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Abstract
Phagocytosis refers to the active process that allows cells to take up large particulate material upon binding to surface receptors. The discovery of phagocytosis in 1883 by Elie Metchnikoff, leading to the concept that specialized cells are implicated in the defense against microbes, was one of the starting points of the field of immunology. After more than a century of research, phagocytosis is now appreciated to be a widely used process that enables the cellular uptake of a remarkable variety of particles, including bacteria, fungi, parasites, viruses, dead cells, and assorted debris and solid materials. Uptake of foreign particles is performed almost exclusively by specialized myeloid cells, commonly termed "professional phagocytes": neutrophils, monocytes, macrophages, and dendritic cells. Phagocytosis of microbes not only stops or at least restricts the spread of infection but also plays an important role in regulating the innate and adaptive immune responses. Activation of the myeloid cells upon phagocytosis leads to the secretion of cytokines and chemokines that convey signals to a variety of immune cells. Moreover, foreign antigens generated by the degradation of microbes following phagocytosis are loaded onto the major histocompatibility complex for presentation to specific T lymphocytes. However, phagocytosis is not restricted to professional myeloid phagocytes; an expanding diversity of cell types appear capable of engulfing apoptotic bodies and debris, playing a critical role in tissue remodeling and in the clearance of billions of effete cells every day.
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Mukhopadhyay H, de Wet B, Clemens L, Maini PK, Allard J, van der Merwe PA, Dushek O. Multisite Phosphorylation Modulates the T Cell Receptor ζ-Chain Potency but not the Switchlike Response. Biophys J 2017; 110:1896-1906. [PMID: 27119648 PMCID: PMC4850346 DOI: 10.1016/j.bpj.2016.03.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/08/2016] [Accepted: 03/15/2016] [Indexed: 11/17/2022] Open
Abstract
Multisite phosphorylation is ubiquitous in cellular signaling and is thought to provide signaling proteins with additional regulatory mechanisms. Indeed, mathematical models have revealed a large number of mechanisms by which multisite phosphorylation can produce switchlike responses. The T cell antigen receptor (TCR) is a multisubunit receptor on the surface of T cells that is a prototypical multisite substrate as it contains 20 sites that are distributed on 10 conserved immunoreceptor tyrosine-based activation motifs (ITAMs). The TCR ζ-chain is a homodimer subunit that contains six ITAMs (12 sites) and exhibits a number of properties that are predicted to be sufficient for a switchlike response. We have used cellular reconstitution to systematically study multisite phosphorylation of the TCR ζ-chain. We find that multisite phosphorylation proceeds by a nonsequential random mechanism, and find no evidence that multiple ITAMs modulate a switchlike response but do find that they alter receptor potency and maximum phosphorylation. Modulation of receptor potency can be explained by a reduction in molecular entropy of the disordered ζ-chain upon phosphorylation. We further find that the tyrosine kinase ZAP-70 increases receptor potency but does not modulate the switchlike response. In contrast to other multisite proteins, where phosphorylations act in strong concert to modulate protein function, we suggest that the multiple ITAMs on the TCR function mainly to amplify subsequent signaling.
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Affiliation(s)
- Himadri Mukhopadhyay
- Sir William Dunn School of Pathology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom
| | - Ben de Wet
- Sir William Dunn School of Pathology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom
| | - Lara Clemens
- Department of Mathematics, University of California-Irvine, Irvine, California
| | - Philip K Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom
| | - Jun Allard
- Department of Mathematics, University of California-Irvine, Irvine, California
| | - P Anton van der Merwe
- Sir William Dunn School of Pathology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom.
| | - Omer Dushek
- Sir William Dunn School of Pathology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom; Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxfordshire, United Kingdom.
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53
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CARs: Synthetic Immunoreceptors for Cancer Therapy and Beyond. Trends Mol Med 2017; 23:430-450. [PMID: 28416139 DOI: 10.1016/j.molmed.2017.03.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
Chimeric antigen receptors (CARs) are versatile synthetic receptors that provide T cells with engineered specificity. Clinical success in treating B-cell malignancies has demonstrated the therapeutic potential of CAR-T cells against cancer, and efforts are underway to expand the use of engineered T cells to the treatment of diverse medical conditions, including infections and autoimmune diseases. Here, we review current understanding of the molecular properties of CARs, how this knowledge informs the rational design and characterization of novel receptors, the successes and shortcomings of CAR-T cells in the clinic, and emerging solutions for the continued improvement of CAR-T cell therapy.
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Irving M, Vuillefroy de Silly R, Scholten K, Dilek N, Coukos G. Engineering Chimeric Antigen Receptor T-Cells for Racing in Solid Tumors: Don't Forget the Fuel. Front Immunol 2017; 8:267. [PMID: 28421069 PMCID: PMC5376574 DOI: 10.3389/fimmu.2017.00267] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 02/23/2017] [Indexed: 12/20/2022] Open
Abstract
T-cells play a critical role in tumor immunity. Indeed, the presence of tumor-infiltrating lymphocytes is a predictor of favorable patient prognosis for many indications and is a requirement for responsiveness to immune checkpoint blockade therapy targeting programmed cell death 1. For tumors lacking immune infiltrate, or for which antigen processing and/or presentation has been downregulated, a promising immunotherapeutic approach is chimeric antigen receptor (CAR) T-cell therapy. CARs are hybrid receptors that link the tumor antigen specificity and affinity of an antibody-derived single-chain variable fragment with signaling endodomains associated with T-cell activation. CAR therapy targeting CD19 has yielded extraordinary clinical responses against some hematological tumors. Solid tumors, however, remain an important challenge to CAR T-cells due to issues of homing, tumor vasculature and stromal barriers, and a range of obstacles in the tumor bed. Protumoral immune infiltrate including T regulatory cells and myeloid-derived suppressor cells have been well characterized for their ability to upregulate inhibitory receptors and molecules that hinder effector T-cells. A critical role for metabolic barriers in the tumor microenvironment (TME) is emerging. High glucose consumption and competition for key amino acids by tumor cells can leave T-cells with insufficient energy and biosynthetic precursors to support activities such as cytokine secretion and lead to a phenotypic state of anergy or exhaustion. CAR T-cell expansion protocols that promote a less differentiated phenotype, combined with optimal receptor design and coengineering strategies, along with immunomodulatory therapies that also promote endogenous immunity, offer great promise in surmounting immunometabolic barriers in the TME and curing solid tumors.
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Affiliation(s)
- Melita Irving
- The Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | | | - Kirsten Scholten
- The Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | - Nahzli Dilek
- Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - George Coukos
- The Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland.,Department of Oncology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
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Stone MB, Shelby SA, Núñez MF, Wisser K, Veatch SL. Protein sorting by lipid phase-like domains supports emergent signaling function in B lymphocyte plasma membranes. eLife 2017; 6. [PMID: 28145867 PMCID: PMC5373823 DOI: 10.7554/elife.19891] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/31/2017] [Indexed: 12/19/2022] Open
Abstract
Diverse cellular signaling events, including B cell receptor (BCR) activation, are hypothesized to be facilitated by domains enriched in specific plasma membrane lipids and proteins that resemble liquid-ordered phase-separated domains in model membranes. This concept remains controversial and lacks direct experimental support in intact cells. Here, we visualize ordered and disordered domains in mouse B lymphoma cell membranes using super-resolution fluorescence localization microscopy, demonstrate that clustered BCR resides within ordered phase-like domains capable of sorting key regulators of BCR activation, and present a minimal, predictive model where clustering receptors leads to their collective activation by stabilizing an extended ordered domain. These results provide evidence for the role of membrane domains in BCR signaling and a plausible mechanism of BCR activation via receptor clustering that could be generalized to other signaling pathways. Overall, these studies demonstrate that lipid mediated forces can bias biochemical networks in ways that broadly impact signal transduction. DOI:http://dx.doi.org/10.7554/eLife.19891.001 Membranes made of molecules called lipids surround every living cell to protect the cell's contents. Cells also communicate with the outside environment via their membranes. Proteins in the membrane receive information from the environment and trigger signaling pathways inside the cell to relay this information to the center of cell. The way in which proteins are organized on the membrane has a major influence on their signaling activity. Some areas of the membrane are more crowded with certain lipids and signaling proteins than others. Lipid and protein molecules of particular types can come together and form distinct areas called “ordered” and “disordered” domains. The lipids in ordered domains are more tightly packed than disordered domains and it is thought that this difference allows domains to selectively exclude or include certain proteins. Ordered domains are also known as "lipid rafts". Lipid rafts and disordered domains may help cells to control the activities of signaling pathways, however, technical limitations have made it difficult to study the roles of these domains. The membranes surrounding immune cells called B cells contain a protein called the B cell receptor, which engages with proteins from microbes and other foreign invaders. When the B cell receptor binds to a foreign protein it forms clusters with other B cell receptors and becomes active, triggering a signaling pathway that leads to immune responses. Stone, Shelby et al. examined lipid rafts and disordered domains in B cells from mice using a technique called super-resolution fluorescence microscopy. The results show that clusters of B cell receptors are present within lipid rafts. These clusters made the lipid rafts larger and more stable. A protein that is needed during the early stages of B cell receptor signaling was also found in the same lipid rafts. Another protein that terminates signaling was excluded because it prefers disordered domains. Together, this provides a local environment in certain areas of the membrane that favors receptor activity and supports the subsequent immune response. Future work is needed to understand how cells control the make-up of lipids and proteins within their membranes, and how defects in this regulation can alter signaling activity and lead to disease. DOI:http://dx.doi.org/10.7554/eLife.19891.002
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Affiliation(s)
- Matthew B Stone
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Sarah A Shelby
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Marcos F Núñez
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Kathleen Wisser
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Sarah L Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, United States
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56
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A novel lectin from Artocarpus lingnanensis induces proliferation and Th1/Th2 cytokine secretion through CD45 signaling pathway in human T lymphocytes. J Nat Med 2017; 71:409-421. [DOI: 10.1007/s11418-017-1073-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/05/2017] [Indexed: 01/01/2023]
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57
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Kulemzin SV, Kuznetsova VV, Mamonkin M, Taranin AV, Gorchakov AA. Engineering Chimeric Antigen Receptors. Acta Naturae 2017; 9:6-14. [PMID: 28461969 PMCID: PMC5406655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Chimeric antigen receptors (CARs) are recombinant protein molecules that redirect cytotoxic lymphocytes toward malignant and other target cells. The high feasibility of manufacturing CAR-modified lymphocytes for the therapy of cancer has spurred the development and optimization of new CAR T cells directed against a broad range of target antigens. In this review, we describe the main structural and functional elements constituting a CAR, discuss the roles of these elements in modulating the anti-tumor activity of CAR T cells, and highlight alternative approaches to CAR engineering.
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Affiliation(s)
- S. V. Kulemzin
- Institute of Molecular and Cellular Biology, SB RAS, Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - V. V. Kuznetsova
- Institute of Molecular and Cellular Biology, SB RAS, Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - M. Mamonkin
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital and Houston Methodist Hospital, Houston, TX, USA
| | - A. V. Taranin
- Institute of Molecular and Cellular Biology, SB RAS, Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia ,Novosibirsk State University, Pirogova str. 2, Novosibirsk, 630090, Russia
| | - A. A. Gorchakov
- Institute of Molecular and Cellular Biology, SB RAS, Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia ,Novosibirsk State University, Pirogova str. 2, Novosibirsk, 630090, Russia
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58
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Dillard P, Pi F, Lellouch AC, Limozin L, Sengupta K. Nano-clustering of ligands on surrogate antigen presenting cells modulates T cell membrane adhesion and organization. Integr Biol (Camb) 2016; 8:287-301. [PMID: 26887857 DOI: 10.1039/c5ib00293a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We investigate the adhesion and molecular organization of the plasma membrane of T lymphocytes interacting with a surrogate antigen presenting cell comprising glass supported ordered arrays of antibody (α-CD3) nano-dots dispersed in a non-adhesive matrix of polyethylene glycol (PEG). The local membrane adhesion and topography, as well as the distribution of the T cell receptors (TCRs) and the kinase ZAP-70, are influenced by dot-geometry, whereas the cell spreading area is determined by the overall average density of the ligands rather than specific characteristics of the dots. TCR clusters are recruited preferentially to the nano-dots and the TCR cluster size distribution has a weak dot-size dependence. On the patterns, the clusters are larger, more numerous, and more enriched in TCRs, as compared to the homogeneously distributed ligands at comparable concentrations. These observations support the idea that non-ligated TCRs residing in the non-adhered parts of the proximal membrane are able to diffuse and enrich the existing clusters at the ligand dots. However, long distance transport is impaired and cluster centralization in the form of a central supramolecular cluster (cSMAC) is not observed. Time-lapse imaging of early cell-surface contacts indicates that the ZAP-70 microclusters are directly recruited to the site of the antibody dots and this process is concomitant with membrane adhesion. These results together point to a complex interplay of adhesion, molecular organization and activation in response to spatially modulated stimulation.
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Affiliation(s)
- Pierre Dillard
- Aix-Marseille Université, CNRS, CINaM-UMR 7325, Marseille, 13288, France. and Laboratoire Adhésion & Inflammation Aix-Marseille Université\Inserm U1067\CNRS-UMR7333, Marseille 13288, France.
| | - Fuwei Pi
- Aix-Marseille Université, CNRS, CINaM-UMR 7325, Marseille, 13288, France.
| | - Annemarie C Lellouch
- Laboratoire Adhésion & Inflammation Aix-Marseille Université\Inserm U1067\CNRS-UMR7333, Marseille 13288, France.
| | - Laurent Limozin
- Laboratoire Adhésion & Inflammation Aix-Marseille Université\Inserm U1067\CNRS-UMR7333, Marseille 13288, France.
| | - Kheya Sengupta
- Aix-Marseille Université, CNRS, CINaM-UMR 7325, Marseille, 13288, France.
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59
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Biswas KH, Groves JT. A Microbead Supported Membrane-Based Fluorescence Imaging Assay Reveals Intermembrane Receptor-Ligand Complex Dimension with Nanometer Precision. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6775-6780. [PMID: 27264296 DOI: 10.1021/acs.langmuir.6b01377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Receptor-ligand complexes spanning a cell-cell interface inevitably establish a preferred intermembrane spacing based on the molecular dimensions and orientation of the complexes. This couples molecular binding events to membrane mechanics and large-scale spatial organization of receptors on the cell surface. Here, we describe a straightforward, epi-fluorescence-based method to precisely determine intermembrane receptor-ligand dimension at adhesions established by receptor-ligand binding between apposed membranes in vitro. Adhesions were reconstituted between planar and silica microbead supported membranes via specific interaction between cognate receptor/ligand pairs (EphA2/EphrinA1 and E-cadherin/anti-E-cadherin antibody). Epi-fluorescence imaging of the ligand enrichment zone in the supported membrane beneath the adhering microbead, combined with a simple geometrical interpretation, proves sufficient to estimate intermembrane receptor-ligand dimension with better than 1 nm precision. An advantage of this assay is that no specialized equipment or imaging methods are required.
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Affiliation(s)
- Kabir H Biswas
- Mechanobiology Institute, National University of Singapore , Singapore 117411, Singapore
| | - Jay T Groves
- Mechanobiology Institute, National University of Singapore , Singapore 117411, Singapore
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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60
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Schmid EM, Bakalar MH, Choudhuri K, Weichsel J, Ann H, Geissler PL, Dustin ML, Fletcher DA. Size-dependent protein segregation at membrane interfaces. NATURE PHYSICS 2016; 12:704-711. [PMID: 27980602 PMCID: PMC5152624 DOI: 10.1038/nphys3678] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 01/29/2016] [Indexed: 05/21/2023]
Abstract
Membrane interfaces formed at cell-cell junctions are associated with characteristic patterns of membrane protein organization, such as E-cadherin enrichment in epithelial junctional complexes and CD45 exclusion from the signaling foci of immunological synapses. To isolate the role of protein size in these processes, we reconstituted membrane interfaces in vitro using giant unilamellar vesicles decorated with synthetic binding and non-binding proteins. We show that size differences between binding and non-binding proteins can dramatically alter their organization at membrane interfaces in the absence of active contributions from the cytoskeleton, with as little as a ~5 nm increase in non-binding protein size driving its exclusion from the interface. Combining in vitro measurements with Monte Carlo simulations, we find that non-binding protein exclusion is also influenced by lateral crowding, binding protein affinity, and thermally-driven membrane height fluctuations that transiently limit access to the interface. This simple, sensitive, and highly effective means of passively segregating proteins has implications for signaling at cell-cell junctions and protein sorting at intracellular contact points between membrane-bound organelles.
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Affiliation(s)
- Eva M Schmid
- Department of Bioengineering, University of California, Berkeley, CA
| | - Matthew H Bakalar
- UC Berkeley / UC San Francisco Graduate Group in Bioengineering, Berkeley, CA
| | - Kaushik Choudhuri
- Skirball Institute, New York University School of Medicine, New York, NY
| | - Julian Weichsel
- Department of Chemistry, University of California, Berkeley, CA
| | - HyoungSook Ann
- Department of Bioengineering, University of California, Berkeley, CA
| | - Phillip L Geissler
- Department of Chemistry, University of California, Berkeley, CA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Michael L Dustin
- Skirball Institute, New York University School of Medicine, New York, NY
- Kennedy Institute, NDORMS, University of Oxford, Oxford, UK
| | - Daniel A Fletcher
- Department of Bioengineering, University of California, Berkeley, CA
- UC Berkeley / UC San Francisco Graduate Group in Bioengineering, Berkeley, CA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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61
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Freeman SA, Goyette J, Furuya W, Woods EC, Bertozzi CR, Bergmeier W, Hinz B, van der Merwe PA, Das R, Grinstein S. Integrins Form an Expanding Diffusional Barrier that Coordinates Phagocytosis. Cell 2016; 164:128-140. [PMID: 26771488 DOI: 10.1016/j.cell.2015.11.048] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 09/07/2015] [Accepted: 11/14/2015] [Indexed: 01/12/2023]
Abstract
Phagocytosis is initiated by lateral clustering of receptors, which in turn activates Src-family kinases (SFKs). Activation of SFKs requires depletion of tyrosine phosphatases from the area of particle engagement. We investigated how the major phosphatase CD45 is excluded from contact sites, using single-molecule tracking. The mobility of CD45 increased markedly upon engagement of Fcγ receptors. While individual CD45 molecules moved randomly, they were displaced from the advancing phagocytic cup by an expanding diffusional barrier. By micropatterning IgG, the ligand of Fcγ receptors, we found that the barrier extended well beyond the perimeter of the receptor-ligand engagement zone. Second messengers generated by Fcγ receptors activated integrins, which formed an actin-tethered diffusion barrier that excluded CD45. The expanding integrin wave facilitates the zippering of Fcγ receptors onto the target and integrates the information from sparse receptor-ligand complexes, coordinating the progression and ultimate closure of the phagocytic cup.
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Affiliation(s)
- Spencer A Freeman
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Jesse Goyette
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Wendy Furuya
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Elliot C Woods
- Department of Chemistry and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-4401, USA
| | - Carolyn R Bertozzi
- Department of Chemistry and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305-4401, USA
| | - Wolfgang Bergmeier
- Department of Biochemistry and Biophysics, University of North Carolina, 120 Mason Farm Road, Chapel Hill, NC 27599-7260, USA
| | - Boris Hinz
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON M5S 3E2, Canada
| | | | - Raibatak Das
- Department of Integrative Biology, University of Colorado, Denver, CO 80217-3364, USA
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Keenan Research Centre, St. Michael's Hospital, Toronto, ON M5S 1T8, Canada.
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62
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Comrie WA, Burkhardt JK. Action and Traction: Cytoskeletal Control of Receptor Triggering at the Immunological Synapse. Front Immunol 2016; 7:68. [PMID: 27014258 PMCID: PMC4779853 DOI: 10.3389/fimmu.2016.00068] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/12/2016] [Indexed: 01/03/2023] Open
Abstract
It is well known that F-actin dynamics drive the micron-scale cell shape changes required for migration and immunological synapse (IS) formation. In addition, recent evidence points to a more intimate role for the actin cytoskeleton in promoting T cell activation. Mechanotransduction, the conversion of mechanical input into intracellular biochemical changes, is thought to play a critical role in several aspects of immunoreceptor triggering and downstream signal transduction. Multiple molecules associated with signaling events at the IS have been shown to respond to physical force, including the TCR, costimulatory molecules, adhesion molecules, and several downstream adapters. In at least some cases, it is clear that the relevant forces are exerted by dynamics of the T cell actomyosin cytoskeleton. Interestingly, there is evidence that the cytoskeleton of the antigen-presenting cell also plays an active role in T cell activation, by countering the molecular forces exerted by the T cell at the IS. Since actin polymerization is itself driven by TCR and costimulatory signaling pathways, a complex relationship exists between actin dynamics and receptor activation. This review will focus on recent advances in our understanding of the mechanosensitive aspects of T cell activation, paying specific attention to how F-actin-directed forces applied from both sides of the IS fit into current models of receptor triggering and activation.
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Affiliation(s)
- William A Comrie
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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63
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Gasparrini F, Feest C, Bruckbauer A, Mattila PK, Müller J, Nitschke L, Bray D, Batista FD. Nanoscale organization and dynamics of the siglec CD22 cooperate with the cytoskeleton in restraining BCR signalling. EMBO J 2016; 35:258-80. [PMID: 26671981 PMCID: PMC4741297 DOI: 10.15252/embj.201593027] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 11/09/2022] Open
Abstract
Receptor organization and dynamics at the cell membrane are important factors of signal transduction regulation. Using super-resolution microscopy and single-particle tracking, we show how the negative coreceptor CD22 works with the cortical cytoskeleton in restraining BCR signalling. In naïve B cells, we found endogenous CD22 to be highly mobile and organized into nanodomains. The landscape of CD22 and its lateral diffusion were perturbed either in the absence of CD45 or when the CD22 lectin domain was mutated. To understand how a relatively low number of CD22 molecules can keep BCR signalling in check, we generated Brownian dynamic simulations and supported them with ex vivo experiments. This combined approach suggests that the inhibitory function of CD22 is influenced by its nanoscale organization and is ensured by its fast diffusion enabling a "global BCR surveillance" at the plasma membrane.
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Affiliation(s)
| | - Christoph Feest
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London, UK
| | - Andreas Bruckbauer
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London, UK
| | - Pieta K Mattila
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London, UK
| | - Jennifer Müller
- Chair of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Lars Nitschke
- Chair of Genetics, Department of Biology, University of Erlangen, Erlangen, Germany
| | - Dennis Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Facundo D Batista
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London, UK
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64
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Srivastava S, Riddell SR. Engineering CAR-T cells: Design concepts. Trends Immunol 2015; 36:494-502. [PMID: 26169254 DOI: 10.1016/j.it.2015.06.004] [Citation(s) in RCA: 306] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/19/2015] [Accepted: 06/19/2015] [Indexed: 12/31/2022]
Abstract
Despite being empirically designed based on a simple understanding of TCR signaling, T cells engineered with chimeric antigen receptors (CARs) have been remarkably successful in treating patients with advanced refractory B cell malignancies. However, many challenges remain in improving the safety and efficacy of this therapy and extending it toward the treatment of epithelial cancers. Other aspects of TCR signaling beyond those directly provided by CD3ζ and CD28 phosphorylation strongly influence a T cell's ability to differentiate and acquire full effector functions. Here, we discuss how the principles of TCR recognition, including spatial constraints, Kon/Koff rates, and synapse formation, along with in-depth analysis of CAR signaling might be applied to develop safer and more effective synthetic tumor targeting receptors.
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Affiliation(s)
- Shivani Srivastava
- Program in Immunology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA
| | - Stanley R Riddell
- Program in Immunology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109, USA.
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65
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Insights into the initiation of TCR signaling. Nat Immunol 2014; 15:798-807. [PMID: 25137454 DOI: 10.1038/ni.2940] [Citation(s) in RCA: 257] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 06/10/2014] [Indexed: 12/13/2022]
Abstract
The initiation of T cell antigen receptor signaling is a key step that can result in T cell activation and the orchestration of an adaptive immune response. Early events in T cell receptor signaling can distinguish between agonist and endogenous ligands with exquisite selectivity, and show extraordinary sensitivity to minute numbers of agonists in a sea of endogenous ligands. We review our current knowledge of models and crucial molecules that aim to provide a mechanistic explanation for these observations. Building on current understanding and a discussion of unresolved issues, we propose a molecular model for initiation of T cell receptor signaling that may serve as a useful guide for future studies.
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Gabaev I, Elbasani E, Ameres S, Steinbrück L, Stanton R, Döring M, Lenac Rovis T, Kalinke U, Jonjic S, Moosmann A, Messerle M. Expression of the human cytomegalovirus UL11 glycoprotein in viral infection and evaluation of its effect on virus-specific CD8 T cells. J Virol 2014; 88:14326-39. [PMID: 25275132 PMCID: PMC4249143 DOI: 10.1128/jvi.01691-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/25/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The human cytomegalovirus (CMV) UL11 open reading frame (ORF) encodes a putative type I transmembrane glycoprotein which displays remarkable amino acid sequence variability among different CMV isolates, suggesting that it represents an important virulence factor. In a previous study, we have shown that UL11 can interact with the cellular receptor tyrosine phosphatase CD45, which has a central role for signal transduction in T cells, and treatment of T cells with large amounts of a soluble UL11 protein inhibited their proliferation. In order to analyze UL11 expression in CMV-infected cells, we constructed CMV recombinants whose genomes either encode tagged UL11 versions or carry a stop mutation in the UL11 ORF. Moreover, we examined whether UL11 affects the function of virus-specific cytotoxic T lymphocytes (CTLs). We found that the UL11 ORF gives rise to several proteins due to both posttranslational modification and alternative translation initiation sites. Biotin labeling of surface proteins on infected cells indicated that only highly glycosylated UL11 forms are present at the plasma membrane, whereas less glycosylated UL11 forms were found in the endoplasmic reticulum. We did not find evidence of UL11 cleavage or secretion of a soluble UL11 version. Cocultivation of CTLs recognizing different CMV epitopes with fibroblasts infected with a UL11 deletion mutant or the parental strain revealed that under the conditions applied UL11 did not influence the activation of CMV-specific CD8 T cells. For further studies, we propose to investigate the interaction of UL11 with CD45 and the functional consequences in other immune cells expressing CD45. IMPORTANCE Human cytomegalovirus (CMV) belongs to those viruses that extensively interfere with the host immune response, yet the precise function of many putative immunomodulatory CMV proteins remains elusive. Previously, we have shown that the CMV UL11 protein interacts with the leukocyte common antigen CD45, a cellular receptor tyrosine phosphatase with a central role for signal transduction in T cells. Here, we examined the proteins expressed by the UL11 gene in CMV-infected cells and found that at least one form of UL11 is present at the cell surface, enabling it to interact with CD45 on immune cells. Surprisingly, CMV-expressed UL11 did not affect the activity of virus-specific CD8 T cells. This finding warrants investigation of the impact of UL11 on CD45 functions in other leukocyte subpopulations.
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Affiliation(s)
- Ildar Gabaev
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Endrit Elbasani
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Stefanie Ameres
- Clinical Cooperation Group Immunooncology, Helmholtz Centre Munich, Munich, Germany
| | - Lars Steinbrück
- Department of Virology, Hannover Medical School, Hannover, Germany
| | - Richard Stanton
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Marius Döring
- Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
| | - Tihana Lenac Rovis
- Department of Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Ulrich Kalinke
- Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
| | - Stipan Jonjic
- Department of Histology and Embryology and Center for Proteomics, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Andreas Moosmann
- Clinical Cooperation Group Immunooncology, Helmholtz Centre Munich, Munich, Germany German Center for Infection Research (DZIF), partner sites, Hannover and Munich, Germany
| | - Martin Messerle
- Department of Virology, Hannover Medical School, Hannover, Germany German Center for Infection Research (DZIF), partner sites, Hannover and Munich, Germany
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Ballek O, Valečka J, Manning J, Filipp D. The pool of preactivated Lck in the initiation of T-cell signaling: a critical re-evaluation of the Lck standby model. Immunol Cell Biol 2014; 93:384-95. [PMID: 25420722 DOI: 10.1038/icb.2014.100] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 12/23/2022]
Abstract
The initiation of T-cell receptor (TCR) signaling, based on the cobinding of TCR and CD4-Lck heterodimer to a peptide-major histocompatibility complex II on antigen presenting cells, represents a classical model of T-cell signaling. What is less clear however, is the mechanism which translates TCR engagement to the phosphorylation of immunoreceptor tyrosine-based activation motifs on CD3 chains and how this event is coupled to the delivery of Lck function. Recently proposed 'standby model of Lck' posits that resting T-cells contain an abundant pool of constitutively active Lck (pY394(Lck)) required for TCR triggering, and this amount, upon TCR engagement, remains constant. Here, we show that although maintenance of the limited pool of pY394(Lck) is necessary for the generation of TCR proximal signals in a time-restricted fashion, the total amount of this pool, ~2%, is much smaller than previously reported (~40%). We provide evidence that this dramatic discrepancy in the content of pY394(Lck)is likely the consequence of spontaneous phosphorylation of Lck that occurred after cell solubilization. Additional discrepancies can be accounted for by the sensitivity of different pY394(Lck)-specific antibodies and the type of detergents used. These data suggest that reagents and conditions used for the quantification of signaling parameters must be carefully validated and interpreted. Thus, the limited size of pY394(Lck) pool in primary T-cells invites a discussion regarding the adjustment of the quantitative parameters of the standby model of Lck and reevaluation of the mechanism by which this pool contributes to the generation of proximal TCR signaling.
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Affiliation(s)
- Ondřej Ballek
- 1] Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic [2] Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jan Valečka
- 1] Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic [2] Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jasper Manning
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic
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Abstract
The molecular interactions underlying regulation of the immune response take place in a nanoscale gap between T cells and antigen-presenting cells, termed the immunological synapse. If these interactions are regulated appropriately, the host is defended against a wide range of pathogens and deranged host cells. If these interactions are disregulated, the host is susceptible to pathogens or tumor escape at one extreme and autoimmunity at the other. Strategies targeting the synapse have helped to establish immunotherapy as a mainstream element in cancer treatment. This Masters' primer will cover the basics of the immunological synapse and some of the applications to tumor immunology.
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Affiliation(s)
- Michael L Dustin
- The Kennedy Institute of Rheumatology, Nuffield Department of Orthopedics, Rheumatology and Musculoskeletal Sciences, The University of Oxford, Headington, United Kingdom.
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69
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Clement M, Fornasa G, Loyau S, Morvan M, Andreata F, Guedj K, Khallou-Laschet J, Larghi P, Le Roux D, Bismuth G, Chiocchia G, Hivroz C, Newman DK, Nicoletti A, Caligiuri G. Upholding the T cell immune-regulatory function of CD31 inhibits the formation of T/B immunological synapses in vitro and attenuates the development of experimental autoimmune arthritis in vivo. J Autoimmun 2014; 56:23-33. [PMID: 25277651 DOI: 10.1016/j.jaut.2014.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 09/03/2014] [Accepted: 09/06/2014] [Indexed: 11/29/2022]
Abstract
CD31, a trans-homophilic inhibitory receptor expressed on both T- and B-lymphocytes, drives the mutual detachment of interacting leukocytes. Intriguingly, T cell CD31 molecules relocate to the immunological synapse (IS), where the T and B cells establish a stable interaction. Here, we show that intact CD31 molecules, which are able to drive an inhibitory signal, are concentrated at the periphery of the IS but are excluded from the center of the IS. At this site, were the cells establish the closest contact, the CD31 molecules are cleaved, and most of the extracellular portion of the protein, including the trans-homophilic binding sites, is shed from the cell surface. T cells lacking CD31 trans-homophilic binding sites easily establish stable interactions with B cells; at the opposite, CD31 signaling agonists inhibit T/B IS formation as well as the ensuing helper T cell activation and function. Confocal microscopy and flow cytometry analysis of experimental T/B IS shows that the T cell inhibitory effects of CD31 agonists depend on SHP-2 signaling, which reduces the phosphorylation of ZAP70. The analysis of synovial tissue biopsies from patients affected by rheumatoid arthritis showed that T cell CD31 molecules are excluded from the center of the T/B cell synapses in vivo. Interestingly, the administration of CD31 agonists in vivo significantly attenuated the development of the clinical signs of collagen-induced arthritis in DBA1/J mice. Altogether, our data indicate that the T cell co-inhibitory receptor CD31 prevents the formation of functional T/B immunological synapses and that therapeutic strategies aimed at sustaining CD31 signaling will attenuate the development of autoimmune responses in vivo.
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Affiliation(s)
- Marc Clement
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Giulia Fornasa
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Stéphane Loyau
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Marion Morvan
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Francesco Andreata
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Kevin Guedj
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Jamila Khallou-Laschet
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Paola Larghi
- Institut Curie, Section Recherche, Inserm U932, F-75005 Paris, France
| | - Delphine Le Roux
- Inserm U1016, Institut Cochin, F-75014 Paris, France; Centre National de la Recherche Scientifique, UMR8104, F-75014 Paris, France; Université Paris Descartes, Paris F-75014, France
| | - Georges Bismuth
- Inserm U1016, Institut Cochin, F-75014 Paris, France; Centre National de la Recherche Scientifique, UMR8104, F-75014 Paris, France; Université Paris Descartes, Paris F-75014, France
| | - Gilles Chiocchia
- Inserm U987, Faculté des Sciences de la Santé "Simone Veil", F-78180 Saint-Quentin-en-Yvelines, France; Laboratoire d'Excellence "Inflamex", F-75018 Paris, France; Université Versailles-Saint-Quentin, F-78180 Saint-Quentin-en-Yvelines, France
| | - Claire Hivroz
- Institut Curie, Section Recherche, Inserm U932, F-75005 Paris, France
| | - Debra K Newman
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | - Antonino Nicoletti
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France
| | - Giuseppina Caligiuri
- Institut National de la Santé et de la Recherche Médicale (Inserm), U1148, "Laboratory of Vascular Translational Science", F-75018 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, F-75018 Paris, France; Département Hospitalo-Universitaire DHU "FIRE", F-75018 Paris, France.
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70
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Jeon M, Zinn K. R3 receptor tyrosine phosphatases: conserved regulators of receptor tyrosine kinase signaling and tubular organ development. Semin Cell Dev Biol 2014; 37:119-26. [PMID: 25242281 DOI: 10.1016/j.semcdb.2014.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/04/2014] [Indexed: 12/25/2022]
Abstract
R3 receptor tyrosine phosphatases (RPTPs) are characterized by extracellular domains composed solely of long chains of fibronectin type III repeats, and by the presence of a single phosphatase domain. There are five proteins in mammals with this structure, two in Drosophila and one in Caenorhabditis elegans. R3 RPTPs are selective regulators of receptor tyrosine kinase (RTK) signaling, and a number of different RTKs have been shown to be direct targets for their phosphatase activities. Genetic studies in both invertebrate model systems and in mammals have shown that R3 RPTPs are essential for tubular organ development. They also have important functions during nervous system development. R3 RPTPs are likely to be tumor suppressors in a number of types of cancer.
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Affiliation(s)
- Mili Jeon
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States; Department of Molecular and Cellular Physiology and Structural Biology, Howard Hughes Medical Institute, Stanford School of Medicine, Palo Alto, CA 94305, United States
| | - Kai Zinn
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States.
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71
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Crites TJ, Padhan K, Muller J, Krogsgaard M, Gudla PR, Lockett SJ, Varma R. TCR Microclusters pre-exist and contain molecules necessary for TCR signal transduction. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 193:56-67. [PMID: 24860189 PMCID: PMC4096552 DOI: 10.4049/jimmunol.1400315] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
TCR-dependent signaling events have been observed to occur in TCR microclusters. We found that some TCR microclusters are present in unstimulated murine T cells, indicating that the mechanisms leading to microcluster formation do not require ligand binding. These pre-existing microclusters increase in absolute number following engagement by low-potency ligands. This increase is accompanied by an increase in cell spreading, with the result that the density of TCR microclusters on the surface of the T cell is not a strong function of ligand potency. In characterizing their composition, we observed a constant number of TCRs in a microcluster, constitutive exclusion of the phosphatase CD45, and preassociation with the signaling adapters linker for activation of T cells and growth factor receptor-bound protein 2. The existence of TCR microclusters prior to ligand binding in a state that is conducive for the initiation of downstream signaling could explain, in part, the rapid kinetics with which TCR signal transduction occurs.
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Affiliation(s)
- Travis J Crites
- Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Kartika Padhan
- Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - James Muller
- Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016; Department of Pathology, New York University School of Medicine, New York, NY 10026
| | - Michelle Krogsgaard
- Department of Pathology, New York University School of Medicine, New York, NY 10026; New York University Cancer Institute, New York University School of Medicine, New York, NY 10026; and
| | - Prabhakar R Gudla
- Optical Microscopy and Analysis Laboratory, Frederick National Laboratory for Cancer Research, Fort Detrick, Frederick, MD 21702
| | - Stephen J Lockett
- Optical Microscopy and Analysis Laboratory, Frederick National Laboratory for Cancer Research, Fort Detrick, Frederick, MD 21702
| | - Rajat Varma
- Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
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Tan YX, Zikherman J, Weiss A. Novel tools to dissect the dynamic regulation of TCR signaling by the kinase Csk and the phosphatase CD45. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2013; 78:131-139. [PMID: 24100586 DOI: 10.1101/sqb.2013.78.020347] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Although the biochemical events induced by T-cell receptor (TCR) triggering have been well studied, both the mediators and function of basal signaling in T cells remain poorly understood. Furthermore, the precise mechanisms by which MHC-peptide interaction with the TCR disrupt the basal equilibrium to induce downstream signaling are also unclear. Here we describe novel approaches to understand the basal state of T cells and the mechanisms of TCR triggering by perturbing regulation of the Src family kinases (SFKs). The SFKs are critical proximal mediators of TCR signaling that are in turn tightly regulated by the tyrosine kinase Csk and the receptor-like tyrosine phosphatase CD45. We have developed a small-molecule analog-sensitive allele of Csk and an allelic series of mice in which expression of CD45 is varied across a broad range. Our studies have unmasked contributions of Csk and CD45 to maintain the basal state of T cells and also suggest that dynamic regulation of Csk may be involved in TCR triggering.
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Affiliation(s)
- Ying Xim Tan
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA
| | - Julie Zikherman
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA
| | - Arthur Weiss
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA.,Howard Hughes Medical Institute, UCSF, San Francisco, CA, 94143, USA
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