Low pH-induced cell fusion in flavivirus-infected Aedes albopictus cell cultures

• Published in: Journal of general virology Vol. 71; no. 8; pp. 1845 - 1850
• Main Authors: Randolph, V.B, Stollar, V
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-08-1990; Society for General Microbiology
• Subjects: Adenosine Triphosphate - metabolism; Aedes; Aedes albopictus; Ammonium Chloride - pharmacology; Animals; Antibodies, Viral; Biological and medical sciences; cell culture; Cell Fusion; Cell Line; Dengue Virus - immunology; Dengue Virus - physiology; Encephalitis Virus, St. Louis - immunology; Encephalitis Virus, St. Louis - physiology; Flavivirus; Flavivirus - physiology; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Microbiology; Replicative cycle, interference, host-virus relations, pathogenicity, miscellaneous strains; Viral Envelope Proteins - immunology; Viral Envelope Proteins - physiology; Virology; Virus Replication - drug effects; Culture medium; Cell culture; Insecta; Togaviridae; Monoclonal antibody; Cell fusion; Dengue virus; Flavivirus; Virus; Aedes albopictus; Saint Louis encephalitis virus; Arthropoda; Culicidae; PH; Infected cell; Invertebrata; ATP; Diptera
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-71-8-1845

Department of Molecular Genetics and Microbiology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 675 Hoes Lane, Piscataway, New Jersey 08854, U.S.A.
Cell-to-cell fusion of Aedes albopictus (mosquito) cells infected with dengue and St Louis encephalitis (SLE) flaviviruses was induced by exposure to low pH. The parameters of this low pH-induced fusion were examined. Syncytium formation was maximal in cultures 36 to 48 h post-infection and occurred when cultures were maintained at the acid pH for 15 min at 35 °C. The optimal pH range for fusion was 5.0 to 6.5 for dengue virus-infected cells and 5.0 to 5.5 for SLE virus-infected cells. Syncytia were not observed in vertebrate cells (Vero and BHK) under these conditions despite similar virus yields. Fusion was shown to be ATP-dependent and could be prevented by the addition of either polyclonal antiviral antibodies or monoclonal antibody to the envelope glycoprotein. The lysosomotropic amine ammonium chloride inhibited the replication of SLE virus in both mosquito and vertebrate cells, consistent with the idea that low pH-induced fusion is necessary for virus entry into both types.
Present address: Lederle Laboratories, North Middletown Road, Pearl River, New York 10965, U.S.A.
Received 23 January 1990;
accepted 9 April 1990.