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Liu X, Hao J, Wei P, Zhao X, Lan Q, Ni L, Chen Y, Bai X, Ni L, Dong C. SMAD4, activated by the TCR-triggered MEK/ERK signaling pathway, critically regulates CD8 + T cell cytotoxic function. SCIENCE ADVANCES 2022; 8:eabo4577. [PMID: 35895826 PMCID: PMC9328680 DOI: 10.1126/sciadv.abo4577] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Transforming growth factor-β is well known to restrain cytotoxic T cell responses to maintain self-tolerance and to promote tumor immune evasion. In this study, we have investigated the role of SMAD4, a core component in the TGF-β signaling pathway, in CD8+ T cells. Unexpectedly, we found that SMAD4 was critical in promoting CD8+ T cell function in both tumor and infection models. SMAD4-mediated transcriptional regulation of CD8+ T cell activation and cytotoxicity was dependent on the T cell receptor (TCR) but not TGF-β signaling pathway. Following TCR activation, SMAD4 translocated into the nucleus, up-regulated genes encoding TCR signaling components and cytotoxic molecules in CD8+ T cells and thus reinforced T cell function. Biochemically, SMAD4 was directly phosphorylated by ERK at Ser367 residue following TCR activation. Our study thus demonstrates a critical yet unexpected role of SMAD4 in promoting CD8+ T cell-mediated cytotoxic immunity.
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Affiliation(s)
- Xinwei Liu
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jing Hao
- Shanghai Immune Therapy Institute, Shanghai Jiaotong University School of Medicine-affiliated Renji Hospital, Shanghai 200127, China
| | - Peng Wei
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xiaohong Zhao
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qiuyan Lan
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Lu Ni
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yongzhen Chen
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xue Bai
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Ling Ni
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chen Dong
- Institute for Immunology and School of Medicine, Tsinghua University, Beijing 100084, China
- Shanghai Immune Therapy Institute, Shanghai Jiaotong University School of Medicine-affiliated Renji Hospital, Shanghai 200127, China
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Kästle M, Merten C, Hartig R, Plaza-Sirvent C, Schmitz I, Bommhardt U, Schraven B, Simeoni L. Type of PaperY192 within the SH2 Domain of Lck Regulates TCR Signaling Downstream of PLC-γ1 and Thymic Selection. Int J Mol Sci 2022; 23:ijms23137271. [PMID: 35806279 PMCID: PMC9267008 DOI: 10.3390/ijms23137271] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 02/04/2023] Open
Abstract
Signaling via the TCR, which is initiated by the Src-family tyrosine kinase Lck, is crucial for the determination of cell fates in the thymus. Because of its pivotal role, ablation of Lck results in a profound block of T-cell development. Here, we show that, in addition to its well-known function in the initiation of TCR signaling, Lck also acts at a more downstream level. This novel function of Lck is determined by the tyrosine residue (Y192) located in its SH2 domain. Thymocytes from knock-in mice expressing a phosphomimetic Y192E mutant of Lck initiate TCR signaling upon CD3 cross-linking up to the level of PLC-γ1 phosphorylation. However, the activation of downstream pathways including Ca2+ influx and phosphorylation of Erk1/2 are impaired. Accordingly, positive and negative selections are blocked in LckY192E knock-in mice. Collectively, our data indicate that Lck has a novel function downstream of PLCγ-1 in the regulation of thymocyte differentiation and selection.
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Affiliation(s)
- Matthias Kästle
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
| | - Camilla Merten
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
| | - Roland Hartig
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
| | - Carlos Plaza-Sirvent
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
- Department of Molecular Immunology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Ingo Schmitz
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
- Department of Molecular Immunology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Ursula Bommhardt
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
- Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany
- Center for Health and Medical Prevention (CHaMP), Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Burkhart Schraven
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
- Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany
- Center for Health and Medical Prevention (CHaMP), Otto-von-Guericke University, 39120 Magdeburg, Germany
- Correspondence: (B.S.); (L.S.)
| | - Luca Simeoni
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; (M.K.); (C.M.); (R.H.); (C.P.-S.); (I.S.); (U.B.)
- Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany
- Center for Health and Medical Prevention (CHaMP), Otto-von-Guericke University, 39120 Magdeburg, Germany
- Correspondence: (B.S.); (L.S.)
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3
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Zheng Y, Fang YC, Li J. PD-L1 expression levels on tumor cells affect their immunosuppressive activity. Oncol Lett 2019; 18:5399-5407. [PMID: 31612048 PMCID: PMC6781757 DOI: 10.3892/ol.2019.10903] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 08/06/2019] [Indexed: 12/14/2022] Open
Abstract
Programmed cell death 1 (PD-1) is an immuno-checkpoint receptor which is primarily expressed on T cells, monocytes, natural killer cells and macrophages. Programmed death-ligand 1 (PD-L1) is the primary ligand of PD-1 and is constitutively expressed on antigen presenting cells, mesenchymal stem cells and bone marrow-derived mast cells. In addition, PD-L1 is also expressed on a wide range of tumor cells, including lung cancer, breast cancer and melanoma. PD-1 and PD-L1 are important members of the immunoglobulin super-family and participate in immune regulation. In the present study, the immune-suppressive effects of a number of tumor cell lines were determined. The breast tumor cell lines MCF-7 and MDA-MB-231 displayed the largest inhibitory effects on T-cell activation and cytokine secretion in a co-culture system. The HepG2, A549 and A375 cells displayed limited inhibitory effects. MCF-7 and MDA-MB-231 cells expressed the highest level of PD-L1 among the cells used, which may explain their higher immuno-suppressive effects. Compound A0-L, a small molecule inhibitor of the PD-1/PD-L1 interaction, restored T cell functions. Additionally, it was demonstrated that the tumor cells with higher levels of PD-L1 expression suppressed signaling pathways involved in T-cell activation, such as the T-cell receptor- zeta chain of T cell receptor associated protein kinase ZAP70-RAS-GTPase-extracellular-signal-regulated kinases and CD28-PI3K-Akt serine/threonine kinases pathways. These findings suggest that tumor cells with higher expression levels of PD-L1 may exhibit higher immuno-suppressive activity, and that drugs targeting the PD-1/PD-L1 interaction may have improved therapeutic effects on tumors expressing higher levels of PD-L1.
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Affiliation(s)
- Yang Zheng
- Chinese Academy of Sciences Key Laboratory of Receptor Research, National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, P.R. China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, P.R. China.,School of Pharmacy, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - You-Chen Fang
- Chinese Academy of Sciences Key Laboratory of Receptor Research, National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, P.R. China.,School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Jing Li
- Chinese Academy of Sciences Key Laboratory of Receptor Research, National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, P.R. China
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Concomitant BCORL1 and BRAF Mutations in Vemurafenib-Resistant Melanoma Cells. Neoplasia 2018; 20:467-477. [PMID: 29605720 PMCID: PMC5915992 DOI: 10.1016/j.neo.2018.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/30/2018] [Accepted: 02/06/2018] [Indexed: 12/18/2022] Open
Abstract
BRAF is the most frequently mutated gene in melanoma. Constitutive activation of mutant BRAFV600E leads to aberrant Ras-independent MAPK signaling and cell transformation. Inhibition of mutant BRAF is a current frontline therapy for such cases, with improved survival compared with chemotherapy. Unfortunately, reactivation of MAPK signaling by several mechanisms has been shown to cause drug resistance and disease recurrence. In this work, we describe the co-occurrence of an in-frame deletion within an amplified BRAFV600E locus and a missense point mutation of the transcriptional repressor BCORL1 in vemurafenib-resistant A375 melanoma cells. Functional data confirmed that truncated p47BRAFV600E and mutant BCORL1Q1076H both contribute to resistance. Interestingly, either endogenous BCORL1 silencing or ectopic BCORL1Q1076H expression mimicked the effects of a CRISPR/Cas9-edited BCORL1Q1076H locus, suggesting a complex mixture of loss- and gain-of-function effects caused by the mutation. Transcriptomic data confirmed this hypothesis. Finally, we show that the pan-RAF inhibitor sorafenib is not affected by expression of BRAF deletion variant and effectively synergizes with vemurafenib to block resistant cells, suggesting a possible intervention for this class of mutants.
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5
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Belmont J, Gu T, Mudd A, Salomon AR. A PLC-γ1 Feedback Pathway Regulates Lck Substrate Phosphorylation at the T-Cell Receptor and SLP-76 Complex. J Proteome Res 2017. [PMID: 28644030 DOI: 10.1021/acs.jproteome.6b01026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Phospholipase C gamma 1 (PLC-γ1) occupies a critically important position in the T-cell signaling pathway. While its functions as a regulator of both Ca2+ signaling and PKC-family kinases are well characterized, PLC-γ1's role in the regulation of early T-cell receptor signaling events is incompletely understood. Activation of the T-cell receptor leads to the formation of a signalosome complex between SLP-76, LAT, PLC-γ1, Itk, and Vav1. Recent studies have revealed the existence of both positive and negative feedback pathways from SLP-76 to the apical kinase in the pathway, Lck. To determine if PLC-γ1 contributes to the regulation of these feedback networks, we performed a quantitative phosphoproteomic analysis of PLC-γ1-deficient T cells. These data revealed a previously unappreciated role for PLC-γ1 in the positive regulation of Zap-70 and T-cell receptor tyrosine phosphorylation. Conversely, PLC-γ1 negatively regulated the phosphorylation of SLP-76-associated proteins, including previously established Lck substrate phosphorylation sites within this complex. While the positive and negative regulatory phosphorylation sites on Lck were largely unchanged, Tyr192 phosphorylation was elevated in Jgamma1. The data supports a model wherein Lck's targeting, but not its kinase activity, is altered by PLC-γ1, possibly through Lck Tyr192 phosphorylation and increased association of the kinase with protein scaffolds SLP-76 and TSAd.
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Affiliation(s)
- Judson Belmont
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Tao Gu
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Ashley Mudd
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States
| | - Arthur R Salomon
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University , Providence, Rhode Island 02912, United States.,Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States
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6
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Leibowitz SM, Yan J. NF-κB Pathways in the Pathogenesis of Multiple Sclerosis and the Therapeutic Implications. Front Mol Neurosci 2016; 9:84. [PMID: 27695399 PMCID: PMC5023675 DOI: 10.3389/fnmol.2016.00084] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/29/2016] [Indexed: 01/01/2023] Open
Abstract
Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways are involved in cell immune responses, apoptosis and infections. In multiple sclerosis (MS), NF-κB pathways are changed, leading to increased levels of NF-κB activation in cells. This may indicate a key role for NF-κB in MS pathogenesis. NF-κB signaling is complex, with many elements involved in its activation and regulation. Interestingly, current MS treatments are found to be directly or indirectly linked to NF-κB pathways and act to adjust the innate and adaptive immune system in patients. In this review, we will first focus on the intricacies of NF-κB signaling, including the activating pathways and regulatory elements. Next, we will theorize about the role of NF-κB in MS pathogenesis, based on current research findings, and discuss some of the associated therapeutic implications. Lastly, we will review four new MS treatments which interrupt NF-κB pathways—fingolimod, teriflunomide, dimethyl fumarate (DMF) and laquinimod (LAQ)—and explain their mechanisms, and the possible strategy for MS treatments in the future.
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Affiliation(s)
- Saskia M Leibowitz
- UQ Centre for Clinical Research, The University of Queensland Brisbane, QLD, Australia
| | - Jun Yan
- UQ Centre for Clinical Research, The University of Queensland Brisbane, QLD, Australia
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7
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HIV-1 Nef compensates for disorganization of the immunological synapse by inducing trans-Golgi network-associated Lck signaling. Blood 2011; 119:786-97. [PMID: 22123847 DOI: 10.1182/blood-2011-08-373209] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Nef protein of HIV-1 facilitates viral replication and disease progression in vivo. Nef disturbs the organization of immunological synapses between infected CD4(+) T lymphocytes and antigen-presenting B-lymphocytes to interfere with TCR proximal signaling. Paradoxically, Nef enhances distal TCR signaling in infected CD4(+) T lymphocytes, an effect thought to be involved in its role in AIDS pathogenesis. Using quantitative confocal microscopy and cell fractionation of Nef-expressing cells and HIV-1-infected primary human T lymphocytes, we found that Nef induces intracellular compartmentalization of TCR signaling to adjust TCR responses to antigenic stimulation. Nef reroutes kinase-active pools of the TCR signaling master switch Lck away from the plasma membrane (PM) to the trans-Golgi network (TGN), thereby preventing the recruitment of active Lck to the immunological synapse after TCR engagement and limiting signal initiation at the PM. Instead, Nef triggers Lck-dependent activation of TGN-associated Ras-Erk signaling to promote the production of the T lymphocyte survival factor IL-2 and to enhance virus spread. Overexpression of the Lck PM transporter Unc119 restores Nef-induced subversions of Lck trafficking and TCR signaling. Nef therefore hijacks Lck sorting to selectively activate TGN-associated arms of compartmentalized TCR signaling. By tailoring T-lymphocyte responses to antigenic stimulation, Nef optimizes the environment for HIV-1 replication.
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8
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Luo Q, Gu Y, Zheng W, Wu X, Gong F, Gu L, Sun Y, Xu Q. Erlotinib inhibits T-cell-mediated immune response via down-regulation of the c-Raf/ERK cascade and Akt signaling pathway. Toxicol Appl Pharmacol 2011; 251:130-6. [DOI: 10.1016/j.taap.2010.12.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 12/08/2010] [Accepted: 12/16/2010] [Indexed: 11/25/2022]
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McCoy ME, Finkelman FD, Straus DB. Th2-specific immunity and function of peripheral T cells is regulated by the p56Lck Src homology 3 domain. THE JOURNAL OF IMMUNOLOGY 2010; 185:3285-94. [PMID: 20729329 DOI: 10.4049/jimmunol.0900027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
T cell activation and effector function is essential for robust immunity. Ag TCR signals are known to regulate T lymphocyte differentiation, but the mechanisms involved in this regulation remain unclear. Recent work has demonstrated that the Src family protein tyrosine kinase p56Lck specifically links TCR signaling to activation of the MAPK pathway through the function of its Src homology 3 (SH3) domain. The MAPK pathway is involved in T cell activation and has previously been implicated in Th2 immunity. We have used Lck SH3 mutant knockin mice (LckW97A) to investigate the potential role of this regulatory mechanism in T lymphocyte activation and effector function. Our results demonstrate that Lck SH3 domain function regulates activation of T lymphocytes as indicated by reduced IL-2 production, CD69 induction, and proliferation of LckW97A T cells following TCR stimulation. Biochemical studies confirm that activation of the MAPK pathway is selectively altered following TCR ligation in LckW97A T lymphocytes. Phospho-ERK induction is reduced, but phospho-phospholipase Cgamma1 induction and calcium mobilization are largely unaffected. Immunization with DNP-keyhole limpet hemocyanin, heat-killed Brucella abortus, or infection with Nippostrongylus brasiliensis demonstrates selectively impaired Th2 immunity with reduced serum levels of IgG1, IgE, and IL-4. In vitro studies show that LckW97A T cells can differentiate into Th2-type cells, but they form IFN-gamma-producing cells under conditions that normally favor Th2 development. These data indicate that the Lck SH3 domain controls T lymphocyte activation by regulating MAPK pathway induction and demonstrate a novel role for Lck in the regulation of Th2-type immunity.
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Affiliation(s)
- Margaret E McCoy
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA
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10
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Obata Y, Fukumoto Y, Nakayama Y, Kuga T, Dohmae N, Yamaguchi N. The Lyn kinase C-lobe mediates Golgi export of Lyn through conformation-dependent ACSL3 association. J Cell Sci 2010; 123:2649-62. [PMID: 20605918 DOI: 10.1242/jcs.066266] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Src-family tyrosine kinase Lyn has a role in signal transduction at the cytoplasmic face of the plasma membrane upon extracellular ligand stimulation. After synthesis in the cytoplasm, Lyn accumulates on the Golgi and is subsequently transported to the plasma membrane. However, the mechanism of Lyn trafficking remains elusive. We show here that the C-lobe of the Lyn kinase domain is associated with long-chain acyl-CoA synthetase 3 (ACSL3) on the Golgi in a manner that is dependent on Lyn conformation but is independent of its kinase activity. Formation of a closed conformation by CSK prevents Lyn from associating with ACSL3, resulting in blockade of Lyn export from the Golgi. Overexpression and knockdown of ACSL3 accelerates and blocks Golgi export of Lyn, respectively. The post-Golgi route of Lyn, triggered by ACSL3, is distinct from that of vesicular stomatitis virus glycoprotein (VSV-G) and of caveolin. Moreover, an ACSL3 mutant lacking the LR2 domain, which is required for the catalytic activity, retains the ability to associate with Lyn and accelerate Golgi export of Lyn. These results suggest that initiation of Golgi export of Lyn involves association of ACSL3 with the Lyn C-lobe, which is exposed to the molecular surface in an open conformation.
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Affiliation(s)
- Yuuki Obata
- Department of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
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11
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Oluwadara O, Giacomelli L, Christensen R, Kossan G, Avezova R, Chiappelli F. LCK, survivin and PI-3K in the molecular biomarker profiling of oral lichen planus and oral squamous cell carcinoma. Bioinformation 2009; 4:249-57. [PMID: 20975919 PMCID: PMC2951717 DOI: 10.6026/97320630004248] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 12/15/2009] [Indexed: 12/29/2022] Open
Abstract
T cell signaling is critical in oral lichen planus (OLP) based on the pathogenesis of this chronic inflammatory autoimmune mucocutaneous lesion. Lck plays a key role in T cell signaling; ultimately this signaling affects other targets such as PI-3K. Excessive activity in PI-3K inhibits apoptosis and promotes uncontrolled cell growth. Molecular biomarker profiling in OLP, Chronic Interface Mucosities (CIM), Epithelial Dysplasia (EpD) and Oral Squamous Cell Carcinoma (SCCA) with application of the principle of biomarker voting may represent a new frontier in the diagnosis, assessment and the arguable debate of OLP transformation to cancer. The presence of Lck, PI-3K and Survivin, a cancer specific anti-apoptotic protein was assessed, using immunohistochemistry and tissue micro-array on patient samples, in OLP, SCCA, CIM and EpD. Lck expression was very high in 78.6 % of OLP patients compared to 3.7% in SCCA; PI-3K was high in 63% of SCCA, 100% of EpD, and 35.7% OLP cases. Survivin was high in 64.3% of OLP cases, 96.3% of SCCA, and 100% of EpD. CIM cases may be slightly different molecularly to OLP. Taken together, our data suggest that biomarker protein voting can be effectively used to isolate high-risk OLP cases. Specifically, we show data with four remarkable cases demonstrating that molecular factors are predictive of histopathology. We conclude that it is safer to treat OLP as premalignant lesions, to adopt aggressive treatment measure in histopathologic described well and moderately differentiated SCCA, and to monitor progress of these diseases molecularly using individualized auto-proteomic approach. The use of Lck inhibitors in OLP management needs to be investigated in the future.
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Affiliation(s)
- Oluwadayo Oluwadara
- 1UCLA School of Dentistry, Division of Oral Biology and Medicine, 10833 Le Conte Avenue CHS - Box 951668, Los Angeles, CA 90095-1668, USA
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12
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Falahati R, Leitenberg D. Selective regulation of TCR signaling pathways by the CD45 protein tyrosine phosphatase during thymocyte development. THE JOURNAL OF IMMUNOLOGY 2009; 181:6082-91. [PMID: 18941197 DOI: 10.4049/jimmunol.181.9.6082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In CD45-deficient animals, there is a severe defect in thymocyte-positive selection, resulting in an absence of mature T cells and the accumulation of thymocytes at the DP stage of development. However, the signaling defect(s) responsible for the block in development of mature single-positive T cells is not well characterized. Previous studies have found that early signal transduction events in CD45-deficient cell lines and thymocytes are markedly diminished following stimulation with anti-CD3. Nevertheless, there are also situations in which T cell activation and TCR signaling events can be induced in the absence of CD45. For example, CD45-independent TCR signaling can be recovered upon simultaneous Ab cross-linking of CD3 and CD4 compared with cross-linking of CD3 alone. These data suggest that CD45 may differentially regulate TCR signaling events depending on the nature of the signal and/or on the differentiation state of the cell. In the current study, we have assessed the role of CD45 in regulating primary thymocyte activation following physiologic stimulation with peptide. Unlike CD3-mediated stimulation, peptide stimulation of CD45-deficient thymocytes induces diminished, but readily detectable TCR-mediated signaling events, such as phosphorylation of TCR-associated zeta, ZAP70, linker for activation of T cells, and Akt, and increased intracellular calcium concentration. In contrast, phosphorylation of ERK, which is essential for positive selection, is more severely affected in the absence of CD45. These data suggest that CD45 has a selective role in regulating different aspects of T cell activation.
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Affiliation(s)
- Rustom Falahati
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University, Washington, DC 20037, USA
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13
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Pulvirenti T, Giannotta M, Capestrano M, Capitani M, Pisanu A, Polishchuk RS, San Pietro E, Beznoussenko GV, Mironov AA, Turacchio G, Hsu VW, Sallese M, Luini A. A traffic-activated Golgi-based signalling circuit coordinates the secretory pathway. Nat Cell Biol 2008; 10:912-22. [PMID: 18641641 DOI: 10.1038/ncb1751] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 06/26/2008] [Indexed: 12/12/2022]
Abstract
As with other complex cellular functions, intracellular membrane transport involves the coordinated engagement of a series of organelles and machineries; however, the molecular basis of this coordination is unknown. Here we describe a Golgi-based signalling system that is activated by traffic and is involved in monitoring and balancing trafficking rates into and out of the Golgi complex. We provide evidence that the traffic signal is due to protein chaperones that leave the endoplasmic reticulum and reach the Golgi complex where they bind to the KDEL receptor. This initiates a signalling reaction that includes the activation of a Golgi pool of Src kinases and a phosphorylation cascade that in turn activates intra-Golgi trafficking, thereby maintaining the dynamic equilibrium of the Golgi complex. The concepts emerging from this study should help to understand the control circuits that coordinate high-order cellular functions.
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Affiliation(s)
- Teodoro Pulvirenti
- Laboratory of Membrane Traffic, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro (Chieti), Italy
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