Functional microdomains of glycolipids with partially fluorinated membrane anchors: impact on cell adhesion

Functional microdomains of glycolipids were designed by mixing neoglycolipids with partially fluorinated alkyl (F-alkyl) chains and matrix lipids with alkyl chains. Fluorescence images of the mixed lipid monolayers at the air-water interface demonstrated that it is possible to control both size and distribution of the microdomains by means of the strong demixing of alkyl and F-alkyl membrane anchors, while the carbohydrate head groups seemed to play a rather minor role. These microdomains in monolayers could be transferred onto hydrophobized substrates and subjected to experiments in a dynamic flow chamber. The results obtained here clearly indicated that the dynamic adhesion of Chinese hamster ovarial cells expressing E-selectin (CHO-E cells) on a lipid monolayer containing microdomains of sialyl Lewisx (sLex) can be both enhanced and reduced by controlled demixing of ligands and matrices. Moreover, the same clusters of sLex could also be formed in giant lipid vesicles, which can be used as a model cell that locally expresses biospecific functions.