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Johansen KH, Golec DP, Huang B, Park C, Thomsen JH, Preite S, Cannons JL, Garçon F, Schrom EC, Courrèges CJF, Veres TZ, Harrison J, Nus M, Phelan JD, Bergmeier W, Kehrl JH, Okkenhaug K, Schwartzberg PL. A CRISPR screen targeting PI3K effectors identifies RASA3 as a negative regulator of LFA-1-mediated adhesion in T cells. Sci Signal 2022; 15:eabl9169. [PMID: 35857633 PMCID: PMC9637254 DOI: 10.1126/scisignal.abl9169] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The integrin lymphocyte function-associated antigen 1 (LFA-1) helps to coordinate the migration, adhesion, and activation of T cells through interactions with intercellular adhesion molecule 1 (ICAM-1) and ICAM-2. LFA-1 is activated during the engagement of chemokine receptors and the T cell receptor (TCR) through inside-out signaling, a process that is partially mediated by phosphoinositide 3-kinase (PI3K) and its product phosphatidylinositol 3,4,5-trisphosphate (PIP3). To evaluate potential roles of PI3K in LFA-1 activation, we designed a library of CRISPR/single guide RNAs targeting known and potential PIP3-binding proteins and screened for effects on the ability of primary mouse T cells to bind to ICAM-1. We identified multiple proteins that regulated the binding of LFA-1 to ICAM-1, including the Rap1 and Ras GTPase-activating protein RASA3. We found that RASA3 suppressed LFA-1 activation in T cells, that its expression was rapidly reduced upon T cell activation, and that its activity was inhibited by PI3K. Loss of RASA3 in T cells led to increased Rap1 activation, defective lymph node entry and egress, and impaired responses to T-dependent immunization in mice. Our results reveal a critical role for RASA3 in T cell migration, homeostasis, and function.
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Affiliation(s)
- Kristoffer H Johansen
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Section of Experimental and Translational Immunology, Department of Health Technology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Dominic P Golec
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bonnie Huang
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chung Park
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julie H Thomsen
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Silvia Preite
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jennifer L Cannons
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fabien Garçon
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Edward C Schrom
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Tibor Z Veres
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Harrison
- Cardiovascular Division, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Meritxell Nus
- Cardiovascular Division, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - James D Phelan
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wolfgang Bergmeier
- Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - John H Kehrl
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Klaus Okkenhaug
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Pamela L Schwartzberg
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Lau D, Garçon F, Chandra A, Lechermann LM, Aloj L, Chilvers ER, Corrie PG, Okkenhaug K, Gallagher FA. Intravital Imaging of Adoptive T-Cell Morphology, Mobility and Trafficking Following Immune Checkpoint Inhibition in a Mouse Melanoma Model. Front Immunol 2020; 11:1514. [PMID: 32793206 PMCID: PMC7387409 DOI: 10.3389/fimmu.2020.01514] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
Efficient T-cell targeting, infiltration and activation within tumors is crucial for successful adoptive T-cell therapy. Intravital microscopy is a powerful tool for the visualization of T-cell behavior within tumors, as well as spatial and temporal heterogeneity in response to immunotherapy. Here we describe an experimental approach for intravital imaging of adoptive T-cell morphology, mobility and trafficking in a skin-flap tumor model, following immune modulation with immune checkpoint inhibitors (ICIs) targeting PD-L1 and CTLA-4. A syngeneic model of ovalbumin and mCherry-expressing amelanotic mouse melanoma was used in conjunction with adoptively transferred OT-1+ cytotoxic T-cells expressing GFP to image antigen-specific live T-cell behavior within the tumor microenvironment. Dynamic image analysis of T-cell motility showed distinct CD8+ T-cell migration patterns and morpho-dynamics within different tumor compartments in response to ICIs: this approach was used to cluster T-cell behavior into four groups based on velocity and meandering index. The results showed that most T-cells within the tumor periphery demonstrated Lévy-like trajectories, consistent with tumor cell searching strategies. T-cells adjacent to tumor cells had reduced velocity and appeared to probe the local environment, consistent with cell-cell interactions. An increased number of T-cells were detected following treatment, traveling at lower mean velocities than controls, and demonstrating reduced displacement consistent with target engagement. Histogram-based analysis of immunofluorescent images from harvested tumors showed that in the ICI-treated mice there was a higher density of CD31+ vessels compared to untreated controls and a greater infiltration of T-cells towards the tumor core, consistent with increased cellular trafficking post-treatment.
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Affiliation(s)
- Doreen Lau
- Cancer Research UK Cambridge Centre, Cambridge, United Kingdom
- Department of Radiology, University of Cambridge, Cambridge, United Kingdom
| | - Fabien Garçon
- Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, United Kingdom
| | - Anita Chandra
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | | | - Luigi Aloj
- Cancer Research UK Cambridge Centre, Cambridge, United Kingdom
- Department of Radiology, University of Cambridge, Cambridge, United Kingdom
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Edwin R. Chilvers
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Pippa G. Corrie
- Department of Oncology, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Klaus Okkenhaug
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Ferdia A. Gallagher
- Cancer Research UK Cambridge Centre, Cambridge, United Kingdom
- Department of Radiology, University of Cambridge, Cambridge, United Kingdom
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Angulo I, Vadas O, Garçon F, Banham-Hall E, Plagnol V, Leahy TR, Baxendale H, Coulter T, Curtis J, Wu C, Blake-Palmer K, Perisic O, Smyth D, Maes M, Fiddler C, Juss J, Cilliers D, Markelj G, Chandra A, Farmer G, Kielkowska A, Clark J, Kracker S, Debré M, Picard C, Pellier I, Jabado N, Morris JA, Barcenas-Morales G, Fischer A, Stephens L, Hawkins P, Barrett JC, Abinun M, Clatworthy M, Durandy A, Doffinger R, Chilvers ER, Cant AJ, Kumararatne D, Okkenhaug K, Williams RL, Condliffe A, Nejentsev S. Phosphoinositide 3-kinase δ gene mutation predisposes to respiratory infection and airway damage. Science 2013; 342:866-71. [PMID: 24136356 DOI: 10.1126/science.1243292] [Citation(s) in RCA: 424] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Genetic mutations cause primary immunodeficiencies (PIDs) that predispose to infections. Here, we describe activated PI3K-δ syndrome (APDS), a PID associated with a dominant gain-of-function mutation in which lysine replaced glutamic acid at residue 1021 (E1021K) in the p110δ protein, the catalytic subunit of phosphoinositide 3-kinase δ (PI3Kδ), encoded by the PIK3CD gene. We found E1021K in 17 patients from seven unrelated families, but not among 3346 healthy subjects. APDS was characterized by recurrent respiratory infections, progressive airway damage, lymphopenia, increased circulating transitional B cells, increased immunoglobulin M, and reduced immunoglobulin G2 levels in serum and impaired vaccine responses. The E1021K mutation enhanced membrane association and kinase activity of p110δ. Patient-derived lymphocytes had increased levels of phosphatidylinositol 3,4,5-trisphosphate and phosphorylated AKT protein and were prone to activation-induced cell death. Selective p110δ inhibitors IC87114 and GS-1101 reduced the activity of the mutant enzyme in vitro, which suggested a therapeutic approach for patients with APDS.
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Affiliation(s)
- Ivan Angulo
- Department of Medicine, University of Cambridge, Cambridge, UK
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Soond DR, Garçon F, Patton DT, Rolf J, Turner M, Scudamore C, Garden OA, Okkenhaug K. Pten loss in CD4 T cells enhances their helper function but does not lead to autoimmunity or lymphoma. J Immunol 2012; 188:5935-43. [PMID: 22611241 DOI: 10.4049/jimmunol.1102116] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PTEN, one of the most commonly mutated or lost tumor suppressors in human cancers, antagonizes signaling by the PI3K pathway. Mice with thymocyte-specific deletion of Pten rapidly develop peripheral lymphomas and autoimmunity, which may be caused by failed negative selection of thymocytes or from dysregulation of postthymic T cells. We induced conditional deletion of Pten from CD4 Th cells using a Cre knocked into the Tnfrsf4 (OX40) locus to generate OX40(Cre)Pten(f) mice. Pten-deficient Th cells proliferated more and produced greater concentrations of cytokines. The OX40(Cre)Pten(f) mice had a general increase in the number of lymphocytes in the lymph nodes, but not in the spleen. When transferred into wild-type (WT) mice, Pten-deficient Th cells enhanced anti-Listeria responses and the clearance of tumors under conditions in which WT T cells had no effect. Moreover, inflammatory responses were exaggerated and resolved later in OX40(Cre)Pten(f) mice than in WT mice. However, in contrast with models of thymocyte-specific Pten deletion, lymphomas and autoimmunity were not observed, even in older OX40(Cre)Pten(f) mice. Hence loss of Pten enhances Th cell function without obvious deleterious effects.
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Affiliation(s)
- Dalya R Soond
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge CB22 3AT, United Kingdom
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Abstract
PI3Ks (phosphoinositide 3-kinases) regulate diverse cellular functions such as metabolism, growth, gene expression and migration. The p110delta isoform of PI3K is mainly expressed in cells of the immune system and contributes to cellular and humoral immunity. In the thymus, p110delta and p110gamma play complementary roles in regulating the transition through key developmental checkpoints. In addition, p110delta regulates the differentiation of peripheral Th (helper T-cells) towards the Th1 and Th2 lineages. Moreover, p110delta is critical for Treg (regulatory T-cell) function. Here, we review the role of PI3Ks in T-cell development and function.
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Affiliation(s)
- D T Patton
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, UK
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Okkenhaug K, Patton DT, Bilancio A, Garçon F, Rowan WC, Vanhaesebroeck B. The p110delta isoform of phosphoinositide 3-kinase controls clonal expansion and differentiation of Th cells. J Immunol 2007; 177:5122-8. [PMID: 17015696 DOI: 10.4049/jimmunol.177.8.5122] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The role of PI3K in T cell activation and costimulation has been controversial. We previously reported that a kinase-inactivating mutation (D910A) in the p110delta isoform of PI3K results in normal T cell development, but impaired TCR-stimulated cell proliferation in vitro. This proliferative defect can be overcome by providing CD28 costimulation, which raises the question as to whether p110delta activity plays a role in T cell activation in vivo, which occurs primarily in the context of costimulation. In this study, we show that the PI3K signaling pathway in CD28-costimulated p110delta D910A/D910A T cells is impaired, but that ERK phosphorylation and NF-kappaB nuclear translocation are unaffected. Under in vitro conditions of physiological Ag presentation and costimulation, p110delta D910A/D910A T cells showed normal survival, but underwent fewer divisions. Differentiation along the Th1 and Th2 lineages was impaired in p110delta D910A/D910A T cells and could not be rescued by exogenous cytokines in vitro. Adoptive transfer and immunization experiments in mice revealed that clonal expansion and differentiation in response to Ag and physiological costimulation were also compromised. Thus, p110delta contributes significantly to Th cell expansion and differentiation in vitro and in vivo, also in the context of CD28 costimulation.
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Affiliation(s)
- Klaus Okkenhaug
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, United Kingdom.
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Affiliation(s)
- Fabien Garçon
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK
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Dufourmantel N, Tissot G, Goutorbe F, Garçon F, Muhr C, Jansens S, Pelissier B, Peltier G, Dubald M. Generation and analysis of soybean plastid transformants expressing Bacillus thuringiensis Cry1Ab protoxin. Plant Mol Biol 2005; 58:659-68. [PMID: 16158241 DOI: 10.1007/s11103-005-7405-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Accepted: 05/16/2005] [Indexed: 05/03/2023]
Abstract
We describe the generation of fertile and homoplasmic soybean plastid transformants, expressing the Bacillus thuringiensis insecticidal protoxin Cry1Ab. Transgenes were targeted in the intergenic region of Glycine max plastome, between the rps12/7 and trnV genes and selection was carried out using the aadA gene encoding spectinomycin resistance. Molecular analysis confirmed the integration of the cry1Ab and aadA expression cassettes at the expected location in the soybean plastome, and the transmission of the transgenes to the next generation. Western blot analyses showed that the Cry1Ab protoxin is highly expressed in leaves, stems and seeds, but not in roots. Its expression confers strong insecticidal activity to the generated transgenic soybean, as exemplified with velvetbean caterpillar (Anticarsia gemmatalis).
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Affiliation(s)
- N Dufourmantel
- Bayer BioScience, 14-20 rue Pierre Baizet, BP9163, 69263, Lyon Cedex 09, France,
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Hagenbeek TJ, Naspetti M, Malergue F, Garçon F, Nunès JA, Cleutjens KBJM, Trapman J, Krimpenfort P, Spits H. The loss of PTEN allows TCR alphabeta lineage thymocytes to bypass IL-7 and Pre-TCR-mediated signaling. ACTA ACUST UNITED AC 2004; 200:883-94. [PMID: 15452180 PMCID: PMC2213281 DOI: 10.1084/jem.20040495] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The phosphatase and tensin homologue deleted on chromosome 10 (PTEN) negatively regulates cell survival and proliferation mediated by phosphoinositol 3 kinases. We have explored the role of the phosphoinositol(3,4,5)P3-phosphatase PTEN in T cell development by analyzing mice with a T cell-specific deletion of PTEN. Pten(flox/flox)Lck-Cre mice developed thymic lymphomas, but before the onset of tumors, they showed normal thymic cellularity. To reveal a regulatory role of PTEN in proliferation of developing T cells we have crossed PTEN-deficient mice with mice deficient for interleukin (IL)-7 receptor and pre-T cell receptor (TCR) signaling. Analysis of mice deficient for Pten and CD3gamma; Pten and gammac; or Pten, gammac, and Rag2 revealed that deletion of PTEN can substitute for both IL-7 and pre-TCR signals. These double- and triple-deficient mice all develop normal levels of CD4CD8 double negative and double positive thymocytes. These data indicate that PTEN is an important regulator of proliferation of developing T cells in the thymus.
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Affiliation(s)
- Thijs J Hagenbeek
- Department of Immunology, Netherlands Cancer Institute, Amsterdam, The Netherlands
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Garçon F, Bismuth G, Isnardon D, Olive D, Nunès JA. Tec Kinase Migrates to the T Cell-APC Interface Independently of Its Pleckstrin Homology Domain. J Immunol 2004; 173:770-5. [PMID: 15240663 DOI: 10.4049/jimmunol.173.2.770] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tec is the prototypical member of the Tec tyrosine kinases family, which plays an important role in T cell signaling. We show in this study that Tec translocates to the immunological synapse when a T cell contacts a dendritic cell. Surprisingly, the presence of the pleckstrin homology (PH) domain of Tec is not required for this accumulation, and despite a strong activation of 3'-phosphorylated phosphoinositide lipids synthesis during the synapse formation, the Tec PH domain is not redistributed to the T cell plasma membrane. In contrast, we demonstrate that an active Src homology 3 domain is absolutely required, underlining the essential role played by this part of the molecule in the recruitment and/or stabilization of Tec at the immunological synapse. Our results nevertheless suggest that the PH domain controls the kinase activity of the molecule in vivo. We finally demonstrate that the two domains are necessary to trigger transcriptional events following Ag presentation. These data support a model in which the plasma membrane recruitment of the PH-containing protein Tec is not dependent on the production of 3'-phosphorylated phosphoinositide lipids by the PI3K, but rather on an intact Src homology 3 domain.
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Affiliation(s)
- Fabien Garçon
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 599, Université de la Méditerranée, Marseille, France
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Garçon F, Ghiotto M, Gérard A, Yang WC, Olive D, Nunès JA. The SH3 domain of Tec kinase is essential for its targeting to activated CD28 costimulatory molecule. Eur J Immunol 2004; 34:1972-80. [PMID: 15214045 DOI: 10.1002/eji.200324777] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Tec family of protein tyrosine kinases plays an important role in T cell signaling. Tec, the prototypical member of this kinase family, can interact with CD28, which is a costimulatory molecule. However, the regulation of Tec upon CD28 stimulation remains poorly understood. Here we show that CD28-B7-mediated interactions are likely involved in the relocalization of Tec at the contact zone between T cells and APC. Upon CD28 ligation with specific antibodies or natural ligands, Tec translocates to the plasma membrane where it colocalizes with the CD28 molecule. The Src-homology 3(SH3) domain of Tec and the two proline-rich motifs of CD28 are involved in this process. Furthermore, we show that CD28 signaling requires the SH3 domain of Tec as well as proline residues present in the intracytoplasmic tail of CD28. These results should provide new insights into the complex regulation of Tec kinases in T cells.
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Affiliation(s)
- Fabien Garçon
- INSERM UMR 599, Equipe labellisée 2001 par la Ligue Nationale contre le Cancer, Université de la Méditerranée, Marseille, France
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Gérard A, Favre C, Garçon F, Némorin JG, Duplay P, Pastor S, Collette Y, Olive D, Nunès JA. Functional interaction of RasGAP-binding proteins Dok-1 and Dok-2 with the Tec protein tyrosine kinase. Oncogene 2003; 23:1594-8. [PMID: 14647425 DOI: 10.1038/sj.onc.1207283] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Dok adaptor family of proteins binding to RasGAP, consisting of Dok-1 and Dok-2, are critical regulators in cell proliferation. These molecules are partners and/or substrates of different protein tyrosine kinases considered as oncoproteins. Here, we show that Dok-1 and Dok-2 are the major tyrosine-phosphorylated proteins associated to Tec, a protein tyrosine kinase expressed in T cells. Furthermore, we evaluate the effect of Dok-1 or Dok-2 on Tec-mediated signalling pathways in T cells. Here, we provide evidence that Dok-1 and Dok-2 proteins are involved in a negative feedback regulation of Tec via a downregulation of its tyrosine phosphorylation and downstream signalling pathways including the Ras pathway. Either Dok-1 or Dok-2 therefore represents a mean of potent retrograde control for protein tyrosine kinase signalling, and then possibly of tumor development.
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Affiliation(s)
- Audrey Gérard
- U119 INSERM, Institut de Cancérologie et d'Immunologie de Marseille, Université de la Méditerranée, 27 Bd Leï Roure, Marseille F-13009, France
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