FMDV Insert T-cell Epitopes Recombinant Virus The Determination Of Pathogenicity And Immunity In Swines

FMD (Foot-and-mouth disease) is infectious disease caused by a small RNA virus foot and mouth disease virus (FMDV) and hot,acute and highly contagious is distinct characterized of FMD, and highly infection rate and rapid spread its two notable features, susceptible animals of FMD virus have a widely range, including cattle, camels, sheep, deer, swiness and other 20 families and about 70 kinds of wild animals and domestic animals.The recombinant virus plasmid were transfected BHK-21 cells until fund Cytopathic Effect (CPE).Continuous subculture, then use real-time quantitative and fluorescent PCR experimental to verification, identy that by verification sequencing, result showed that T cell epitopes was successful inserted and we successfully rescue two recombinant virus (named rAsia I-OM3A, rAsia I-O3A). In addition, we determined that the recombinant virus compared to the parental virus (rAsia I) on BHK21 cells and suckling mice pathogenicity. The results showed that recombinant virus rAsia I-OM3A TCID50 is 10-7, LD50 is 10-6, rAsia I-03A TCID50 is 10-7.5, LD50 was 10-6.5, the parent virus rAsia I TCID50 is 10-8.33, LD50 is 10 -8, and compared to the parental virus the virulence is becoming weaker.The recombinant virus with the parent strain rAsia I are pathogenic test on susceptible animals swines. The results showed that two groups of recombinant virus rAsia I-OM3A and rAsia I-O3A strain, poison attack group five swiness were not fund FMD clinical symptoms, while parent virus (rAsia I) three of five swiness in group were fund typical FMD clinical symptoms. Two recombinant virus attack virus group were not expersion toxemia and infection antibody; and the parental virus strain attack virus group were fund toxemia and infection antibodies. This indicates that these two genes inserted in FMD virus make FMDV pathogenicity weakened.Two recombinant virus and parental virus inactivated vaccine were prepared, and then make immunized protection test on the body of animals swines. The results showed that the recombinant virus viccine immune animals can induce early humoral immune response andinduce high levels ratio of CD4+/CD8+, CD21+ and proportion of CD 172+ cell Subsets. Following, use O serotypes of FMD virus to Infected animals, the parents immune groups two of three swiness in the group are onset, rAsia I-OM3A group of five animals immunized only one hair disease, rAsia I-O3A immunohistochemistry four in five animal hair disease. The results showed that the rAsia I-OM3A vaccine has a protective effect with swines and induce a broad spectrum of immune response. The above data shows that the recombinant virus attenuated virulence and pathogenicity of swiness decreased, while has a protective effect to against O serotype FMD virus, can be used as a vaccine candidate.