Control of Cell Functions by Functioralized Liposomes

E-cadherin是一种细胞间粘附分子，在小鼠畸胎瘤F9上表达，首次研究了E-cadherin从细胞向脂质体的转移。改变脂质体的脂质组成和与细胞的孵育条件，优化膜蛋白的转移。为了证明E-cadherin从脂质体再转移到另一个细胞，然后将Jurkat细胞或b16黑色素瘤等细胞与脂质体共培养，在脂质体上通过膜间蛋白转移重建含有E-cadherin的膜蛋白。这些细胞最初不粘附于F9细胞，但与脂质体共孵育后获得了对F9细胞的粘附活性。提示e -钙粘蛋白从脂质体转移到其他细胞膜上，并保持其粘附活性，说明e -钙粘蛋白的引入成功修饰了细胞的功能。介绍了一种测定活细胞摄氧量的新方法。将两种培养的哺乳动物细胞置于2.0 ml体积的比色皿中孵育，比色皿中装有专门设计的氧电极，用于测量培养基中的氧浓度（[02]）。这种新方法允许1)即时测定活细胞的呼吸活动，2)同时监测细胞对细胞外刺激的反应。

Transfer of E-cadherin, which is a cell-cell adhesion molecule and expressed on mouse teratocarcinoma F9, from the cell to liposome was first investigated. The lipid composition of liposome and the condition of the incubation with cell were altered, and the transfer of membrane proteins was optimized. For the demonstration of the retransfer of E-cadherin from liposome to another cell, then cells such as Jurkat cell or B 16 melanoma were coincubated with the liposome on which membrane proteins containing E-cadherin was reconstituted by intermembrane protein transfer. Originally these cells do not adhere to F9 cell, however they acquired the adhesion activity to F9 cell after coincubation with the liposome. It was suggested that E-cadherin was transferred from the liposome to other cell membranes keeping its adhesion activity, and meant that the function of cells were successfully modified by the introduction of E-cadherin.A new method to determine oxygen uptake rate of living cells is described. Two kinds of cultured mammalian cells were incubated in a 2.0 ml vol cuvette, which was equipped with an oxygen electrode as specially designed to measure the oxygen concentration ([02]) in the culture medium. This new method allowed 1) instant determination of the respiratory activity of living cells, and 2) simultaneous monitoring of responses of cell against extracellular stimuli.