Fig. 4

Efficient immunogenicity of E2ZJ in mice. Twenty six-week-old female BALB/c mice were randomly divided into 4 groups (A, B, C and D, n = 5). Groups A to C were respectively immunized twice with 50 μg of E2 (E2ZJ, E2HZ or E2C). Group D was injected with PBS as control. a, b Detection of CSFV-specific antibodies in mouse sera elicited with different E2s (E2ZJ, E2HZ and E2C) with CSFV infected cells. PK-15 cells were infected with HZ08, C-strain or Shimen at MOI of 0.1. Cells were stained respectively with diluted serum (1:200) collected at 14 dpi and 21 dpi. Negative serum was from mice without any immunization. Anti-E2 mAb 6D10 was used as controls to indicate successful infection. c Detection of E2-specific antibodies in mouse serum with ELISA. Diluted serum samples (1:200) after days post vaccination were determined by indirect ELISA. d Detection of CSFV neutralizing antibodies against HZ08 strain in mouse serum. Serum samples were collected at weekly intervals after immunization with different E2s. PBS group is the sera from mice injected with PBS only. Experiments were performed in triplicate and data are shown as mean ± SD. Statistical significance is indicated as (ns) (P > 0.05); *(P < 0.05)