CD8(+) T cells that produce interleukin-17 regulate myeloid-derived suppressor cells and are associated with survival time of patients with gastric cancer.
OBJECTIVE
CD8(+) T cells that produce interleukin (IL)-17 (Tc17 cells) promote inflammation and have been identified in tumors. We investigated their role in the pathogenesis of gastric cancer.


METHODS
We used flow cytometry analyses to determine levels and phenotype of Tc17 cells in blood and tumor samples from 103 patients with gastric cancer. We performed multivariate analysis to identify factors associated with overall survival using the Cox proportional hazards model. CD8(+) T cells and monocytes were isolated and cocultured in an assay for induction of Tc17 cells. Tumor cells and myeloid-derived suppressor cells (MDSCs) were isolated and used in assays of Tc17 cell function.


RESULTS
Tc17 cells with distinct cytokine and functional profiles were found in gastric tumor samples from patients. The percentage of Tc17 cells increased with tumor progression and was associated with overall survival time. Tumor-activated monocytes secreted IL-6, IL-1β, and IL-23, which promoted development of Tc17 cell populations. Supernatants from cultured Tc17 cells induced production of the chemokine CXCL12 by tumor cells; this promoted CXCR4-dependent migration of MDSCs and impaired functions of anti-tumor CD8(+) cytotoxic T cells via a cell contact-dependent mechanism.


CONCLUSIONS
Percentages of Tc17 cells in gastric tumors are associated with survival times of patients. These cells promote chemotaxis of MDSCs, which might promote tumor progression.
Department of Clinical Microbiology and Immunology, College of Medical Laboratory Science, Third Military Medical University, Chongqing, China.
Yuan
Y
Zhuang
Liu-Sheng
LS
Peng
Yong-Liang
YL
Zhao
Yun
Y
Shi
Xu-Hu
XH
Mao
Weisan
W
Chen
Ken C
KC
Pang
Xiao-Fei
XF
Liu
Tao
T
Liu
Jin-Yu
JY
Zhang
Hao
H
Zeng
Kai-Yun
KY
Liu
Gang
G
Guo
Wen-De
WD
Tong
Yan
Y
Shi
Bin
B
Tang
Na
N
Li
Shu
S
Yu
Ping
P
Luo
Wei-Jun
WJ
Zhang
Dong-Shui
DS
Lu
Pei-Wu
PW
Yu
Quan-Ming
QM
Zou
D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D054377:Chemokine CXCL12 / Q000378:metabolism; D002633:Chemotaxis; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006098:Granulocytes / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D020381:Interleukin-17 / Q000096:biosynthesis*; D053583:Interleukin-1beta / Q000378:metabolism; D053759:Interleukin-23 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D015999:Multivariate Analysis; D023461:Myeloid Progenitor Cells / Q000378:metabolism; D010641:Phenotype; D011379:Prognosis; D016016:Proportional Hazards Models; D019718:Receptors, CXCR4 / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology
C527276:CXCR4 protein, human; D054377:Chemokine CXCL12; D020381:Interleukin-17; D053583:Interleukin-1beta; D053759:Interleukin-23; D015850:Interleukin-6; D019718:Receptors, CXCR4