Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 265.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 265.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 265.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Warning: imagejpeg(C:\Inetpub\vhosts\kidney.de\httpdocs\phplern\24259296
.jpg): Failed to open stream: No such file or directory in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 117 Int+J+Cancer
2014 ; 134
(12
): 2853-64
Nephropedia Template TP
gab.com Text
Twit Text FOAVip
Twit Text #
English Wikipedia
Subpopulations of myeloid-derived suppressor cells impair T cell responses
through independent nitric oxide-related pathways
#MMPMID24259296
Raber PL
; Thevenot P
; Sierra R
; Wyczechowska D
; Halle D
; Ramirez ME
; Ochoa AC
; Fletcher M
; Velasco C
; Wilk A
; Reiss K
; Rodriguez PC
Int J Cancer
2014[Jun]; 134
(12
): 2853-64
PMID24259296
show ga
The accumulation of myeloid-derived suppressor cells (MDSC) in tumor-bearing
hosts is a hallmark of malignancy-associated inflammation and a major mediator
for the induction of T cell suppression in cancer. MDSC can be divided
phenotypically into granulocytic (G-MDSC) and monocytic (Mo-MDSC) subgroups.
Several mechanisms mediate the induction of T cell anergy by MDSC; however, the
specific role of these pathways in the inhibitory activity of MDSC subpopulations
remains unclear. Therefore, we aimed to determine the effector mechanisms by
which subsets of tumor-infiltrating MDSC block T cell function. We found that
G-MDSC had a higher ability to impair proliferation and expression of effector
molecules in activated T cells, as compared to Mo-MDSC. Interestingly, both MDSC
subgroups inhibited T cells through nitric oxide (NO)-related pathways, but
expressed different effector inhibitory mechanisms. Specifically, G-MDSC impaired
T cells through the production of peroxynitrites (PNT), while Mo-MDSC suppressed
by the release of NO. The production of PNT in G-MDSC depended on the expression
of gp91(phox) and endothelial NO synthase (eNOS), while inducible NO synthase
(iNOS) mediated the generation of NO in Mo-MDSC. Deletion of eNOS and gp91(phox)
or scavenging of PNT blocked the suppressive function of G-MDSC and induced
anti-tumoral effects, without altering Mo-MDSC inhibitory activity. Furthermore,
NO-scavenging or iNOS knockdown prevented Mo-MDSC function, but did not affect
PNT production or suppression by G-MDSC. These results suggest that MDSC
subpopulations utilize independent effector mechanisms to regulate T cell
function. Inhibition of these pathways is expected to specifically block MDSC
subsets and overcome immune suppression in cancer.
|Animals
[MESH]
|CD8-Positive T-Lymphocytes/*immunology
[MESH]
|Cell Line, Tumor
[MESH]
|Cell Proliferation
[MESH]
|Female
[MESH]
|Granulocytes/*immunology
[MESH]
|Humans
[MESH]
|Lymphocyte Activation/immunology
[MESH]
|Membrane Glycoproteins/genetics
[MESH]
|Mice
[MESH]
|Mice, Inbred C57BL
[MESH]
|Monocytes/*immunology
[MESH]
|NADPH Oxidase 2
[MESH]
|NADPH Oxidases/genetics
[MESH]
|Neoplasms/immunology
[MESH]
|Nitric Oxide Synthase Type II/genetics
[MESH]
|Nitric Oxide Synthase Type III/biosynthesis/genetics
[MESH]