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Liu Y, Zheng P. Preserving the CTLA-4 Checkpoint for Safer and More Effective Cancer Immunotherapy. Trends Pharmacol Sci 2019; 41:4-12. [PMID: 31836191 PMCID: PMC7210725 DOI: 10.1016/j.tips.2019.11.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 01/07/2023]
Abstract
A major paradigm in cancer immunotherapy is the use of checkpoint inhibitors to break regulatory mechanisms that usually guard the host against autoimmune diseases. CTLA-4-targeting immunotherapy was the first example that helped establish this paradigm. However, the clinically tested anti-CTLA-4 antibodies exhibit suboptimal efficacy but high toxicity. Recent studies have demonstrated that immunotherapy-related adverse events (irAE) and the cancer immunotherapeutic effect (CITE) represent distinct and therapeutically separable activities of anti-CTLA-4 antibodies. The former is attributable to inactivation of the CTLA-4 checkpoint, while the latter is due to selective depletion of regulatory T cells (Treg) in a tumor microenvironment. Here we argue that for safer and more effective CTLA-4-targeting immune therapy, one should preserve rather than inhibit the CTLA-4 checkpoint while enhancing the efficacy and selectivity of Treg depletion in a tumor microenvironment.
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Affiliation(s)
- Yang Liu
- Division of Immunotherapy, Institute of Human Virology and Department of Surgery, University of Maryland, Baltimore, MD 21201, USA; OncoImmune, Inc., Rockville, MD 20850, USA.
| | - Pan Zheng
- Division of Immunotherapy, Institute of Human Virology and Department of Surgery, University of Maryland, Baltimore, MD 21201, USA; OncoImmune, Inc., Rockville, MD 20850, USA.
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Khailaie S, Rowshanravan B, Robert PA, Waters E, Halliday N, Badillo Herrera JD, Walker LSK, Sansom DM, Meyer-Hermann M. Characterization of CTLA4 Trafficking and Implications for Its Function. Biophys J 2018; 115:1330-1343. [PMID: 30219287 PMCID: PMC6170599 DOI: 10.1016/j.bpj.2018.08.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 07/06/2018] [Accepted: 08/02/2018] [Indexed: 12/21/2022] Open
Abstract
CTLA4 is an essential negative regulator of T-cell immune responses and a key checkpoint regulating autoimmunity and antitumor responses. Genetic mutations resulting in quantitative defects in the CTLA4 pathway are also associated with the development of immune dysregulation syndromes in humans. It has been proposed that CTLA4 functions to remove its ligands CD80 and CD86 from opposing cells by a process known as transendocytosis. A quantitative characterization of CTLA4 synthesis, endocytosis, degradation, and recycling and how these affect its function is currently lacking. In a combined in vitro and in silico study, we developed a mathematical model and identified these trafficking parameters. Our model predicts optimal ligand removal in an intermediate affinity range. The intracellular CTLA4 pool as well as fast internalization, recovery of free CTLA4 from internalized complexes, and recycling is critical for sustained functionality. CD80-CTLA4 interactions are predicted to dominate over CD86-CTLA4. Implications of these findings in the context of control of antigen-presenting cells by regulatory T cells and of pathologic genetic deficiencies are discussed. The presented mathematical model can be reused in the community beyond these questions to better understand other trafficking receptors and study the impact of CTLA4 targeting drugs.
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Affiliation(s)
- Sahamoddin Khailaie
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Centre for Individualised Infection Medicine, Hannover, Germany
| | - Behzad Rowshanravan
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Hospital, London, United Kingdom
| | - Philippe A Robert
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Erin Waters
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Hospital, London, United Kingdom
| | - Neil Halliday
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Hospital, London, United Kingdom
| | - Jesus David Badillo Herrera
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Lucy S K Walker
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Hospital, London, United Kingdom
| | - David M Sansom
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, Royal Free Hospital, London, United Kingdom.
| | - Michael Meyer-Hermann
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany; Centre for Individualised Infection Medicine, Hannover, Germany; Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany.
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Du X, Tang F, Liu M, Su J, Zhang Y, Wu W, Devenport M, Lazarski CA, Zhang P, Wang X, Ye P, Wang C, Hwang E, Zhu T, Xu T, Zheng P, Liu Y. A reappraisal of CTLA-4 checkpoint blockade in cancer immunotherapy. Cell Res 2018; 28:416-432. [PMID: 29472691 PMCID: PMC5939050 DOI: 10.1038/s41422-018-0011-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/11/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022] Open
Abstract
It is assumed that anti-CTLA-4 antibodies cause tumor rejection by blocking negative signaling from B7-CTLA-4 interactions. Surprisingly, at concentrations considerably higher than plasma levels achieved by clinically effective dosing, the anti-CTLA-4 antibody Ipilimumab blocks neither B7 trans-endocytosis by CTLA-4 nor CTLA-4 binding to immobilized or cell-associated B7. Consequently, Ipilimumab does not increase B7 on dendritic cells (DCs) from either CTLA4 gene humanized (Ctla4h/h) or human CD34+ stem cell-reconstituted NSG™ mice. In Ctla4h/m mice expressing both human and mouse CTLA4 genes, anti-CTLA-4 antibodies that bind to human but not mouse CTLA-4 efficiently induce Treg depletion and Fc receptor-dependent tumor rejection. The blocking antibody L3D10 is comparable to the non-blocking Ipilimumab in causing tumor rejection. Remarkably, L3D10 progenies that lose blocking activity during humanization remain fully competent in inducing Treg depletion and tumor rejection. Anti-B7 antibodies that effectively block CD4 T cell activation and de novo CD8 T cell priming in lymphoid organs do not negatively affect the immunotherapeutic effect of Ipilimumab. Thus, clinically effective anti-CTLA-4 mAb causes tumor rejection by mechanisms that are independent of checkpoint blockade but dependent on the host Fc receptor. Our data call for a reappraisal of the CTLA-4 checkpoint blockade hypothesis and provide new insights for the next generation of safe and effective anti-CTLA-4 mAbs.
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Affiliation(s)
- Xuexiang Du
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Fei Tang
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Mingyue Liu
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Juanjuan Su
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Yan Zhang
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Wei Wu
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | | | - Christopher A Lazarski
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Peng Zhang
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Xu Wang
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Peiying Ye
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | | | - Eugene Hwang
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA
| | - Tinghui Zhu
- Alphamab, Inc., Suzhou, Jiangsu, 215125, China
| | - Ting Xu
- Alphamab, Inc., Suzhou, Jiangsu, 215125, China
| | - Pan Zheng
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA. .,OncoImmune, Inc., Rockville, MD, 20852, USA.
| | - Yang Liu
- Center for Cancer and Immunology Research, Children's Research Institute, Children's National Health System, Washington, DC, 20010, USA.,OncoImmune, Inc., Rockville, MD, 20852, USA
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Verma N, Burns SO, Walker LSK, Sansom DM. Immune deficiency and autoimmunity in patients with CTLA-4 (CD152) mutations. Clin Exp Immunol 2017; 190:1-7. [PMID: 28600865 DOI: 10.1111/cei.12997] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2017] [Indexed: 12/15/2022] Open
Abstract
Immune deficiency disorders are a heterogeneous group of diseases of variable genetic aetiology. While the hallmark of immunodeficiency is susceptibility to infection, it is increasingly clear that autoimmunity is prevalent, suggestive of a more general immune dysregulation in some cases. With the increasing use of genetic technologies, the underlying causes of immune dysregulation are beginning to emerge. Here we provide a review of the heterozygous mutations found in the immune checkpoint protein CTLA-4, identified in cases of common variable immunodeficiency disorders (CVID) with accompanying autoimmunity. Study of these mutations provides insights into the biology of CTLA-4 as well as suggesting approaches for rational treatment of these patients.
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Affiliation(s)
- N Verma
- Clinical Immunology Department, Royal Free Hospital, London, UK
| | - S O Burns
- Clinical Immunology Department, Royal Free Hospital, London, UK.,Division of Infection and Immunity, School of Life and Medical Sciences, Institute of Immunity and Transplantation, University College London, Royal Free Hospital, London, UK
| | - L S K Walker
- Division of Infection and Immunity, School of Life and Medical Sciences, Institute of Immunity and Transplantation, University College London, Royal Free Hospital, London, UK
| | - D M Sansom
- Division of Infection and Immunity, School of Life and Medical Sciences, Institute of Immunity and Transplantation, University College London, Royal Free Hospital, London, UK
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Walker LS. EFIS Lecture: Understanding the CTLA-4 checkpoint in the maintenance of immune homeostasis. Immunol Lett 2017; 184:43-50. [DOI: 10.1016/j.imlet.2017.02.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 02/13/2017] [Indexed: 01/08/2023]
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Abstract
The response of peripheral T lymphocytes (T cell) is controlled by multiple checkpoints to avoid unwanted activation against self-tissues. Two opposing costimulatory receptors, CD28 and CTLA-4, on T cells bind to the same ligands (CD80 and CD86) on antigen-presenting cells (APCs), and provide positive and negative feedback for T-cell activation, respectively. Early studies suggested that CTLA-4 is induced on activated T cells and binds to CD80/CD86 with much stronger affinity than CD28, providing a competitive inhibition. Subsequent studies by many researchers revealed the more complex mode of T-cell inhibition by CTLA-4. After T-cell activation, CTLA-4 is stored in the intracellular vesicles, and recruited to the immunological synapse formed between T cells and APCs, and inhibits further activation of T cells by blocking signals initiated by T-cell receptors and CD28. CTLA-4-positive cells can also provide cell-extrinsic regulation on other autoreactive T cells, and are considered to provide an essential regulatory mechanism for FoxP3+ regulatory T cells. Genetic deficiency of CTLA-4 leads to CD28-mediated severe autoimmunity in mice and humans, suggesting its function as a fundamental brake that restrains the expansion and activation of self-reactive T cells. In cancer, therapeutic approaches targeting CTLA-4 by humanized blocking antibodies has been demonstrated to be an effective immunotherapy by reversing T-cell tolerance against tumors. This chapter introduces CTLA-4 biology, including its discovery and mechanism of action, and discusses questions related to CTLA-4.
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Affiliation(s)
- Shunsuke Chikuma
- Department of Microbiology and Immunology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.
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Walker LSK, Sansom DM. Confusing signals: recent progress in CTLA-4 biology. Trends Immunol 2015; 36:63-70. [PMID: 25582039 PMCID: PMC4323153 DOI: 10.1016/j.it.2014.12.001] [Citation(s) in RCA: 248] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/04/2014] [Accepted: 12/09/2014] [Indexed: 02/07/2023]
Abstract
Cell extrinsic and cell intrinsic mechanisms of action of CTLA-4 are unclear. Data suggest that the extracellular domain of CTLA4 elicits regulatory function. The function of CTLA-4 tail may lie in regulating localization rather than signaling. Membrane levels of CTLA-4 directly impact access of CD28 to shared ligands.
The mechanism of action of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) remains surprisingly unclear. Regulatory T (Treg) cells can use CTLA-4 to elicit suppression; however, CTLA-4 also operates in conventional T cells, reputedly by triggering inhibitory signals. Recently, interactions mediated via the CTLA-4 cytoplasmic domain have been shown to preferentially affect Treg cells, yet other evidence suggests that the extracellular domain of CTLA-4 is sufficient to elicit suppression. Here, we discuss these paradoxical findings in the context of CTLA-4-mediated ligand regulation. We propose that the function of CTLA-4 cytoplasmic domain is not to transmit inhibitory signals but to precisely control the turnover, cellular location, and membrane delivery of CTLA-4 to facilitate its central function: regulating the access of CD28 to their shared ligands.
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Affiliation(s)
- Lucy S K Walker
- Institute for Immunity & Transplantation, University College London Division of Infection & Immunity, Royal Free Campus, London, NW3 2PF, UK.
| | - David M Sansom
- Institute for Immunity & Transplantation, University College London Division of Infection & Immunity, Royal Free Campus, London, NW3 2PF, UK.
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Hajilooi M, Lotfi P, Seif F, Bazmani A, Momeni M, Ravary A, Kazemi Arababadi M, Khalilian AR. The Cytotoxic T Lymphocyte Antigen-4 +49A/G Single Nucleotide Polymorphism Association With Visceral Leishmaniasis. Jundishapur J Microbiol 2014; 7:e12143. [PMID: 25632324 PMCID: PMC4295314 DOI: 10.5812/jjm.12143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/04/2013] [Accepted: 09/10/2013] [Indexed: 01/26/2023] Open
Abstract
Background: Several lines of evidence approve that innate and adaptive immunity play key roles in the defense against visceral leishmaniasis (VL). The polymorphism within the cytotoxic T lymphocyte antigen 4 (CTLA-4) gene alters its expression. Objectives: The main aim of this study was to evaluate the polymorphism within the +49 position of the CTLA-4 gene of Iranian patients with VL in comparison with healthy controls. Materials and Methods: In this cross-sectional study, 88 patients with clinical presentations of VL, who were seropositive for Leishmania (group 1), 86 patients without clinical presentations but seropositive (group 2), and 115 healthy controls (group 3) were assessed with respect to the CTLA-4 +49A/G polymorphism, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The anti-Leishmania antibody titration was evaluated using an immunofluorescence method. Results: Our results indicated that both CTLA-4 +49A/G polymorphisms were significantly associated with VL. Conclusions: According to the results, the polymorphisms within the +49 position of CTLA-4 can be associated with VL and may be considered as risk factors for the disease.
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Affiliation(s)
- Mehrdad Hajilooi
- Department of Immunology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Pegah Lotfi
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Farhad Seif
- Department of Immunology and Microbiology, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
| | - Ahad Bazmani
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | - Mohammad Momeni
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Ali Ravary
- Occupational Environment Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, IR Iran
| | - Mohammad Kazemi Arababadi
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Ali Reza Khalilian
- Faculty of Medicine, Shahid Beheshti Hospital, Hamadan University of Medical Sciences, Hamadan, IR Iran
- Corresponding author: Ali Reza Khalilian, Shahid Beheshti Hospital, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran. Tel: +98-8118271560, Fax: +98-8118254073, E-mail:
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Abstract
Three years ago, two research groups independently identified a previously undescribed T cell cosignaling molecule; one referred to it as V-domain Ig suppressor of T cell activation (VISTA), and the other used the term programmed death-1 homolog (PD-1H). Recombinant and ectopically expressed PD-1H functions as a coinhibitory ligand for T cell responses. However, the function of endogenous PD-1H is not clear. In this issue of the JCI, Flies and colleagues demonstrate that endogenous PD-1H on both T cells and APCs serves as a coinhibitory molecule for T cell activation and provide further support for targeting PD-1H as a therapeutic strategy for transplantation and cancers.
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Intestinal and peripheral fibrinogen-like protein 2 expression in inflammatory bowel disease. Dig Dis Sci 2014; 59:769-77. [PMID: 24287641 PMCID: PMC7087870 DOI: 10.1007/s10620-013-2962-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 11/14/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND Fibrinogen-like protein 2 (FGL2), a new member of the fibrinogen-like family, has recently been identified as a novel immunosuppressive molecule. AIM The purpose of this work was to investigate intestinal and peripheral expression of FGL2 in patients with inflammatory bowel disease (IBD), mainly ulcerative colitis (UC) and Crohn's disease (CD). METHODS FGL2 expression in mucosal biopsies from three groups (UC group (n = 61), CD group (n = 54), and controls group (n = 35)) was detected by immunohistochemistry. Concentrations of FGL2 in plasma from 50 UC patients, 45 CD patients, and 30 controls were analyzed by enzyme-linked immunosorbent assay. Western blot of FGL2 protein and real-time fluorescent quantitative PCR of FGL2 mRNA expression by peripheral mononuclear cells was performed. Correlations of FGL2 expression with disease type, activity, and location, and with measured laboratory data, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), were examined. RESULTS Intestinal and peripheral FGL2 protein data showed that FGL2 expression was significantly up-regulated in both UC and CD patients compared with controls (P < 0.001). Expression of FGL2 was higher in UC and CD patients with active disease than in those with inactive disease (P < 0.001). Moreover, FGL2 mRNA expression was significantly higher in patients with active disease than in those with inactive disease (P < 0.050). Expression of FGL2 protein was correlated with disease activity indices, CRP levels, and ESR levels. CONCLUSION Expression of FGL2 was up-regulated in IBD patients with active disease. Measurement of FGL2 may be used as a helpful biomarker for understanding immunopathogenesis and for assessment of IBD.
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Abstract
T cell activation is a key event in the adaptive immune response and vital to the generation of both cellular and humoral immunity. Activation is required not only for effective CD4 T cell responses but also to provide help for B cells and the generation of cytotoxic T cell responses. Unsurprisingly, impaired T cell activation results in infectious pathology, whereas dysregulated activation can result in autoimmunity. The decision to activate is therefore tightly regulated and the CD28/CTLA-4 pathway represents this apical decision point at the molecular level. In particular, CTLA-4 (CD152) is an essential checkpoint control for autoimmunity; however, the molecular mechanism(s) by which CTLA-4 achieves its regulatory function are not well understood, especially how it functionally intersects with the CD28 pathway. In this chapter, we review the established molecular and cellular concepts relating to CD28 and CTLA-4 biology, and attempt to integrate these by discussing the transendocytosis of ligands as a new model of CTLA-4 function.
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Affiliation(s)
- Blagoje Soskic
- School of Immunity and Infection, University of Birmingham, Birmingham, United Kingdom
| | | | - Tiezheng Hou
- UCL Institute of Immunity and Transplantation, Royal Free Campus, London, United Kingdom
| | - David M Sansom
- UCL Institute of Immunity and Transplantation, Royal Free Campus, London, United Kingdom.
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Yeung MY, Najafian N, Sayegh MH. Targeting CD28 to prevent transplant rejection. Expert Opin Ther Targets 2013; 18:225-42. [PMID: 24329604 DOI: 10.1517/14728222.2014.863875] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The pivotal role of costimulatory pathways in regulating T-cell activation versus tolerance has stimulated tremendous interest in their manipulation for therapeutic purposes. Of these, the CD28-B7 pathway is arguably the most important and best studied. Therapeutic targets of CD28 are currently used in the treatment of melanoma, autoimmune diseases and in transplantation. AREAS COVERED In this review, we summarize our current knowledge of CD28 and cytotoxic T-lymphocyte antigen-4 (CTLA-4) signaling, and review the current state and challenges of harnessing them to promote transplant tolerance. EXPERT OPINION Despite the success of belatacept, a first-in-class CTLA-4 fusion protein now clinically used in transplantation, it is apparent that we have only scratched the surface in understanding the complexities of how costimulatory pathways modulate the immune system. Our initial assumption that positive costimulators activate effector T cells and prevent tolerance, while negative costimulators inhibit effector T cells and promote tolerance, is clearly an oversimplified view. Indeed, belatacept is not only capable of blocking deleterious CD28-B7 interactions that promote effector T-cell responses but can also have undesired effects on tolerogenic regulatory T-cell populations.
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Affiliation(s)
- Melissa Y Yeung
- Brigham and Women's Hospital, Transplantation Research Center, Harvard Medical School, Renal Division , Boston, MA , USA +1 617 525 8005 ; +1 617 732 5254 ;
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Intlekofer AM, Thompson CB. At the bench: preclinical rationale for CTLA-4 and PD-1 blockade as cancer immunotherapy. J Leukoc Biol 2013; 94:25-39. [PMID: 23625198 DOI: 10.1189/jlb.1212621] [Citation(s) in RCA: 278] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Tumors can avoid immune surveillance by stimulating immune inhibitory receptors that function to turn off established immune responses. By blocking the ability of tumors to stimulate inhibitory receptors on T cells, sustained, anti-tumor immune responses can be generated in animals. Thus, therapeutic blockade of immune inhibitory checkpoints provides a potential method to boost anti-tumor immunity. The CTLA-4 and PD-1Rs represent two T cell-inhibitory receptors with independent mechanisms of action. Preclinical investigations revealed that CTLA-4 enforces an activation threshold and attenuates proliferation of tumor-specific T lymphocytes. In contrast, PD-1 functions primarily as a stop signal that limits T cell effector function within a tumor. The unique mechanisms and sites of action of CTLA-4 and PD-1 suggest that although blockade of either has the potential to promote anti-tumor immune responses, combined blockade of both might offer even more potent anti-tumor activity. See related review At the Bedside: CTLA-4 and PD-1 blocking antibodies in cancer immunotherapy.
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Affiliation(s)
- Andrew M Intlekofer
- Department of Medicine, Cancer Biology and Genetics Program, and Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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Corse E, Allison JP. Cutting Edge: CTLA-4 on Effector T Cells Inhibits In Trans. THE JOURNAL OF IMMUNOLOGY 2012; 189:1123-7. [DOI: 10.4049/jimmunol.1200695] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Wang CJ, Kenefeck R, Wardzinski L, Attridge K, Manzotti C, Schmidt EM, Qureshi OS, Sansom DM, Walker LSK. Cutting edge: cell-extrinsic immune regulation by CTLA-4 expressed on conventional T cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:1118-22. [PMID: 22753931 DOI: 10.4049/jimmunol.1200972] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The CTLA-4 pathway is a key regulator of T cell activation and a critical failsafe against autoimmunity. Although early models postulated that CTLA-4 transduced a negative signal, in vivo evidence suggests that CTLA-4 functions in a cell-extrinsic manner. That multiple cell-intrinsic mechanisms have been attributed to CTLA-4, yet its function in vivo appears to be cell-extrinsic, has been an ongoing paradox in the field. Although CTLA-4 expressed on conventional T cells (Tconv) can mediate inhibitory function, it is unclear why this fails to manifest as an intrinsic effect. In this study, we show that Tconv-expressed CTLA-4 can function in a cell-extrinsic manner in vivo. CTLA-4(+/+) T cells, from DO11/rag(-/-) mice that lack regulatory T cells, were able to regulate the response of CTLA-4(-/-) T cells in cotransfer experiments. This observation provides a potential resolution to the above paradox and suggests CTLA-4 function on both Tconv and regulatory T cells can be achieved through cell-extrinsic mechanisms.
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Affiliation(s)
- Chun Jing Wang
- Medical Research Council Centre for Immune Regulation, University of Birmingham Medical School, Birmingham B15 2TT, United Kingdom
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Activation of the Hippo pathway by CTLA-4 regulates the expression of Blimp-1 in the CD8+ T cell. Proc Natl Acad Sci U S A 2012; 109:E2223-9. [PMID: 22745171 DOI: 10.1073/pnas.1209115109] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
During the primary response, the commitment of the CD8(+) T cell to Blimp-1 expression and the terminal differentiation that Blimp-1 induces must be timed so as not to impair the process of clonal expansion. We determined whether the Hippo pathway, which links cell-cell contact to differentiation in other cell lineages, controls Blimp-1 expression. Activating the CD8(+) T cell with antigen and IL-2 causes expression of the core Hippo pathway components, including the pivotal transcriptional cofactor Yap. Contact between activated CD8(+) T cells induces Hippo pathway-mediated Yap degradation and Blimp-1 expression; a Hippo-resistant, stable form of Yap suppresses Blimp-1 expression. Cytotoxic T lymphocyte antigen 4 (CTLA-4) and CD80 comprise the receptor-ligand pair that mediates contact-dependent Hippo pathway activation. In vivo, CD8(+) T cells expressing Hippo resistant-Yap or lacking CTLA-4 have diminished expression of the senescence marker, KLRG1, during a viral infection. The CTLA-4/Hippo pathway/Blimp-1 system may couple terminal differentiation of CD8(+) T cell with the magnitude of clonal expansion.
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Walker LSK, Sansom DM. The emerging role of CTLA4 as a cell-extrinsic regulator of T cell responses. Nat Rev Immunol 2011; 11:852-63. [PMID: 22116087 DOI: 10.1038/nri3108] [Citation(s) in RCA: 536] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The T cell protein cytotoxic T lymphocyte antigen 4 (CTLA4) was identified as a crucial negative regulator of the immune system over 15 years ago, but its mechanisms of action are still under debate. It has long been suggested that CTLA4 transmits an inhibitory signal to the cells that express it. However, not all the available data fit with a cell-intrinsic function for CTLA4, and other studies have suggested that CTLA4 functions in a T cell-extrinsic manner. Here, we discuss the data for and against the T cell-intrinsic and -extrinsic functions of CTLA4.
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Affiliation(s)
- Lucy S K Walker
- MRC Centre for Immune Regulation, University of Birmingham Medical School, Birmingham, UK.
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Sakaguchi S, Wing K, Onishi Y, Prieto-Martin P, Yamaguchi T. Regulatory T cells: how do they suppress immune responses? Int Immunol 2009; 21:1105-11. [PMID: 19737784 DOI: 10.1093/intimm/dxp095] [Citation(s) in RCA: 626] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Regulatory T cells (Tregs), either natural or induced, suppress a variety of physiological and pathological immune responses. One of the key issues for understanding Treg function is to determine how they suppress other lymphocytes at the molecular level in vivo and in vitro. Here we propose that there may be a key suppressive mechanism that is shared by every forkhead box p3 (Foxp3)(+) Treg in vivo and in vitro in mice and humans. When this central mechanism is abrogated, it causes a breach in self-tolerance and immune homeostasis. Other suppressive mechanisms may synergistically operate with this common mechanism depending on the environment and the type of an immune response. Further, Treg-mediated suppression is a multi-step process and impairment or augmentation of each step can alter the ultimate effectiveness of Treg-mediated suppression. These findings will help to design effective ways for controlling immune responses by targeting Treg suppressive functions.
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Affiliation(s)
- Shimon Sakaguchi
- Department of Experimental Pathology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
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19
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Peggs KS, Quezada SA, Chambers CA, Korman AJ, Allison JP. Blockade of CTLA-4 on both effector and regulatory T cell compartments contributes to the antitumor activity of anti-CTLA-4 antibodies. ACTA ACUST UNITED AC 2009; 206:1717-25. [PMID: 19581407 PMCID: PMC2722174 DOI: 10.1084/jem.20082492] [Citation(s) in RCA: 696] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a critical negative regulator of immune responses. Uniquely among known inhibitory receptors, its genetic ablation results in a fulminating and fatal lymphoproliferative disorder. This central regulatory role led to the development of antibodies designed to block CTLA-4 activity in vivo, aiming to enhance immune responses against cancer. Despite their preclinical efficacy and promising clinical activity against late stage metastatic melanoma, the critical cellular targets for their activity remains unclear. In particular, debate has focused on whether the effector T cell (T(eff)) or regulatory T cell (T reg cell) compartment is the primary target of antibody-mediated blockade. We developed a mouse expressing human instead of mouse CTLA-4, allowing us to evaluate the independent contributions of CTLA-4 blockade of each T cell compartment during cancer immunotherapy in an in vivo model of mouse melanoma. The data show that although blockade on effector cells significantly improves tumor protection, unicompartmental blockade on regulatory cells completely fails to enhance antitumor responses. However, concomitant blockade of both compartments leads to a synergistic effect and maximal antitumor activity. We conclude that the combination of direct enhancement of T(eff) cell function and concomitant inhibition of T reg cell activity through blockade of CTLA-4 on both cell types is essential for mediating the full therapeutic effects of anti-CTLA-4 antibodies during cancer immunotherapy.
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Affiliation(s)
- Karl S Peggs
- Howard Hughes Medical Institute, Department of Immunology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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20
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Friedline RH, Brown DS, Nguyen H, Kornfeld H, Lee J, Zhang Y, Appleby M, Der SD, Kang J, Chambers CA. CD4+ regulatory T cells require CTLA-4 for the maintenance of systemic tolerance. ACTA ACUST UNITED AC 2009; 206:421-34. [PMID: 19188497 PMCID: PMC2646578 DOI: 10.1084/jem.20081811] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3+ regulatory T cells. CTLA-4–deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4–deficient and –sufficient bone marrow (BM)–derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4−/− T cells in trans by CTLA-4–sufficient T cells is a reversible process that requires the persistent presence of FOXP3+ regulatory T cells with a diverse TCR repertoire. Based on gene expression studies, the regulatory T cells do not appear to act directly on T cells, suggesting they may instead modulate the stimulatory activities of antigen-presenting cells. These results demonstrate that CTLA-4 is absolutely required for FOXP3+ regulatory T cell function in vivo.
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Affiliation(s)
- Randall H Friedline
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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21
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Abstract
Although the inhibitory receptor CTLA-4 (CD152) has been implicated in peripheral CD4 T-cell tolerance, its mechanism of action remains poorly defined. We analyzed mechanisms of CD4 cell tolerance in a model of tolerance induction involving establishment of mixed hematopoietic chimerism in recipients of fully MHC-mismatched allogeneic bone marrow cells with anti-CD154 mAb. Animals lacking CD80 and CD86 failed to achieve chimerism. We detected no T cell-intrinsic requirement for CD28 for chimerism induction. However, a CD4 T cell-intrinsic signal through CTLA-4 was shown to be essential within the first 48 hours of exposure to alloantigen for the establishment of tolerance and mixed chimerism. This signal must be provided by a recipient CD80/86(+) non-T-cell population. Donor CD80/86 expression was insufficient to achieve tolerance. Together, our findings demonstrate a surprising role for interactions of CTLA-4 expressed by alloreactive peripheral CD4 T cells with CD80/86 on recipient antigen-presenting cells (APCs) in the induction of early tolerance, suggesting a 3-cell tolerance model involving directly alloreactive CD4 cells, donor antigen-expressing bone marrow cells, and recipient antigen-presenting cells. This tolerance is independent of regulatory T cells and culminates in the deletion of directly alloreactive CD4 T cells.
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22
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Love VA, Grabie N, Duramad P, Stavrakis G, Sharpe A, Lichtman A. CTLA-4 ablation and interleukin-12 driven differentiation synergistically augment cardiac pathogenicity of cytotoxic T lymphocytes. Circ Res 2007; 101:248-57. [PMID: 17569889 DOI: 10.1161/circresaha.106.147124] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CD8+ cytotoxic T lymphocytes contribute to viral and autoimmune myocarditis and cardiac allograft rejection. The role of cytotoxic T-lymphocyte-associated antigen (CTLA)-4 as a negative regulator of CD4+ T cells is well defined, yet CTLA-4 regulation of CD8+ T cells is less clear. We studied CTLA-4 regulation of cytotoxic T lymphocytes in a transgenic model of CD8+ T-cell-mediated myocarditis. We generated CTLA-4(-/-) Rag 2(-/-) OT-1 mice, the CD8+ T cells of which express an ovalbumin (OVA) peptide-specific, class I major histocompatibility complex-restricted T-cell receptor. CTLA-4(-/-Tc12) OT-1 effectors, differentiated with interleukin-12 present, are hyperproliferative in vitro, compared with CTLA-4(+/+)Tc12 OT-1 controls. Transfer of low doses of CTLA-4(-/-Tc12) OT-1 cells to cMy-mOVA mice, which express OVA on cardiac myocytes, causes severe myocarditis, with 99% mortality, compared with no mortality after transfer of low doses of CTLA-4(+/+)Tc12 OT-1 cells. High doses of CTLA-4(+/+)Tc12 cells cause lethal myocarditis in cMy-mOVA mice, but high doses of CTLA-4(+/+)Tc0 CTL, generated without interleukin-12, are hypoproliferative within the cardiac-draining lymph node and do not significantly infiltrate the heart. In contrast, CTLA-4(-/-Tc0) cytotoxic T lymphocytes do proliferate in the cardiac-draining lymph node and diffusely infiltrate the heart. Nonetheless, high doses of CTLA-4(-/-Tc0) cells cause only limited tissue damage, and the disease is not lethal. These data show that CTLA-4 regulates myocarditic CD8+ T cell responses and that CTLA-4 deficiency partly overcomes a differentiation block that exists when naïve CD8+ T cells are stimulated without interleukin-12. Therefore, targeting CTLA-4 solely or in conjunction with interleukin-12 could influence effector CD8+ T cell responses in therapeutically beneficial ways.
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MESH Headings
- Adoptive Transfer
- Animals
- Antigens, CD/genetics
- Antigens, CD/physiology
- Antigens, Differentiation/genetics
- Antigens, Differentiation/physiology
- CTLA-4 Antigen
- Cell Differentiation
- Cells, Cultured/drug effects
- Cells, Cultured/immunology
- Crosses, Genetic
- Cytotoxicity, Immunologic
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- Egg Proteins/immunology
- Egg Proteins/pharmacology
- Egg Proteins/toxicity
- Interferon-gamma/metabolism
- Interleukin-12/physiology
- Lymph Nodes/pathology
- Lymphocyte Activation
- Lymphokines/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Models, Immunological
- Myocarditis/immunology
- Myocarditis/physiopathology
- Myocarditis/prevention & control
- Ovalbumin/immunology
- Ovalbumin/pharmacology
- Ovalbumin/toxicity
- Peptide Fragments
- Specific Pathogen-Free Organisms
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
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Affiliation(s)
- Victoria A Love
- Vascular Research Division, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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23
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Homann D, Dummer W, Wolfe T, Rodrigo E, Theofilopoulos AN, Oldstone MBA, von Herrath MG. Lack of intrinsic CTLA-4 expression has minimal effect on regulation of antiviral T-cell immunity. J Virol 2007; 80:270-80. [PMID: 16352552 PMCID: PMC1317527 DOI: 10.1128/jvi.80.1.270-280.2006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
CTLA-4 is considered one of the most potent negative regulators of T-cell activation. To circumvent experimental limitations due to fatal lymphoproliferative disease associated with genetic ablation of CTLA-4, we have used radiation chimeras reconstituted with a mixture of CTLA-4+/+ and CTLA-4-/- bone marrow that retain a normal phenotype and allow the evaluation of long-term T-cell immunity under conditions of intrinsic CTLA-4 deficiency. Following virus infection, we profiled primary, memory, and secondary CD8+ and CD4+ T-cell responses directed against eight different viral epitopes. Our data demonstrate unaltered antigen-driven proliferation, acquisition of effector functions, distribution of epitope hierarchies, T-cell receptor repertoire selection, functional avidities, and long-term memory maintenance in the absence of CTLA-4. Moreover, regulation of memory T-cell survival and homeostatic proliferation, as well as secondary responses, was equivalent in virus-specific CTLA4+/+ and CTL-A-4-/- T-cell populations. Thus, lack of CTLA-4 expression by antigen-specific T cells can be compensated for by extrinsic factors in the presence of CTLA-4 expression by other cells. These findings have implications for the physiologic, pathological, and therapeutic regulation of costimulation.
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Affiliation(s)
- Dirk Homann
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center. Mail stop B140, P.O. Box 6511, Aurora, CO 80045, USA.
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Raué HP, Slifka MK. Pivotal advance: CTLA-4+ T cells exhibit normal antiviral functions during acute viral infection. J Leukoc Biol 2007; 81:1165-75. [PMID: 17215523 DOI: 10.1189/jlb.0806535] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Previous studies have shown that T cells, which are genetically deficient in CTLA-4/CD152 expression, will proliferate uncontrollably, resulting in lethal autoimmune disease. This and other evidence indicate that CTLA-4 plays a critical role in the negative regulation of effector T cell function. In contrast to expectations, BrdU incorporation experiments demonstrated that CTLA-4 expression was associated with normal or even enhanced in vivo proliferation of virus-specific CD4+ and CD8+ T cells following acute lymphocytic choriomeningitis virus or vaccinia virus infection. When compared with CTLA-4- T cells directly ex vivo, CTLA-4+ T cells also exhibited normal antiviral effector functions following stimulation with peptide-coated cells, virus-infected cells, plate-bound anti-CD3/anti-CTLA-4, or the cytokines IL-12 and IL-18. Together, this indicates that CTLA-4 does not directly inhibit antiviral T cell expansion or T cell effector functions, at least not under the normal physiological conditions associated with either of these two acute viral infections.
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Affiliation(s)
- Hans-Peter Raué
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, 505 N.W. 185th Avenue, Beaverton, OR 97006, USA
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25
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Zaunders JJ, Ip S, Munier ML, Kaufmann DE, Suzuki K, Brereton C, Sasson SC, Seddiki N, Koelsch K, Landay A, Grey P, Finlayson R, Kaldor J, Rosenberg ES, Walker BD, Fazekas de St Groth B, Cooper DA, Kelleher AD. Infection of CD127+ (interleukin-7 receptor+) CD4+ cells and overexpression of CTLA-4 are linked to loss of antigen-specific CD4 T cells during primary human immunodeficiency virus type 1 infection. J Virol 2006; 80:10162-72. [PMID: 17005693 PMCID: PMC1617311 DOI: 10.1128/jvi.00249-06] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We recently found that human immunodeficiency virus (HIV)-specific CD4+ T cells express coreceptor CCR5 and activation antigen CD38 during early primary HIV-1 infection (PHI) but then rapidly disappear from the circulation. This cell loss may be due to susceptibility to infection with HIV-1 but could also be due to inappropriate apoptosis, an expansion of T regulatory cells, trafficking out of the circulation, or dysfunction. We purified CD38+++CD4+ T cells from peripheral blood mononuclear cells, measured their level of HIV-1 DNA by PCR, and found that about 10% of this population was infected. However, a small subset of HIV-specific CD4+) T cells also expressed CD127, a marker of long-term memory cells. Purified CD127+CD4+ lymphocytes contained fivefold more copies of HIV-1 DNA per cell than did CD127-negative CD4+ cells, suggesting preferential infection of long-term memory cells. We observed no apoptosis of antigen-specific CD4+ T cells in vitro and only a small increase in CD45RO+CD25+CD127dimCD4+ T regulatory cells during PHI. However, 40% of CCR5+CD38+++ CD4+ T cells expressed gut-homing integrins, suggesting trafficking through gut-associated lymphoid tissue (GALT). Furthermore, 80% of HIV-specific CD4+ T cells expressed high levels of the negative regulator CTLA-4 in response to antigen stimulation in vitro, which was probably contributing to their inability to produce interleukin-2 and proliferate. Taken together, the loss of HIV-specific CD4+ T cells is associated with a combination of an infection of CCR5+ CD127+ memory CD4+ T cells, possibly in GALT, and a high expression of the inhibitory receptor CTLA-4.
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Affiliation(s)
- John J Zaunders
- Centre for Immunology, St. Vincent's Hospital, Victoria Street, Darlinghurst, NSW 2010, Australia.
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26
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Gattinoni L, Ranganathan A, Surman DR, Palmer DC, Antony PA, Theoret MR, Heimann DM, Rosenberg SA, Restifo NP. CTLA-4 dysregulation of self/tumor-reactive CD8+ T-cell function is CD4+ T-cell dependent. Blood 2006; 108:3818-23. [PMID: 16882704 PMCID: PMC1679662 DOI: 10.1182/blood-2006-07-034066] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) maintains peripheral tolerance by suppressing T-cell activation and proliferation but its precise role in vivo remains unclear. We sought to elucidate the impact of CTLA-4 expression on self/tumor-reactive CD8(+) T cells by using the glycoprotein (gp) 100-specific T-cell receptor (TCR) transgenic mouse, pmel-1. pmel-1 CLTA-4(-/-) mice developed profound, accelerated autoimmune vitiligo. This enhanced autoimmunity was associated with a small but highly activated CD8(+) T-cell population and large numbers of CD4(+) T cells not expressing the transgenic TCR. Adoptive transfer of pmel-1 CLTA-4(-/-) CD8(+) T cells did not mediate superior antitumor immunity in the settings of either large established tumors or tumor challenge, suggesting that the mere absence of CTLA-4-mediated inhibition on CD8(+) T cells did not directly promote enhancement of their effector functions. Removal of CD4(+) T cells by crossing the pmel-1 CLTA-4(-/-) mouse onto a Rag-1(-/-) background resulted in the complete abrogation of CD8(+) T-cell activation and autoimmune manifestations. The effects of CD4(+) CLTA-4(-/-) T cells were dependent on the absence of CTLA-4 on CD8(+) T cells. These results indicated that CD8(+) CLTA-4(-/-) T-cell-mediated autoimmunity and tumor immunity required CD4(+) T cells in which the function was dysregulated by the absence of CTLA-4-mediated negative costimulation.
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Affiliation(s)
- Luca Gattinoni
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Mark O. Hatfield Clinical Research Center, 10 Center Drive, Room 3-5750, Bethesda, MD 20892, USA
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27
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Santner-Nanan B, Berberich-Siebelt F, Xiao Z, Poser N, Sennefelder H, Rauthe S, Vallabhapurapu DS, Berberich I, Schimpl A, Kreth HW, Nanan R. Blimp-1 is expressed in human and mouse T cell subsets and leads to loss of IL-2 production and to defective proliferation. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/sita.200500062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Within the paradigm of the two-signal model of lymphocyte activation, the interest in costimulation has witnessed a remarkable emergence in the past few years with the discovery of a large array of molecules that can serve this role, including some with an inhibitory function. Interest has been further enhanced by the realization of these molecules' potential as targets to modulate clinical immune responses. Although the therapeutic translation of mechanistic knowledge in costimulatory molecules has been relatively straightforward, the capacity to target their inhibitory counterparts has remained limited. This limited capacity is particularly apparent in the case of the cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a major negative regulator of T cell responses. Because there have been several previous comprehensive reviews on the function of this molecule, we focus here on the physiological implications of its structural features. Such an exercise may ultimately help us to design immunotherapeutic agents that target CTLA-4.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, CD
- Antigens, Differentiation/chemistry
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Biological Transport, Active
- CTLA-4 Antigen
- Dimerization
- Evolution, Molecular
- Humans
- Ligands
- Lymphocyte Activation
- Models, Immunological
- Molecular Biology
- Molecular Sequence Data
- Polymorphism, Genetic
- Protein Structure, Quaternary
- Sequence Homology, Amino Acid
- Signal Transduction
- T-Lymphocytes/immunology
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Affiliation(s)
- Wendy A Teft
- The FOCIS Center for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada, N6A 5K8
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29
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Dillon TJ, Carey KD, Wetzel SA, Parker DC, Stork PJS. Regulation of the small GTPase Rap1 and extracellular signal-regulated kinases by the costimulatory molecule CTLA-4. Mol Cell Biol 2005; 25:4117-28. [PMID: 15870282 PMCID: PMC1087740 DOI: 10.1128/mcb.25.10.4117-4128.2005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mitogen-activated protein kinase extracellular signal-regulated kinase (ERK) is activated following engagement of the T-cell receptor and is required for interleukin 2 (IL-2) production and T-cell proliferation. This activation is enhanced by stimulation of the coreceptor CD28 and inhibited by the coreceptor CTLA-4. We show that the small G protein Rap1 is regulated in the opposite manner; it is inhibited by CD28 and activated by CTLA-4. Together, CD3 and CTLA-4 activate Rap1 in a sustained manner. To delineate T-cell function in the absence of Rap1 activity, we generated transgenic mice expressing Rap1GAP1, a Rap1-specific GTPase-activating protein. Transgenic mice showed lymphadenopathy, and transgenic T cells displayed increased ERK activation, proliferation, and IL-2 production. More significantly, the inhibitory effect of CTLA-4 on T-cell function in Rap1GAP1-transgenic T cells was reduced. We demonstrate that CTLA-4 activates Rap1, and we propose that intracellular signals from CTLA-4 antagonize CD28, at least in part, at the level of Rap1.
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Affiliation(s)
- Tara J Dillon
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
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30
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Abstract
Mechanisms of immunosuppression by CD4(+)CD25(+) suppressor T cells have been addressed using many in vitro and in vivo conditions. However, those studies have not yielded a single mode of action. This review will discuss the mechanisms of suppression, which include the local secretion of cytokines such as TGF-beta and direct cell contact through binding of cell surface molecules such as CTLA-4 on suppressor T cells to CD80 and CD86 molecules on effector T cells. Suppression requires the appropriate colocalization of suppressor and effector T cells in different tissue and may involve the interference with T cell receptor signaling that triggers transcription factors important in regulating effector cell function.
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Affiliation(s)
- Harald von Boehmer
- Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
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31
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Sanderson K, Scotland R, Lee P, Liu D, Groshen S, Snively J, Sian S, Nichol G, Davis T, Keler T, Yellin M, Weber J. Autoimmunity in a phase I trial of a fully human anti-cytotoxic T-lymphocyte antigen-4 monoclonal antibody with multiple melanoma peptides and Montanide ISA 51 for patients with resected stages III and IV melanoma. J Clin Oncol 2004; 23:741-50. [PMID: 15613700 DOI: 10.1200/jco.2005.01.128] [Citation(s) in RCA: 307] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Nineteen patients with high-risk resected stage III and IV melanoma were immunized with three tumor antigen epitope peptides from gp100, MART-1, and tyrosinase emulsified with adjuvant Montanide ISA 51 and received a fully human anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) monoclonal antibody MDX-010. Each of three cohorts received escalating doses of antibody with vaccine primarily to evaluate the toxicities and maximum-tolerated dose (MTD) of MDX-010 with vaccine. MDX-010 pharmacokinetics and immune responses were secondary end points. PATIENTS AND METHODS Peptide immunizations with MDX-010 were administered every 4 weeks for 6 months and then every 12 weeks for 6 months. A leukapheresis to obtain peripheral-blood mononuclear cells for immune analyses was performed before treatment and after the sixth vaccination. Patients were observed until relapse. RESULTS Grade 3 gastrointestinal (GI) toxicity (diarrhea or abdominal pain) was observed in three patients in the highest dose cohort and one in the middle dose cohort who seemed to be autoimmune. That defined the MTD with vaccine on this schedule at 1 mg/kg. Of eight patients with evidence of autoimmunity, three have experienced disease relapse. Of 11 patients without autoimmune symptoms, nine have experienced disease relapse. Significant immune responses were measured by tetramer and enzyme-linked immunospot assays against gp100 and MART-1. CONCLUSION Dose-related autoimmune adverse events, predominantly skin and GI toxicities, were reversible. Patients mounted an antigen-specific immune response to a peptide vaccine when combined with a human anti-CTLA-4 antibody.
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Affiliation(s)
- Kristin Sanderson
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Zheng X, Gao JX, Chang X, Wang Y, Liu Y, Wen J, Zhang H, Zhang J, Liu Y, Zheng P. B7-CD28 Interaction Promotes Proliferation and Survival but Suppresses Differentiation of CD4−CD8− T Cells in the Thymus. THE JOURNAL OF IMMUNOLOGY 2004; 173:2253-61. [PMID: 15294937 DOI: 10.4049/jimmunol.173.4.2253] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Costimulatory molecules play critical roles in the induction and effector function of T cells. More recent studies reveal that costimulatory molecules enhance clonal deletion of autoreactive T cells as well as generation and homeostasis of the CD25(+)CD4(+) regulatory T cells. However, it is unclear whether the costimulatory molecules play any role in the proliferation and differentiation of T cells before they acquire MHC-restricted TCR. In this study, we report that targeted mutations of B7-1 and B7-2 substantially reduce the proliferation and survival of CD4(-)CD8(-) (double-negative (DN)) T cells in the thymus. Perhaps as a result of reduced proliferation, the accumulation of RAG-2 protein in the DN thymocytes is increased in B7-deficient mice, which may explain the increased expression of TCR gene and accelerated transition of CD25(+)CD44(-) (DN3) to CD25(-)CD44(-) (DN4) stage. Qualitatively similar, but quantitatively less striking effects were observed in mice with a targeted mutation of CD28, but not CTLA4. Taken together, our results demonstrate that the development of DN in the thymus is subject to modulation by the B7-CD28 costimulatory pathway.
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Affiliation(s)
- Xincheng Zheng
- Division of Cancer Immunology, Department of Pathology, Ohio State University Medical Center and Comprehensive Cancer Center, Columbus, OH 43210, USA
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33
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Pandiyan P, Gärtner D, Soezeri O, Radbruch A, Schulze-Osthoff K, Brunner-Weinzierl MC. CD152 (CTLA-4) determines the unequal resistance of Th1 and Th2 cells against activation-induced cell death by a mechanism requiring PI3 kinase function. ACTA ACUST UNITED AC 2004; 199:831-42. [PMID: 15007096 PMCID: PMC2212725 DOI: 10.1084/jem.20031058] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Survival of antigen-experienced T cells is essential for the generation of adaptive immune responses. Here, we show that the genetic and antibody-mediated inactivation of CD152 (cytotoxic T lymphocyte antigen 4) in T helper (Th) effector cells reduced the frequency of nonapoptotic cells in a completely Fas/Fas ligand (FasL)–dependent manner. CD152 cross-linking together with stimulation of CD3 and CD28 on activated Th2 cells prevented activation-induced cell death (AICD) as a result of reduced Fas and FasL expression. Apoptosis protection conferred by CD152 correlated with the up-regulation of Bcl-2 and was mediated by phosphatidylinositol 3 kinase, which prevented FasL expression through the inhibitory phosphorylation of Forkhead transcription factor FKHRL1. We show that signals induced by CD152 act directly on activated T lymphocytes and, due to its differential surface expression on activated Th1 and Th2 cells, induce resistance to AICD mainly in Th2 cells.
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Affiliation(s)
- Pushpa Pandiyan
- Deutsches Rheuma-Forschungszentrum, Schumannstrasse 21/22, 10117 Berlin, Germany
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34
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Watanabe N, Gavrieli M, Sedy JR, Yang J, Fallarino F, Loftin SK, Hurchla MA, Zimmerman N, Sim J, Zang X, Murphy TL, Russell JH, Allison JP, Murphy KM. BTLA is a lymphocyte inhibitory receptor with similarities to CTLA-4 and PD-1. Nat Immunol 2003; 4:670-9. [PMID: 12796776 DOI: 10.1038/ni944] [Citation(s) in RCA: 644] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2003] [Accepted: 05/13/2003] [Indexed: 12/30/2022]
Abstract
During activation, T cells express receptors for receiving positive and negative costimulatory signals. Here we identify the B and T lymphocyte attenuator (BTLA), an immunoglobulin domain-containing glycoprotein with two immunoreceptor tyrosine-based inhibitory motifs. BTLA is not expressed by naive T cells, but it is induced during activation and remains expressed on T helper type 1 (T(H)1) but not T(H)2 cells. Crosslinking BTLA with antigen receptors induces its tyrosine phosphorylation and association with the Src homology domain 2 (SH2)-containing protein tyrosine phosphatases SHP-1 and SHP-2, and attenuates production of interleukin 2 (IL-2). BTLA-deficient T cells show increased proliferation, and BTLA-deficient mice have increased specific antibody responses and enhanced sensitivity to experimental autoimmune encephalomyelitis. B7x, a peripheral homolog of B7, is a ligand of BTLA. Thus, BTLA is a third inhibitory receptor on T lymphocytes with similarities to cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1).
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MESH Headings
- Abatacept
- Amino Acid Sequence
- Animals
- Antigens, CD
- Antigens, Differentiation/physiology
- Antigens, Surface
- Apoptosis Regulatory Proteins
- B7-1 Antigen/physiology
- CTLA-4 Antigen
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Immunoconjugates
- Interleukin-2/biosynthesis
- Intracellular Signaling Peptides and Proteins
- Lymphocyte Activation
- Mice
- Molecular Sequence Data
- Phosphorylation
- Programmed Cell Death 1 Receptor
- Protein Tyrosine Phosphatase, Non-Receptor Type 1
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/physiology
- Proteins/physiology
- RNA, Messenger/analysis
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- T-Lymphocytes/immunology
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Affiliation(s)
- Norihiko Watanabe
- Department of Pathology & Immunology, Howard Hughes Medical Institute, Washington University School of Medicine, Box 8118, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA
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35
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Grohmann U, Puccetti P. CTLA-4, T helper lymphocytes and dendritic cells: an internal perspective of T-cell homeostasis. Trends Mol Med 2003; 9:133-5. [PMID: 12727137 DOI: 10.1016/s1471-4914(03)00026-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In mice and humans, the size of the peripheral lymphocyte pool remains relatively constant throughout adult life, in the absence of disease. Among the factors that influence the survival and homeostasis of T cells, external stimuli such as infections have long been considered to be of primary importance. However, emerging data indicate that internal stimuli, including self-peptide (presented in association with major-histocompatibility-complex molecules) and cytokines, might also control the size and composition of T-cell pools. Recent evidence suggests that cytotoxic-T-lymphocyte-associated antigen 4, an immune attenuator, contributes significantly to the homeostatic control of T-helper-cell proliferation through mechanisms that are both intrinsic and extrinsic to the T cell.
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Affiliation(s)
- Ursula Grohmann
- Department of Experimental Medicine, Via del Giochetto, University of Perugia, 06126 Perugia, Italy.
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36
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Walker LSK, Ausubel LJ, Chodos A, Bekarian N, Abbas AK. CTLA-4 differentially regulates T cell responses to endogenous tissue protein versus exogenous immunogen. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:6202-9. [PMID: 12444125 DOI: 10.4049/jimmunol.169.11.6202] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
CTLA-4 is critical to the regulation of CD4 T cell homeostasis in vivo. However, whether CTLA-4 regulates responses to both self and foreign proteins is not clear. We have directly compared the role of CTLA-4 in controlling T cell responses to the same protein presented as an endogenous tissue Ag vs a foreign immunizing Ag. We show that CTLA-4 only modestly reduces responses to Ag administered with adjuvant, but dramatically inhibits responses to the same Ag expressed transgenically as a tissue self protein. The critical consequence of CTLA-4 engagement is to inhibit T cell accumulation in the local lymph node draining the Ag-bearing tissue, and failure of this control leads to the onset of autoimmune tissue destruction. Thus, CTLA-4 may preferentially dampen pathologic immune responses to self proteins while permitting protective immunity to foreign agents.
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Affiliation(s)
- Lucy S K Walker
- Department of Pathology, University of California, San Francisco 94143, USA.
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37
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Tivol EA, Gorski J. Re-establishing peripheral tolerance in the absence of CTLA-4: complementation by wild-type T cells points to an indirect role for CTLA-4. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:1852-8. [PMID: 12165509 DOI: 10.4049/jimmunol.169.4.1852] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CTLA-4 plays an important role in the down-regulation of activated T cells and in the establishment of peripheral tolerance. It has been hypothesized that CTLA-4 on the cell surface signals directly into T cells during primary immune responses, resulting in intrinsic T cell down-regulation. It is not known, however, whether CTLA-4 directly inhibits the less intense activating signals received by autoreactive T cells in the periphery. We investigated whether CTLA-4 acts intrinsically upon self-reactive cells in vivo, or whether it inhibits autoreactive cells indirectly, in a non-cell autonomous manner. The adoptive transfer of CTLA-4-deficient splenocytes or Thy 1(+) cells into recombinase-activating gene 2-deficient mice resulted in fatal inflammation and tissue destruction similar to that seen in CTLA-4-deficient mice. When an equivalent number of splenocytes or Thy 1(+) cells from wild-type animals was transferred with the CTLA-4-deficient cells, recipient mice survived indefinitely. Since CTLA-4 was absent in the T cells responsible for the inflammatory phenotype, the down-regulation of these autoreactive cells must have been facilitated indirectly by wild-type Thy 1(+) cells. In addition, a rapid reduction in the ratio of CTLA-4-deficient to wild-type cells was observed. We propose two possible indirect mechanisms by which CTLA-4 may function in the establishment and maintenance of peripheral tolerance.
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Affiliation(s)
- Elizabeth A Tivol
- Blood Research Institute, Blood Center of Southeastern Wisconsin, Milwaukee WI 53201, USA
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38
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Abstract
The immune system is fighting a constant war against pathogens in its own territory. This requires a potent arsenal for efficient control of pathogens but also requires tight regulatory mechanisms in order to avoid excessive collateral damage. Maintaining equilibrium is the daily challenge of the immune system. Interactions between pathogens, antigen-presenting cells (APCs) and lymphocytes are critical in this balancing act. Of particular importance for the generation of protective immune responses is the induction of activation programs in APCs directly by pathogens or by T cell derived factors, such as CD40L, RANKL or cytokines. In order to counterbalance overshooting immune responses, T cells and APCs secrete anti-inflammatory cytokines that are key for maintaining a healthy balance between protection and immunopathology.
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Affiliation(s)
- Martin F Bachmann
- Cytos Biotechnology AG, Wagistrasse 25, Zürich, Schlieren-Zürich, Switzerland.
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39
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Egen JG, Kuhns MS, Allison JP. CTLA-4: new insights into its biological function and use in tumor immunotherapy. Nat Immunol 2002; 3:611-8. [PMID: 12087419 DOI: 10.1038/ni0702-611] [Citation(s) in RCA: 657] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The discovery of multiple costimulatory cell surface molecules that influence the course of T cell activation has increased our appreciation of the complexity of the T cell response. It remains clear, however, that CD28 and cytotoxic T lymphocyte antigen 4 (CTLA-4) are the critical costimulatory receptors that determine the early outcome of stimulation through the T cell antigen receptor (TCR). Details of how the T cell integrates TCR stimulation with the costimulatory signals of CD28 and the inhibitory signals of CTLA-4 remain to be established, but unique features of the cell biology of CTLA-4 provide important insights into its function. We summarize here recent findings that suggest a previously unrecognized role for CTLA-4 in the regulation of T cell responses. We also describe preclinical and clinical results that indicate manipulation of CTLA-4 has considerable promise as a strategy for the immunotherapy of cancer.
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Affiliation(s)
- Jackson G Egen
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, Cancer Research Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA
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40
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Abstract
The past year has seen significant advances in our understanding of critical roles of negative immunoregulatory signals delivered through the B7-CD28 superfamily in regulating T cell activation and tolerance. Structural data on CTLA-4 have provided novel insights into the inhibitory functions of CTLA-4. Initial characterization of the PD-1-PD-1-ligand pathway has revealed that this pathway can downregulate TCR- and CD28-mediated signals. Recent studies indicate that ICOS exerts distinct effects at different phases of an immune response: ICOS can inhibit as well as stimulate T cell responses.
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Affiliation(s)
- Rebecca J Greenwald
- Immunology Research Division, Department of Pathology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA 02115, USA.
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41
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Bai XF, Liu J, May KF, Guo Y, Zheng P, Liu Y. B7-CTLA4 interaction promotes cognate destruction of tumor cells by cytotoxic T lymphocytes in vivo. Blood 2002; 99:2880-9. [PMID: 11929778 DOI: 10.1182/blood.v99.8.2880] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Costimulatory molecules B7-1 and B7-2 (hereby collectively called B7) interact with CD28 and CTLA4 on T cells and promote antitumor immunity. The function of B7-CTLA4 interaction in antitumor CTL response remains controversial. Here we used CD28(-/-) and CD28(+/-) or CD28(+/+) transgenic mice that express the T-cell receptor specific for an unmutated tumor antigen, P1A, and for tumor cells expressing a CTLA4-specific B7 mutant to evaluate the function of CD28-B7 and CTLA4-B7 interactions in induction and effector phases of antitumor immunity. We report that B7-CD28 and B7-CTLA4 interactions promote tumor rejection. However, this is achieved by distinct mechanisms. B7-CD28 interaction enhances T-cell clonal expansion, though a role for this interaction in the effector phase cannot be ruled out. In contrast, B7-CTLA4 interaction enhances the CTL-mediated destruction of tumors, but not T-cell clonal expansion.
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MESH Headings
- Abatacept
- Adoptive Transfer
- Animals
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation/immunology
- Antigens, Differentiation/metabolism
- Antigens, Neoplasm/immunology
- B7-1 Antigen/genetics
- B7-1 Antigen/immunology
- B7-1 Antigen/metabolism
- B7-2 Antigen
- CD28 Antigens/genetics
- CD28 Antigens/metabolism
- CTLA-4 Antigen
- Cytotoxicity, Immunologic/drug effects
- Immunity
- Immunoconjugates
- Lymphocyte Activation/drug effects
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/immunology
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Transgenic
- Mutation
- Neoplasms, Experimental/therapy
- Protein Binding/immunology
- Receptors, Antigen, T-Cell/immunology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/transplantation
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Affiliation(s)
- Xue-Feng Bai
- Department of Pathology and the Comprehensive Cancer Center, Ohio State University Medical Center, Columbus 43210, USA
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42
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Gao JX, Zhang H, Bai XF, Wen J, Zheng X, Liu J, Zheng P, Liu Y. Perinatal blockade of b7-1 and b7-2 inhibits clonal deletion of highly pathogenic autoreactive T cells. J Exp Med 2002; 195:959-71. [PMID: 11956287 PMCID: PMC2193695 DOI: 10.1084/jem.20011948] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A number of in vitro studies have suggested that costimulatory molecules B7-1 and B7-2 and their receptor CD28 can promote clonal deletion, and limited in vivo studies have indicated that CD28 is involved in the clonal deletion of some T cells. However, the significance of B7-mediated clonal deletion in preventing autoimmune diseases has not been studied systematically. Here we report that the perinatal blockade of B7-1 and B7-2 substantially inhibits the clonal deletion of T cells in the thymus and leads to an accumulation of T cells capable of inducing fatal multiorgan inflammation. These results reveal a critical role for costimulatory molecules B7-1 and B7-2 in deleting pathogenic autoreactive T cells in the thymus. The critical role of B7-1 and B7-2 in T cell clonal deletion may explain, at least in part, the paradoxical increase of autoimmune disease in mice deficient for this family of costimulatory molecules, such as cytotoxic T lymphocyte associated molecule 4, CD28, and B7-2. The strong pathogenicity of the self-reactive T cells supports a central hypothesis in immunology, which is that clonal deletion plays an important role in preventing autoimmune diseases.
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Affiliation(s)
- Jian-Xin Gao
- Department of Pathology and Comprehensive Cancer Center, Division of Cancer Immunology, Ohio State University Medical Center, Columbus, OH 43210, USA
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Rogers KA, DeKrey GK, Mbow ML, Gillespie RD, Brodskyn CI, Titus RG. Type 1 and type 2 responses to Leishmania major. FEMS Microbiol Lett 2002; 209:1-7. [PMID: 12007646 DOI: 10.1111/j.1574-6968.2002.tb11101.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Leishmania major is a protozoan parasite that is transmitted to the mammalian host by its sand fly vector when the fly probes in the host's skin for a blood meal and injects the parasite within its saliva. In mice experimentally infected with L. major, outgrowth of CD4 type 1 (Th1) cells leads to resolution of the infection, but outgrowth of type 2 (Th2) cells exacerbates disease. To design an effective vaccine against the parasite (and other pathogens that induce polarized Th1 and Th2 responses), we must determine the mechanism underlying this phenomenon so that we can design the vaccine to elicit the appropriate (i.e., protective) Th cell. Recent work indicates that Th bias is influenced by a number of signals delivered by antigen-presenting cells, including cytokines and co-stimulatory molecules. Moreover, recent work also suggests that sand fly saliva influences the immune response to L. major and Th polarization. Determining the mechanisms that lead to polarized Th responses should expand our knowledge regarding immunity to L. major, and should add to our understanding of immunoregulation in general.
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Affiliation(s)
- Kathleen A Rogers
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Ft. Collins 80523, USA
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44
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Haspot F, Villemain F, Laflamme G, Coulon F, Olive D, Tiollier J, Soulillou JP, Vanhove B. Differential effect of CD28 versus B7 blockade on direct pathway of allorecognition and self-restricted responses. Blood 2002; 99:2228-34. [PMID: 11877302 DOI: 10.1182/blood.v99.6.2228] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunosuppression with B7 antagonists might have 2 opposite effects: reducing T-cell costimulation through CD28 but also preventing CTLA-4 from transmitting its negative regulatory signal. We therefore hypothesized that a selective blockade of CD28 might be qualitatively different from blocking B7. It was previously reported that CD28 modulation prolongs allograft survival in the rat and reverses induction of experimental autoimmune encephalomyelitis in mice. However, whether CD28 or B7 blockade results in similar immunosuppression on alloimmune and self-restricted responses to soluble antigens has not yet been investigated. Here, we addressed this issue in vitro with antagonist anti-CD28 Fab fragments and in vivo using the modulating anti-rat JJ319 monoclonal antibody. As in the inhibition of B7 with CTLA4 immunoglobulin, anti-CD28 Fab fragments inhibited allogenic T-cell proliferation in mixed cultures. In vivo modulation of CD28 blocked the expansion of alloreactive T cells and promoted their apoptosis. In contrast, selective blockade of CD28 did not modify T-cell proliferative responses and antibody production to soluble antigens, whereas blocking B7 with CTLA4 immunoglobulin did. Our data show that blocking CD28, while leaving CTLA4-B7 interactions undisturbed, inhibits alloreactive CD4+ T-cell expansion but does not modify the response to nominal antigens presented in the context of a self-major histocompatibility complex. That B7 engagement is needed for self-restricted responses whereas engagement of CD28 is not essential adds to the suggestion that another unidentified ligand of B7 might deliver a costimulatory signal in the absence of CD28.
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Affiliation(s)
- Fabienne Haspot
- ITERT-INSERM U437, CHU Hotel Dieu, 30 Boulevard Jean Monnet, 44093 Nantes, France
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