Inhibitory oligonucleotides block the induction of AP-1 transcription factor by stimulatory CpG oligonucleotides in B cells.
The proliferative response of primary B cells to CpG oligonucleotides (ODN) involves induction of nuclear activation promoting-1 (AP-1) transcription factor. AP-1 subunits c-Fos, Fos-B, Jun-B, and Jun-D, but not Fra-1 or Fra-2, were all induced by CpG ODNs in B cells within 30 minutes of stimulation, followed by c-Jun at 1-2 hours. c-Jun reached maximum at 6 hours. By 40 hours, Jun-B and Jun-D became dominant. Synthetic ODNs containing a single guanosine triplet/tetrad appropriately distanced from the 5' pyrimidine-rich unit, which inhibit CpG-driven cell cycle entry and apoptosis protection, blocked AP-1 induction by stimulatory ODNs when they were added simultaneously. After 30 minutes of stimulation, adding inhibitor no longer affected AP-1 at 6 hours. No AP-1 subunits escaped ODN inhibition. In a cell line transfected with an AP-1-beta-galactosidase reporter construct, CpG ODN-induced AP-1 transcriptional activity was prevented by inhibitory ODN, but lipopolysaccharide (LPS)-induced AP-1 activity was not. These data suggest that inhibitory ODNs block the CpG ODN-driven signaling pathway at a site proximal to AP-1 induction.
Lenert
Petar
P
Department of Internal Medicine, University of Iowa, College of Medicine, Iowa City, IA 52242, USA. petar-lenert@uiowa.edu
Yi
Ae-Kyung
AK
Krieg
Arthur M
AM
Stunz
Laura L
LL
Ashman
Robert F
RF
D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D001693:Biological Transport, Active; D002460:Cell Line; D005260:Female; D017930:Genes, Reporter; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000494:pharmacology; D007700:Kinetics; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D009838:Oligodeoxyribonucleotides / Q000235:genetics / Q000276:immunology / Q000493:pharmacokinetics / Q000494:pharmacology*; D015398:Signal Transduction; D013873:Thionucleotides / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
D000276:Adjuvants, Immunologic; C408982:CPG-oligonucleotide; D007166:Immunosuppressive Agents; D009838:Oligodeoxyribonucleotides; D013873:Thionucleotides; D018808:Transcription Factor AP-1