We have developed a novel platform technology that can express high levels of recombinant lipoproteins with intrinsic adjuvant properties. In this study, Ag473 (a lipoprotein from Neisseria meningitidis) can be produced in high yields using Escherichia coli strain C43 (DE3). After testing a non-lipoimmunogen (E3, from dengue virus) fused with different lipid signal peptides from other lipoproteins as well as Ag473 fragments of different lengths, we identified that the fusion sequence has to contain at least the N-terminal 40 residues, D1, of Ag473 to achieve high expression levels of the recombinant lipo-immunogen (rlipo-D1E3). The rlipo-D1E3 was found to elicit stronger anti-E3 and virus neutralizing antibody responses in animal studies than those from rE3 alone or rE3 formulated with alum adjuvant. These results have successfully demonstrated the merit of lipo-immunogens for novel vaccine development.
