Preexposure of murine macrophages to CpG oligonucleotide results in a biphasic tumor necrosis factor alpha response to subsequent lipopolysaccharide challenge.
Bacterial DNA and synthetic oligonucleotides containing CpG sequences (CpG-DNA and CpG-ODN) provoke a proinflammatory cytokine response (tumor necrosis factor alpha [TNF-alpha], interleukin-12 [IL-12], and IL-6) and increased mortality in lipopolysaccharide (LPS)-challenged mice via a TNF-alpha-mediated mechanism. It was hypothesized that preexposure of macrophages to CpG-ODN would result in an increased TNF-alpha response to subsequent LPS challenge in vitro. Using the murine macrophage cell line RAW 264.7, we demonstrated both a rapid proinflammatory cytokine response (TNF-alpha) and a delayed inhibitory cytokine response (IL-10) with CpG-ODN. Preexposure of macrophages to CpG-ODN for brief periods (1 to 3 h) augmented TNF-alpha secretion and mRNA accumulation following subsequent LPS challenge (1 microg/ml). However, prolonged preexposure to CpG-ODN (6 to 9 h) resulted in suppression of the TNF-alpha protein and mRNA response to LPS. The addition of anti-IL-10 antibody to CpG-ODN during preexposure resulted in an increase in the LPS-induced TNF-alpha response over that induced by CpG-ODN preexposure alone. Thus, while brief preexposure of macrophages to CpG-ODN augments the proinflammatory cytokine response to subsequent LPS challenge, prolonged preexposure elicits IL-10 production, which inhibits the TNF-alpha response. Although the initial proinflammatory effects of CpG-DNA are well established, the immune response to CpG-DNA may also include autocrine or paracrine feedback mechanisms, leading to a complex interaction of proinflammatory and inhibitory cytokines.
Crabtree
T D
TD
Surgical Infectious Disease Laboratory, Department of Surgery, University of Virginia, Charlottesville, Virginia 22908, USA.
Jin
L
L
Raymond
D P
DP
Pelletier
S J
SJ
Houlgrave
C W
CW
Gleason
T G
TG
Pruett
T L
TL
Sawyer
R G
RG
D000818:Animals; D002478:Cells, Cultured; D015226:Dinucleoside Phosphates / Q000494:pharmacology*; D005260:Female; D016753:Interleukin-10 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009841:Oligonucleotides / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D015226:Dinucleoside Phosphates; D016753:Interleukin-10; D008070:Lipopolysaccharides; D009841:Oligonucleotides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C015772:CpG dinucleotide