[The construction of attenuated Tiantan recombinant vaccinia virus vector with IFN-gamma receptor gene deletion].
OBJECTIVE
B8R gene encodes a secreted protein with homology to IFN-gamma receptor, which neutralizes the antiviral and immunological regulation activities of IFN-gamma. To improve the safety of vaccinia virus vector, an attenuated recombinant vaccinia virus with the B8R gene deletion from Tiantan vaccine strain (VTT) was constructed.


METHODS
The transfer vectors were generated by joining B8R left flank, B8R right flank, vv promoter, LacZ, multicloning site and pBRSK fragments. The recombinant viruses VTTdeltaB8RLacZ (VTT with B8R deletion and LacZ insertion) were constructed by homologous recombination.


RESULTS
The B8R deletion mutants were confirmed by dot blot with B8R gene probe and PCR amplification. The replication ability of VTTdeltaB8RLacZ strain in vitro was similar to that of the VTT. The skin lesions formed by VTTdeltaB8RLacZ (10(6) pfu) were significantly smaller and healed faster than those formed by VTT when injected intradermally to the rabbits,and no visible ulceration occurred. Meanwhile LacZ in VTKgpedeltaB8RLacZ was expressed stably.


CONCLUSIONS
The attenuated vector with B8R gene deletion improves the safety of recombinant vaccinia virus vaccine B8R locus may be used as a new site for insertion of foreign genes in vaccinia virus vector.
Huang
Wei
W
National Center for STD/AIDS Prevevtion and Control China CDC, Beijing 100050, China.
Liu
Ying
Y
Duan
Dan-li
DL
Li
Hai-shan
HS
Liu
Yong
Y
Hong
Kun-Xue
KX
Zhu
Jia-hong
JH
Shao
Yi-ming
YM
D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D017353:Gene Deletion; D005822:Genetic Vectors; D006801:Humans; D011817:Rabbits; D017471:Receptors, Interferon / Q000235:genetics / Q000502:physiology*; D011995:Recombination, Genetic; D014613:Vaccines, Attenuated / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity*; D014774:Virulence; D014779:Virus Replication; D000096743:Interferon gamma Receptor
D017471:Receptors, Interferon; D014613:Vaccines, Attenuated; D000096743:Interferon gamma Receptor