Biochemical and Biophysical Research Communications, Vol.522, No.1, 26-32, 2020
Early secreted antigenic target 6-kDa from Mycobacterium tuberculosis enhanced the protective innate immunity of macrophages partially via HIF1 alpha
Early secreted antigenic target 6-kDa protein (ESAT6) is an essential virulence factor of Mycobacterium tuberculosis (MTb). However, ESAT6 helped fighting MTb infection according to vaccine studies. It's unclear whether ESAT6 confers protection via enhancing the innate immunity of macrophages, which are the first-line defense against MTb. We profiled the global transcriptional changes and characterized the innate immunity of THP-1 macrophages treated with ESAT6. We found ESAT6 promoted the phagocytosis ability, enhanced reactive oxygen species (ROS) generation and accelerated glucose metabolism in macrophages. Meanwhile, ESAT6 induced a distinctive phenotype of macrophages with a concurrence of pro-inflammatory and anti-inflammatory cytokines and chemokines. ESAT6 increased the expression of HIF1 alpha mRNA and protein. Interfering HIF1 alpha with siRNA defected the capacity of phagocytosis and ROS generation as well as glucose metabolism. Thus, ESAT6 enhanced the protective innate immunity of macrophages partially via HIF1 alpha. This study provided clues for developing therapies against tuberculosis by targeting ESAT6. (C) 2019 Elsevier Inc. All rights reserved.