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Norbury CC. Defining cross presentation for a wider audience. Curr Opin Immunol 2016; 40:110-6. [DOI: 10.1016/j.coi.2016.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/03/2016] [Indexed: 01/10/2023]
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Esensten JH, Helou YA, Chopra G, Weiss A, Bluestone JA. CD28 Costimulation: From Mechanism to Therapy. Immunity 2016; 44:973-88. [PMID: 27192564 PMCID: PMC4932896 DOI: 10.1016/j.immuni.2016.04.020] [Citation(s) in RCA: 526] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Indexed: 02/07/2023]
Abstract
Ligation of the CD28 receptor on T cells provides a critical second signal alongside T cell receptor (TCR) ligation for naive T cell activation. Here, we discuss the expression, structure, and biochemistry of CD28 and its ligands. CD28 signals play a key role in many T cell processes, including cytoskeletal remodeling, production of cytokines, survival, and differentiation. CD28 ligation leads to unique epigenetic, transcriptional, and post-translational changes in T cells that cannot be recapitulated by TCR ligation alone. We discuss the function of CD28 and its ligands in both effector and regulatory T cells. CD28 is critical for regulatory T cell survival and the maintenance of immune homeostasis. We outline the roles that CD28 and its family members play in human disease and we review the clinical efficacy of drugs that block CD28 ligands. Despite the centrality of CD28 and its family members and ligands to immune function, many aspects of CD28 biology remain unclear. Translation of a basic understanding of CD28 function into immunomodulatory therapeutics has been uneven, with both successes and failures. Such real-world results might stem from multiple factors, including complex receptor-ligand interactions among CD28 family members, differences between the mouse and human CD28 families, and cell-type specific roles of CD28 family members.
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Affiliation(s)
- Jonathan H Esensten
- Department of Laboratory Medicine, University of California, San Francisco, CA 94143, USA.
| | - Ynes A Helou
- Division of Rheumatology, Department of Medicine, Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, University of California, San Francisco, CA 94143, USA
| | - Gaurav Chopra
- Department of Chemistry, Purdue Center for Drug Discovery, Purdue University, West Lafayette, IN 47907, USA
| | - Arthur Weiss
- Division of Rheumatology, Department of Medicine, Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, University of California, San Francisco, CA 94143, USA; Howard Hughes Medical Institute, University of California, San Francisco, CA 94143, USA
| | - Jeffrey A Bluestone
- Diabetes Center and Department of Medicine, University of California, San Francisco, CA 94143, USA.
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Steele S, Radlinski L, Taft-Benz S, Brunton J, Kawula TH. Trogocytosis-associated cell to cell spread of intracellular bacterial pathogens. eLife 2016; 5. [PMID: 26802627 PMCID: PMC4786427 DOI: 10.7554/elife.10625] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 01/22/2016] [Indexed: 11/13/2022] Open
Abstract
Macrophages are myeloid-derived phagocytic cells and one of the first immune cell types to respond to microbial infections. However, a number of bacterial pathogens are resistant to the antimicrobial activities of macrophages and can grow within these cells. Macrophages have other immune surveillance roles including the acquisition of cytosolic components from multiple types of cells. We hypothesized that intracellular pathogens that can replicate within macrophages could also exploit cytosolic transfer to facilitate bacterial spread. We found that viable Francisella tularensis, as well as Salmonella enterica bacteria transferred from infected cells to uninfected macrophages along with other cytosolic material through a transient, contact dependent mechanism. Bacterial transfer occurred when the host cells exchanged plasma membrane proteins and cytosol via a trogocytosis related process leaving both donor and recipient cells intact and viable. Trogocytosis was strongly associated with infection in mice, suggesting that direct bacterial transfer occurs by this process in vivo.
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Affiliation(s)
- Shaun Steele
- University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Lauren Radlinski
- University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Sharon Taft-Benz
- University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Jason Brunton
- University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Thomas H Kawula
- University of North Carolina at Chapel Hill, Chapel Hill, United States
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Shao Z, Harfuddin Z, Pang WL, Nickles E, Koh LK, Schwarz H. Trogocytic CD137 transfer causes an internalization of CD137 ligand on murine APCs leading to reduced T cell costimulation. J Leukoc Biol 2015; 97:909-919. [DOI: 10.1189/jlb.3a0213-079rrr] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
Abstract
CD137 ligand (CD137L) is expressed on APCs and crosslinks CD137, a powerful costimulatory molecule on T cells during cognate interactions, and thereby greatly enhances immune responses. We report that CD137 can be transferred from activated T cells and from tumor cells that express CD137 to other cells via trogocytosis. This trogocytic transfer is independent of CD137L expression by the recipient cell. However, if CD137L is present on the recipient cell, the transferred CD137 binds to CD137L and the CD137-CD137L complex becomes internalized. The removal of CD137L from the surface of APCs lowers their ability to costimulate T cells, as evidenced by a reduced IFN-γ secretion. Removal of CD137L on APCs by trogocytic transfer of CD137 occurs within 1 h and requires cell-cell contact and the continuous presence of CD137-expressing cells. Bidirectional signaling exists for the CD137 receptor/ligand system, because CD137L also signals into APCs. We propose that the trogocytic transfer of CD137 from activated T cells to APCs and the subsequent removal of CD137L from APCs is a physiologic regulatory mechanism that limits immune activity. Furthermore, we hypothesize that the trogocytic transfer of CD137 occurs in cancers and quenches the activity of APCs, contributing to the cancer cells escaping immune surveillance. Taken together, our findings demonstrate that the trogocytic transfer of CD137 leads to an internalization of CD137L on APCs and a reduction in immune activity.
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Affiliation(s)
- Zhe Shao
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Zulkarnain Harfuddin
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , Singapore , Singapore
| | - Wan Lu Pang
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Emily Nickles
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Liang Kai Koh
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Herbert Schwarz
- Department of Physiology, National University of Singapore , Singapore , Singapore
- Immunology Programme, National University of Singapore , Singapore , Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , Singapore , Singapore
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55
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Bjarnadottir U, Lemarquis AL, Halldorsdottir S, Freysdottir J, Ludviksson BR. The suppressive function of human CD8(+) iTregs is inhibited by IL-1β and TNFα. Scand J Immunol 2015; 80:313-22. [PMID: 25039313 DOI: 10.1111/sji.12212] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/22/2014] [Accepted: 06/25/2014] [Indexed: 12/17/2022]
Abstract
CD8(+) Tregs display an immunoregulatory activity and may play an essential role in the immunopathology of several diseases. Therefore, their therapeutic potential is exquisite and further studies on their differentiation and function are essential. The aim of this study was to evaluate the role of the innate immune system in CD8(+) iTreg differentiation and function. Naive human CD8(+) CD25(-) CD45RA(+) T cells were cultured in Treg-inducing conditions with or without IL-1β, TNFα or monocyte-derived dendritic cells (DCs). The differentiation of CD8(+) CD127(-) CD25(hi) FoxP3(hi) -induced Tregs (CD8(+) iTregs) is dependent on TGF-β1 and IL-2, which had synergistic effect upon their differentiation. CD8(+) iTregs were also induced in a coculture with allogeneic mature DCs (mDCs). The CD8(+) iTregs suppressive function was confirmed, which was diminished in the presence of IL-1β and TNFα. The IL-1β-prevented suppressive function was associated with reduced secretion of IL-10 and IFNγ, whereas the presence of TNFα did not affect their secretion. Furthermore, the presence of TNFα reduced IL-10 and TGF-β1 secretion by CD8(+) iTregs, whereas only IL-10 secretion was decreased by IL-1β. Together, these results suggest that IL-1β and TNFα prevent IL-2- and TGF-β1-driven CD8(+) iTregs suppressive function in human T cells. Such pro-inflammatory innate immune response possibly mediates its negative tolerogenic effect through reduced IFNγ-, IL-10- and TGF-β1-driven mechanism.
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Affiliation(s)
- U Bjarnadottir
- Department of Immunology, Landspitali - The National University Hospital of Iceland, Reykjavík, Iceland
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56
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Mesenchymal stem cells alleviate atherosclerosis by elevating number and function of CD4(+)CD25 (+)FOXP3 (+) regulatory T-cells and inhibiting macrophage foam cell formation. Mol Cell Biochem 2014; 400:163-72. [PMID: 25389006 DOI: 10.1007/s11010-014-2272-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/29/2014] [Indexed: 10/24/2022]
Abstract
Atherosclerosis is a chronic inflammatory disease characterized by the formation of plaques inside arteries, leading to narrowing and blockage. Potential therapeutic strategies include expanding the population of regulatory T-cells (Tregs) to enhance atheroprotective immunity, and inhibiting the formation of macrophage foam cells. Here, we studied the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on atherosclerotic plaque formation in Apolipoprotein E(-/-) (ApoE-KO) mice, and elucidated the underlying mechanism. BM-MSCs isolated from 4 week-old ApoE-KO mice were evaluated by flow cytometry for expression of MSC-specific markers. Thirty eight week-old ApoE-KO mice were randomly divided into three experimental groups (n = 10 per group): 1. MSC group-received BM-MSCs intravenously; 2. Vehicle group-received DMEM; 3. Control group-did not receive any treatment. Administration of MSCs resulted in a marked decrease in the size of atherosclerotic plaques 3 months after treatment. In addition, the number and function of CD4(+)CD25(+)FOXP3(+) regulatory T-cells (Tregs) in cultured splenocytes, and the expression of FOXP3 at both mRNA and protein levels, was significantly increased in the MSC group. In vitro experiments further indicated that the formation of macrophage foam cells was inhibited by treatment with MSCs, accompanied by a significant downregulation in CD36 and scavenger receptor A (SRA). Our findings suggest that MSCs play an atheroprotective role by enhancing the number and function of Tregs and inhibiting the formation of macrophage foam cells. Hence, administration of MSCs to atherosclerotic patients might have significant clinical benefits.
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Chistiakov DA, Sobenin IA, Orekhov AN, Bobryshev YV. Dendritic cells in atherosclerotic inflammation: the complexity of functions and the peculiarities of pathophysiological effects. Front Physiol 2014; 5:196. [PMID: 24904430 PMCID: PMC4034414 DOI: 10.3389/fphys.2014.00196] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 05/09/2014] [Indexed: 12/31/2022] Open
Abstract
Atherosclerosis is considered as a chronic disease of arterial wall, with a strong contribution of inflammation. Dendritic cells (DCs) play a crucial role in the initiation of proatherogenic inflammatory response. Mature DCs present self-antigens thereby supporting differentiation of naïve T cells to effector cells that further propagate atherosclerotic inflammation. Regulatory T cells (Tregs) can suppress proinflammatory function of mature DCs. In contrast, immature DCs are able to induce Tregs and prevent differentiation of naïve T cells to proinflammatory effector T cells by initiating apoptosis and anergy in naïve T cells. Indeed, immature DCs showed tolerogenic and anti-inflammatory properties. Thus, DCs play a double role in atherosclerosis: mature DCs are proatherogenic while immature DCs appear to be anti-atherogenic. Tolerogenic and anti-inflammatory capacity of immature DCs can be therefore utilized for the development of new immunotherapeutic strategies against atherosclerosis.
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Affiliation(s)
- Dimitry A Chistiakov
- Department of Medical Nanobiotechnology, Pirogov Russian State Medical University Moscow, Russia
| | - Igor A Sobenin
- Skolkovo Innovative Center, Institute for Atherosclerosis Research Moscow, Russia ; Institute of General Pathology and Pathophysiology, Russian Academy of Sciences Moscow, Russia ; Laboratory of Medical Genetics, Russian Cardiology Research and Production Complex Moscow, Russia
| | - Alexander N Orekhov
- Skolkovo Innovative Center, Institute for Atherosclerosis Research Moscow, Russia ; Institute of General Pathology and Pathophysiology, Russian Academy of Sciences Moscow, Russia
| | - Yuri V Bobryshev
- Skolkovo Innovative Center, Institute for Atherosclerosis Research Moscow, Russia ; Faculty of Medicine, School of Medical Sciences, University of New South Wales, Kensington, Sydney NSW, Australia
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Kowalczyk A, D'Souza CA, Zhang L. Cell-extrinsic CTLA4-mediated regulation of dendritic cell maturation depends on STAT3. Eur J Immunol 2014; 44:1143-55. [PMID: 24338929 DOI: 10.1002/eji.201343601] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 11/28/2013] [Accepted: 12/10/2013] [Indexed: 01/21/2023]
Abstract
Regulatory T (Treg) cells suppress immune responses by downregulating the expression of costimulatory molecules CD80 and CD86 on dendritic cells (DCs) through cytotoxic T lymphocyte antigen 4 (CTLA4). However, it is unclear whether inducible Treg (iTreg) cells can hamper immune responses via the same mechanism. Moreover, whether a reverse signal sent by CTLA4 alone is sufficient to prevent maturation of DCs has never been evaluated. Here, we demonstrate that stimulation of DCs with CTLA4, either expressed by inducible Treg cells or by cross-linking with CTLA4Fc fusion protein, can significantly inhibit LPS-induced CD80 and CD86 mRNA and protein expression in both mouse and human DCs. Importantly, CTLA4Fc-treated DCs had reduced ability to stimulate CD4(+) and CD8(+) T-cell proliferation and cytokine production in both syngeneic and allogeneic settings. We also investigated the molecular mechanism involved in the induction of tolerogenic DCs by CTLA4. We determined that the interaction of CTLA4 with its high affinity ligand CD80 on DCs induces STAT3 phosphorylation followed by reduction of NF-κB activity, leading to suppression of CD80 and CD86 gene transcription and protein production. Our work opens new windows for the generation of tolerogenic DCs that could ultimately be used for treating autoimmune diseases and transplant rejection.
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Affiliation(s)
- Aleksandra Kowalczyk
- Toronto General Research Institute, the University Health Network, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, Department of Immunology, University of Toronto, Toronto, ON, Canada
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59
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Cobbold SP, Waldmann H. Regulatory cells and transplantation tolerance. Cold Spring Harb Perspect Med 2013; 3:3/6/a015545. [PMID: 23732858 DOI: 10.1101/cshperspect.a015545] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transplantation tolerance is a continuing therapeutic goal, and it is now clear that a subpopulation of T cells with regulatory activity (Treg) that express the transcription factor foxp3 are crucial to this aspiration. Although reprogramming of the immune system to donor-specific transplantation tolerance can be readily achieved in adult mouse models, it has yet to be successfully translated in human clinical practice. This requires that we understand the fundamental mechanisms by which donor antigen-specific Treg are induced and function to maintain tolerance, so that we can target therapies to enhance rather than impede these regulatory processes. Our current understanding is that Treg act via numerous molecular mechanisms, and critical underlying components such as mTOR inhibition, are only now emerging.
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Affiliation(s)
- Stephen P Cobbold
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
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60
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Chistiakov DA, Sobenin IA, Orekhov AN, Bobryshev YV. WITHDRAWN: Dendritic cells: A double-edge sword in atherosclerotic inflammation. Atherosclerosis 2013:S0021-9150(13)00190-1. [PMID: 23578357 DOI: 10.1016/j.atherosclerosis.2013.03.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/07/2013] [Accepted: 03/09/2013] [Indexed: 11/25/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Dimitry A Chistiakov
- Pirogov Russian State Medical University, Department of Medical Nanobiotechnology, Moscow, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow, Russia
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Chistiakov DA, Sobenin IA, Orekhov AN. Regulatory T cells in atherosclerosis and strategies to induce the endogenous atheroprotective immune response. Immunol Lett 2013; 151:10-22. [DOI: 10.1016/j.imlet.2013.01.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 01/30/2023]
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Duncan R, Richardson SCW. Endocytosis and intracellular trafficking as gateways for nanomedicine delivery: opportunities and challenges. Mol Pharm 2012; 9:2380-402. [PMID: 22844998 DOI: 10.1021/mp300293n] [Citation(s) in RCA: 248] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
More than 40 nanomedicines are already in routine clinical use with a growing number following in preclinical and clinical development. The therapeutic objectives are often enhanced disease-specific targeting (with simultaneously reduced access to sites of toxicity) and, especially in the case of macromolecular biotech drugs, improving access to intracellular pharmacological target receptors. Successful navigation of the endocytic pathways is usually a prerequisite to achieve these goals. Thus a comprehensive understanding of endocytosis and intracellular trafficking pathways in both the target and bystander normal cell type(s) is essential to enable optimal nanomedicine design. It is becoming evident that endocytic pathways can become disregulated in disease and this, together with the potential changes induced during exposure to the nanocarrier itself, has the potential to significantly impact nanomedicine performance in terms of safety and efficacy. Here we overview the endomembrane trafficking pathways, discuss the methods used to determine and quantitate the intracellular fate of nanomedicines, and review the current status of lysosomotropic and endosomotropic delivery. Based on the lessons learned during more than 3 decades of clinical development, the need to use endocytosis-relevant clinical biomarkers to better select those patients most likely to benefit from nanomedicine therapy is also discussed.
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Affiliation(s)
- Ruth Duncan
- School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
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