Figure 2.

GM-CSF as a rHBV vaccine adjuvant breaks the immune tolerance of HBsAg-Tg mice. (a) Schematic illustration of the immunization regimen. HBsAg-Tg mice were immunized with GM-CSF (10 μg or 30 μg) and rHBV (1 μg) as shown. Mice were immunized on days 0, 14, and 28. (b) Total serum anti-HBsAg IgG was analyzed on the seventh day after third immunization. Mean antibody titers are expressed as IU mL⁻¹ (ns > 0.05, **p < 0.01). (c) Serum HBsAg was analyzed on the seventh day after third immunization. (d) Alanine aminotransferase (ALT) activity in the serum was analyzed on the seventh day after the third immunization. (e) Mice were challenged with rHBVvac on the seventh day after the third immunization, and DTH was measured 24 and 48 h later (ns > 0.05, *p < 0.05, **p < 0.01). (f) Representative eFluor670 plots of the proliferating T cells are shown; splenic T cells were isolated on day 14 after the third immunization and labeled with eFluor670, cultured with rHBsAg (10 μg mL⁻¹) for three days and stained for CD3. (g) The percentage increase in T-cell proliferation is summarized (*p < 0.05). There were five mice in each group. Data shown are representative of three independent experiments.