Page 18 - O. Microbiology

[O. Microbiology-17]

Down-regulation of Herp suppresses mycobacterial growth in

macrophages

Sang-Hun Son¹˙², Ji-Ae Choi¹˙², Junghwan Lee¹˙², Soo-Na Cho¹˙², Doan Tam Nguyen¹˙², Seongahn Lee¹˙²,
Chang-Hwa Song¹˙²˙³˙*

¹Department of Microbiology, College of Medicine, Chungnam National University, Daejeon 35015, South Korea,

²Department of Medical Science, Chungnam National University, Daejeon 35015, South Korea, ³Translational
Immunology Institute, Daejeon 34134, South Korea

Spreading of multidrug-resistant tuberculosis (MDR-TB) is one of the difficult problems to control TB. Previous

reports have suggested that endoplasmic reticulum (ER) stress and autophagy affect the intracellular survival of
mycobacteria. Here, we suggest that Homocysteine inducible ER protein with ubiquitin like domain 1 (Herp) plays

an important role in suppression of Mtb growth in macrophages. We found that production of Homocysteine
inducible ER protein with ubiquitin like domain 1 (Herp) is increased in Mtb-infected macrophages via ER stress

pathway. In Herp deficient conditions, NADPH oxidase 2 (NOX2) production was increased and it sequentially leads
to reactive oxygen species (ROS) production. Interestingly, the increased ROS production was not associated with

apoptosis but autophagy is increased in Herp-/- macrophages. Moreover, MHC-II expression on Herp deficient
macrophages was markedly increased. Finally, we revealed that silencing of Herp expression decreased the

intracellular survival of mycobacteria in vitro and in vivo. Thus, regulation of Herp in Mtb-infected macrophages
could lead to suppression of intracellular growth of Mtb via increased ROS and autophagy activation.