The engagement of IG Fc receptors on the surface of mononuclear phagocytes triggers a number of cellular responses including particle ingestion, secretion, and respiratory burst activity all of which are integral part of the antimicrobial activity of these cells. The mechanism by which cells within the immune system translate ligand binding to specific membrane receptors into internal messages which direct phagocytosis or secretion remains unclear. It is the aim of this proposal to expand our electrophysiological investigations on the alveolar macrophage, studying the role of both ligand and voltage dependent ion channels in the activation of mononuclear phagocytes using extracellular patch clamp recording techniqus. In this technique, a glass pipette is sealed against a cell allowing one to control the voltage across a small patch of membrane 2-5 Mum2 in area and thereby measure the flow of current through individual membrane channels which open as a result of ligand binding, changes in membrane voltage, or changes in the concentration of an ionic species at one surface of the membrane. We have tentatively identified two populations of voltage dependent K+ selective channels both of which are present in the non-activated macrophage membrane. Experiments will be designed to study the Ca++ dependence of the larger of the two conductance channels in attempt to determine whether this channel is the ubiquitous Ca++ dependent K+ channel and whether the activity of this channel is increased during the phagocytic response. We will study the effects of local anesthetics known to effect both macrophage morphology and activation on K+ channel gating. We will continue our investigations of the IgG-dependent ion channel, which we have characterized in preliminary studies, specifically addressing the question of its Ca++ permeability as well as the Ca++ and voltage dependence of its open state. We will examine the specificity of the reaction using a variety of Fc receptor ligands and the multivalent nature of the response looking at current activation elicited by known oligomeric forms of IgG. We will use the electrical response to IgG as a bioassay to assess the action of Gamma-interferon on monocytes. We will relate current generation to biological response comparing the electrophysiological consequences of agents which induce cellular activation as well as depolarization to those producing only cellular depolarization, using (1) C-reactive protein (2) C3b fragment of complement, (3) f-MLP and analogs and (4) PMA and analogs at both whole cell and single channel level.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM036823-05
Application #
3291369
Study Section
Allergy and Immunology Study Section (ALY)
Project Start
1986-07-01
Project End
1992-06-30
Budget Start
1990-07-01
Budget End
1992-06-30
Support Year
5
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Chicago
Department
Type
Schools of Medicine
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
Meijer, Laurent; Nelson, Deborah J; Riazanski, Vladimir et al. (2016) Modulating Innate and Adaptive Immunity by (R)-Roscovitine: Potential Therapeutic Opportunity in Cystic Fibrosis. J Innate Immun 8:330-49
Riazanski, Vladimir; Gabdoulkhakova, Aida G; Boynton, Lin S et al. (2015) TRPC6 channel translocation into phagosomal membrane augments phagosomal function. Proc Natl Acad Sci U S A 112:E6486-95
Domingue, Jada C; Ao, Mei; Sarathy, Jayashree et al. (2014) HEK-293 cells expressing the cystic fibrosis transmembrane conductance regulator (CFTR): a model for studying regulation of Cl- transport. Physiol Rep 2:
Farmer, Laurel M; Le, Brandy N; Nelson, Deborah J (2013) CLC-3 chloride channels moderate long-term potentiation at Schaffer collateral-CA1 synapses. J Physiol 591:1001-15
Riazanski, Vladimir; Deriy, Ludmila V; Shevchenko, Pavel D et al. (2011) Presynaptic CLC-3 determines quantal size of inhibitory transmission in the hippocampus. Nat Neurosci 14:487-94
Deriy, Ludmila V; Gomez, Erwin A; Jacobson, David A et al. (2009) The granular chloride channel ClC-3 is permissive for insulin secretion. Cell Metab 10:316-23
Deriy, Ludmila V; Gomez, Erwin A; Zhang, Guangping et al. (2009) Disease-causing mutations in the cystic fibrosis transmembrane conductance regulator determine the functional responses of alveolar macrophages. J Biol Chem 284:35926-38
Mitchell, Jennifer; Wang, Xueqing; Zhang, Guangping et al. (2008) An expanded biological repertoire for Ins(3,4,5,6)P4 through its modulation of ClC-3 function. Curr Biol 18:1600-5
Di, Anke; Brown, Mary E; Deriy, Ludmila V et al. (2006) CFTR regulates phagosome acidification in macrophages and alters bactericidal activity. Nat Cell Biol 8:933-44
Wang, Xue Qing; Deriy, Ludmila V; Foss, Sarah et al. (2006) CLC-3 channels modulate excitatory synaptic transmission in hippocampal neurons. Neuron 52:321-33

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