ROLE OF ION CHANNELS IN MONONUCLEAR PHAGOCYTE ACTIVATION

单核巨噬细胞表面免疫球蛋白Fc受体的结合 引发了大量的细胞反应，包括颗粒摄入， 分泌和呼吸爆发活动，所有这些都是 这些细胞的抗菌活性。 细胞通过这种机制 在免疫系统内将配体结合到特定的膜上 受体转化为内部信息， 仍不清楚 这一建议的目的是扩大我们的 肺泡巨噬细胞的电生理研究，研究 配体和电压依赖性离子通道在细胞内的作用 用细胞外膜片钳激活单核吞噬细胞 记录技术 在这项技术中，玻璃移液管是密封的， 一种允许人们控制一小片膜上电压的细胞 2-5 Mum2的面积，从而测量通过个体的电流 由于配体结合而打开的膜通道， 膜电压，或离子种类浓度的变化， 膜的一个表面。 我们初步确定了两个 电压依赖性K+选择性通道的群体，两者都是 存在于未活化的巨噬细胞膜中。 实验将 旨在研究两种电导率中较大者的Ca ++依赖性， 通道，试图确定该通道是否是无处不在的 Ca~（++）依赖性K~（++）通道的活性以及该通道的活性是否受 在吞噬反应期间增加。 我们将研究 已知影响巨噬细胞形态和活化的局部麻醉剂 K+通道门控。 我们将继续调查 IgG依赖性离子通道，我们已经在初步的 研究，特别是解决其Ca ++渗透性的问题， 以及其开放态的Ca~（++）和电压依赖性。 我们将研究 使用多种Fc受体配体的反应的特异性， 反应的多价性， 由已知的IgG寡聚体形式引起。 我们将使用电力 对IgG的反应作为评估γ-干扰素作用的生物测定， 单核细胞 我们将把当代与生物反应联系起来 比较诱发神经元损伤的药物的电生理学后果， 细胞活化以及去极化到那些只产生 细胞去极化，使用（1）C-反应蛋白（2）C3b片段 补体，（3）f-MLP和类似物，以及（4）PMA和类似物 单元格和单通道级别。

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.