Abstract:
To develop a novel subunit vaccine for
Mycobacterium tuberculosis (Mtb), biological nanoparticle was used to display the main antigen of Mtb, ESAT6. The gene fragment of
ESAT6 was cloned into the loop2 of the norovirus P domain in pGEX-4T-1. The resulting chimeric gene was expressed in
E. coli BL21(DE3), and the chimeric protein was purified by the GST affinity column. The formation efficiency of chimeric nanoparticle was analyzed by the fast protein liquid chromatography (FPLC), and the immunogenicity was evaluated by immunizing BALB/c mice. The results showed that we successfully cloned
ESAT6 gene into the Loop2 of norovirus P domain. Protein structure homology-model showed that ESAT6 could be displayed on the surface of P nanoparticle. FPLC analysis showed that the purified chimeric protein could self-assemble into nanoparticle efficiently. Immunization of mice with this chimeric nanoparticle induced specific antibody against ESAT6 nanoparticle. Further analysis revealed that the induced antibody was mainly against the peptide 51-70aa of ESAT6, rather than the peptide 1-20aa. In conclusion, the main antigen ESAT6 of Mtb was successfully displayed by norovirus P particle in this study, which laid a foundation for the further development of novel Mtb subunit vaccine.