Neetu Gupta, Ph.D.
Assistant Staff

Neetu Gupta, Ph.D.

Assistant Staff

  • Department of Immunology
  • Lerner Research Institute (NB30)
  • The Cleveland Clinic Foundation
  • 9500 Euclid Avenue
  • Cleveland, Ohio 44195
  • (216) 444-7455
  • (216) 444-9329

Other Academic Affiliations

  • Assistant Professor, Cleveland Clinic Lerner College of Medicine of CWRU
  • Trainer, Immunology Training Program, Department of Pathology, CWRU
  • Adjunct Faculty, BGES, Cleveland State University
  • Associate Member, Case Comprehensive Cancer Center

Areas of General Research Interest

Lymphocyte activation; Signal transduction; Membrane-cytoskeletal dynamics; Lymphoma/Leukemia; Autoimmunity.

Current program

  • Antigen receptor signaling at the membrane-cytoskeletal interface in B cells.

OVERVIEW OF RESEARCH

The B cell antigen receptor (BCR) serves key roles in directing the activation of B cells that make antibodies reactive to foreign agents such as pathogens, tumors and transplants, and also in preventing B cells from making antibodies reactive to its own self. Underactive or overactive B cells are often associated with immunodeficiency, cancer and autoimmune disorders. B cell immune response involves communication of signals from the cell’s surface to its core, the nucleus, where gene expression occurs. Simultaneous rearrangement of the B cell membrane and the underlying actin cytoskeleton facilitates dynamic recruitment of key signaling components into signalosomes at the cell surface. An understanding of the molecular mechanisms of antigen receptor signaling are critical for design of better vaccines against infectious agents as well as identification of therapeutic targets in autoimmunity and cancer. In order to probe the molecular mechanisms of B cell activation, we employ a mixture of cutting edge technologies including high definition live cell imaging, intravital in situ imaging, quantitative proteomics, transgenic/knockout mice, as well as standard biochemistry and molecular biology methods.


RECENT FINDINGS

We have demonstrated that BCR cross-linking induces fusion of nanoscale membrane raft units to generate patches that ultimately coalesce into stable, micron-sized rafts. Using systems biology and live cell imaging, we identified ezrin, a member of the ezrin-radixin-moesin (ERM) family, as a regulator of antigen-induced lipid raft coalescence via a conformational switch in its structure. The conformational inactivation occurs upon antigen-induced dephosphorylation of ezrin at the conserved threonine residue in its actin-binding domain.

Using scanning electron microscopy and total internal reflection microscopy (TIRF), we have further shown that a transient switch in the conformation of ezrin from active to dormant is a critical trigger that initiates morphological changes associated with cell polarization, and regulates B cell migration.

Ezrin can also potentially participate in signal transduction via an adaptor function. We have observed that BCR stimulation induces phosphorylation of ezrin on unconserved tyrosine residues, and that mutation of these residues impairs specific signaling pathways in B cell activation. Our data suggest that ezrin has a unique role in antigen-induced signal transduction.

ONGOING RESEARCH DIRECTIONS

We are currently engaged in structure-function analysis of ezrin through in vitro biochemistry and transgenic mouse modeling, as well as high definition live cell imaging. We are also interested in exploring the role of unconventional myosins in B cell development and activation.

Investigators

  • Neetha Parameswaran, Ph.D., Postdoctoral Fellow
  • Debasis Pore, Ph.D., Postdoctoral Fellow
  • Gospel Enyindah-Asonye, Molecular Medicine Graduate Student

Collaborators

  • Andrea McClatchey, Ph.D., Harvard University
  • Sarah Veatch, Ph.D., University of Michigan
  • Bernd Wollscheid, Ph.D., Swiss Federal Research Institute, Zurich
  • Alex Huang, M.D., Ph.D., Case Western Reserve University
  • Gospel Enyindah-Asonye
  • Molecular Medicine Student
  • Location:NE4-253
  • enyindg@ccf.org
  • (216) 445-4064
  • Neetha Parameswaran Ph.D.
  • Post Doctoral Research Fellow
  • Location:NE4-253A
  • paramen@ccf.org
  • (216) 445-4064
  • (216) 444-9329
  • Debasis Pore Ph.D.
  • Postdoctoral Fellow
  • Location:NE4-253
  • pored@ccf.org
  • (216) 445-4064
  • Hannah Wang
  • Medical Student
  • Location:NE4-253A
  • wangh@ccf.org
  • (626) 215-7430

click on picture for zoom out


Selected Recent Publications

•  Gupta, N., and DeFranco, A.L. 2003. Visualizing lipid raft dynamics and early signaling events during antigen receptor-mediated B cell activation. Mol. Biol. Cell. 14:432-44 .

•  Gupta, N., Wollscheid, B., Watts, J., Scheer, B., Aebersold, R.A., and DeFranco, A.L. 2006. Quantitative proteomic analysis of B cell lipid rafts reveals a role for ezrin in the regulation of antigen receptor-mediated lipid raft dynamics. Nat. Immunol. 7:625-633 .

•  Parameswaran, N., Matsui, K., and Gupta, N. 2011. Conformational switching in ezrin regulates chemokine-induced morphological and cytoskeletal changes required for B cell migration. J. Immunol. 186:4088-4097 . PMCID: PMC3106416

•  Matsui, K., Parameswaran, N., Bagheri, N., Willard, B., and Gupta, N. 2011. Proteomics analysis of the ezrin interactome in B cells reveals a novel association with Myo18a a . J. Proteome Res. 10:3983-3992 . PMCID: PMC3181492

•  Kish, D.D., Gorbachev, A.V., Parameswaran, N., Gupta, N., and Fairchild, R.F. 2012. Neutrophil expression of FasL and perforin directs effector CD8 T cell infiltration into antigen-challenged skin. J. Immunol. 189:2191-2202 . PMCID: PMC3424302.

•  Parameswaran, N., Enyindah-Asonye, G., Liggett, L., Shah, N., Bagheri, N., and Gupta, N. 2013. Spatial coupling of JNK activation to the B cell antigen receptor by tyrosine-phosphorylated ezrin. J. Immunol. 190:2017-2026 .

 

Invited review articles

1.   Gupta, N., and DeFranco AL. 2007. Review: Lipid rafts and B cell signaling. Semin. Cell Dev. Biol. 18:616-626 .

2.   Viola, A., and Gupta, N. 2007. Review: Tether and Trap: Regulation of membrane raft dynamics by actin-binding proteins. Nat. Rev. Immunol. 7:889-896.

 

Book Chapters

Neetu Gupta, Anthony L. DeFranco, and Arthur Weiss. Signal transduction by T and B lymphocyte antigen receptors. In Primary Immunodeficiency Diseases, a Molecular and Genetic Approach, 2nd Edition, H. D. Ochs, C. I. E. Smith, and J. Puck, eds ., Oxford Press, Oxford, UK. 2007 .