Galectin-9 promotes TGF-β1-dependent induction of regulatory T cells via the TGF-β/Smad signaling pathway.
TGF-β1 induces the conversion of CD4+CD25- T cells into CD4+CD25+Foxp3+ regulatory T cells (Tregs). Galectin-9, one of the β-galactoside-binding animal lectins belonging to the galectin family, induces apoptosis of eosinophils, cancer cells and T cells. In this study, we report the effects of galectin-9 on the conversion of CD4+CD25- T cells into Foxp3-expressing induced Tregs (iTregs). Galectin-9 together with TGF-β1 had synergistic effects on the rate of conversion to iTregs in vitro. TGF-β1 signaling appears to be essential for the effects of galectin-9 on the generation of iTregs, as galectin-9 promotes TGF-β1-induced phosphorylation of Smad2/3, ERK1/2 and formation of the Smad2/3-Smad4 complex. These data suggest a role for galectin-9 as a promoter of the TGF-β1-dependent conversion of CD4+CD25- T cells into iTregs in vitro. Therefore, in addition to inducing apoptosis, galectin-9 may contribute to the regulation of inflammation via the expansion of peripheral Tregs.
Central Laboratory, Yijishan Hospital, Wannan Medical College, Wuhu 241001, PR China. lvkun315@126.com
Kun
K
Lv
Yingying
Y
Zhang
Mengying
M
Zhang
Min
M
Zhong
Qifeng
Q
Suo
D000818:Animals; D004357:Drug Synergism; D051858:Forkhead Transcription Factors / Q000378:metabolism; D037161:Galectins / Q000494:pharmacology*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D015398:Signal Transduction / Q000187:drug effects*; D051785:Smad Proteins / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
D051858:Forkhead Transcription Factors; D037161:Galectins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D046912:Multiprotein Complexes; D051785:Smad Proteins; D053773:Transforming Growth Factor beta1; C498833:Foxp3 protein, mouse; C508186:galectin 9, mouse