Figure 3. Antigen-specific CD4⁺ memory T cells induced by aAVC-OVA show the multi-functionality.

(a) Kinetics of serum anti-OVA antibody isotype of OT-II transferred, aAVC-OVA immunized mice at indicated time points. C57BL/6 mice were transferred with 1 × 10⁵ OT-II cells and then immunized with 5 × 10⁵ aAVC-OVA 24 h later. OVA-specific IgG1 and IgG2b antibody levels were measured by ELISA 2, 4 and 8 weeks later. (Mean±SEM, n = 4–16) (b–d) Antigen-specific CD4⁺ T cells response after immunization of aAVC-OVA immunized mice. (b) As shown in (a) but the mice were immunized with or without 5 × 10⁵ aAVC-OVA. One week or 4 weeks after immunization, OT-II cells in spleen were analyzed for the frequency (left) and the expression of CD44 and CD62L (middle). The subsets were shown (right). (Mean±SEM, n = 4–9). (c,d) As shown in (b) but cytokine production by OT-II was analyzed by intracellular cytokine staining using IFN-γ-APC and IL-2-PE or IL-4-APC or IL-10-PE after stimulation with OVA peptide in vitro for 6 h gating on CD45.1⁺CD4⁺ cells. (Mean ± SEM, n = 4–9) **P < 0.01, ***P < 0.001.