Open AccessSt Louis encephalitis virus establishes a productive, cytopathic and persistent infection of Sf9 cells
Author(s) -
Peng-Fei Zhang,
Michael Klutch,
Jacqueline Müller,
Carol J. Marcus-Sekura
Publication year - 1993
Publication title -
journal of general virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.55
H-Index - 167
eISSN - 1465-2099
pISSN - 0022-1317
DOI - 10.1099/0022-1317-74-8-1703
Subject(s) - sf9 , virology , virus , biology , cell culture , viral encephalitis , antibody dependent enhancement , immune system , recombinant virus , encephalitis , recombinant dna , viral replication , spodoptera , immunology , gene , biochemistry , genetics
The Sf9 cell line, commonly used for gene expression by recombinant baculovirus, has been productively infected by St Louis encephalitis (SLE) virus, a flavivirus. SLE viral infection produced a c.p.e. in the Sf9 cells characterized by giant cells and the presence of 10-fold fewer cells in the infected cultures after the first week of infection compared with uninoculated control cultures. Infected Sf9 cells expressed SLE viral antigens, and intracellular virus particles were observed by electron microscopy. Titres of cell-associated SLE virus rose slightly over an 8 week period, whereas titres of cell-free virus remained stable, suggesting that SLE virus establishes a productive and persistent infection of Sf9 cells. The SLE virus produced by the Sf9 cells could be neutralized by SLE virus-immune mouse ascitic fluid, and no evidence of escape mutants was detected. Sf9 cells persistently infected with SLE virus could be superinfected with a recombinant baculovirus and expressed recombinant antigen. The successful infection of Sf9 cells by SLE virus represents the first report of production of c.p.e. by SLE virus in insect cells under routine cell culture conditions and of the infection of Sf9 cells by a human pathogen.