Comparison of the Virulence of Wild-type Thymidine Kinase (tk)-deficient and tk+ Phenotypes of Vaccinia Virus Recombinants after Intranasal Inoculation of Mice
A recombinant vaccinia virus vector was constructed which expressed the major surface glycoprotein G of human respiratory syncytial virus (RSV) and the thymidine kinase (tk) gene of vaccinia virus. The virulence of this tk+ recombinant virus was compared with that of a tk− recombinant and the wild-type (wt) virus after intranasal inoculation of mice. Respiratory infection with wt virus resulted in a lethal infection with widespread dissemination of virus. In contrast, infection with the tk− recombinant was not lethal and the virus had a reduced ability to disseminate to extrapulmonary tissue compared with wt virus. Insertion of the tk gene restored the virulence of the recombinant virus to the level of that of the wt virus. Despite a dramatic reduction in virulence of the tk− recombinant, virus could occasionally be recovered from the brains of mice. The expression of the attachment glycoprotein of RSV appeared to enhance the ability of the tk− recombinant virus to replicate in the lungs when compared with recombinants expressing fusion or nucleoprotein genes. The results confirm that inactivation of the tk gene results in a dramatic reduction of virulence for mice but suggest that there is still a potential danger of infection of the brain following intranasal administration of virus.
BallL. A.,
YoungK. K.-Y.,
AndersonK.,
CollinsP. L.,
WertzG. W.1986; Expression of the major glycoprotein G of human respiratory syncytial virus from recombinant vaccinia virus vectors. Proceedings of the National Academy of Sciences, U.S.A 86:246–250
BullerR. M. L.,
SmithG. L.,
CremerK.,
NotkinsA. L.,
MossB.1985; Decreased virulence of recombinant vaccinia expression vectors is associated with a thymidine kinase-negative phenotype. Nature, London 317:813–815
KingA. M. Q.,
StottE. J.,
LangerS. J.,
YoungK. K.-Y.,
BallL. A.,
WertzG. W.1987; Recombinant vaccinia virus carrying the N gene of human respiratory syncytial virus: studies of gene expression in cell culture and immune response in mice. Journal of Virology 61:2885–2890
MurphyB. R.,
OlmsteadR. A.,
CollinsP. L.,
ChanockR. M.,
PrinceG. A.1988; Passive transfer of respiratory syncytial virus (RSV) antiserum suppresses the immune response to the RSV fusion (F) and large (G) glycoproteins expressed by recombinant vaccinia viruses. Journal of Virology 61:3907–3910
MurphyB. R.,
CollinsP. L.,
LawrenceL.,
ZubakJ.,
ChanockR. M.,
PrinceG. A.1989; Immunosuppression of the antibody response to respiratory syncytial virus (RSV) by pre-existing serum antibodies: partial prevention by topical infection of the respiratory tract with vaccinia virus-RSV recombinants. Journal of General Virology 70:2185–2190
PanicaliD.,
PaolettiE.1982; Construction of poxviruses as cloning vectors: insertion of the thymidine kinase gene from herpes simplex virus into the DNA of infectious vaccinia virus. Proceedings of the National Academy of Sciences, U.S.A 79:4927–4931
RoizmanB.,
SearsA. E.1990; Herpes simplex viruses and their replication. In Virology 2nd edn. pp. 1795–1841 Edited by
FieldsB. N.,
KnipeD. M.
New York: Raven Press;
SmallP. A.,
SmithG. L.,
MossB.1985; Intranasal vaccination with recombinant vaccinia containing influenza hemagglutinin prevents both influenza pneumonia and nasal infection: intradermal vaccination prevents only viral pneumonia. In Vaccinia Viruses as Vectors for Vaccine Antigens pp. 175–177 Edited by
QuinnanG. V.
New York: Elsevier;
SmithG. L.,
MurphyB. R.,
MossB.1983b; Construction and characterization of an infectious vaccinia virus recombinant that expresses the influenza hemagglutinin gene and induces resistance to influenza virus infection in hamsters. Proceedings of the National Academy of Sciences, U.S.A 80:7155–7159
StottE. J.,
BallL. A.,
YoungK. K.-Y.,
FurzeJ.,
WertzG. W.1986; Human respiratory syncytial virus glycoprotein G expressed from a recombinant vaccinia virus vector protects mice against live-virus challenge. Journal of Virology 60:607–613
StottE. J.,
TaylorG.,
BallL. A.,
AndersonK.,
YoungK. K.-Y.,
KingA. M. Q.,
WertzG. W.1987; Immune and histopathological responses in animals vaccinated with recombinant vaccinia viruses that express individual genes of human respiratory syncytial virus. Journal of Virology 61:3855–3861
WertzG. W.,
StottE. J.,
YoungK. K.-Y.,
AndersonK.,
BallL. A.1987; Expression of the fusion protein of human respiratory syncytial virus from recombinant vaccinia virus vectors and protection of vaccinated mice. Journal of Virology 61:294–301
Comparison of the Virulence of Wild-type Thymidine Kinase (tk)-deficient and tk+ Phenotypes of Vaccinia Virus Recombinants after Intranasal Inoculation of Mice