Article Figures & Data
Figures
- Fig. 1.
Determination of anti-E2 isotype antibodies in the immunized mice. IgG1 (A) and IgG2a (B) isotypes of anti-E2 antibodies in sera from immunized mice were determined by ELISA using purified hghE2t protein and isotype-specific secondary antibodies. The mean titers of anti-E2 antibodies of eight mice per group (plus standard error of the mean) obtained at week 3 after the first (□), second (▨), and final (■) injections are shown. The different vaccination regimens are at the bottom; the number of injections are indicated.
- Fig. 2.
E2-specific CTL responses in the immunized BALB/c mice. Spleen cells obtained at week 3 after third (A and B) or second (C and D) immunizations were maintained in RPMI 1640 medium supplemented with 10 mM HEPES buffer, 5 × 10−5 M 2-mercaptoethanol, and 10% fetal bovine serum (GIBCO BRL). Responder cells (2.0 × 107) were restimulated in vitro with mitomycin C-treated (25 μg/ml) CT26-hghE2t cells (1.0 × 106) at 37°C. After a 1-week in vitro culture, effector cells were tested in a conventional cytotoxicity assay against two different target cells, such as CT26-hghE2t (A and C) or P815 infected with recombinant vaccinia virus expressing HCV core and E1 and E2 proteins (B and D). Data are represented as percentage of specific lysis (plus standard error of the mean) versus effector-to-target ratios, where n = 8.
- Fig. 3.
Protection of immunized mice from modified CT26 tumor cells expressing hghE2t. BALB/c (nine per group) mice immunized with control vector, pTV2sE2t, and/or gDE2t protein were injected s.c. with 2.0 × 106 CT26-hghE2t tumor cells. The vitality of individual mice was monitored for 20 weeks after tumor cell injection.
Tables
- Table 1.
The end point titers of antibodies in the immunized mice
Group no. DNA and/or protein (no. of injections)a No. of mice Anti-E2 IgG titer (102) 3 weeks afterb: First injection Second injection Third injection I pTV2 (3) 17 2 ± 1 4 ± 2 9 ± 3 II pTV2 (2), gDE2t (1) 8 2 ± 1 4 ± 2 277 ± 67 III pTV2sE2t (2), gD (1) 8 53 ± 9 199 ± 33 312 ± 45 IV pTV2sE2t (2), gDE2t (1) 17 61 ± 12 245 ± 44 7,003 ± 2,234 V pTV2sE2t (3) 17 57 ± 11 212 ± 33 673 ± 121 VI gDE2t (2), pTV2sE2t (1) 8 232 ± 42 1,098 ± 212 1,520 ± 235 VII gDE2t (3) 17 267 ± 55 1,123 ± 234 3,121 ± 458 VIII pTV2sE2t (1), gDE2t (1) 8 55 ± 11 601 ± 173 ↵a Female BALB/c mice were injected with 100 μg of DNA (i.m.) or 5 μg of protein (s.c.) and then boosted one time (group VIII) or two times (groups I to VII) with an identical dose of DNA or protein at 4-week intervals.
↵b Data shown represent geometric mean titers ± standard errors for each group of animals.
