Persistent infections were established by serial undiluted passages of the Toscana virus of the genus Phlebovirus in Vero cells. Persistence was maintained through more than 70 passages over a period of 2 years. The persistently infected cells were morphologically similar to the parental Vero cells and released variable amounts of infectious virus. A small percentage of the persistently infected cells produced infectious virus while a larger percentage was shown to possess viral antigens by fluorescent antibody staining. Temperature sensitivity and host cell interferon production were not involved in establishment or maintenance of persistence. The persistently infected cultures were resistant to superinfection with homologous Toscana virus, but they were susceptible to superinfection with heterologous viruses of different genera or families. Toscana virus persistently infected cells showed a selective graded resistance to the replication of other Phleboviruses. Additionally, the virus from persistently infected cells interfered with the replication of standard Toscana virus when they co-infected normal cells. The characteristics of the persistently infected cultures are compatible with some of the characteristics described for the persistence mediated by defective-interfering particles of other viruses.
DesmyterJ.,
MelnickJ. L.,
RawlsW. R.1968; Defectiveness of interferon production and of rubella virus interference in a line of African green monkey kidney cells (Vero). Journal of Virology 2:955–961
HollandJ. J.,
VillarrealL. P.,
BreindlM.1976; Factors involved in the generation and replication of rhabdovirus defective T particles. Journal of Virology 17:805–815
KowalK. J.,
StollarV.1980; Differential sensitivity of infectious and defective-interfering particles of Sindbis virus to ultraviolet irradiation. Virology 103:149–157
NewtonS. E.,
ShortN. J.,
DalgarnoL.1981; Bunyamwera virus replication in cultured Aedes albopictus (mosquito) cells: establishment of a persistent viral infection. Journal of Virology 38:1015–1024
PrebleO. T.,
YoungnerJ. S.1975; Temperature-sensitive viruses and the etiology of chronic and inapparent infection. Journal of Infectious Diseases 131:467–473
TeshR. B.,
PeraltaP. H.,
ShopeR. E.,
ChaniotisB. N.,
JohnsonK. M.1975; Antigenic relationships among phlebotomus fever group arboviruses and their implications for the epidemiology of sandfly fever. American Journal of Tropical Medicine and Hygiene 24:135–144
TeshR. B.,
PetersC. J.,
MeeganJ. M.1982; Studies on the antigenic relationship among Phleboviruses. American Journal of Tropical Medicine and Hygiene 31:149–155
VeraniP.,
LopesM. C.,
NicolettiL.,
BalducciM.1980; Studies on Phlebotomus-transmitted viruses in Italy: I. Isolation and characterization of a sandfly fever Naples-like virus. In Arboviruses in the Mediterranean Countries. Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene supplement 9 pp 195–201 Edited by
Vesenjak-HirjanJ.,
PorterfieldJ. S.,
ArslanagicE.
Stuttgart: Gustav Fischer Verlag;
VeraniP.,
NicolettiL.,
CiufoliniM. G.1984; Antigenic and biological characterization of Toscana virus, a new Phlebotomus fever group virus isolated in Italy. Acta virologica (in press)
WeissB.,
RosenthalR.,
SchlesingerS.1980; Establishment and maintenance of persistent infection by Sindbis virus in BHK cells. Journal of Virology 33:463–474