Effect of IL-2 co-expressed or co-inoculated with immuno-dominant epitopes from VP1 protein of FMD virus on immune responses in BALB/c mice.

Figures

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  Figure 1. (a) Immuno-dominant epitopes of the VP1 protein of foot-and-mouth disease (FMD) virus. (b) A tandem-repeat multiple-epitope gene (polytope). (c) Construction of the Polytope/interleukin-2 (IL-2)/FcIgG synthetic gene. (d) Gene fragments isolated from the polytope-IL-2-FcIgG fusion gene that were used to construct recombinant vaccines

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  Figure 2. (A) Predicted 3D structure of the polytope protein in comparison with the natural VP1 protein of foot-and-mouth disease (FMD) virus. This figure showed the structure superimposition between the polytope protein and the VP1 of FMDV by PyMOL software. The natural VP1 of FMDV was shown by blue line and the polytope protein was shown by red line. (B) 3D structure of the polytope-IL-2 protein

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  Figure 3. (A) Enzymatic digestion of the recombinant plasmids by EcoRI and XhoI (lane 1: undigested pET32a, lane 2: digested pET32a, lane 3: 1 kb DNA size marker, lane 4, 5 and 6: digested pET32/Polytope- interleukin-2 (IL-2), pET32/Polytope and pET32/IL-2 plasmids

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  Figure 4. (A) SDS-PAGE analysis of the recombinant polytope protein. Lane 1, 2, 3, 4, 5 and 6: bacterial lysate expressing the induced pET32a, pET32a/polytope before the induction, pET32a/polytope protein in 1, 2 and 3 hr after induction and protein marker, respectively. (B) Analysis of the recombinant polytope- interleukin-2 (IL-2) protein. Lane 1, 2, 3, 4, 5 and 6: the bacterial lysate containing pET32a/polytope-IL-2 before the induction, pET32a/polytope-IL-2 protein in 1, 2 and 3 hr after induction, protein marker and induced pET32a, respectively. (C) Analysis of the recombinant IL-2 protein. Lane 1, 2, 3, 4, 5 and 6: the bacterial lysate containing pET32a/IL-2 before the induction, pET32a/IL-2 protein in 1, 2, 3 and 4 hr after induction and protein marker

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  Figure 5. (A) SDS-PAGE analysis of the purified recombinant proteins including interleukin-2 (IL-2), polytope and polytope-IL-2. (B) Dot-blot analysis using anti-His tag antibody. Lane 1: extract of the transformed bacteria uninduced by isopropyl β-D-1-thiogalactopyranoside (IPTG), Lane 2, 3 and 4: the extract of transformed bacteria (Escherichia coli/pET32a/polytope-IL-2, E. coli/pET32a/Polytope and E. coli/pET32a/IL-2) induced by IPTG

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  Figure 6. Antibody responses in the immunized mice. Data represent the mean±standard error of triplicates from 6 mice/group. Different letters refer to statistically significant differences between experimental groups (P< .05)

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  Figure 7. Cytokine responses in the mice immunized with the recombinant vaccines. The concentrations of each cytokine were determined (pg/ml) by ELISA. Data represent the mean±standard error of triplicates from 6 mice/group. Different letters indicate statistically significant differences between the experimental immunized groups (P< .05)