[Construction and in vitro evaluation of an infectious clone of the equine infectious anemia virus vaccine strain EIAV(FDDV) with four reverse-mutated vaccine-specific sites in the S2 gene].
To elucidate the function of the S2 gene in equine infectious anemia virus (EIAV) and its role in the attenuation of the Chinese attenuated EIAV vaccine strains, the S2 in the EIAV vaccine strain EIAV (FDDV) was reverse-mutated and the in vitro replication character of the resultant virus was evaluated. Based on the sequence variation of the S2 gene between the EIAV virulent strains and vaccine strains, all the four vaccine-specific sites in the S2 of an EIAV(FDDV) infectious clone, pFDDV3-8, were reverse-mutated to the sequences of the virulent strain EIAV(DV115). The reverse-mutated molecular clone pFDDVS2r1-3-4-5 was used to transfect fetal donkey dermal (FDD) cells for rescuing the derived virus vpFDDVS2r1-3-4-5. The production and replication of vpFDDVS2r1-3-4-5 in FDD cells were proved by RT-PCR, immune fluorescence assay and reverse transcriptase activity assay. Typical virons of EIAV were clearly observed under the electron microscopy. The parallel analysis of the dynamic replication of the reverse-mutated viral clone vpFDDVS2r1-3-4-5 and its parental virus vpFDDV3-8 showed that the virus with four reverse mutations in the S2 replicated only slightly slower than its parental vaccine strain in FDD cells. This result implicates that the mutations in the S2 of the EIAV vaccine strains did not significantly alter the viral replication in vitro. Further studies on the in vivo replication of the reverse-mutated viral clone are required for understanding the relationship between the S2 and the attenuated pathogenesis of EIAV attenuated vaccines.
Gao
Xu
X
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China. ybuac@126.com
Jiang
Cheng-Gang
CG
Han
Xiu-E
XE
Zhao
Li-Ping
LP
Shen
Rong-Xian
RX
Xiang
Wen-Hua
WH
Zhou
Jian-Hua
JH
D000818:Animals; D002460:Cell Line; D005818:Genetic Engineering; D000882:Haplorhini; D004860:Infectious Anemia Virus, Equine / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014765:Viral Vaccines / Q000235:genetics*; D014779:Virus Replication
C402643:S2 protein, Equine infectious anemia virus; D014764:Viral Proteins; D014765:Viral Vaccines