Abstract: Objective: To study the inductive effect of recombinant MUC1-MBP fusion protein combined with R848 on the immune activity of T cells in the mice,and to provide experimental basis for searching the suitable adjuvants of recombinant MUC1-MBP fusion protein. Methods: A total of 21 C57BL/6 mice were randomly divided into control group(treat with normal saline),MUC1-MBP+R848 group (treated with MUC1-MBP+R848),and MUC1-MBP+baillus calmette guerin(BCG) group(treated with MUC1-MBP+BCG)(n=7).After immunized for 4-7 d,the spleen tissue was taken and the spleen indexes of the mice in various groups were measured; the stimmulus index(SI) of the mice was detected by lymphocyte proliferation response;the levels of tumor necrosis factor-γ(TNF-γ) and interleukin-4(IL-4) were detected by ELISA method;the proprotions of T lymphocyte subsets in spleen cells were analyzed by flow cytometry. Results: Compared with control group,the spleen indexes,SI,and TNF-γ levels of the mice in MUC1-MBP+ R848 and MUC1-MBP+BCG groups were significantly increased (P<0.05 or P<0.01);the indexes metioned above of the mice in MUC1-MBP+ R848 were higher than those in MUC1-MBP+BCG group;the IL-4 levels had no significant difference(P>0.05).Compared with control group,the proprotions of CD3⁺T,CD4⁺T,and CD8⁺ T cells of the mice in MUC1-MBP+ R848 group and MUC1-MBP+BCG group were significantly increased(P<0.05 or P<0.01). Conclusion: Both MUC1-MBP fusion protein combined with R848 and BCG can induce the Th1 type of immune activity in the mice,and R848 is the potential candidate adjuvant for MUC1-MBP.

Key words: R848, MUC1-MBP, adjuvant, cancer vaccine