AUTHOR=Xiang Zhi-hao , Sun Rui-feng , Lin Chen , Chen Fu-zeng , Mai Jun-tao , Liu Yu-xiao , Xu Zi-yan , Zhang Lu , Liu Jun 

TITLE=Immunogenicity and Protective Efficacy of a Fusion Protein Tuberculosis Vaccine Combining Five Esx Family Proteins

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=7

YEAR=2017

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2017.00226

DOI=10.3389/fcimb.2017.00226

ISSN=2235-2988

ABSTRACT=<p>One strategy to develop the next generation of tuberculosis vaccines is to construct subunit vaccines based on T cell antigens. In this study, we have evaluated the vaccine potential of a fusion protein combining EsxB, EsxD, EsxG, EsxU, and EsxM of <italic>Mycobacterium tuberculosis</italic> (<italic>M. tb</italic>). This recombinant protein, named BM, was expressed in and purified from <italic>Escherichia coli</italic>. Immunization of C57BL/6 mice with purified BM protein formulated in Freund's incomplete adjuvant induced the production of Th1 cytokines (IFN-γ, TNF, and IL-2) and multifunctional CD4<sup>+</sup> T cells. Vaccination of BALB/c mice with BM protein followed by intravenous challenge with <italic>Mycobacterium bovis</italic> BCG resulted in better levels of protection than the two leading antigens, Ag85A and PPE18. Taken together, these results indicate that BM is a protective antigen. Future studies to combine BM with other antigens and evaluate its effectiveness as a booster of BCG or as a therapeutic vaccine are warranted.</p>