Mesenchymal Stromal Cell Secretion of Programmed Death-1 Ligands Regulates T Cell Mediated Immunosuppression.
Stem Cells
; 35(3): 766-776, 2017 03.
Article
in En
| MEDLINE
| ID: mdl-27671847
ABSTRACT
Mesenchymal stromal cells (MSCs) exert broad immunosuppressive potential, modulating the activity of cells of innate and adaptive immune systems. As MSCs become accepted as a therapeutic option for the treatment of immunological disorders such as Graft versus Host Disease, our need to understand the intricate details by which they exert their effects is crucial. Programmed death-1 (PD-1) is an important regulator in T cell activation and homeostatic control. It has been reported that this pathway may be important in contact-dependent mediated immunomodulation by MSCs. The aim of this study was to establish whether MSCs, in addition to their cell-surface expression, are able to secrete PD-1 ligands (PD-L1 and PD-L2) and their potential importance in modulating contact-independent mechanisms of MSC immunosuppression. Here we report that MSCs express and secrete PD-L1 and PD-L2 and that this is regulated by exposure to interferon γ and tumor necrosis factor α. MSCs, via their secretion of PD-1 ligands, suppress the activation of CD4+ T cells, downregulate interleukin-2 secretion and induce irreversible hyporesponsiveness and cell death. Suppressed T cells demonstrated a reduction in AKT phosphorylation at T308 and a subsequent increase in FOXO3 expression that could be reversed with blockade of PD-L1. In conclusion, we demonstrate for the first time, that MSCs are able to secrete PD-1 ligands, with this being the first known report of a biological role for PD-L2 in MSCs. These soluble factors play an important role in modulating immunosuppressive effects of MSCs directly on T cell behavior and induction of peripheral tolerance. Stem Cells 2017;35766-776.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
T-Lymphocytes
/
Immunosuppression Therapy
/
Mesenchymal Stem Cells
/
B7-H1 Antigen
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Stem Cells
Year:
2017
Type:
Article