Down-regulation of TLR9 expression affects the maturation and function of murine bone marrow-derived dendritic cells induced by CpG.
Toll-like receptor 9 (TLR9) is expressed intracellularly by dendritic cells (DCs) and specifically recognizes unmethylated CpG motif. Recognition of TLR9 to CpG DNA can induce DC maturation followed by the subsequent immune responses. Here, RNA interference (RNAi) was used to identify the effect of CpG DNA signaling on DC function. The results showed that transfection of DCs with siRNA specific for TLR9 gene significantly down-regulated TLR9 expression. Immature DCs transfected with TLR9 siRNA did not differentiate into mature DCs with exposure to CpG. TLR9 siRNA-treated DCs expressed low levels of MHC II and CD40 without reducing endocytosis. Furthermore, TLR9 siRNA-transfected DCs exhibited a decreased allostimulatory capacity in a lymphocyte proliferation assay and attenuated Th1 responses by decreasing IL-12p70 production. Our findings indicate that siRNA in silencing TLR9 gene in DCs may offer a potential tool to study the TLR9-CpG pathway.
Ma
Ling
L
Immunology and Reproductive Biology Lab, Medical School & State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, China.
Zhao
Guangfeng
G
Hua
Chunyan
C
Li
Xiaoxi
X
Zhao
Xiaoyin
X
Sun
Lingyun
L
Hou
Yayi
Y
D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014162:Transfection
D019013:CD40 Antigens; D000949:Histocompatibility Antigens Class II; D009838:Oligodeoxyribonucleotides; D034741:RNA, Small Interfering; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9; D018664:Interleukin-12