. Author manuscript; available in PMC: 2019 Apr 10.

Published in final edited form as: Expert Opin Ther Targets. 2018 Apr 10;22(4):353–363. doi: 10.1080/14728222.2018.1451514

Table 2.

Mechanisms used by Treg for immune suppression in the TME

Mechanism	Reference
Inhibitory cytokine production:	[41,96–98]
IL-10, TGF-β, IL-35
Soluble inhibitory factors:
IDO, PGE₂	[50,99]
T effector cell cytolysis:
Granzyme B, perforin	[100,101]
Metabolic interruption:
IL-2 deprivation	[102]
Adenosine production	[50,51]
cAMP-mediated effects	[103]
Receptor/ligand signaling:
Fas/FasL, TGF-β/TGFRII	[96,104]
Checkpoint Inhibition:
CTLA4, PD-1, TIM-3, LAG-3, TIGIT	[105]
Exosomes	[106,107]