ADHESION MOLECULE EXPRESSION DURING NEUTROPHIL CHEMOTAXIS

该项目的目标是确定人中性粒细胞(PMN) 中性粒细胞向中性粒细胞迁移后表面抗原表达的改变 炎症性刺激。我们之前已经证明了PMN的粘附性 中性粒细胞趋化后，分子表达明显下调。 本研究是为了检查PMN中发生的变化 氨基肽酶N(CD13)的表面分子表达及FCG 中性粒细胞体外趋化后的受体FcRII(CD32)和FcRIII(CD16)。 中性粒细胞的两个群体很容易识别和分开 体外聚碳酸酯膜趋化系统；一个种群不 向化学吸引剂(非迁徙人口)迁移并保持不变 膜的上表面，而其他种群则迁移 通过膜孔到达膜的下表面 (流动人口)。PMN，悬浮孵化，有或不有 N-甲酰基肽趋化因子(FMLP)与迁移的比较 以及暴露在FMLP梯度下的非迁移性亚群。 用一组识别PMN的单抗进行PMN染色 氨基肽酶N(CD13)，或FCG受体，FcRII(CD32)和FcRIII (CD16)，并用流式细胞仪对细胞表面表达进行定量。 中性粒细胞趋化后CD13的表达无明显变化。CD13 迁移性和非迁移性PMN的表达是相同的。 相反，FcRII和FcRIII的表达在 与之相比，迁移PMN亚群的比例分别为42%和58% 具有非迁移性PMN亚群。CD32的下调确实如此 未贴壁的PMN用化学诱导剂刺激时不会发生 然而，暂停时，CD16的表达下调了42% 悬液中加入FMLP刺激未贴壁的PMN。 本研究结果表明，PMN表面分子 中性粒细胞趋化后，其表达被选择性下调。这 实验系统提供了一种量化表达的方法 在炎症反应中起重要作用的髓系抗原。

The goal of this project is to determine whether human neutrophil (PMN) surface antigen expression is altered after PMN have migrated towards an inflammatory stimulus. We have previously shown that PMN adhesion molecule expression is differentially downregulated after PMN chemotaxis. The present study was undertaken to examine the changes that occur in PMN surface molecule expression of aminopeptidase N (CD13) and the Fcg receptors, FcRII (CD32) and FcRIII (CD16), after PMN chemotaxis in vitro. Two populations of PMN are easily identified and separated with an in vitro polycarbonate membrane chemotaxis system; one population does not migrate towards chemoattractant (nonmigrating population) and remains on the upper surface of the membrane, whereas the other population migrates through the membrane pores to the lower surface of the membrane (migrating population). PMN, incubated in suspension with or without the N-formyl peptide chemoattractant (FMLP), were compared with the migrating and nonmigrating subpopulations which were exposed to a gradient of FMLP. PMN were stained with a panel of monoclonal antibodies which recognize aminopeptidase N (CD13), or the Fcg receptors, FcRII (CD32) and FcRIII (CD16), and surface expression was quantified with a flow cytometer. CD13 expression was not significantly altered after PMN chemotaxis. CD13 expression on migrating and non-migrating PMN populations was equivalent. In contrast, FcRII and FcRIII expression was down- regulated on the migrating PMN subpopulation by 42% and 58%, respectively, when compared with the non- migrating PMN subpopulation. Down-regulation of CD32 did not occur when non-adherent PMN were stimulated with chemoattractant in suspension, however, CD16 expression was down-regulated by 42% when non-adherent PMN were stimulated with FMLP in suspension. The results of this study demonstrate that PMN surface molecule expression is selectively down-regulated after PMN chemotaxis. This experimental system provides a means for quantifying the expression of myeloid antigens which are important in inflammatory responses.