Study On The Immunogenicity Of The DNA Vaccine PIRES-OAAT-P1-2A-3C Against Foot-And-Mouth Diseas

Foot-and-mouth disease(FMD) caused by FMD virus(FMDV) is one of the most contagious animal virus diseases.At present,FMD is spreaded in all of the world.Serotype O,A and Asia I FMD once happened in history of China,and are often epidemic in the country around China and Southeast Asia.Our country has been threatened by Serotype O,A and Asia I FMD at present.The multivalent DNA vaccine pIRES-OAAT-P1-2A-3C was constructed using the cassette OAAT and P1-2A-3C(AsiaI),the recombinant plasmid was Identificated by restricted endonuclease。Transfect HeLa cells with the constructed multivalent FMDV DNA vaccine pIRES-OAAT-P1-2A-3C and identify the expressed product by IFA,and the result show that the production of expression could both react between FMDV polyclonal rabbit antibody of O type and FMDV polyclonal rabbit antibody of AsiaⅠtype.BALB/c mice which was used as experimental model were innoculated by DNA recombinant strain as before.The humoral and cell immunity level were detected.The results showed that special antibody aiming at O,AsiaⅠtype could be generated in group of pIRES-OAAT-P1-2A-3C.were lower than that of inactivated vaccination group,but is all higher than that of control group(p＜0.01).The result from flow cytometry after statistics analyse indicated that contrast with the inactivated vaccination group pIRE1neo group and PBS group the mice which immuned with pIRES-OAAT-P1-2A-3C,could found the significant elevation of T lympholeukocyte subgroup CD4+ and CD8+.The results of ELISPOT detection for number of IFN-γblot showed the number(64.726) of groups pIRES-OAAT-P1-2A-3C was higher (p＜0.05) than inactivated vaccination group(39.625).And the difference between control group were quiet.The results of Lymphoproliferation of peripheral blood lymphocytes showed that group of pIRES-OAAT-P1-2A-3C and inactivated vaccination group both to appear specificity and non-specificity Lymphoproliferation. Furthermore reproductive activity of pIRES-OAAT-P1-2A-3C group is better than inactivated vaccination group(p＜0.05).In this study,guinea pigs were inoculated intramuscularly twice.All of Guinea pigs were challenged with 250ID50 FMDV.To evaluate the prophylaxtic efficacy of this vaccine candidate,The four guinea pigs in inactivated vaccination group all not emerge FMD symptom.Indicate that the group has obtained completely protection. There is two guinea pigs obtained protected completely from the FMDV in the DNA vaccine group.The result show that the combination of cassette OAAT and P1-2A-3C(AsiaI) has good immunogenicity.It will give experiment base to develop vaccine using the combination for other vector..Also do certain preparation and provide material reserve for developing effective FMD multivalent DNA vaccine.