Evaluation on the Efficacy and Immunogenicity of Recombinant DNA Plasmids Expressing Spike Genes from Porcine Transmissible Gastroenteritis Virus and Porcine Epidemic Diarrhea Virus

Meng, Fandan; Ren, Yudong; Suo, Siqingaowa; Sun, Xuejiao; Li, Xunliang; Li, Pengchong; Yang, Wei; Li, Guangxing; Li, Lu; Schwegmann-Wessels, Christel; Herrler, Georg; Ren, Xiaofeng

Flow cytometry data showed that the levels of CD 4 + and CD 8 + T lymphocytes in peripheral blood gradually increased from 14 dpi to 42 dpi (Figure 3 ). The levels of CD 4 + cells ( Figure 5A ) in mice immunized with pIRES-(TGEV-S1-PEDV-S) was significantly (p,0.01) increased already at 28 dpi. By 42 dpi the number of CD 4 + T cells from mice immunized with pIRES-(TGEV-S1-PEDV-S1) was also increased but the value for mice immunized with pIRES-(TGEV-S1-PEDV-S) was higher. In the case of CD 8 + cells, cell numbers were increased at 28 dpi in mice immunized with pIRES-(TGEV-S1-PEDV-S1) and pIRES-(TGEV-S1-PEDV-S) to a similar extent ( Figure 5B) . A further increase by 42 dpi was observed in the pIRES-(TGEV-S1-PEDV-S) group (p,0.05) whereas in the pIRES-(TGEV-S1-PEDV-S1) group at 42 dpi only a slight increase was determined. When spleen CD 4 + lymphocyte numbers were examined by flow cytometry, the results again showed a gradual increase from 14 dpi to 42 dpi ( Figure 6A ), and the highest value was determined for the pIRES-(TGEV-S1-PEDV-S) group at 42 dpi. Analyses of spleen-derived CD 8 + T cells ( Figure 6B ) in animals immunized with pIRES-(TGEV-S1-PEDV-S1) or pIRES-(TGEV-S1-PEDV-S) showed a clear increase of the cell numbers by 28 and 42 dpi.