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ISSN 1672-9145 Acta Biochim Biophys Sin 2004, 36(10): 701-706 CN 31-1940/Q

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The Effect of Bovine IFN-a on the Immune Response in Guinea Pigs Vaccinated with DNA Vaccine of Foot-and-Mouth Disease Virus

Hui-Chen GUO, Zai-Xin LIU*, Shi-Qi SUN, Qing-Wen LENG¹, Dong LI, Xiang-Tao LIU, and Qing-Ge XIE*

Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China;
¹College of Animal Science and Technology, Shihezi University, Shihezi 832003, China

Abstract In this study, we constructed recombinant plasmid pcDNA3.1/P12X3C3D including P1, 2A, 3C, 3D and part of 2B gene of FMDV and pcDNA3.1/IFN containing the gene encoding bovine IFN-a. We inoculated the DNA vaccine pcDNA3.1/P12X3C3D with or without pcDNA3.1/IFN to evaluate the efficiency of this DNA vaccine and the immunogenicity of DNA vaccine enhanced by the co-delivery with pcDNA3.1/IFN. After two times of vaccination with DNA vaccine, all of guinea pigs were challenged with 10³ ID₅₀ FMDV type O. Anti-FMDV antibody levels were detected by ELISA and T lymphocyte proliferation response was tested by MTT assay. The result shows that guinea pigs inoculated by pcDNA3.1/P12X3C3D alone or with pcDNA3.1/IFN generated specific antibodies and induced an FMDV-specific T lymphocyte proliferation response. FMDV challenge tests showed that one in four guinea pigs immunized by pcDNA3.1/P12X3C3D with pcDNA3.1/IFN was protected from the FMDV serotype O infection. This result indicated that the efficiency of the DNA vaccine was enhanced by co-delivery with pcDNA3.1/IFN. However, the protection rate was considerably lower than that immunized with conventional FMD vaccine.

Key words foot-and-mouth disease virus (FMDV); DNA vaccine; IFN-a; gene vaccination

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Received: May 21, 2004 Accepted: August 21, 2004

This work was supported by a grant from the Major State Basic Research Development Program of China (No. G1999011903)

*Corresponding author: Tel, 86-931-8342585; Fax, 86-931-8340799; E-mail, [email protected] & [email protected]