Ichnovirus infection of an established gypsy moth cell line

In the present study, a lepidopteran cell line (Ld-652Y, from the gypsy moth, Lymantria dispar) exposed to Hyposoter fugitivus polydnavirus (HfPV) was found to display a variety of cytopathic effects. These included a transient inhibition of cell proliferation, rounding up, aggregation and apoptosis. In addition, unusual paracrystalline structures appeared within the lumen of the rough endoplasmic reticulum; similar structures were observed in the spherulocytes of parasitized Malacosoma disstria. Following Coomassie Blue staining, two new cell-associated polypeptides were detected; one of these, an 8 kDa polypeptide, could also be observed following exposure of Ld-652Y cells to media taken from infected cultures or to cell-free haemolymph from parasitized M. disstria. After a period of 2-4 weeks, the L. dispar cell cultures were observed to largely recover from the effects of exposure to virus, and resumed proliferation; 'transformed' cell populations tended to form aggregates, and adhered less tightly to the substrate. Viral DNA was stably maintained in all recovered cell lines, possibly in chromosomally integrated form.