Fig. 4
SRIP-SP70 confers dual protective immunity against JEV or EV71 challenge via Th1-predominant immune response. Survival rates were evaluated for groups of one-day-old ICR newborns from their mothers that had been immunized with PBS alone, SRIP or SRIP-SP70 using SRIP immunization protocol (a) or by prime-boost SRIP immunization protocol (b). These newborns were lethally challenged by either 1 × 103 PFU of JEV rRP-9 (the left part of panels a and b) or 4 LD50 of EV71/MP4 (the right part of panels a and b). c Serum specific IgG from immunized dams. To measure serum specific anti-SP70 IgG titers by ELISA, the SRIP-SP70-immunized sera were collected from groups of female ICR mice at the indicated times after prime-boost SRIP immunization protocol. d Serum IgG subtyping from each pregnant mouse. The specific anti-SP70 IgG in serum was subtyped by ELISA isotype binding assays, and each individual serum was collected and analyzed 4 week after immunization protocol completed in (c). Data are shown as mean for group mice (n = 5). The symbols represent immunized ICR mice and parentheses indicate survival rate of newborns after challenges. The serum titer that was less than 27 dilutions will be marked as 0. ELISA plates were coated with 10 μg/ml of synthetic SP70 peptide as antigen. Star * indicates p value < 0.05. ND means no difference