[Comparison of proviral genomes between the Chinese EIAV donkey leukocyte-attenuated vaccine and its parental virulent strain].
The donkey leukocyte-attenuated vaccine of equine infectious anemia virus (EIAV) was the first lentiviral vaccine that induced solid protection from the infection of virulent strains. To elucidate the mechanism of increased immunogenicity and attenuated virulence of the vaccine, the proviral genomic DNA of an EIAV vaccine strain, EIAV(DLV121) was analyzed and compared with the genome of a parental virulent strain EIAV(DV117). Full length viral genomic DNAs were amplified as two segments by LA-PCR and were cloned. Because of the genomic diversity of retroviral quasispecies, 10 full-length sequences of EIAV(DLV121) and 4 full-length sequences of EIAV(DV117) from randomly picked clones were analyzed. Results showed that the average length of the complete nucleotide sequence of EIAV(DLV121) was 8,236bp and EIAV(DV117) was 8,249bp, with the inter-strain diversity of 2.8%. As for individual genes between the vaccine and virulent strains, the differences in nucleotide sequence of S2, LTR and env were significantly higher than the other genes with the diversity of 4.1%, 3.7% and 3.1%, respectively. Considerable variations in deduced amino acid sequences were found in S2, S3 and env. The diversities were 10.4%, 5.6% and 4.8%, respectively. Furthermore, the LTR of EIAV(DLV121) consisted of at least 5 subtypes grouped by their nucleotide sequences. There were two additional N-linked glycosylation sites in the deduced amino acid sequence of EIAV(DV117) gp90 than that of EIAV(DLV121). Among glycosylation sites in the gp90 of virulent strain, 3 were found unique only in EIAV(DV117), of which 2 were located in the principle neutralizing domain (PND). In addition, there was one EIAV(DLV121) -specific glycosylation site, which was positioned in the PND, too. Taken together, it is clear that greatly increased genomic diversity exists in the EIAV vaccine strain, which provides important information for the further study on biological characters of the Chinese EIAV attenuated vaccine.
Wang
Xue-Feng
XF
Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150001, China.
Jiang
Cheng-Gang
CG
Guo
Wei
W
Xiang
We
W
Lv
Xiao-Ling
XL
Zhao
Li-Ping
LP
Wang
Feng-Long
FL
Kong
Xian-Gang
XG
Zhang
Xiao-Yan
XY
Shao
Yi-Ming
YM
Zhou
Jian-Hua
JH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018397:Equidae; D016679:Genome, Viral; D004860:Infectious Anemia Virus, Equine / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D007962:Leukocytes / Q000276:immunology / Q000821:virology; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014613:Vaccines, Attenuated / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014774:Virulence
D014613:Vaccines, Attenuated; D014764:Viral Proteins