modulation of CD8+ T cell responses to AAV vectors with IgG-derived MHC class II epitopes. Mol Ther 2013; 21:1727-37. [PMID: 23857231 PMCID: PMC3776637 DOI: 10.1038/mt.2013.166] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 07/08/2013] [Indexed: 02/03/2023] Open
Abstract
Immune responses directed against viral capsid proteins constitute a main safety concern in the use of adeno-associated virus (AAV) as gene transfer vectors in humans. Pharmacological immunosuppression has been proposed as a solution to the problem; however, the approach suffers from several potential limitations. Using MHC class II epitopes initially identified within human IgG, named Tregitopes, we showed that it is possible to modulate CD8+ T cell responses to several viral antigens in vitro. We showed that incubation of peripheral blood mononuclear cells with these epitopes triggers proliferation of CD4+CD25+FoxP3+ T cells that suppress killing of target cells loaded with MHC class I antigens in an antigen-specific fashion, through a mechanism that seems to require cell-to-cell contact. Expression of a construct encoding for the AAV capsid structural protein fused to Tregitopes resulted in reduction of CD8+ T cell reactivity against the AAV capsid following immunization with an adenoviral vector expressing capsid. This was accompanied by an increase in frequency of CD4+CD25+FoxP3+ T cells in spleens and lower levels of inflammatory infiltrates in injected tissues. This proof-of-concept study demonstrates modulation of CD8+ T cell reactivity to an antigen using regulatory T cell epitopes is possible.
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13
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Su Y, Rossi R, De Groot AS, Scott DW. Regulatory T cell epitopes (Tregitopes) in IgG induce tolerance in vivo and lack immunogenicity per se. J Leukoc Biol 2013; 94:377-83. [PMID: 23729499 DOI: 10.1189/jlb.0912441] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Tregitopes are a set of epitopes, derived from IgG, that bind to MHCII, activate nTregs, and promote tolerance. We have now confirmed that coadministration of Tregitopes with a range of proteins (autoantigens and nominal antigens, such as OVA) in vitro and in vivo leads to suppression of T cell and antibody responses to the test antigens. In this study, we demonstrate that Tregitopes are not immunogenic in vivo even when emulsified with strong adjuvants, such as IFA or CFA. Moreover, in vivo administration of Tregitopes with IFA or CFA does not induce Th1 or Th2 cytokine expression under restimulation conditions in vitro. We investigated tolerance induction by codelivering Tregitopes with OVA using B cells. When B cells were pulsed with OVA plus Tregitopes and transferred into naïve mice, we found that cellular and humoral immune responses to the OVA were suppressed. As a result of their ability to induce Tregs and the absence of immunogenicity in the context of strong adjuvants, Tregitopes might be considered a novel immunomodulatory approach for the suppression of immune responses to protein therapeutics (such as FVIII and mAb), as well as for treatment of autoimmune diseases.
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Affiliation(s)
- Yan Su
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Cousens LP, Su Y, McClaine E, Li X, Terry F, Smith R, Lee J, Martin W, Scott DW, De Groot AS. Application of IgG-derived natural Treg epitopes (IgG Tregitopes) to antigen-specific tolerance induction in a murine model of type 1 diabetes. J Diabetes Res 2013; 2013:621693. [PMID: 23710469 PMCID: PMC3655598 DOI: 10.1155/2013/621693] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 01/11/2013] [Accepted: 01/19/2013] [Indexed: 12/16/2022] Open
Abstract
HLA class II-restricted regulatory T cell (Treg) epitopes in IgG (also called "Tregitopes") have been reported to suppress immune responses to coadministered antigens by stimulating the expansion of natural Tregs (nTregs). Here we evaluate their impact on human immune responses to islet cell antigens ex vivo and on the modulation of type 1 diabetes (T1D) in a murine model in vivo. Co-administration of Tregitopes and T1D antigens delayed development of hyperglycemia and reduced the incidence of diabetes in NOD mice. Suppression of diabetes could be observed even following onset of disease. To measure the impact of Tregitope treatment on T cell responses, we evaluated the effect of Tregitope treatment in DO11.10 mice. Upregulation of FoxP3 in KJ1-26-stained OVA-specific CD4(+) T cells was observed following treatment of DO11.10 mice with Tregitopes, along with reductions in anti-OVA Ig and T effector responses. In ex vivo studies of human T cells, peripheral blood mononuclear cells' (PBMC) responses to GAD65 epitopes in the presence and absence of Tregitope were variable. Suppression of immune responses to GAD65 epitopes ex vivo by Tregitope appeared to be more effective in assays using PBMC from a newly diagnosed diabetic subject than for other more established diabetic subjects, and correlation of the degree of suppression with predicted HLA restriction of the Tregitopes was confirmed. Implementation of these defined regulatory T cell epitopes for therapy of T1D and other autoimmune diseases may lead to a paradigm shift in disease management.
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Affiliation(s)
| | - Yan Su
- University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Xin Li
- University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Frances Terry
- EpiVax, Inc., 146 Clifford Street, Providence, RI 02903, USA
| | - Robert Smith
- Alpert Medical School of Brown University, Providence, RI 02912, USA
| | - Jinhee Lee
- University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - William Martin
- EpiVax, Inc., 146 Clifford Street, Providence, RI 02903, USA
| | - David W. Scott
- University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Uniformed Services University of Health Sciences (USUHS), Bethesda, MD 20814, USA
| | - Anne S. De Groot
- EpiVax, Inc., 146 Clifford Street, Providence, RI 02903, USA
- *Anne S. De Groot:
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Cousens LP, Tassone R, Mazer BD, Ramachandiran V, Scott DW, De Groot AS. Tregitope update: mechanism of action parallels IVIg. Autoimmun Rev 2012; 12:436-43. [PMID: 22944299 DOI: 10.1016/j.autrev.2012.08.017] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 08/22/2012] [Indexed: 12/12/2022]
Abstract
In the course of screening immunoglobulin G (IgG) sequences for T cell epitopes, we identified novel Treg epitope peptides, now called Tregitopes, contained in the highly conserved framework regions of Fab and Fc. Tregitopes may provide one explanation for the expansion and stimulation of Treg cells following intravenous immunoglobulin (IVIg) therapy. Their distinguishing characteristics include in silico signatures that suggest high-affinity binding to multiple human HLA class II DR and conservation across IgG isotypes and mammalian species with only minor amino acid modifications. Tregitopes induce expansion of CD4(+)/CD25(hi)/FoxP3(+) T cells and suppress immune responses to co-incubated antigens in vitro. By comparing the human IgG Tregitopes (hTregitopes 167 and 289, located in the IgG CH1 and CH2 domains) and Fab to murine sequences, we identified class II-restricted murine Tregitope homologs (mTregitopes). In vivo, mTregitopes suppress inflammation and reproducibly induce Tregs to expand. In vitro studies suggest that the Tregitope mechanism of action is to induce Tregs to respond, leading to production of regulatory signals, followed by modulation of dendritic cell phenotype. The identification of Treg epitopes in IgG suggests that additional Tregitopes may also be present in other autologous proteins; methods for identifying and validating such peptides are described here. The discovery of Tregitopes in IgG and other autologous proteins may lead to the development of new insights as to the role of Tregs in autoimmune diseases.
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