Hyposoter fugitivus polydnavirus (HfPV) infection in vitro: Cytopathology and viral genome sequence maintenance in a tissue culture cell line.
Date
1998
Authors
Kim, Min Kyung.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
Polydnaviruses replicate only in the ovaries of certain species of endoparasitic wasp. Polydnavirus is a difficult virus to study since there is no tissue culture system that could support viral infection and replication. Developing in vitro models for polydnavirus infection is important in order to find some of the factors that are involved in successful parasitism in vivo. Hyposoter fugitivus polydnavirus (HfPV) is one of the ichnoviruses that is involved in the parasitization of Malacosoma disstria by the wasp, Hyposoter fugitivus. To understand polydnavirus infection in vitro, three different lepidopteran cell lines were exposed to HfPV, and one of the cell lines, Ld 652Y, a cell line derived from the gypsy moth, Lymantria dispar, was found to exhibit a variety of cytopathic effects resulting from the viral infection.
Early signs of cytopathology in Ld 652Y cells were similar to the responses of haemocytes to viral infection in vivo: transient inhibition of cell growth, rounding up, aggregation, and apoptosis. In addition, changes in protein synthesis in two different cell lines were observed following introduction of viral DNA into Ld 652Y cells either by infection or transfection. The persistence of viral genomic DNA, another aspect of viral infection in vivo was also studied in Ld 652Y cells. After virus-infected cells recovered from an initial wave of cytopathic effects, certain viral genome segments were found to be maintained in the HfPV-infected cells.
However, the mechanism of how some viral genome segments persist in Ld 652Y cells appears to be different from that of parasitized Malacosoma disstria. While viral DNA appears to be maintained in episomal form in vivo, certain viral genome segments are maintained in an integrated form in the chromosomal DNA of Ld 652Y cells. Further investigation identified two HfPV genome segments I and upsilon which were integrated in the chromosomal DNA of Ld 652Y cells. In addition, the integrative property of genome segment I was demonstrated by transfection.
Thesis (Ph.D.)--Dalhousie University (Canada), 1998.
Early signs of cytopathology in Ld 652Y cells were similar to the responses of haemocytes to viral infection in vivo: transient inhibition of cell growth, rounding up, aggregation, and apoptosis. In addition, changes in protein synthesis in two different cell lines were observed following introduction of viral DNA into Ld 652Y cells either by infection or transfection. The persistence of viral genomic DNA, another aspect of viral infection in vivo was also studied in Ld 652Y cells. After virus-infected cells recovered from an initial wave of cytopathic effects, certain viral genome segments were found to be maintained in the HfPV-infected cells.
However, the mechanism of how some viral genome segments persist in Ld 652Y cells appears to be different from that of parasitized Malacosoma disstria. While viral DNA appears to be maintained in episomal form in vivo, certain viral genome segments are maintained in an integrated form in the chromosomal DNA of Ld 652Y cells. Further investigation identified two HfPV genome segments I and upsilon which were integrated in the chromosomal DNA of Ld 652Y cells. In addition, the integrative property of genome segment I was demonstrated by transfection.
Thesis (Ph.D.)--Dalhousie University (Canada), 1998.
Keywords
Biology, Molecular., Biology, Cell., Biology, Microbiology.