Abstract：Mycobacterium cell wall is rich in lipid components, and some of the lipids may have antigenicity or play an important role in the process of immune regulation. To investigate the effects of the lipids from Mycobacterium cell wall in tuberculosis subunit vaccine, the total lipids were extracted from bacillus CalmetteGuérin (BCG) cell wall and separated by silica column into three different groups: the nonpolar lipids, the intermediate polar lipids and the polar lipids. The lipids were used as the antigen to screen the immune responses in general population. Furthermore, the total lipids and the three groups of lipids were mixed with fusion protein LT70(ESAT6-Ag85BMPT64<1901-98>Mtb8.4-Rv2626c) in adjuvant of N, N′dimethylN, N′dioctadecylammonium(DDA) and Poly (I:C) respectively. The subunit vaccines containing lipids were used to immunize mice and the protective efficacy were evaluated by challenging with BCG. The results showed that the level of lipidspecific IgG in tuberculosis patients was significantly higher than that in healthy people (P＜0.05). For the protective efficacy, the number of bacteria harbored in mice immunized with LT70total lipids significantly declined compared with BCG vaccination (P＜0.05). In BCG primesubunit vaccine boost strategy, LT70total lipids and LT70intermediate polar lipids vaccines resulted in significantly low bacterial number than BCG (P＜0.01) and LT70 (P＜0.05). In conclusion, lipids from Mycobacterium cell wall have high immunogenicity; combination of them, especially the total lipids or intermediate polar lipids, with fusion protein antigen can enhance the antimycobacterial protective efficacy of subunit vaccine.
