Evidence for a multistep mechanism for cell-cell fusion by herpes simplex virus with mutations in the syn 3 locus using heparin derivatives during fusion from within.
Addition of heparin-Na+ as well as related substances of high and intermediate MW (Arteparon and polyanion SP54) 3 h after infection inhibit fusion from within (FFWI) induced by HSV strains with mutations in the syn 3 locus only. The concentration of heparin-Na+ required to inhibit FFWI is 10-fold higher (1 mg/ml) than that needed to inhibit adsorption. Instead of fusion, cell rounding is observed. The effect is readily reversible. A low MW heparin disaccharide is ineffective. Neomycin, at a concentration of 8 mM, inhibits FFWI induced by all HSV-1 but not HSV-2 strains, whereas adsorption is inhibited at 3 mM. We conclude from our observations that cell-cell fusion (FFWI) induced by syn 3 locus mutants of HSV-1 depends on a multistep mechanism. One may be constituted by pre-existing cell-cell connections or microfusions leading to cell rounding, whereas another may be active using newly appearing cell bridges during FFWI; also the three-dimensional structure of the cell membrane may be of importance. Moreover, the molecular mechanisms of FFWI induced by mutations in the syn 3 locus compared to the other 5 syn loci should be different.
Seck
T
T
Division of Experimental Virology, Johannes Gutenberg University Mainz, Federal Republic of Germany.
Lingen
M
M
Weise
K
K
Falke
D
D
D000818:Animals; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D015726:Giant Cells / Q000382:microbiology*; D006493:Heparin / Q000494:pharmacology; D016296:Mutagenesis; D018139:Simplexvirus / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014709:Vero Cells
D006493:Heparin