Effects of remantadine on fusion of lipid membranes of influenza A virus with plasma and internal membranes of lymphoblastic cells

The method of fluorescence dequenching was used to study the interaction between influenza virus A/Krasnodar/101/59 and Namalwa and Raji lymphoblastoid cells. Experiments with endocytosis inhibitors and fluorescence quenchers have shown that at pH = 5.0 the virus lipid envelopes are fused with the plasma membranes of the cells, and at pH = 7.4 the virus lipid envelopes are fused with the internal, presumably endosomal, membranes of the cells. Remantadine at a concentration of 50-1000 micrograms/ml did not influence the fusion of virus lipid envelopes with intracellular membranes at pH = 7.4 whereas at pH = 5.0 it inhibited, beginning from 25 micrograms/ml concentration, the fusion of virus lipid envelopes with the plasma membranes of cells.