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Hodapp SJ, Gravel N, Kannan N, Newton AC. Cancer-associated mutations in protein kinase C theta are loss-of-function. Biochem J 2024; 481:759-775. [PMID: 38752473 PMCID: PMC11346454 DOI: 10.1042/bcj20240148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/11/2024]
Abstract
The Ca2+-independent, but diacylglycerol-regulated, novel protein kinase C (PKC) theta (θ) is highly expressed in hematopoietic cells where it participates in immune signaling and platelet function. Mounting evidence suggests that PKCθ may be involved in cancer, particularly blood cancers, breast cancer, and gastrointestinal stromal tumors, yet how to target this kinase (as an oncogene or as a tumor suppressor) has not been established. Here, we examine the effect of four cancer-associated mutations, R145H/C in the autoinhibitory pseudosubstrate, E161K in the regulatory C1A domain, and R635W in the regulatory C-terminal tail, on the cellular activity and stability of PKCθ. Live-cell imaging studies using the genetically-encoded fluorescence resonance energy transfer-based reporter for PKC activity, C kinase activity reporter 2 (CKAR2), revealed that the pseudosubstrate and C1A domain mutations impaired autoinhibition to increase basal signaling. This impaired autoinhibition resulted in decreased stability of the protein, consistent with the well-characterized behavior of Ca2+-regulated PKC isozymes wherein mutations that impair autoinhibition are paradoxically loss-of-function because the mutant protein is degraded. In marked contrast, the C-terminal tail mutation resulted in enhanced autoinhibition and enhanced stability. Thus, the examined mutations were loss-of-function by different mechanisms: mutations that impaired autoinhibition promoted the degradation of PKC, and those that enhanced autoinhibition stabilized an inactive PKC. Supporting a general loss-of-function of PKCθ in cancer, bioinformatics analysis revealed that protein levels of PKCθ are reduced in diverse cancers, including lung, renal, head and neck, and pancreatic. Our results reveal that PKCθ function is lost in cancer.
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Affiliation(s)
- Stefanie J. Hodapp
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, U.S.A
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Nathan Gravel
- Department of Biochemistry and Molecular Biology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, U.S.A
| | - Natarajan Kannan
- Department of Biochemistry and Molecular Biology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, U.S.A
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, U.S.A
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2
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Zeng S, Zeng M, Yuan S, He L, Jin Y, Huang J, Zhang M, Yang M, Pan Y, Wang Z, Chen Y, Xu X, Huang W. Discovery of potent and selective HPK1 inhibitors based on the 2,4-disubstituted pyrimidine scaffold with immune modulatory properties for ameliorating T cell exhaustion. Bioorg Chem 2023; 139:106728. [PMID: 37536217 DOI: 10.1016/j.bioorg.2023.106728] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 08/05/2023]
Abstract
Hematopoietic progenitor kinase 1 (HPK1), a member of the mitogen-activated protein kinase (MAP4K) family, is a serine/threonine (SER/THR) kinase and has been demonstrated as a negative regulator of T cell receptor signaling. Targeting HPK1 has been considered as an attractive therapeutic strategy for immune-oncology. Here, we describe the discovery and structure-activity relationship (SAR) of potent HPK1 inhibitors based on the 2,4-disubstituted pyrimidine scaffold. Systematically SAR exploration afforded the desired compound HMC-H8 (F1) with potent HPK1 inhibition (IC50 = 1.11 nM) and highly selectivity profile. Compound HMC-H8 also exhibited robust inhibition of p-SLP 76 (IC50 = 283.0 nM) and promotion IL-2 release (EC50 = 157.08 nM), and INF-γ production in a dose-dependent manner in vitro assays. Strikingly, HMC-H8 shown effective immune reversal response in immunesuppressive condition. Moreover, Compound HMC-H8 displayed acceptable metabolic stability (T1/2 = 56.87 min), along with low CYP450 inhibition in human liver microsomes and good oral bioavailability (F = 15.05%) in rat. Furthermore, HMC-H8 was found to modulate the expression of c-Myc in Western blotting experiments. Taken together, this study provides new potent HPK1 inhibitors for further anticancer drug discovery based on immuno-oncology.
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Affiliation(s)
- Shenxin Zeng
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College
| | - Ming Zeng
- School of Pharmacy and Life Science, Jiujiang University, Jiujiang 332005 China
| | - Shuai Yuan
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College
| | - Liuxun He
- School of Pharmacy and Life Science, Jiujiang University, Jiujiang 332005 China
| | - Yuyuan Jin
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College
| | - Jiandong Huang
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China
| | - Manxuan Zhang
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China
| | - Menghan Yang
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China
| | - Youlu Pan
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College
| | - Zunyuan Wang
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College
| | - Yinqiao Chen
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China
| | - Xiangwei Xu
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China.
| | - Wenhai Huang
- Affiliated Yongkang First People's Hospital and School of Pharmaceutical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 311399, China; Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China; Key Discipline of Zhejiang Province in Public Health and Preventive Medicine (First Class, Category A), Hangzhou Medical College.
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3
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Gallego RA, Bernier L, Chen H, Cho-Schultz S, Chung L, Collins M, Del Bel M, Elleraas J, Costa Jones C, Cronin CN, Edwards M, Fang X, Fisher T, He M, Hoffman J, Huo R, Jalaie M, Johnson E, Johnson TW, Kania RS, Kraus M, Lafontaine J, Le P, Liu T, Maestre M, Matthews J, McTigue M, Miller N, Mu Q, Qin X, Ren S, Richardson P, Rohner A, Sach N, Shao L, Smith G, Su R, Sun B, Timofeevski S, Tran P, Wang S, Wang W, Zhou R, Zhu J, Nair SK. Design and Synthesis of Functionally Active 5-Amino-6-Aryl Pyrrolopyrimidine Inhibitors of Hematopoietic Progenitor Kinase 1. J Med Chem 2023; 66:4888-4909. [PMID: 36940470 DOI: 10.1021/acs.jmedchem.2c02038] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2023]
Abstract
Immune activating agents represent a valuable class of therapeutics for the treatment of cancer. An area of active research is expanding the types of these therapeutics that are available to patients via targeting new biological mechanisms. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of immune signaling and a target of high interest for the treatment of cancer. Herein, we present the discovery and optimization of novel amino-6-aryl pyrrolopyrimidine inhibitors of HPK1 starting from hits identified via virtual screening. Key components of this discovery effort were structure-based drug design aided by analyses of normalized B-factors and optimization of lipophilic efficiency.
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Affiliation(s)
- Rebecca A Gallego
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Louise Bernier
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Hui Chen
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Sujin Cho-Schultz
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Loanne Chung
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Michael Collins
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Matthew Del Bel
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Jeff Elleraas
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Cinthia Costa Jones
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Ciaran N Cronin
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Martin Edwards
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Xu Fang
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Timothy Fisher
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Mingying He
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Jacqui Hoffman
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Ruiduan Huo
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Mehran Jalaie
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Eric Johnson
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Ted W Johnson
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Robert S Kania
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Manfred Kraus
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Jennifer Lafontaine
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Phuong Le
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Tongnan Liu
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Michael Maestre
- La Jolla Laboratories, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Jean Matthews
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Michele McTigue
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Nichol Miller
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Qiming Mu
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Xulong Qin
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Shijian Ren
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Paul Richardson
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Allison Rohner
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Neal Sach
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Li Shao
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Graham Smith
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Ruirui Su
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Bin Sun
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Sergei Timofeevski
- Oncology Research Unit, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Phuong Tran
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Shuiwang Wang
- WuXi AppTec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Wei Wang
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Ru Zhou
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Jinjiang Zhu
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
| | - Sajiv K Nair
- Oncology Medicinal Chemistry, Pfizer Worldwide Research and Development, 10770 Science Center Drive, La Jolla, California 92121, United States
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4
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Wang Y, Gao N, Feng Y, Cai M, Li Y, Xu X, Zhang H, Yao D. Protein kinase C theta (Prkcq) affects nerve degeneration and regeneration through the c-fos and c-jun pathways in injured rat sciatic nerves. Exp Neurol 2021; 346:113843. [PMID: 34418453 DOI: 10.1016/j.expneurol.2021.113843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/23/2021] [Accepted: 08/15/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Previous finding using DNA microarray and bioinformatics analysis, we have reported some key factors which regulated gene expression and signaling pathways in injured sciatic nerve during Wallerian Degeneration (WD). This research is focused on protein kinase C theta (Prkcq) participates in the regulation of the WD process. METHODS In this study, we explored the molecular mechanism by which Prkcq in Schwann cells (SCs) affects nerve degeneration and regeneration in vivo and in vitro after rat sciatic nerve injury. RESULTS Study of the cross-sectional model showed that Prkcq expression decreased significantly during sciatic nerve repair. Functional analysis showed that upregulation and downregulation of Prkcq could affect the proliferation, migration and apoptosis of Schwann cells and lead to the expression of related factors through the activation of the β-catenin, c-fos, and p-c-jun/c-jun pathways. CONCLUSION The study provides insights into the role of Prkcq in early WD during peripheral nerve degeneration and/or regeneration.
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Affiliation(s)
- Yi Wang
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Nannan Gao
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Yumei Feng
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Min Cai
- Medical School of Nantong University, Nantong, Jiangsu 226001, PR China.
| | - Yuting Li
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Xi Xu
- Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Huanhuan Zhang
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Dengbing Yao
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China.
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5
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Érsek B, Silló P, Cakir U, Molnár V, Bencsik A, Mayer B, Mezey E, Kárpáti S, Pós Z, Németh K. Melanoma-associated fibroblasts impair CD8+ T cell function and modify expression of immune checkpoint regulators via increased arginase activity. Cell Mol Life Sci 2020; 78:661-673. [PMID: 32328671 PMCID: PMC7581550 DOI: 10.1007/s00018-020-03517-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 03/12/2020] [Accepted: 03/30/2020] [Indexed: 01/05/2023]
Abstract
Abstract This study shows that melanoma-associated fibroblasts (MAFs) suppress cytotoxic T lymphocyte (CTL) activity and reveals a pivotal role played by arginase in this phenomenon. MAFs and normal dermal fibroblasts (DFs) were isolated from surgically resected melanomas and identified as Melan-A-/gp100-/FAP+ cells. CTLs of healthy blood donors were activated in the presence of MAF- and DF-conditioned media (CM). Markers of successful CTL activation, cytotoxic degranulation, killing activity and immune checkpoint regulation were evaluated by flow cytometry, ELISPOT, and redirected killing assays. Soluble mediators responsible for MAF-mediated effects were identified by ELISA, flow cytometry, inhibitor assays, and knock-in experiments. In the presence of MAF-CM, activated/non-naïve CTLs displayed dysregulated ERK1/2 and NF-κB signaling, impeded CD69 and granzyme B production, impaired killing activity, and upregulated expression of the negative immune checkpoint receptors TIGIT and BTLA. Compared to DFs, MAFs displayed increased amounts of VISTA and HVEM, a known ligand of BTLA on T cells, increased l-arginase activity and CXCL12 release. Transgenic arginase over-expression further increased, while selective arginase inhibition neutralized MAF-induced TIGIT and BTLA expression on CTLs. Our data indicate that MAF interfere with intracellular CTL signaling via soluble mediators leading to CTL anergy and modify immune checkpoint receptor availability via l-arginine depletion. Graphic abstract ![]()
Electronic supplementary material The online version of this article (10.1007/s00018-020-03517-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Barbara Érsek
- Department of Genetics, Cell and Immunobiology, Semmelweis University, 4 Nagyvarad ter, VII/709, Budapest, 1089, Hungary.,Office for Research Groups Attached to Universities and Other Institutions of the Hungarian Academy of Sciences, Budapest, 1051, Hungary
| | - Pálma Silló
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, Budapest, 1085, Hungary
| | - Ugur Cakir
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, Budapest, 1085, Hungary
| | - Viktor Molnár
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, 1083, Hungary
| | - András Bencsik
- Department of Genetics, Cell and Immunobiology, Semmelweis University, 4 Nagyvarad ter, VII/709, Budapest, 1089, Hungary
| | - Balázs Mayer
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, Budapest, 1085, Hungary
| | - Eva Mezey
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20815, USA
| | - Sarolta Kárpáti
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, Budapest, 1085, Hungary
| | - Zoltán Pós
- Department of Genetics, Cell and Immunobiology, Semmelweis University, 4 Nagyvarad ter, VII/709, Budapest, 1089, Hungary.
| | - Krisztián Németh
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, Budapest, 1085, Hungary
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6
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Yang S, Svensson MND, Harder NHO, Hsieh WC, Santelli E, Kiosses WB, Moresco JJ, Yates JR, King CC, Liu L, Stanford SM, Bottini N. PTPN22 phosphorylation acts as a molecular rheostat for the inhibition of TCR signaling. Sci Signal 2020; 13:13/623/eaaw8130. [PMID: 32184287 DOI: 10.1126/scisignal.aaw8130] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The hematopoietic-specific protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is encoded by a major autoimmunity risk gene. PTPN22 inhibits T cell activation by dephosphorylating substrates involved in proximal T cell receptor (TCR) signaling. Here, we found by mass spectrometry that PTPN22 was phosphorylated at Ser751 by PKCα in Jurkat and primary human T cells activated with phorbol ester/ionomycin or antibodies against CD3/CD28. The phosphorylation of PTPN22 at Ser751 prolonged its half-life by inhibiting K48-linked ubiquitination and impairing recruitment of the phosphatase to the plasma membrane, which is necessary to inhibit proximal TCR signaling. Additionally, the phosphorylation of PTPN22 at Ser751 enhanced the interaction of PTPN22 with the carboxyl-terminal Src kinase (CSK), an interaction that is impaired by the PTPN22 R620W variant associated with autoimmune disease. The phosphorylation of Ser751 did not affect the recruitment of PTPN22 R620W to the plasma membrane but protected this mutant from degradation. Together, out data indicate that phosphorylation at Ser751 mediates a reciprocal regulation of PTPN22 stability versus translocation to TCR signaling complexes by CSK-dependent and CSK-independent mechanisms.
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Affiliation(s)
- Shen Yang
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mattias N D Svensson
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nathaniel H O Harder
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.,Division of Cellular Biology, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Wan-Chen Hsieh
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Eugenio Santelli
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - William B Kiosses
- Core Microscopy, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - James J Moresco
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Charles C King
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lin Liu
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, 92037, USA.,Veterans Affairs San Diego Healthcare System, San Diego, CA 90026, USA
| | - Stephanie M Stanford
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.,Division of Cellular Biology, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Nunzio Bottini
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA. .,Division of Cellular Biology, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
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7
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Katoh T. Facile Preparation of 3-Substituted-2,6-difluoropyridines and Application to the Synthesis of 2,3,6-Trisubstituted Pyridines for PKCθ Inhibitors. J SYN ORG CHEM JPN 2020. [DOI: 10.5059/yukigoseikyokaishi.78.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Zhang YW, Xu XY, Zhang J, Yao X, Lu C, Chen CX, Yu CH, Sun J. Missense mutation in PRKCQ is associated with Crohn's disease. J Dig Dis 2019; 20:243-247. [PMID: 30828974 DOI: 10.1111/1751-2980.12717] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 02/21/2019] [Accepted: 03/01/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Recent genome-wide association studies have demonstrated that rs2236379 in PRKCQ is a novel significant locus for Crohn's disease (CD). However, the association has not been replicated in any populations. We therefore aimed to investigate the prevalence of the PRKCQ rs2236379 variant in the Chinese Han population and evaluate whether the genetic variant of PRKCQ confers susceptibility to CD and is associated with its clinical characteristics. METHODS A total of 283 patients with CD and 381 healthy controls were enrolled. Genomic DNA was extracted from their whole blood samples and polymerase chain reaction-restriction fragment length polymorphism was used for genotyping. The association between PRKCQ polymorphisms and susceptibility to CD, and between genotypes and clinical phenotypes was analyzed. RESULTS A higher frequency of the T allele was discovered in CD patients than in healthy controls (P = 0.027). A significant difference in the distribution of the TT and CT/CC genotypes was observed between CD patients and controls (P = 0.024). The TT genotype showed a significant association with susceptibility to CD (odds ratio 1.647, 95% confidence interval: 1.088-2.574, P = 0.019). Patients with CD with the rs2236379 TT mutant risk genotype were most likely to exhibit perianal disease (P = 0.044). CONCLUSIONS Our research revealed an association between the PRKCQ rs2236379 (C>T) and CD. The TT homozygous mutation increased the risk of developing CD and may contribute to perianal disease.
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Affiliation(s)
- Yu Wei Zhang
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xiao Ying Xu
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jie Zhang
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xin Yao
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Chao Lu
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Chun Xiao Chen
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Chao Hui Yu
- Department of Gastroenterology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jing Sun
- Department of Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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9
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Targeting the NFAT:AP-1 transcriptional complex on DNA with a small-molecule inhibitor. Proc Natl Acad Sci U S A 2019; 116:9959-9968. [PMID: 31019078 DOI: 10.1073/pnas.1820604116] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The transcription factor nuclear factor of activated T cells (NFAT) has a key role in both T cell activation and tolerance and has emerged as an important target of immune modulation. NFAT directs the effector arm of the immune response in the presence of activator protein-1 (AP-1), and T cell anergy/exhaustion in the absence of AP-1. Envisioning a strategy for selective modulation of the immune response, we designed a FRET-based high-throughput screen to identify compounds that disrupt the NFAT:AP-1:DNA complex. We screened ∼202,000 small organic compounds and identified 337 candidate inhibitors. We focus here on one compound, N-(3-acetamidophenyl)-2-[5-(1H-benzimidazol-2-yl)pyridin-2-yl]sulfanylacetamide (Compound 10), which disrupts the NFAT:AP-1 interaction at the composite antigen-receptor response element-2 site without affecting the binding of NFAT or AP-1 alone to DNA. Compound 10 binds to DNA in a sequence-selective manner and inhibits the transcription of the Il2 gene and several other cyclosporin A-sensitive cytokine genes important for the effector immune response. This study provides proof-of-concept that small molecules can inhibit the assembly of specific DNA-protein complexes, and opens a potential new approach to treat human diseases where known transcription factors are deregulated.
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10
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Hatmal MM, Taha MO. Simulated annealing molecular dynamics and ligand-receptor contacts analysis for pharmacophore modeling. Future Med Chem 2017; 9:1141-1159. [PMID: 28722471 DOI: 10.4155/fmc-2017-0061] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 04/20/2017] [Indexed: 12/14/2022] Open
Abstract
AIM Ligand-based pharmacophore modeling requires long list of inhibitors, while pharmacophores based on single ligand-receptor crystallographic structure can be too restricted or promiscuous. METHODOLOGY This prompted us to combine simulated annealing molecular dynamics (SAMD) with ligand-receptor contacts analysis as means to construct pharmacophore model(s) from single ligand-receptor complex. Ligand-receptor contacts that survive numerous heating-cooling SAMD cycles are considered critical and are used to guide pharmacophore development. RESULTS This methodology was implemented to develop pharmacophores for acetylcholinesterase and protein kinase C-θ. The resulting models were validated by receiver-operating characteristic analysis and in vitro bioassay. Assay identified four new protein kinase C-θ inhibitors among captured hits, two of which exhibited nanomolar potencies. CONCLUSION The results illustrate the ability of the new method to extract valid pharmacophores from single ligand-protein complex.
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Affiliation(s)
- Ma'mon M Hatmal
- Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, The Hashemite University, P.O. Box 330127, Zarqa 13133, Jordan
| | - Mutasem O Taha
- Drug Discovery Unit, Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman 11942, Jordan
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11
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Katoh T, Tomata Y, Setoh M, Sasaki S, Takai T, Yoshitomi Y, Yukawa T, Nakagawa H, Fukumoto S, Tsukamoto T, Nakada Y. Practical application of 3-substituted-2,6-difluoropyridines in drug discovery: Facile synthesis of novel protein kinase C theta inhibitors. Bioorg Med Chem Lett 2017; 27:2497-2501. [PMID: 28400232 DOI: 10.1016/j.bmcl.2017.03.099] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/30/2017] [Accepted: 03/31/2017] [Indexed: 12/11/2022]
Abstract
We previously reported a facile preparation method of 3-substituted-2,6-difluoropyridines, which were easily converted to 2,3,6-trisubstituted pyridines by nucleophilic aromatic substitution with good regioselectivity and yield. In this study, we demonstrate the synthetic utility of 3-substituted-2,6-difluoropyridines in drug discovery via their application in the synthesis of various 2,3,6-trisubstituted pyridines, including macrocyclic derivatives, as novel protein kinase C theta inhibitors in a moderate to good yield. This synthetic approach is useful for the preparation of 2,3,6-trisubstituted pyridines, which are a popular scaffold for drug candidates and biologically attractive compounds.
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Affiliation(s)
- Taisuke Katoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
| | - Yoshihide Tomata
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Masaki Setoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Satoshi Sasaki
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takafumi Takai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yayoi Yoshitomi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tomoya Yukawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hideyuki Nakagawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Shoji Fukumoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tetsuya Tsukamoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yoshihisa Nakada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
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12
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Katoh T, Takai T, Yukawa T, Tsukamoto T, Watanabe E, Mototani H, Arita T, Hayashi H, Nakagawa H, Klein MG, Zou H, Sang BC, Snell G, Nakada Y. Discovery and optimization of 1,7-disubstituted-2,2-dimethyl-2,3-dihydroquinazolin-4(1H)-ones as potent and selective PKCθ inhibitors. Bioorg Med Chem 2016; 24:2466-2475. [PMID: 27117263 DOI: 10.1016/j.bmc.2016.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 11/25/2022]
Abstract
A high-throughput screening campaign helped us to identify an initial lead compound (1) as a protein kinase C-θ (PKCθ) inhibitor. Using the docking model of compound 1 bound to PKCθ as a model, structure-based drug design was employed and two regions were identified that could be explored for further optimization, i.e., (a) a hydrophilic region around Thr442, unique to PKC family, in the inner part of the hinge region, and (b) a lipophilic region at the forefront of the ethyl moiety. Optimization of the hinge binder led us to find 1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one as a potent and selective hinge binder, which resulted in the discovery of compound 5. Filling the lipophilic region with a suitable lipophilic substituent boosted PKCθ inhibitory activity and led to the identification of compound 10. The co-crystal structure of compound 10 bound to PKCθ confirmed that both the hydrophilic and lipophilic regions were fully utilized. Further optimization of compound 10 led us to compound 14, which demonstrated an improved pharmacokinetic profile and inhibition of IL-2 production in a mouse.
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Affiliation(s)
- Taisuke Katoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
| | - Takafumi Takai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takafumi Yukawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tetsuya Tsukamoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Etsurou Watanabe
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hideyuki Mototani
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takeo Arita
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hiroki Hayashi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hideyuki Nakagawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Michael G Klein
- Takeda California, 10410 Science Center Drive, San Diego, CA 92121, USA
| | - Hua Zou
- Takeda California, 10410 Science Center Drive, San Diego, CA 92121, USA
| | - Bi-Ching Sang
- Takeda California, 10410 Science Center Drive, San Diego, CA 92121, USA
| | - Gyorgy Snell
- Takeda California, 10410 Science Center Drive, San Diego, CA 92121, USA
| | - Yoshihisa Nakada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraoka-higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
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13
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Phetsouphanh C, Kelleher AD. The Role of PKC-θ in CD4+ T Cells and HIV Infection: To the Nucleus and Back Again. Front Immunol 2015; 6:391. [PMID: 26284074 PMCID: PMC4519685 DOI: 10.3389/fimmu.2015.00391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/17/2015] [Indexed: 11/13/2022] Open
Abstract
Protein kinase C (PKC)-θ is the only member of the PKC family that has the ability to translocate to the immunological synapse between T cells and antigen-presenting cells upon T cell receptor and MHC-II recognition. PKC-θ interacts functionally and physically with other downstream effector molecules to mediate T cell activation, differentiation, and migration. It plays a critical role in the generation of Th2 and Th17 responses and is less important in Th1 and CTL responses. PKC-θ has been recently shown to play a role in the nucleus, where it mediates inducible gene expression in the development of memory CD4+ T cells. This novel PKC (nPKC) can up-regulate HIV-1 transcription and PKC-θ activators such as Prostratin have been used in early HIV-1 reservoir eradication studies. The exact manner of the activation of virus by these compounds and the role of PKC-θ, particularly its nuclear form and its association with NF-κB in both the cytoplasmic and nuclear compartments, needs further precise elucidation especially given the very important role of NF-κB in regulating transcription from the integrated retrovirus. Continued studies of this nPKC isoform will give further insight into the complexity of T cell signaling kinases.
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Affiliation(s)
- Chansavath Phetsouphanh
- The Kirby Institute of Infectious Diseases in Society, University of New South Wales , Sydney, NSW , Australia
| | - Anthony D Kelleher
- The Kirby Institute of Infectious Diseases in Society, University of New South Wales , Sydney, NSW , Australia
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14
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Lutz-Nicoladoni C, Wolf D, Sopper S. Modulation of Immune Cell Functions by the E3 Ligase Cbl-b. Front Oncol 2015; 5:58. [PMID: 25815272 PMCID: PMC4356231 DOI: 10.3389/fonc.2015.00058] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/24/2015] [Indexed: 01/10/2023] Open
Abstract
Maintenance of immunological tolerance is a critical hallmark of the immune system. Several signaling checkpoints necessary to balance activating and inhibitory input to immune cells have been described so far, among which the E3 ligase Cbl-b appears to be a central player. Cbl-b is expressed in all leukocyte subsets and regulates several signaling pathways in T cells, NK cells, B cells, and different types of myeloid cells. In most cases, Cbl-b negatively regulates activation signals through antigen or pattern recognition receptors and co-stimulatory molecules. In line with this function, cblb-deficient immune cells display lower activation thresholds and cblb knockout mice spontaneously develop autoimmunity and are highly susceptible to experimental autoimmunity. Interestingly, genetic association studies link CBLB-polymorphisms with autoimmunity also in humans. Vice versa, the increased activation potential of cblb-deficient cells renders them more potent to fight against malignancies or infections. Accordingly, several reports have shown that cblb knockout mice reject tumors, which mainly depends on cytotoxic T and NK cells. Thus, targeting Cbl-b may be an interesting strategy to enhance anti-cancer immunity. In this review, we summarize the findings on the molecular function of Cbl-b in different cell types and illustrate the potential of Cbl-b as target for immunomodulatory therapies.
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Affiliation(s)
- Christina Lutz-Nicoladoni
- Department of Hematology and Oncology, Medical University Innsbruck , Innsbruck , Austria ; Tumor Immunology Laboratory, Tyrolean Cancer Research Institute , Innsbruck , Austria
| | - Dominik Wolf
- Medical Clinic III for Oncology, Haematology and Rheumatology, University Clinic Bonn (UKB) , Bonn , Germany
| | - Sieghart Sopper
- Department of Hematology and Oncology, Medical University Innsbruck , Innsbruck , Austria ; Tumor Immunology Laboratory, Tyrolean Cancer Research Institute , Innsbruck , Austria
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15
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Nifedipine inhibits ox-LDL-induced lipid accumulation in human blood-derived macrophages. Biochem Biophys Res Commun 2015; 457:440-4. [DOI: 10.1016/j.bbrc.2015.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 01/05/2015] [Indexed: 11/20/2022]
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16
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George DM, Breinlinger EC, Argiriadi MA, Zhang Y, Wang J, Bansal-Pakala P, Duignan DB, Honore P, Lang Q, Mittelstadt S, Rundell L, Schwartz A, Sun J, Edmunds JJ. Optimized Protein Kinase Cθ (PKCθ) Inhibitors Reveal Only Modest Anti-inflammatory Efficacy in a Rodent Model of Arthritis. J Med Chem 2014; 58:333-46. [DOI: 10.1021/jm5013006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Dawn M. George
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Eric C. Breinlinger
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Maria A. Argiriadi
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Yang Zhang
- WuXi AppTec (Shanghai) Co., Ltd., 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, P. R. China
| | - Jianfei Wang
- WuXi AppTec (Shanghai) Co., Ltd., 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, P. R. China
| | - Pratima Bansal-Pakala
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - David B. Duignan
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Prisca Honore
- AbbVie, Inc., 1 North Waukegan
Road, North Chicago, Illinois 60064, United States
| | - QingYu Lang
- AbbVie China R&D Center, 5F, North Jin Chuang Building #1, 4560 Jinke Road, Pudong New District, Shanghai 201201, P. R. China
| | - Scott Mittelstadt
- AbbVie, Inc., 1 North Waukegan
Road, North Chicago, Illinois 60064, United States
| | - Lian Rundell
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Annette Schwartz
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
| | - Jiakang Sun
- WuXi AppTec (Shanghai) Co., Ltd., 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, P. R. China
| | - Jeremy J. Edmunds
- AbbVie Bioresearch Center, 381
Plantation Street, Worcester, Massachusetts 01605, United States
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17
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de Weerd A, Kho M, Kraaijeveld R, Zuiderwijk J, Weimar W, Baan C. The protein kinase C inhibitor sotrastaurin allows regulatory T cell function. Clin Exp Immunol 2014; 175:296-304. [PMID: 24131367 DOI: 10.1111/cei.12225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2013] [Indexed: 12/28/2022] Open
Abstract
The novel immunosuppressant sotrastaurin is a selective inhibitor of protein kinase C isoforms that are critical in signalling pathways downstream of the T cell receptor. Sotrastaurin inhibits nuclear factor (NF)-κB, which directly promotes the transcription of forkhead box protein 3 (FoxP3), the key regulator for the development and function of regulatory T cells (Tregs). Our center participated in a randomized trial comparing sotrastaurin (n = 14) and the calcineurin inhibitor Neoral (n = 7) in renal transplant recipients. We conducted ex vivo mixed lymphocyte reaction (MLR) and flow cytometry studies on these patient samples, as well as in vitro studies on samples of blood bank volunteers (n = 38). Treg numbers remained stable after transplantation and correlated with higher trough levels of sotrastaurin (r = 0·68, P = 0·03). A dose-dependent effect of sotrastaurin on alloresponsiveness was observed: the half maximal inhibitory concentration (IC50 ) to inhibit alloactivated T cell proliferation was 45 ng/ml (90 nM). In contrast, Treg function was not affected by sotrastaurin: in the presence of in vitro-added sotrastaurin (50 ng/ml) Tregs suppressed the proliferation of alloactivated T effector cells at a 1:5 ratio by 35 versus 47% in the absence of the drug (P = 0·33). Signal transducer and activator of transcription 5 (STAT)-5 phosphorylation in Tregs remained intact after incubation with sotrastaurin. This potent Treg function was also found in cells of patients treated with sotrastaurin: Tregs inhibited the anti-donor response in MLR by 67% at month 6, which was comparable to pretransplantation (82%). Sotrastaurin is a potent inhibitor of alloreactivity in vitro, while it did not affect Treg function in patients after kidney transplantation.
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Affiliation(s)
- A de Weerd
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, the Netherlands
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18
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Na BR, Kim HR, Kwon MS, Lee HS, Piragyte I, Choi EJ, Choi HK, Han WC, Lee SH, Jun CD. Aplotaxene blocks T cell activation by modulation of protein kinase C-θ-dependent pathway. Food Chem Toxicol 2013; 62:23-31. [PMID: 23941771 DOI: 10.1016/j.fct.2013.08.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 07/15/2013] [Accepted: 08/07/2013] [Indexed: 12/12/2022]
Abstract
Aplotaxene, (8Z, 11Z, 14Z)-heptadeca-1, 8, 11, 14-tetraene, is one of the major components of essential oil obtained from Inula helenium root, which is used in Oriental medicine. However, the effects of aplotaxene on immunity have not been investigated. Here, we show that aplotaxene inhibits T cell activation in terms of IL-2 and CD69 expression. Aplotaxene, at a concentration that optimally inhibits IL-2 production, has little effect on apoptotic or necrotic cell death, suggesting that apoptosis is not a mechanism for aplotaxene-mediated inhibition of T cell activation. Aplotaxene affects neither superantigeninduced conjugate formation between Jurkat T cells and Raji B cells nor clustering of CD3 and LFA-1 at the immunological synapse. Aplotaxene significantly inhibits PKC-θ phosphorylation and translocation to the immunological synapse, and blocks PMA-induced T-cell receptor internalization. Furthermore, aplotaxene leads to inhibition of mitogen-activated protein kinases (JNK, ERK and p38) phosphorylation and NF-κB, NF-AT, and AP-1 promoter activities in Jurkat T cells. Taken together, our findings provide evidence for the immunosuppressive effect of aplotaxene on activated T cells through the modulation of the PKC-θ and MAPK pathways, suggesting that aplotaxene may be a novel immunotherapeutic agent for immunological diseases related to the overactivation of T cells.
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Affiliation(s)
- Bo-Ra Na
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
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19
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Ma AZS, Zhang Q, Song ZY. TNFa alter cholesterol metabolism in human macrophages via PKC-θ-dependent pathway. BMC BIOCHEMISTRY 2013; 14:20. [PMID: 23914732 PMCID: PMC3751201 DOI: 10.1186/1471-2091-14-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 07/27/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Studies have shown that inflammation promoted atherosclerotic progression; however, it remains unclear whether inflammation promoted atherosclerotic progression properties by altering cholesterol metabolism in human macrophages. In the present study, we evaluated a potential mechanism of inflammation on atherogenic effects. We evaluated the ability of TNFa to affect Reverse cholesterol transport (RCT) and cholesterol uptake and its mechanism(s) of action in human macrophages. RESULTS We initially determined the potential effects of TNFa on cholesterol efflux in the human macrophages. We also determined alterations in mRNA and protein levels of ABCA1, ABCG1, LXRa, CD-36, SR-A in human macrophages using quantitative real-time polymerase chain reaction (PCR) and Western immunoblot analyses. The cholesterol efflux rate and protein expression of ABCA1, ABCG1, LXRa, CD-36, SR-A were quantified in human macrophages under PKC-θ inhibition using PKC-θ siRNA. Our results showed that TNFa inhibited the rate of cholesterol efflux and down-regulation the expression levels of ABCA1, ABCG1 and LXRa and up-regulation the expression levels of CD-36, SR-A in human macrophages; PKC-θ inhibition by PKC-θ siRNA attenuated the effect of TNFa on ABCA1, ABCG1, LXRa, SR-A, CD-36 expression. CONCLUSIONS Our results suggest TNFa alter cholesterol metabolism in human macrophages through the inhibition of Reverse cholesterol transport and enhancing cholesterol uptake via PKC-θ-dependent pathway, implicating a potential mechanism of inflammation on atherogenic effects.
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Affiliation(s)
- A Zhi Sha Ma
- Department of Cardiology, Southwest Hospital, The Third Military Medical University, Chongqing, China
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20
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Yan W, Xu R, Ma LL, Han W, Geevarghese SK, Williams PE, Sciammas R, Chong AS, Yin DP. B cells assist allograft rejection in the deficiency of protein kinase c-theta. Transpl Int 2013; 26:919-27. [PMID: 23841454 DOI: 10.1111/tri.12143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/29/2013] [Accepted: 06/10/2013] [Indexed: 11/28/2022]
Abstract
We have previously shown that mice deficient in protein kinase C theta (PKCθ) have the ability to reject cardiac allografts, but are susceptible to tolerance induction. Here we tested role of B cells in assisting alloimmune responses in the absence of PKCθ. Mouse cardiac allograft transplantations were performed from Balb/c (H-2d) to PKCθ knockout (PKCθ(-/-)), PKCθ and B cell double-knockout (PBDK, H-2b) mice and wild-type (WT) C57BL/6 (H-2b) mice. PBDK mice spontaneously accepted the allografts with the inhibition of NF-κB activation in the donor cardiac allograft. Anti-B cell antibody (rituximab) significantly delayed allograft rejection in PKCθ(-/-), but not in WT mice. Co-transfer of PKCθ(-/-) T plus PKCθ(-/-) B cells or primed sera triggered allograft rejection in Rag1(-/-) mice, and only major histocompatibility complex class II-enriched B cells, but not class I-enriched B cells, were able to promote rejection. This, together with the inability of PKCθ(-/-) and CD28(-/-) double-deficient (PCDK) mice to acutely reject allografts, suggested that an effective cognate interaction between PKCθ(-/-) T and B cells for acute rejection is CD28 molecule dependent. We conclude that T-B cell interactions synergize with PKCθ(-/-) T cells to mediate acute allograft rejection.
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Affiliation(s)
- Wenwei Yan
- Division of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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21
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Identification of the activator-binding residues in the second cysteine-rich regulatory domain of protein kinase Cθ (PKCθ). Biochem J 2013; 451:33-44. [PMID: 23289588 DOI: 10.1042/bj20121307] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PKC (protein kinase C) θ is predominantly expressed in T-cells and is critically involved in immunity. Design of PKCθ-selective molecules to manage autoimmune disorders by targeting its activator-binding C1 domain requires the knowledge of its structure and the activator-binding residues. The C1 domain consists of twin C1 domains, C1A and C1B, of which C1B plays a critical role in the membrane translocation and activation of PKCθ. In the present study we determined the crystal structure of PKCθC1B to 1.63 Å (1 Å=0.1 nm) resolution, which showed that Trp(253) at the rim of the activator-binding pocket was orientated towards the membrane, whereas in PKCδC1B the homologous tryptophan residue was orientated away from the membrane. This particular orientation of Trp(253) affects the size of the activator-binding pocket and the membrane affinity. To further probe the structural constraints on activator-binding, five residues lining the activator-binding site were mutated (Y239A, T243A, W253G, L255G and Q258G) and the binding affinities of the PKCθC1B mutants were measured. These mutants showed reduced binding affinities for phorbol ester [PDBu (phorbol 12,13-dibutyrate)] and diacylglycerol [DOG (sn-1,2-dioctanoylglycerol), SAG (sn-1-stearoyl 2-arachidonyl glycerol)]. All five full-length PKCθ mutants exhibited reduced phorbol-ester-induced membrane translocation compared with the wild-type. These results provide insights into the PKCθ activator-binding domain, which will aid in future design of PKCθ-selective molecules.
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Oswald-Richter KA, Richmond BW, Braun NA, Isom J, Abraham S, Taylor TR, Drake JM, Culver DA, Wilkes DS, Drake WP. Reversal of global CD4+ subset dysfunction is associated with spontaneous clinical resolution of pulmonary sarcoidosis. THE JOURNAL OF IMMUNOLOGY 2013; 190:5446-53. [PMID: 23630356 DOI: 10.4049/jimmunol.1202891] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Sarcoidosis pathogenesis is characterized by peripheral anergy and an exaggerated, pulmonary CD4(+) Th1 response. In this study, we demonstrate that CD4(+) anergic responses to polyclonal TCR stimulation are present peripherally and within the lungs of sarcoid patients. Consistent with prior observations, spontaneous release of IL-2 was noted in sarcoidosis bronchoalveolar lavage CD4(+) T cells. However, in contrast to spontaneous hyperactive responses reported previously, the cells displayed anergic responses to polyclonal TCR stimulation. The anergic responses correlated with diminished expression of the Src kinase Lck, protein kinase C-θ, and NF-κB, key mediators of IL-2 transcription. Although T regulatory (Treg) cells were increased in sarcoid patients, Treg depletion from the CD4(+) T cell population of sarcoidosis patients did not rescue IL-2 and IFN-γ production, whereas restoration of the IL-2 signaling cascade, via protein kinase C-θ overexpression, did. Furthermore, sarcoidosis Treg cells displayed poor suppressive capacity indicating that T cell dysfunction was a global CD4(+) manifestation. Analyses of patients with spontaneous clinical resolution revealed that restoration of CD4(+) Th1 and Treg cell function was associated with resolution. Conversely, disease progression exhibited decreased Th1 cytokine secretion and proliferative capacity, and reduced Lck expression. These findings implicate normalized CD4(+) T cell function as a potential therapeutic target for sarcoidosis resolution.
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Affiliation(s)
- Kyra A Oswald-Richter
- Department of Pathology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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23
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Black AR, Black JD. Protein kinase C signaling and cell cycle regulation. Front Immunol 2013; 3:423. [PMID: 23335926 PMCID: PMC3547298 DOI: 10.3389/fimmu.2012.00423] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 12/21/2012] [Indexed: 12/20/2022] Open
Abstract
A link between T cell proliferation and the protein kinase C (PKC) family of serine/threonine kinases has been recognized for about 30 years. However, despite the wealth of information on PKC-mediated control of, T cell activation, understanding of the effects of PKCs on the cell cycle machinery in this cell type remains limited. Studies in other systems have revealed important cell cycle-specific effects of PKC signaling that can either positively or negatively impact proliferation. The outcome of PKC activation is highly context-dependent, with the precise cell cycle target(s) and overall effects determined by the specific isozyme involved, the timing of PKC activation, the cell type, and the signaling environment. Although PKCs can regulate all stages of the cell cycle, they appear to predominantly affect G0/G1 and G2. PKCs can modulate multiple cell cycle regulatory molecules, including cyclins, cyclin-dependent kinases (cdks), cdk inhibitors and cdc25 phosphatases; however, evidence points to Cip/Kip cdk inhibitors and D-type cyclins as key mediators of PKC-regulated cell cycle-specific effects. Several PKC isozymes can target Cip/Kip proteins to control G0/G1 → S and/or G2 → M transit, while effects on D-type cyclins regulate entry into and progression through G1. Analysis of PKC signaling in T cells has largely focused on its roles in T cell activation; thus, observed cell cycle effects are mainly positive. A prominent role is emerging for PKCθ, with non-redundant functions of other isozymes also described. Additional evidence points to PKCδ as a negative regulator of the cell cycle in these cells. As in other cell types, context-dependent effects of individual isozymes have been noted in T cells, and Cip/Kip cdk inhibitors and D-type cyclins appear to be major PKC targets. Future studies are anticipated to take advantage of the similarities between these various systems to enhance understanding of PKC-mediated cell cycle regulation in T cells.
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Affiliation(s)
- Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center Omaha, NE, USA
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24
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Sun Z. Intervention of PKC-θ as an immunosuppressive regimen. Front Immunol 2012; 3:225. [PMID: 22876242 PMCID: PMC3410430 DOI: 10.3389/fimmu.2012.00225] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 07/10/2012] [Indexed: 01/04/2023] Open
Abstract
PKC-θ is selectively enriched in T cells and specifically translocates to immunological synapse where it mediates critical T cell receptor signals required for T cell activation, differentiation, and survival. T cells deficient in PKC-θ are defective in their ability to differentiate into inflammatory effector cells that mediate actual immune responses whereas, their differentiation into regulatory T cells (Treg) that inhibits the inflammatory T cells is enhanced. Therefore, the manipulation of PKC-θ activity can shift the ratio between inflammatory effector T cells and inhibitory Tregs, to control T cell-mediated immune responses that are responsible for autoimmunity and allograft rejection. Indeed, PKC-θ-deficient mice are resistant to the development of several Th2 and Th17-dependent autoimmune diseases and are defective in mounting alloimmune responses required for rejection of transplanted allografts and graft-versus-host disease. Selective inhibition of PKC-θ is therefore considered as a potential treatment for prevention of autoimmune diseases and allograft rejection.
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Affiliation(s)
- Zuoming Sun
- Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, CA, USA
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25
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Ma J, Ding Y, Fang X, Wang R, Sun Z. Protein kinase C-θ inhibits inducible regulatory T cell differentiation via an AKT-Foxo1/3a-dependent pathway. THE JOURNAL OF IMMUNOLOGY 2012; 188:5337-47. [PMID: 22539794 DOI: 10.4049/jimmunol.1102979] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Protein kinase C (PKC)-θ has been shown to be a critical TCR signaling molecule that promotes the activation and differentiation of naive T cells into inflammatory effector T cells. In this study, we demonstrate that PKC-θ-mediated signals inhibit inducible regulatory T cell (iTreg) differentiation via an AKT-Foxo1/3A pathway. TGF-β-induced iTreg differentiation was enhanced in PKC-θ(-/-) T cells or wild-type cells treated with a specific PKC-θ inhibitor, but was inhibited by the PKC-θ activator PMA, or by CD28 crosslinking, which enhances PKC-θ activation. PKC-θ(-/-) T cells had reduced activity of the AKT kinase, and the expression of a constitutively active form of AKT in PKC-θ(-/-) T cells restored the ability to inhibit iTreg differentiation. Furthermore, knockdown or overexpression of the AKT downstream targets Foxo1 and Foxo3a was found to inhibit or promote iTreg differentiation in PKC-θ(-/-) T cells accordingly, indicating that the AKT-Foxo1/3A pathway is responsible for the inhibition of iTreg differentiation of iTregs downstream of PKC-θ. We conclude that PKC-θ is able to control T cell-mediated immune responses by shifting the balance between the differentiation of effector T cells and inhibitory Tregs.
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Affiliation(s)
- Jian Ma
- Division of Immunology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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26
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Ameliorated ConA-induced hepatitis in the absence of PKC-theta. PLoS One 2012; 7:e31174. [PMID: 22347449 PMCID: PMC3274545 DOI: 10.1371/journal.pone.0031174] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 01/04/2012] [Indexed: 11/23/2022] Open
Abstract
Severe liver injury that occurs when immune cells mistakenly attack an individual's own liver cells leads to autoimmune hepatitis. In mice, acute hepatitis can be induced by concanavalin A (ConA) treatment, which causes rapid activation of CD1d-positive natural killer (NK) T cells. These activated NKT cells produce large amounts of cytokines, which induce strong inflammation that damages liver tissues. Here we show that PKC-θ−/− mice were resistant to ConA-induced hepatitis due to essential function of PKC-θ in NKT cell development and activation. A dosage of ConA (25 mg/kg) that was lethal to wild-type (WT) mice failed to induce death resulting from liver injury in PKC-θ−/− mice. Correspondingly, ConA-induced production of cytokines such as IFNγ, IL-6, and TNFα, which mediate the inflammation responsible for liver injury, were significantly lower in PKC-θ−/− mice. Peripheral NKT cells had developmental defects at early stages in the thymus in PKC-θ−/− mice, and as a result their frequency and number were greatly reduced. Furthermore, PKC-θ−/− bone marrow adoptively transferred to WT mice displayed similar defects in NKT cell development, suggesting an intrinsic requirement for PKC-θ in NKT cell development. In addition, upon stimulation with NKT cell-specific lipid ligand, peripheral PKC-θ−/− NKT cells produced lower levels of inflammatory cytokines than that of WT NKT cells, suggesting that activation of NKT cells also requires PKC-θ. Our results suggest PKC-θ is an essential molecule required for activation of NKT cell to induce hepatitis, and thus, is a potential drug target for prevention of autoimmune hepatitis.
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Wang R, Xie H, Huang Z, Shang W, Sun Z. Developing and activated T cell survival depends on differential signaling pathways to regulate anti-apoptotic Bcl-x(L). Clin Dev Immunol 2011; 2012:632837. [PMID: 22235227 PMCID: PMC3253460 DOI: 10.1155/2012/632837] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/07/2011] [Indexed: 12/22/2022]
Abstract
Survival of T cells in both the central and peripheral immune system determines its ultimate function in the regulation of immune responses. In the thymus, developing T cells undergo positive and negative selection to generate a T cell repertoire that responds to foreign, but not self, antigens. During T cell development, the T cell receptor α chain is rearranged. However, the first round of rearrangement may fail, which triggers another round of α chain rearrangement until either successful positive selection or cell death occurs. Thus, the lifespan of double positive (CD4(+)CD8(+); DP) thymocytes determines how many rounds of α chain rearrangement can be carried out and influences the likelihood of completing positive selection. The anti-apoptotic protein Bcl-x(L) is the ultimate effector regulating the survival of CD4(+)CD8(+) thymocytes subject to the selection process, and the deletion of Bcl-x(L) leads to premature apoptosis of thymocytes prior to the completion of the developmental process. In addition to its critical function in the thymus, Bcl-x(L) also regulates the survival of peripheral T cells. Upon engagement with antigens, T cells are activated and differentiated into effectors. Activated T cells upregulate Bcl-x(L) to enhance their own survival. Bcl-x(L)-mediated survival is required for the generation of effectors that carry out the actual immune responses. In the absence of Bcl-x(L), mature T cells undergo apoptosis prior to the completion of the differentiation process to become effector cells. Therefore, Bcl-x(L) ensures the survival of both developing and peripheral T cells, which is essential for a functional immune system.
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Affiliation(s)
- Ruiqing Wang
- Division of Immunology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
- Irell and Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA 91010, USA
| | - Huimin Xie
- Department of Microbiology and Immunology, Medical School of the University of Illinois, Chicago, IL 60612, USA
| | - Zhaofeng Huang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Weirong Shang
- Department of Gynecology and Obstetrics, Emory University School of Medicine, 550 Peachtree Street, Suite 1800, Atlanta, GA 30308, USA
| | - Zuoming Sun
- Division of Immunology, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
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Lee HS, Kim YD, Na BR, Kim HR, Choi EJ, Han WC, Choi HK, Lee SH, Jun CD. Phytocomponent p-Hydroxycinnamic acid inhibits T-cell activation by modulation of protein kinase C-θ-dependent pathway. Int Immunopharmacol 2011; 12:131-8. [PMID: 22101249 DOI: 10.1016/j.intimp.2011.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/01/2011] [Accepted: 11/02/2011] [Indexed: 11/19/2022]
Abstract
The phytocomponent p-hydoxycinnamic acid (HCA) has been shown to have many beneficial effects in terms of antioxidant activity, inhibition of melanogenesis, bone resorption, and platelet activity, and stimulation of mineralization. However, effects of HCA in immune functions have not been investigated. Here, we show that HCA has a profound effect on IL-2 production in Jurkat T cells as well as in human peripheral blood leukocytes. HCA, at a concentration that optimally inhibits IL-2 production, had little effect on apoptotic or necrotic cell death of Jurkat T cells, suggesting that apoptosis is not a mechanism for HCA-induced T-cell suppression. On the contrary, HCA dramatically inhibited PKC-θ accumulation and further phosphorylation at the immunological synapse which formed at the contact site between T cells and superantigen SEE-loaded antigen presenting cells. In addition, HCA significantly inhibited ERK and p38 kinase phosphorylation in both anti-CD3/28- and PMA/A23187-stimulated T cells. Consequently, HCA inhibited both AP-1 and NF-κB promoter activities in Jurkat T cells. Collectively, our results provide evidence for the immunosuppressive effect of HCA on activated T cells, through modulation of PKC-θ pathway.
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Affiliation(s)
- Hyun-Su Lee
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
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29
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Mirandola P, Gobbi G, Masselli E, Micheloni C, Di Marcantonio D, Queirolo V, Chiodera P, Meschi T, Vitale M. Protein kinase Cε regulates proliferation and cell sensitivity to TGF-1β of CD4+ T lymphocytes: implications for Hashimoto thyroiditis. THE JOURNAL OF IMMUNOLOGY 2011; 187:4721-32. [PMID: 21964026 DOI: 10.4049/jimmunol.1003258] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have studied the functional role of protein kinase Cε (PKCε) in the control of human CD4(+) T cell proliferation and in their response to TGF-1β. We demonstrate that PKCε sustains CD4(+) T cell proliferation triggered in vitro by CD3 stimulation. Transient knockdown of PKCε expression decreases IL-2R chain transcription, and consequently cell surface expression levels of CD25. PKCε silencing in CD4 T cells potentiates the inhibitory effects of TGF-1β, whereas in contrast, the forced expression of PKCε virtually abrogates the inhibitory effects of TGF-1β. Being that PKCε is therefore implicated in the response of CD4 T cells to both CD3-mediated proliferative stimuli and TGF-1β antiproliferative signals, we studied it in Hashimoto thyroiditis (HT), a pathology characterized by abnormal lymphocyte proliferation and activation. When we analyzed CD4 T cells from HT patients, we found a significant increase of PKCε expression, accounting for their enhanced survival, proliferation, and decreased sensitivity to TGF-1β. The increased expression of PKCε in CD4(+) T cells of HT patients, which is described for the first time, to our knowledge, in this article, viewed in the perspective of the physiological role of PKCε in normal Th lymphocytes, adds knowledge to the molecular pathophysiology of HT and creates potentially new pharmacological targets for the therapy of this disease.
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Affiliation(s)
- Prisco Mirandola
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Parma, 43126 Parma, Italy
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30
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Protein kinase C-theta in platelet activation. FEBS Lett 2011; 585:3208-15. [DOI: 10.1016/j.febslet.2011.09.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/20/2011] [Accepted: 09/12/2011] [Indexed: 02/05/2023]
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31
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López-Huertas MR, Mateos E, Díaz-Gil G, Gómez-Esquer F, Sánchez del Cojo M, Alcamí J, Coiras M. Protein kinase Ctheta is a specific target for inhibition of the HIV type 1 replication in CD4+ T lymphocytes. J Biol Chem 2011; 286:27363-77. [PMID: 21669868 DOI: 10.1074/jbc.m110.210443] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Integration of HIV-1 genome in CD4(+) T cells produces latent reservoirs with long half-life that impedes the eradication of the infection. Control of viral replication is essential to reduce the size of latent reservoirs, mainly during primary infection when HIV-1 infects CD4(+) T cells massively. The addition of immunosuppressive agents to highly active antiretroviral therapy during primary infection would suppress HIV-1 replication by limiting T cell activation, but these agents show potential risk for causing lymphoproliferative disorders. Selective inhibition of PKC, crucial for T cell function, would limit T cell activation and HIV-1 replication without causing general immunosuppression due to PKC being mostly expressed in T cells. Accordingly, the effect of rottlerin, a dose-dependent PKC inhibitor, on HIV-1 replication was analyzed in T cells. Rottlerin was able to reduce HIV-1 replication more than 20-fold in MT-2 (IC(50) = 5.2 μM) and Jurkat (IC(50) = 2.2 μM) cells and more than 4-fold in peripheral blood lymphocytes (IC(50) = 4.4 μM). Selective inhibition of PKC, but not PKCδ or -ζ, was observed at <6.0 μM, decreasing the phosphorylation at residue Thr(538) on the kinase catalytic domain activation loop and avoiding PKC translocation to the lipid rafts. Consequently, the main effector at the end of PKC pathway, NF-κB, was repressed. Rottlerin also caused a significant inhibition of HIV-1 integration. Recently, several specific PKC inhibitors have been designed for the treatment of autoimmune diseases. Using these inhibitors in combination with highly active antiretroviral therapy during primary infection could be helpful to avoid massive viral infection and replication from infected CD4(+) T cells, reducing the reservoir size at early stages of the infection.
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Affiliation(s)
- María Rosa López-Huertas
- AIDS Immunopathology Unit, National Center of Microbiology, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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32
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Magnuson NS, Wang Z, Ding G, Reeves R. Why target PIM1 for cancer diagnosis and treatment? Future Oncol 2011; 6:1461-78. [PMID: 20919829 DOI: 10.2217/fon.10.106] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The highly conserved proto-oncogenic protein PIM1 is an unusual serine or threonine kinase, in part because it is constitutively active. Overexpression of PIM1 experimentally leads to tumor formation in mice, while complete knockout of the protein has no observable phenotype. It appears to contribute to cancer development in three major ways when it is overexpressed; by inhibiting apoptosis, by promoting cell proliferation and by promoting genomic instability. Expression in normal tissues is nearly undetectable. However, in hematopoietic malignancies and in a variety of solid tumors, increased PIM1 expression has been shown to correlate with the stage of disease. This characteristic suggests it can serve as a useful biomarker for cancer diagnosis and prognosis. Several specific and potent inhibitors of PIM1’s kinase activity have also been shown to induce apoptotic death of cancer cells, to sensitize cancer cells to chemotherapy and to synergize with other anti-tumor agents, thus making it an attractive therapeutic target.
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Affiliation(s)
- Nancy S Magnuson
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, USA
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Newton RH, Leverrier S, Srikanth S, Gwack Y, Cahalan MD, Walsh CM. Protein kinase D orchestrates the activation of DRAK2 in response to TCR-induced Ca2+ influx and mitochondrial reactive oxygen generation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 186:940-50. [PMID: 21148796 PMCID: PMC3133617 DOI: 10.4049/jimmunol.1000942] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DRAK2 is a serine/threonine kinase highly enriched in lymphocytes that raises the threshold for T cell activation and maintains T cell survival following productive activation. T cells lacking DRAK2 are prone to activation under suboptimal conditions and exhibit enhanced calcium responses to AgR stimulation. Despite this, mice lacking DRAK2 are resistant to organ-specific autoimmune diseases due to defective autoreactive T cell survival. DRAK2 kinase activity is induced by AgR signaling, and in this study we show that the induction of DRAK2 activity requires Ca(2+) influx through the Ca(2+) release-activated Ca(2+) channel formed from Orai1 subunits. Blockade of DRAK2 activity with the protein kinase D (PKD) inhibitor Gö6976 or expression of a kinase-dead PKD mutant prevented activation of DRAK2, whereas a constitutively active PKD mutant promoted DRAK2 function. Knockdown of PKD in T cells strongly blocked endogenous DRAK2 activation following TCR ligation, implicating PKD as an essential intermediate in the activation of DRAK2 by Ca(2+) influx. Furthermore, we identify DRAK2 as a novel substrate of PKD, and demonstrate that DRAK2 and PKD physically interact under conditions that activate PKD. Mitochondrial generation of reactive oxygen intermediates was necessary and sufficient for DRAK2 activation in response to Ca(2+) influx. Taken together, DRAK2 and PKD form a novel signaling module that controls calcium homeostasis following T cell activation.
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Affiliation(s)
- Ryan H. Newton
- Institute for Immunology, University of California, Irvine, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697
| | - Sabrina Leverrier
- Institute for Immunology, University of California, Irvine, Irvine, CA 92697
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697
| | - Sonal Srikanth
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Yousang Gwack
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Michael D. Cahalan
- Institute for Immunology, University of California, Irvine, Irvine, CA 92697
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697
| | - Craig M. Walsh
- Institute for Immunology, University of California, Irvine, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697
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Thompson J, Burger ML, Whang H, Winoto A. Protein kinase C regulates mitochondrial targeting of Nur77 and its family member Nor-1 in thymocytes undergoing apoptosis. Eur J Immunol 2010; 40:2041-9. [PMID: 20411565 DOI: 10.1002/eji.200940231] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nur77 orphan steroid receptor and its family member Nor-1 are required for apoptosis of developing T cells. In thymocytes, signals from the TCR complex induce Nur77 and Nor-1 expression followed by translocation from the nucleus to mitochondria. Nur77 and Nor-1 associate with Bcl-2 in the mitochondria, resulting in a conformation change that exposes the Bcl-2 BH3 domain, a presumed pro-apoptotic molecule of Bcl-2. As Nur77 and Nor-1 are heavily phosphorylated, we examined the requirement of Nur77 and Nor-1 phosphorylation in mitochondria translocation and Bcl-2 BH3 exposure. We found that HK434, a PKC agonist, in combination with calcium ionophore, can induce Nur77 and Nor-1 phosphorylation, translocation, Bcl-2 BH3 exposure and thymocyte apoptosis. Inhibitors of both classical and novel forms of PKC were able to block this process. In contrast, only the general but not classical PKC-specific inhibitors were able to block the same process initiated by PMA, a commonly used PKC agonist. These data demonstrate a differential activation of PKC isoforms by PMA and HK434 in thymocytes, and show the importance of PKC in mitochondria translocation of Nur77/Nor-1 and Bcl-2 conformation change during TCR-induced thymocyte apoptosis.
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Affiliation(s)
- Jennifer Thompson
- Cancer Research Laboratory and Department of Molecular and Cell Biology, Division of Immunology and Pathogenesis, University of California, Berkeley, CA, USA
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35
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Zhu P, Jiang W, Cao L, Yu W, Pei Y, Yang X, Wan B, Liu JO, Yi Q, Yu L. IL-2 mRNA stabilization upon PMA stimulation is dependent on NF90-Ser647 phosphorylation by protein kinase CbetaI. THE JOURNAL OF IMMUNOLOGY 2010; 185:5140-9. [PMID: 20870937 DOI: 10.4049/jimmunol.1000849] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-2 is an important cytokine produced in T cells in response to Ag or mitogen stimulation. It is regulated at both transcriptional and posttranscriptional levels. One of the key regulators of IL-2 mRNA stability is NF90. Upon T cell activation, NF90 translocates from the nucleus into the cytoplasm, where it binds to the AU-rich element-containing 3' untranslated regions of IL-2 mRNA and stabilizes it. Our previous work showed that CD28 costimulation of T cells activated AKT to phosphorylate NF90 at Ser(647) and caused NF90 to undergo nuclear export and stabilize IL-2 mRNA. Phorbol ester (PMA) is a protein kinase C (PKC) activator. Through transcription activation and mRNA stabilization, IL-2 mRNA levels increase promptly when T cells are stimulated with PMA. However, how PMA stabilizes IL-2 mRNA was still unclear. In this study, we demonstrate that PMA stimulation led to phosphorylation of NF90 at Ser(647) via PKCβI. This phosphorylation was necessary for nuclear export of NF90 in response to PMA and for IL-2 mRNA stabilization. We show that phosphorylation at NF90-Ser(647) upregulated IL-2 production in response to PMA stimulation. Our results support a model in which PMA stimulation activates PKCβI to phosphorylate NF90-Ser(647), and this phosphorylation triggers NF90 relocation to the cytoplasm and stabilize IL-2 mRNA. Thus, our study elucidates the mechanism by which PMA activates and stabilizes IL-2 expression in T cells.
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Affiliation(s)
- Ping Zhu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, China
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36
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Protein kinase C θ deficiency increases resistance of C57BL/6J mice to Plasmodium berghei infection-induced cerebral malaria. Infect Immun 2010; 78:4195-205. [PMID: 20660606 DOI: 10.1128/iai.00465-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Protein kinase C θ (PKCθ) functions as a core component of the immunological synapse and serves as a key protein in the integrated T-cell antigen receptor (TCR)/CD28-induced signaling cascade leading to T-cell activation. However, the involvement of PKCθ in host-mediated immune responses to pathogens has not been thoroughly investigated. We tested the consequences of PKCθ ablation on the host response to infection by Plasmodium berghei ANKA (PbA). We found that both PKCθ(+/+) and PKCθ(-/-) C57BL/6J mice are susceptible to infection with PbA. However, despite a similar parasite burden, PKCθ(+/+) mice had an earlier onset of neurological signs, characteristics of experimental cerebral malaria (ECM), resulting in an earlier death. These mice suffered from an early and pronounced splenomegaly with a concomitant increase in the total number of CD4(+) splenic T cells. In contrast, a large proportion of PbA-infected PKCθ(-/-) mice overcame the acute phase characterized by neurological symptoms and survived longer than PKCθ(+/+) mice. The partial resistance of PKCθ(-/-) mice to ECM was associated with an impaired production of Th1-type cytokines, including gamma interferon and tumor necrosis factor alpha/lymphotoxin-α, which are known to exacerbate symptoms leading to ECM. In addition, PbA infection-induced LFA-1 expression in CD8(+) T cells was suppressed in PKCθ-deficient T cells, suggesting a diminished ability to adhere to endothelial cells and sequester in brain microvasculature, which may explain the decrease in neurological symptoms. These data implicate PKCθ in CD4(+) Th1(+) and CD8(+) T-cell-mediated immune responses during PbA infection that contribute to the development of ECM.
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Nakayama T, Yamashita M. The TCR-mediated signaling pathways that control the direction of helper T cell differentiation. Semin Immunol 2010; 22:303-9. [PMID: 20488727 DOI: 10.1016/j.smim.2010.04.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 03/06/2010] [Accepted: 04/23/2010] [Indexed: 10/19/2022]
Abstract
In the periphery, upon antigen recognition by alphabetaTCR, naïve CD4 T cells undergo functional differentiation and acquire the ability to produce a specific set of cytokines. At least four Th cell subsets, i.e., Th1, Th2, Th17 and iTreg cells have so far been identified and the differentiation of each subset is driven by distinct cytokine sets. Antigen recognition by TCR and the activation of the TCR-mediated signaling pathways that follows, however, are most critical for initiating Th cell differentiation. This review focuses on the TCR signal strength and the TCR-mediated signaling pathways that control the differentiation into these four Th cell subsets.
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Affiliation(s)
- Toshinori Nakayama
- Department of Immunology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba 260-8670, Japan.
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Deenick EK, Po L, Chapatte L, Murakami K, Lu YC, Elford AR, Saibil SD, Ruland J, Gerondakis S, Mak TW, Ohashi PS. c-Rel phenocopies PKCtheta but not Bcl-10 in regulating CD8+ T-cell activation versus tolerance. Eur J Immunol 2010; 40:867-77. [PMID: 19950170 DOI: 10.1002/eji.200939445] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Elucidating the signaling events that promote T-cell tolerance versus activation provides important insights for manipulating immunity in vivo. Previous studies have suggested that the absence of PKCtheta results in the induction of anergy and that the balance between the induction of the transcription factors NFAT, AP1 and NF-kappaB plays a key role in determining whether T-cell anergy or activation is induced. Here, we examine whether Bcl-10 and specific family members of NF-kappaB act downstream of PKCtheta to alter CD8(+) T-cell activation and/or anergy. We showed that T cells from mice deficient in c-Rel but not NF-kappaB1 (p50) have increased susceptibility to the induction of anergy, similar to T cells from PKCtheta-deficient mice. Surprisingly T cells from Bcl-10-deficient mice showed a strikingly different phenotype to the PKCtheta-deficient T cells, with a severe block in TCR-mediated activation. Furthermore, we have also shown that survival signals downstream of NF-kappaB, are uncoupled from signals that mediate T-cell anergy. These results suggest that c-Rel plays a critical role downstream of PKCtheta in controlling CD8(+) T-cell anergy induction.
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Affiliation(s)
- Elissa K Deenick
- Campbell Family Institute, Ontario Cancer Institute, University of Toronto, Toronto, ON, Canada.
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Ohayon A, Babichev Y, Pasvolsky R, Dong G, Sztarkier I, Benharroch D, Altman A, Isakov N. Hodgkin’s lymphoma cells exhibit high expression levels of the PICOT protein. J Immunotoxicol 2010; 7:8-14. [DOI: 10.3109/15476910903427654] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Weckbecker G, Pally C, Beerli C, Burkhart C, Wieczorek G, Metzler B, Morris RE, Wagner J, Bruns C. Effects of the novel protein kinase C inhibitor AEB071 (Sotrastaurin) on rat cardiac allograft survival using single agent treatment or combination therapy with cyclosporine, everolimus or FTY720. Transpl Int 2009; 23:543-52. [PMID: 20003043 DOI: 10.1111/j.1432-2277.2009.01015.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
NVP-AEB071 (AEB, sotrastaurin), an oral inhibitor of protein kinase C (PKC), effectively blocks T-cell activation. The immunosuppressive effects of oral AEB were demonstrated in a rat local graft versus host (GvH) reaction and rat cardiac transplantation models. T-cell activation was suppressed by 95% in blood from AEB-treated rats, with a positive correlation between T-cell inhibition and AEB blood concentration. In GvH studies, AEB inhibited lymph node swelling dose-dependently (3-30 mg/kg). BN and DA cardiac allografts were acutely rejected within 6-10 days post-transplantation in untreated LEW rats. AEB at 10 and 30 mg/kg b.i.d. prolonged BN graft survival to a mean survival time of 15 and >28 days, and DA grafts to 6.5 and 17.5 days, respectively. In the DA to LEW model, combining a nonefficacious dose of AEB (10 mg/kg b.i.d.) with a nonefficacious dose of cyclosporine, everolimus or FTY720 led to prolonged median survival times (26 days, >68 days and >68 days, respectively). Pharmacokinetic monitoring excluded drug-drug interactions, suggesting synergy. In conclusion, these studies are the first to demonstrate that AEB prolongs rat heart allograft survival safely as monotherapy and in combination with nonefficacious doses of cyclosporine, everolimus or FTY720. Thus, AEB may have the potential to offer an alternative to calcineurin inhibitor-based therapies.
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Affiliation(s)
- Gisbert Weckbecker
- Novartis Institutes for BioMedical Research, Autoimmunity and Transplantation Disease Area, Novartis Pharma AG, Basel, Switzerland.
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Evenou JP, Wagner J, Zenke G, Brinkmann V, Wagner K, Kovarik J, Welzenbach KA, Weitz-Schmidt G, Guntermann C, Towbin H, Cottens S, Kaminski S, Letschka T, Lutz-Nicoladoni C, Gruber T, Hermann-Kleiter N, Thuille N, Baier G. The potent protein kinase C-selective inhibitor AEB071 (sotrastaurin) represents a new class of immunosuppressive agents affecting early T-cell activation. J Pharmacol Exp Ther 2009; 330:792-801. [PMID: 19491325 DOI: 10.1124/jpet.109.153205] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2025] Open
Abstract
There is a pressing need for immunosuppressants with an improved safety profile. The search for novel approaches to blocking T-cell activation led to the development of the selective protein kinase C (PKC) inhibitor AEB071 (sotrastaurin). In cell-free kinase assays AEB071 inhibited PKC, with K(i) values in the subnanomolar to low nanomolar range. Upon T-cell stimulation, AEB071 markedly inhibited in situ PKC catalytic activity and selectively affected both the canonical nuclear factor-kappaB and nuclear factor of activated T cells (but not activator protein-1) transactivation pathways. In primary human and mouse T cells, AEB071 treatment effectively abrogated at low nanomolar concentration markers of early T-cell activation, such as interleukin-2 secretion and CD25 expression. Accordingly, the CD3/CD28 antibody- and alloantigen-induced T-cell proliferation responses were potently inhibited by AEB071 in the absence of nonspecific antiproliferative effects. Unlike former PKC inhibitors, AEB071 did not enhance apoptosis of murine T-cell blasts in a model of activation-induced cell death. Furthermore, AEB071 markedly inhibited lymphocyte function-associated antigen-1-mediated T-cell adhesion at nanomolar concentrations. The mode of action of AEB071 is different from that of calcineurin inhibitors, and AEB071 and cyclosporine A seem to have complementary effects on T-cell signaling pathways.
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Affiliation(s)
- Jean-Pierre Evenou
- Novartis Institute for BioMedical Research, WSJ-386.5.27, CH-4002 Basel, Switzerland.
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Pores-Fernando AT, Ranaghan MYD, Zweifach A. No specific subcellular localization of protein kinase C is required for cytotoxic T cell granule exocytosis. J Biol Chem 2009; 284:25107-15. [PMID: 19592494 DOI: 10.1074/jbc.m109.011866] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytotoxic T cells kill virus-infected cells and tumor cells by releasing lytic granules that contain cell-killing contents. Exocytosis requires calcium influx and protein kinase C (PKC) activation. Here, we extend our previous finding regarding the lack of isoform specificity of PKCs in the granule release step, showing that mutant constitutively active PKCdelta can substitute for phorbol esters and support exocytosis. PKCdelta, a novel PKC isoform, was recently shown to play a role in lytic granule reorientation. Surprisingly, however, our results suggested that mutant PKCdelta did not localize to the plasma membrane (PM). To test directly whether PKC has to be in the PM to drive exocytosis, we generated mutants of various PKC isoforms that were tethered either to the outer mitochondrial membrane or to the PM. Tethered mutant PKCdeltas were able to promote exocytosis as effectively as the untethered version. The substrates of PKCs involved in lytic granule exocytosis are currently unknown, but subcellular localization is believed to be a critical factor in determining PKC accessibility to substrates. That there is no requirement for specific PKC localization in lytic granule exocytosis may have important implications for the identity of PKC substrates.
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Affiliation(s)
- Arun T Pores-Fernando
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269-3125, USA
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Baier G, Wagner J. PKC inhibitors: potential in T cell-dependent immune diseases. Curr Opin Cell Biol 2009; 21:262-7. [DOI: 10.1016/j.ceb.2008.12.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Accepted: 12/30/2008] [Indexed: 10/21/2022]
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Abstract
CD28 is recognized as the primary costimulatory molecule involved in the activation of naïve T cells. However, the biochemical signaling pathways that are activated by CD28 and how these pathways are integrated with TCR signaling are still not understood. We have recently shown that there are at least two independent activation pathways induced by CD28 costimulation. One is integrated with TCR signaling in the context of the immunological synapse and is mediated through transcriptional enhancement and the second is mediated through the induction of mRNA stability. Here, we review the immunological consequences and biochemical mechanisms associated with CD28 costimulation and discuss the major questions that need to be resolved to understand the molecular mechanisms that transduce CD28 costimulation.
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Gupta S, Manicassamy S, Vasu C, Kumar A, Shang W, Sun Z. Differential requirement of PKC-theta in the development and function of natural regulatory T cells. Mol Immunol 2008; 46:213-24. [PMID: 18842300 PMCID: PMC2700121 DOI: 10.1016/j.molimm.2008.08.275] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Accepted: 08/27/2008] [Indexed: 01/25/2023]
Abstract
CD4+CD25+ natural Treg cells, which are developed in the thymus, migrate to the periphery to actively maintain self-tolerance. Similar to conventional T cells, TCR signals are critical for the development and activation of Treg cell inhibitory function. While PKC-theta-mediated TCR signals are required for the activation of peripheral naïve T cells, they are dispensable for their thymic development. Here, we show that mice deficient in PKC-theta had a greatly reduced number of CD4+Foxp3+ Treg cells, which was independent of PKC-theta-regulated survival, as transgenic Bcl-x(L) could not restore the Treg cell population in PKC-theta(-/-) mice. Active and WT PKC-theta markedly stimulated, whereas inactive PKC-theta and dominant negative NFAT inhibited Foxp3 promoter activity. In addition, mice-deficient in calcineurin Abeta had a decreased Treg cell population, similar to that observed in PKC-theta deficient mice. It is likely that PKC-theta promoted the development of Treg cells by enhancing Foxp3 expression via activation of the calcineurin/NFAT pathway. Finally, Treg cells deficient in PKC-theta were as potent as WT Treg cells in inhibiting T cell activation, indicating that PKC-theta was not required for Treg cell-mediated inhibitory function. Our data highlight the contrasting roles PKC-theta plays in conventional T cell and natural Treg cell function.
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Affiliation(s)
- Sonal Gupta
- Department of Microbiology & Immunology, School of Medicine, University of Illinois, Chicago, IL 60612, USA
| | - Santhakumar Manicassamy
- Department of Microbiology & Immunology, School of Medicine, University of Illinois, Chicago, IL 60612, USA
| | - Chenthamarakshan Vasu
- Department of Surgery, School of Medicine, University of Illinois, Chicago, IL 60612, USA
| | - Anvita Kumar
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL, 60612, USA
| | - Weirong Shang
- Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, GA 30308
| | - Zuoming Sun
- Department of Microbiology & Immunology, School of Medicine, University of Illinois, Chicago, IL 60612, USA
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Manicassamy S, Yin D, Zhang Z, Molinero LL, Alegre ML, Sun Z. A critical role for protein kinase C-theta-mediated T cell survival in cardiac allograft rejection. THE JOURNAL OF IMMUNOLOGY 2008; 181:513-20. [PMID: 18566417 DOI: 10.4049/jimmunol.181.1.513] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Protein kinase C (PKC)-theta mediates the critical TCR signals required for T cell activation. Previously, we have shown that in response to TCR stimulation, PKC-theta-/- T cells undergo apoptosis due to greatly reduced levels of the anti-apoptotic molecule, Bcl-xL. In this study, we demonstrate that PKC-theta-regulated expression of Bcl-xL is essential for T cell-mediated cardiac allograft rejection. Rag1-/- mice reconstituted with wild-type T cells readily rejected fully mismatched cardiac allografts, whereas Rag1-/- mice reconstituted with PKC-theta-/- T cells failed to promote rejection. Transgenic expression of Bcl-xL in PKC-theta-/- T cells was sufficient to restore cardiac allograft rejection, suggesting that PKC-theta-regulated survival is required for T cell-mediated cardiac allograft rejection in this adoptive transfer model. In contrast to adoptive transfer experiments, intact PKC-theta-/- mice displayed delayed, but successful cardiac allograft rejection, suggesting the potential compensation for PKC-theta function. Finally, a subtherapeutic dose of anti-CD154 Ab or CTLA4-Ig, which was not sufficient to prevent cardiac allograft rejection in the wild-type mice, prevented heart rejection in the PKC-theta-/- mice. Thus, in combination with other treatments, inhibition of PKC-theta may facilitate achieving long-term survival of allografts.
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Affiliation(s)
- Santhakumar Manicassamy
- Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
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Wang Y, Shibuya K, Yamashita Y, Shirakawa J, Shibata K, Kai H, Yokosuka T, Saito T, Honda SI, Tahara-Hanaoka S, Shibuya A. LFA-1 decreases the antigen dose for T cell activation in vivo. Int Immunol 2008; 20:1119-27. [PMID: 18644832 DOI: 10.1093/intimm/dxn070] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Leukocyte adhesion molecule leukocyte function-associated antigen (LFA)-1 not only mediates intercellular binding but also delivers co-stimulatory signals in T cells. LFA-1 has been shown to decrease the threshold of TCR signal and an antigen dose required for T cell activation and proliferation in vitro. However, physiological significance of the role of LFA-1 in TCR signal has remained unclear. We examined whether LFA-1 decreased the antigen dose for T cell activation in vivo. We showed here that, although collagen-induced arthritis (CIA) could not be induced by immunization and challenge with a standard amount of type-II collagen in LFA-1-deficient mice, a higher dose of the antigen did induce CIA in the absence of LFA-1. We also showed that CD4+ T cells could be primed by immunization with a high, but not low, dose of ovalbumin antigen in LFA-1-deficient mice. These results suggest that LFA-1 decreases the threshold of TCR signal for T cell activation in vivo as well as in vitro. Further studies using TCR-transgenic LFA-1-deficient mice showed that LFA-1 cooperated with TCR in sustained Erk1/2 phosphorylation. Moreover, TCR could induce sustained Erk1/2 phosphorylation in the absence of LFA-1 when T cells were stimulated with a high, but not low, dose of antigen, suggesting that LFA-1 may cooperate with TCR in sustaining Erk1/2 phosphorylation.
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Affiliation(s)
- Yinan Wang
- Department of Immunology, Institute of Basic Medical Sciences and Center for TARA, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan
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Pores-Fernando AT, Gaur S, Grybko MJ, Zweifach A. ERK activation is only one role of PKC in TCR-independent cytotoxic T cell granule exocytosis. Biochem Biophys Res Commun 2008; 371:630-4. [PMID: 18413231 DOI: 10.1016/j.bbrc.2008.04.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 04/04/2008] [Indexed: 11/18/2022]
Abstract
Cytotoxic T cells (CTLs) kill target cells by releasing lytic agents via regulated exocytosis. Three signals are known to be required for exocytosis: an increase in intracellular Ca(2+), activation of protein kinase C (PKC) and activation of extracellular signal regulated signal kinase (ERK). ERK activation required for exocytosis depends on activity of PKC. The simplest possibility is that the sole effect of PKC required for exocytosis is ERK activation. Testing this requires dissociating ERK and PKC activation. We did this using TCR-independent stimulation of TALL-104 human leukemic CTLs. When cells are stimulated with thapsigargin and PMA, agents that increase intracellular Ca(2+) and activate PKC, respectively, PKC-dependent ERK activation is required for lytic granule exocytosis. Expressing a constitutively active mutant MAP kinase kinase activates ERK independent of PKC. However, activating ERK without PKC does not support lytic granule exocytosis, indicating that there are multiple effects of PKC required for granule exocytosis.
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Affiliation(s)
- Arun T Pores-Fernando
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, 91 N Eagleville Road, Unit 3125, Storrs, CT 06268-3125, USA
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T-cell fate and function: PKC-theta and beyond. Trends Immunol 2008; 29:179-85. [PMID: 18328786 DOI: 10.1016/j.it.2008.01.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/24/2008] [Accepted: 01/24/2008] [Indexed: 11/20/2022]
Abstract
The serine/threonine-specific protein kinase C-theta (PKC-theta) is a core component of the immunological synapse that was shown in vitro to play a central role in the activation of T cells after T cell receptor (TCR) and co-stimulatory molecule engagement. In recent years, a series of in vivo studies have shown that the situation is far more complex; specifically, PKC-theta signaling is differentially required for Th1, Th2, Th17 and CD8+ cytotoxic T-cell responses. These studies highlight the combination of signals that directly regulate T-cell differentiation and effector responses. In this review, we highlight recent in vivo studies investigating PKC-theta function and discuss this in the context of how the integration of extrinsic signals determines T cell fate and function.
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T-cell receptor-induced NF-kappaB activation is negatively regulated by E3 ubiquitin ligase Cbl-b. Mol Cell Biol 2008; 28:2470-80. [PMID: 18227156 DOI: 10.1128/mcb.01505-07] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
It has previously been shown that E3 ubiquitin ligase Casitas B-lineage lymphoma-b (Cbl-b) negatively regulates T-cell activation, but the molecular mechanism(s) underlying this inhibition is not completely defined. In this study, we report that the loss of Cbl-b selectively results in aberrant activation of NF-kappaB upon T-cell antigen receptor (TCR) ligation, which is mediated by phosphatidylinositol 3-kinase (PI3-K)/Akt and protein kinase C-theta (PKC-theta). TCR-induced hyperactivation of Akt in the absence of Cbl-b may potentiate the formation of caspase recruitment domain-containing membrane-associated guanylate kinase protein 1 (CARMA1)-B-cell lymphoma/leukemia 10 (Bcl10)-mucosa-associated lymphatic tissue 1(MALT1) (CBM) complex, which appears to be independent of PKC-theta. Cbl-b associates with PKC-theta upon TCR stimulation and regulates TCR-induced PKC-theta activation via Vav-1, which couples PKC-theta to PI3-K and allows it to be phosphorylated. PKC-theta then couples IkappaB kinases (IKKs) to the CBM complex, resulting in the activation of the IKK complex. Therefore, our data provide the first evidence to demonstrate that the down-regulation of TCR-induced NF-kappaB activation by Cbl-b is mediated coordinately by both Akt-dependent and PKC-theta-dependent signaling pathways in primary T cells.
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