Title |
Autophagy of bovine mammary epithelial cell induced by intracellular Staphylococcus aureus |
Author |
Na Geng1, Kangping Liu2, Jianwei Lu1, Yuliang Xu1, Xiaozhou Wang1, Run Wang1, Jianzhu Liu2, Yongxia Liu1*, and Bo Han3 |
Address |
1College of Veterinary Medicine, Shandong Agricultural University, Tai`an 271018, P. R. China, 2Research Center for Animal Disease Control Engineering, Shandong Agricultural University, Tai`an 271018, P. R. China, 3College of Veterinary Medicine, China Agricultural University, Beijing 100193, P. R. China |
Bibliography |
Journal of Microbiology, 58(4),320-329, 2020,
|
DOI |
10.1007/s12275-020-9182-8
|
Key Words |
bovine mastitis, Staphylococcus aureus, autophagy,
bovine mammary epithelial cells, intracellular infection |
Abstract |
Bovine mastitis is a common disease in the dairy industry
that causes great economic losses. As the primary pathogen
of contagious mastitis, Staphylococcus aureus (S. aureus) can
invade bovine mammary epithelial cells, thus evading immune
defenses and resulting in persistent infection. Recently,
autophagy has been considered an important mechanism for
host cells to clear intracellular pathogens. In the current study,
autophagy caused by S. aureus was detected, and the correlation
between autophagy and intracellular S. aureus survival
was assessed. First, a model of intracellular S. aureus infection
was established. Then, the autophagy of MAC-T cells was
evaluated by confocal microscopy and western blot. Moreover,
the activation of the PI3K-Akt-mTOR and ERK1/2 signaling
pathways was determined by western blot. Finally, the
relationship between intracellular bacteria and autophagy
was analyzed by using autophagy regulators (3-methyladenine
[3-MA], rapamycin [Rapa] and chloroquine [CQ]). The
results showed that S. aureus caused obvious induction of
autophagosome formation, transformation of LC3I/II, and
degradation of p62/SQSTM1 in MAC-T cells; furthermore,
the PI3K-Akt-mTOR and ERK1/2 signaling pathways were
activated. The number of intracellular S. aureus increased
significantly with autophagy activation by rapamycin, whereas
the number decreased when the autophagy flux was inhibited
by chloroquine. Therefore, this study indicated that intracellular
S. aureus can induce autophagy and utilize it to survive
in bovine mammary epithelial cells. |