AUTHOR=Yin Yuelan , Lian Kai , Zhao Dan , Tao Chengwu , Chen Xiang , Tan Weijun , Wang Xiaobo , Xu Zhengzhong , Hu Maozhi , Rao Yan , Zhou Xiaohui , Pan Zhiming , Zhang Xiaoming , Jiao Xin'an 

TITLE=A Promising Listeria-Vectored Vaccine Induces Th1-Type Immune Responses and Confers Protection Against Tuberculosis

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.2017.00407

DOI=10.3389/fcimb.2017.00407

ISSN=2235-2988

ABSTRACT=<p>Deaths associated with tuberculosis (TB) is rising and accounted for 1.4 million deaths in 2015 many of which were due to drug-resistant bacteria. Vaccines represent an important medical intervention, but the current Bacilli Calmette-Guerin (BCG) vaccine is not ideal for the protection of teenagers and adults. Therefore, a safe and effective vaccine is urgently needed. In this study, we designed a novel vaccine using an attenuated <italic>Listeria monocytogenes</italic> strain carrying fusion antigen FbpB-ESAT-6 (rLM) and characterized its safety and protective efficacy against <italic>Mycobacterium tuberculosis</italic> (<italic>M.tb</italic>) infection in mice. Compared to the wild type strain yzuLM4 and parental strain LMΔ<italic>actA/plcB</italic> (LM1-2), the virulence of rLM was significantly reduced as judged by its infectious kinetics and LD<sub>50</sub> dose. Further characterization of intravenous immunization showed that prime-boost vaccination significantly increased the levels of Th1 cytokines (IFN-γ, IL-17, and IL-6), and enhanced cytotoxic T lymphocyte (CTL) CTLs activity, suggesting that rLM could elicit potent Th1/Th17 responses. More importantly, rLM significantly conferred the protection against <italic>M.tb</italic> H37Rv challenge. Collectively, our findings indicated that rLM is a novel and useful tool to prevent <italic>M.tb</italic> infection, and can be potentially be used to boost BCG-primed immunity.</p>