NK cells kill mycobacteria directly by releasing perforin and granulysin
Journal
Journal of Leukocyte Biology
Journal Volume
96
Journal Issue
6
Pages
1119-1129
Date Issued
2014
Author(s)
Lu C.-C.
Wu T.-S.
Hsu Y.-J.
Chang C.-J.
Lin C.-S.
Chia J.-H.
Wu T.-L.
Huang T.-T.
Martel J.
Ojcius D.M.
Young J.D.
Abstract
Although the mechanisms underlying the cytotoxic effect of NK cells on tumor cells and intracellular bacteria have been studied extensively, it remains unclear how these cells kill extracellular bacterial pathogens. In this study, we examine how human NK cells kill Mycobacterium kansasii and M.tb. The underlying mechanism is contact dependent and requires two cytolytic proteins: perforin and granulysin. Mycobacteria induce enhanced expression of the cytolytic proteins via activation of the NKG2D/NCR cell-surface receptors and intracellular signaling pathways involving ERK, JNK, and p38 MAPKs. These results suggest that NK cells use similar cellular mechanisms to kill both bacterial pathogens and target host cells. This report reveals a novel role for NK cells, perforin, and granulysin in killing mycobacteria and highlights a potential alternative defense mechanism that the immune system can use against mycobacterial infection.
SDGs
Type
journal article