Abstract: Objective:To investigate the MUC1 specific immune response enhanced by thmosinα1(Tα1) using MUC1-MBP as the specific antigen,and to discuss the feasibility of MUC1-MBP as an adjuvant. Methods: The C57BL/6 mice were randomly divided into normal saline group,MUC1-MBP+BCG group and MUC1-MBP+Tα1 group.The T cellular immune activities,MUC1 special antibody and subclass,anti-tumor effect of Tα1 combined with MUC1-MBP were detected.4-7d after the 3rd immunization,the spleen indexes of the mice in various groups were measured; the lymphocyte proliferation response was used to detect the stimulate index(SI) of the mice in various groups; the levels of specific cytokines IFN-γ,IL-2,IL-4 and IL-10 in the supernatant of spleen cells of the mice were detected by ELISA; the level of serum MUC1-specific antibody was detected by ELISA.The C57BL/6 mice were inoculated with B16-MUC1 7 d after the last immunization and the survival of the mice was observed. Results: Compared with normal saline group,the spleen index and SI of the mice in MUC1-MBP+Tα1 and MUC1-MBP+BCG groups were significantly increased (P< 0.05 or P<0.01); the specific SI of MUC1 were significantly increased (P< 0.05).Compared with normal saline group,the levels of IFN-γ and IL-2 in the supernatant of spleen cells of the mice in MUC1-MBP+BCG group were obviously increased (P<0.05);the levels of IL-4 and IL-10 were slightly increased,but there were no significant differences (P>0.05); compared with normal saline group,the level of IL-4 in MUC1-MBP+Tα1 group was obviously increased (P< 0.01);the levels of IFN-γ,IL-2 and IL-10 were slightly increased,but there were no significant differences (P>0.05). The titer of MUC1 specific antibody was increased with the increase of concentration of Tα1. The antibody subtype detection results showed that compared with normal saline group,the level of IgG1 in MUC1-MBP+BCG group was significantly increased(P< 0.05 or P< 0.01),and the level of IgG2a had no obvious change.The tumor prevention experiment results showed that compared with normal saline group,the survival rates of the mice in MUC1-MBP+BCG group and MUC1-MBP+Tα1 group had no significant differences. Conclusion: MUC1-MBP combined with Tα1 prefers to Th2 immune responses in the mice.It indicates that Tα1 can be used as an adjuvanted preventive vaccines,but not suitable for therapeutic vaccines.

Key words: thmosin α1, adjuvant, mucin1-maltose brinding protein fusion protein, vaccines, Th2 immune response