Optimization strategy for plasmid DNAs containing multiple-epitopes of foot-and-mouth disease virus by cis-expression with IL-2.
To optimize previous candidate DNA vaccine, a cis-expression plasmid DNA encoding two genes, human IL-2 and multiple-epitopes genes of foot-and-mouth disease virus (FMDV) was constructed with internal ribosome entry site (IRES) from encephalomyocarditis virus (EMCV) and intramuscularly inoculated into mice at 1-week interval. Specific antibodies in serum and cytokines (IL-2, IL-4 and IFN-gamma) from splenocytes were detected by indirect ELISA. Splenocytes proliferation rate was determined by a standard 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) method. The results showed that higher specific antibody, proliferate rate and cytokines were induced by plasmid DNA cis-expression with IL-2 compared to non-cis-expression plasmid DNA. Another series of mice were inoculated with plasmid DNA and boosted with antigenic protein. Specific antibody, proliferation rate and cytokines were induced significantly higher than those of mice immunized with protein or plasmid DNA only. However, only the cis-expression plasmid DNA elicited higher neutralization antibody in mice and provided one third protection against homologous virus in guinea pigs. In conclusion, cis-expression strategy with IL-2 up-regulated specific immunological response and provide protection against homologous virus.
Zhang
Hong-Ying
HY
Nanjing Center for Disease Control and Prevention, 2 Zizhulin Road, Nanjing 210003, China. xiao99now@yahoo.com.cn
Sun
Shu-Han
SH
Guo
Ying-Jun
YJ
Zhu
Wei-Jia
WJ
Shi
Ke
K
Xu
Gen-Xing
GX
Wang
Jian-Jun
JJ
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D016207:Cytokines / Q000032:analysis / Q000096:biosynthesis; D004686:Encephalomyocarditis virus / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D005536:Foot-and-Mouth Disease / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D015870:Gene Expression; D006168:Guinea Pigs; D006801:Humans; D007115:Immunization Schedule; D007273:Injections, Intramuscular; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D010957:Plasmids / Q000378:metabolism*; D054657:Ribosome Subunits / Q000378:metabolism; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000914:Antibodies, Viral; D016207:Cytokines; D000939:Epitopes; D007376:Interleukin-2; D019444:Vaccines, DNA; D014765:Viral Vaccines