Effects of TGF-β stimulation on mouse splenic dendritic cells
Objective 
To investigate the mechanisms modulating the functions of dendritic cells (DCs) and suppressing the activation and proliferation of T cells by transforming growth factor-β (TGF-β). 
 
 
Methods 
Mouse splenic DCs were purified with CD11c+ immunomagnetic beads and the purity of isolated DCs were detected by flow cytometry. Gene chip was used to detect gene expression in DCs after stimulation with TGF-β, and then real-time PCR was performed to analyze the differentially expressed genes in microarray at mRNA level. The activation and proliferation of CD4+ T cells which were co-cultured with DCs after stimulation with TGF-β were detected by flow cytometry. 
 
 
Results 
The purity of DCs reached over 95% after isolation. TGF-β down-regulated the expression of cell surface markers CD53, CD69, CD33, CD74 and CD93 on DCs; decreased the expression of chemokines Ccl3, Ccl5, Ccl9, Ccl6, Ccl17, Cxcl10, Ccl22, Ccl4, Ccr7, Ccl2, Cxcl9 and Ccl7; inhibited the expression of inflammatory cytokines IL-2ra, IL-12rb2, IL-15ra, IL-1b and IL-15. Moreover, the DCs-mediated activation and proliferation of CD4+ T cells were suppressed by TGF-β. 
 
 
Conclusion 
TGF-β inhibits the DCs-mediated activation and proliferation of CD4+ T cells by suppressing the expression of surface markers on DCs and down-regulating the expression of chemokines and inflammatory cytokines. 
 
 
Key words: 
TGF-β; Gene chip; Dendritic cell; CD4+ T cell