Interaction between enteroviruses and human endothelial cells in vitro. Alterations in the physical properties of endothelial cell plasma membrane and adhesion of human granulocytes

Fluorescent molecular probes were used for study of the interaction between enteroviruses (Echo 9, Echo 12, and Coxsackie B3 virus) and human endothelial cells in monolayer culture. With the use of the monomer-excimer method with pyrene decanoic acid it was shown that a marked dose-dependent restructuring of the plasma membrane occurred following addition of virus to the endothelial cells. This took the form of an increase in the lipid surface available to the lipophil reporter molecules, probably due to an alteration in the domain structure of the plasma membrane caused by insertion of virus capsid proteins. Experiments with diphenylhexatriene indicated that the enteroviruses had only a slight tendency to make the plasma membrane of the endothelial cell more fluid. Concomitant with these alterations in the biophysical properties of the membrane, a virus-induced increase in granulocyte adherence to the endothelial cells was observed for all three enteroviruses studied. Possible mechanisms for this elevated adherence are discussed, as well as the significance of the results for the phenomenon of virus-induced granulocytopenia.