Authors : Liuqun Hu, Guoping Liu, Meng-Yuan Liu and Li-Xin Ma
Abstract: The DNA sequence encoding the truncated SLT-IIeB and FedF of the Escherichia coli Ee strain which is the major immunogenic fragment for the edema disease in piglets were subcloned and fused to the C terminus of Glutathione S-Transferase (GST) in a pGEX-KG expression vector, to obtain a fusion protein expression plasmid pKSF. Fusion protein was expressed as inclusion body. The anti-serum of GST-SF was able to restrain the toxicity of SLT-IIe to Vero-E6 cells and inhibit the adhesion of F18 fimbriae to the porcine small intestinal brush border cells in vitro. SPF KM mice were vaccinated subcutaneously at 0 and 2 weeks with 25 μg GST-SF, GST-B and GST-F, respectively and were challenged with 5 times the LD50 volume of the Ee strain. The IgG titers against SLT-IIeB or FedF in the GST-SF group were higher and were maintained for a longer time compared to the GST-B and GST-F groups. GST-SF can induce a better immune response and can provide the protection rate of the 70%. These results show the fusion protein GST-SF had stronger immunogenicity and better protective effects against the Ee strain and thus can be used for vaccination against the edema disease of swine.
Liuqun Hu, Guoping Liu, Meng-Yuan Liu and Li-Xin Ma, 2013. Fusion of FedF and SLT-IIe B Subunit is an Candidate Antigen Against Edema Disease of Swine. Journal of Animal and Veterinary Advances, 12: 1461-1467.