Stably expressed FIPV peplomer protein induces cell fusion and elicits neutralizing antibodies in mice.
We have established bovine papilloma virus (BPV)-transformed mouse C127 cell lines that synthesize the peplomer protein of the feline infectious peritonitis virus (FIPV) strain 79-1146. For this purpose, a new cassette expression vector pHSL, which carries the Drosophila HSp70 promotor and the polyadenylation signal of the Moloney murine leukemia virus long terminal repeat, was constructed. Cocultivation of the BPV-transformed cell lines with FIPV-permissive feline fcwf-D cells resulted in polykaryocyte formation. Since it depended on the presence of fcwf-D cells, binding of E2 to the cell receptor may be required for membrane fusion. E2 was synthesized as a core-glycosylated protein of 180K which was only slowly transported from the endoplasmic reticulum to the medial Golgi: of the E2-molecules labeled during a 1-hr pulse about half was still completely sensitive to endoglycosidase H after a 2-hr chase, while the remaining E2 had been chased into multiple, partially endoglycosidase H-resistant forms. Immunofluorescence studies also indicated that most E2 was retained intracellularly. Mice immunized with whole lysates of the transformed cells produced FIPV-neutralizing antibodies as shown by plaque reduction.
De Groot
R J
RJ
Department of Infectious Diseases and Immunology, State University Utrecht, The Netherlands.
Van Leen
R W
RW
Dalderup
M J
MJ
Vennema
H
H
Horzinek
M C
MC
Spaan
W J
WJ
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D001692:Biological Transport; D052688:Bovine papillomavirus 1 / Q000235:genetics; D002459:Cell Fusion; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D003332:Coronaviridae / Q000235:genetics* / Q000502:physiology; D005822:Genetic Vectors; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D011499:Protein Processing, Post-Translational; D014162:Transfection; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology
D000914:Antibodies, Viral; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins