title: Involvement of DNA-PKcs in the type I IFN response to CpG-ODNs in conventional dendritic cells in TLR9-dependent or -independent manners.
abstract: CpG-ODNs activate dendritic cells (DCs) to produce interferon alpha (IFNα) and beta (IFNβ). Previous studies demonstrated that Toll-like receptor 9 (TLR9) deficient DCs exhibited a residual IFNα response to CpG-A, indicating that yet-unidentified molecules are also involved in induction of IFNα by CpG-A. Here, we report that the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) but not Ku70 deficient BMDCs showed defective IFNα and IFNβ responses to CpG-A or CpG-B. Loss of both DNA-PKcs and TLR9 further reduced the IFNα response to CpG-A. These DNA-PKcs and TLR9 effects were mediated by their downstream Akt/mTORC1 pathway and downstream events IRAK1 and IKKα. Loss of DNA-PKcs, TLR9, MyD88 or IRAK4 impaired phosphorylation of Akt(S473), S6K, S6, IRAK1, or IKKα in BMDCs in response to CpG-ODNs. The residual IFNα and IFNβ in DNA-PKcs-deficient BMDCs were partially responsible for the induction of IL-6 and IL-12 by CpG-ODNs and their stimulatory effect was blocked by IFNAR1 neutralizing antibodies. Further analysis indicated that CpG-ODN associated with DNA-PKcs and Ku70, and induced DNA-PKcs's interaction with TRAF3. Intriguingly, DNA-PKcs but not Ku70 expression level was reduced in TLR9-deficient BMDCs. Taken together, our data suggest that DNA-PKcs is an important mediator in the type I IFN response to CpG-ODNs in TLR9-dependent or -independent fashions.
authors: Department of Cancer Biology, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, United States of America.
authors: Chi
authors: C
authors: Ma
authors: Department of Cancer Biology, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, United States of America.
authors: Narrissa P
authors: NP
authors: Spies
authors: Department of Cancer Biology, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, United States of America.
authors: Ting
authors: T
authors: Gong
authors: Department of Cancer Biology, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, United States of America.
authors: Can Xin
authors: CX
authors: Jones
authors: Department of Cancer Biology, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, United States of America.
authors: Wen-Ming
authors: WM
authors: Chu
mesh_terms: D000818:Animals; D034961:Antigens, Nuclear / Q000276:immunology / Q000378:metabolism; D051747:DNA-Activated Protein Kinase / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D007370:Interferon Type I / Q000494:pharmacology*; D053592:Interleukin-1 Receptor-Associated Kinases / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism / Q000494:pharmacology; D000072200:Ku Autoantigen; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D018345:Mice, Knockout; D046912:Multiprotein Complexes / Q000378:metabolism; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D010766:Phosphorylation; D011485:Protein Binding; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D050794:STAT1 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D048008:TNF Receptor-Associated Factor 3 / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000378:metabolism*
chemical_list: D034961:Antigens, Nuclear; C408982:CPG-oligonucleotide; D004268:DNA-Binding Proteins; D007370:Interferon Type I; D015850:Interleukin-6; D046912:Multiprotein Complexes; D053594:Myeloid Differentiation Factor 88; D009838:Oligodeoxyribonucleotides; D050794:STAT1 Transcription Factor; D048008:TNF Receptor-Associated Factor 3; D051217:Toll-Like Receptor 9; D018664:Interleukin-12; D051747:DNA-Activated Protein Kinase; D053592:Interleukin-1 Receptor-Associated Kinases; D000076222:Mechanistic Target of Rapamycin Complex 1; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen