ABSTRACT
To develop a reverse genetics system of Peste des petits ruminants virus(PPRV), five pairs of oligonucleotide primers were designed on the basis of the full-length genomic sequence of PPRV Nigeria 75/ 1 strain. Using RT-PCR technique, five over-lapping cDNA fragments, designated as JF1, JF2, JF3, JF4 and JF5, respectively, were amplified, followed by cloning into pcDNA3.1(+)vector. An AscI restriction enzyme site and a T7 promoter sequence were introduced immediately upstream of 5'-end, while a PacI restriction enzyme site was engineered downstream of 3'-end. Using pok12 as a plasmid vector, the full-length cDNA clone pok12-PPRV of Nigeria 75/1 was assembled by connecting the five cDNA fragments via the unique restriction endonuclease site of PPRV genome. The resultant nucleotide sequence of the PPRV Nigeria 75/1 strain in the study was compared with other members of genus morbillivirus, and phylogenetic analysis was used to examine the evolutionary relationships. The results showed that PPRV Nigeria 75/ 1 was antigenically closely related to Rinderpest virus and Measles virus. Successful construction of full-length cDNA clone of PPRV Nigeria 75/1 strain lays the basis rescuing PPRV effectively and enables further research of PPRV at molecular level.
Subject(s)
Animals , Base Sequence , Cloning, Molecular , DNA, Complementary , Genetics , Genome, Viral , Molecular Sequence Data , Peste-des-Petits-Ruminants , Virology , Peste-des-petits-ruminants virus , Classification , Genetics , Phylogeny , Sequence Analysis, DNAABSTRACT
The full-length P32 gene and the truncated P32 gene (MP-32) were amplified from the recombinant plasmid pMD-P32 by polymerase chain reaction (PCR) and cloned into pcDNA3. 1(+) and pcDNA3.1-CpG respectively. The recombinant plasmids (pcDNA3.1-P32, pcDNA3.1-CpG-P32 and pcDNA3. 1-CpG-MP32) were transfected into BHK-21 cells by using lipofectin. The expressed P32 protein was confirmed by indirect immunofluorescence assay (IFA). The BALB/c mice were immunized with these recombinant plasmids by intramuscular injection. The specific antibodies aginst CPV were detected by ELISA kit weekly. The murine splenic T lymphocyte subgroups CD4+ and CD8+ were detected by flow cytometry. Results showed that the P32 protein was expressed successfully in vitro. After 2 weeks post im munization, the specific IgG antibodies against CPV were detected in the vaccinated mice. The percentage of CD4+ /CD8+ T cells was significantly higher than that of the control. In conclusion, these constructed eukaryotic vectors could induce humoral and celluar immune responses in mice.