Fig. 6.

Analysis of cytokines secreted by lymphocyte of mice. Lymphocytes isolated from the spleen of mice at 56 dpi were stimulated with PCV2 strain DF-1 for 72 h, the supernatants were collected to detect the concentrations of cytokine of IFN-γ (a), IL-10 (b), IL-18 (c), TNF-ɑ (d), GM-CSF (e) by ELISA method and the T-lymphocyte proliferation (f) . Date are shown as mean ± SEM, statistical differences between each group was measured by one-way ANOVA, *P < 0.05, **P < 0.01, ***P < 0.001, ns represented not significant