Abstract: Objective To investigate the specific immune response induced by topical application of liposome-entrapped herpes simplex virus-2 glycoprotein D(HSV-2gD)-Bacillus tuberculosis heat shock protein(HSP)70 fusion protein in mice.Methods Forty BALB/C mice were randomly divided into 4 groups to be immunized by empty liposomes,liposome-entrapped gD,liposome-entrapped gD and HSP70, and liposome-entrapped gD-HSP70 fusion protein,respectively,once a day for 3 weeks.At 4 weeks after the last immunization,the serum level of anti-HSV-2gD IgG antibody was assessed.At the same time,lympho-cytes were isolated from the spleen of the vaccinated mice and stimulated with HSV-2gD protein,the prolif-eration of lymphocytes was measured by MTT assay,and ELISA assay was utilized to measure the levels of IFN-γand IL-4 in the culture medium of lymphocytes.Results Liposome-entrapped gD,gD+HSP70,and HSP70-gD fusion protein all induced the production of IgG antibody against HSV-2gD,the proliferation of lymphocytes,and secretion of IFN-γand IL-4 by these lymphocytes.The serum level of IgG antibody against HSV-2gD,stimulation index of spleen lymphocytes,and levels of IFN-γand IL-4 were all significantly higher in mice immunized by liposome-entrapped HSP70-gD fusion protein than in those immunized by gD and gD+HSP70(all P<0.05).Conclusion These results suggest that HSP70 could promote the induction of specific immune response in mice by HSV-2gD.

Key words: Heat-shock proteins 70, Glycoproteins, Herpes simplex virus vaccine, Liposomes