INTERACTION OF HUMAN NEUTROPHILS WITH OXIDIZED CHEMOTACTIC PEPTIDE

继续与Robert Aksamit博士进行合作研究， 化学制备趋化肽的氧化衍生物， F-met-leu-phe：F-met-leu-phe亚砜和F-met-leu-phe砜。在 先前的研究表明，氧化的F-met-leu-phe衍生物结合 并激活中性粒细胞的氧化代谢爆发 而不激活趋化性，表明这些修饰的肽可以 是探索中性粒细胞功能激活的有用探针。我们 还将这些氧化衍生物用于一系列酶释放 测定氧化衍生物是否会活化 中性粒细胞溶酶体酶释放。我们定量了 溶菌酶、弹性蛋白酶、髓过氧化物酶、β-葡萄糖醛酸酶和乳铁蛋白， 并观察到氧化衍生物刺激了这些 中性粒细胞的酶。它们激活酶的相对效力 释放与其结合亲和力相关：母体>砜> 亚砜进行了额外的研究，以评价 这些肽对中性粒细胞定向、内吞作用和 细胞骨架F-肌动蛋白聚合。在这些测定中的每一个中，氧化的 肽-是中性粒细胞活化的有效刺激物。研究正在 放射性标记的氧化衍生物的进展，以确定是否 氧化衍生物与N-甲酰基的高或低亲和态结合 肽受体的纯化中性粒细胞质膜。其他研究 也在进行中，以确定是否氧化衍生物的 F-met-leu-phe的加工或再循环方式与母体形式不同， 中性粒细胞释放肽。这些研究将提供重要的新 关于激活的信号处理要求的信息 中性粒细胞

A collaborative study was continued with Dr. Robert Aksamit in which we chemically prepared the oxidized derivatives of the chemotactic peptide, F-met-leu-phe: F-met-leu-phe sulfoxide and F-met-leu-phe sulfone. In previous studies we have shown that oxidized F-met-leu-phe derivatives bind to neutrophils and activate the oxidative metabolic burst of neutrophils without activating chemotaxis, indicating that these modified peptides may be useful probes for exploring the activation of neutrophil function. We have also used these oxidized derivatives in a series of enzyme release assays to determine whether the oxidized derivatives would activate neutrophil lysosomal enzyme release. We quantitated the release of lysozyme, elastase, myeloperoxidase, beta-glucuronidase, and lactoferrin, and observed that the oxidized derivatives stimulated the release of these enzymes from neutrophils. Their relative potency in activation of enzyme release correlated with their binding affinities: parent> sulfone> sulfoxide. Additional studies were performed to evaluate the effects of these peptides on neutrophil orientation, endocytosis, and activation of cytoskeletal F-actin polymerization. In each of these assays, the oxidized peptides-were potent stimuli for neutrophil activation. Studies are in progress with radiolabeled oxidized derivatives to determine whether the oxidized derivatives bind to the high or low affinity states of N-formyl peptide receptors on purified neutrophil plasma membranes. Other studies are also in progress to-determine whether the oxidized derivatives of F-met-leu-phe are processed or recycled differently than the parent form of the peptide by neutrophils. These studies should provide significant new information about the requirements for signal processing by activated neutrophils.