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. 2009 Sep;157(3):423-36.
doi: 10.1111/j.1365-2249.2009.03981.x.

Exaggerated inflammatory response of primary human myeloid dendritic cells to lipopolysaccharide in patients with inflammatory bowel disease

D C Baumgart  1 , S Thomas, I Przesdzing, D Metzke, C Bielecki, S M Lehmann, S Lehnardt, Y Dörffel, A Sturm, A Scheffold, J Schmitz, A Radbruch
Affiliations

Exaggerated inflammatory response of primary human myeloid dendritic cells to lipopolysaccharide in patients with inflammatory bowel disease

D C Baumgart et al. Clin Exp Immunol. 2009 Sep.

Abstract

Inflammatory bowel disease (IBD) results from a breakdown of tolerance towards the indigenous flora in genetically susceptible hosts. Failure of dendritic cells (DC) to interpret molecular microbial patterns appropriately when directing innate and adaptive immune responses is conceivable. Primary (conventional, non-monocyte generated) CD1c(+)CD11c(+)CD14(-)CD16(-)CD19(-) myeloid blood or mucosal dendritic cells (mDC) from 76 patients with Crohn's disease (CD) or ulcerative colitis (UC) in remission, during flare-ups (FU) and 76 healthy or non-IBD controls were analysed by fluorescence activated cell sorter (FACS) flow cytometry and real-time polymerase chain reaction. Cytokine secretion of freshly isolated, cultured and lipopolysaccharide (LPS)-stimulated highly purified mDC (purity >95%) was assessed using cytometric bead arrays (CBA). More cultured and stimulated circulating mDC express CD40 in IBD patients. Stimulated circulating mDC from IBD patients secrete significantly more tumour necrosis factor (TNF)-alpha and interleukin (IL)-8. Toll-like receptor (TLR)-4 expression by mDC was higher in remission and increased significantly in flaring UC and CD patients compared with remission (P < 0.05) and controls (P < 0.001). Fluorochrome-labelled LPS uptake by mDC was evaluated at different time-points over 24 h by measuring mean fluorescence intensity (MFI). Circulating mDC from IBD patients take up more LPS and the uptake begins earlier compared with controls (P < 0.05 in CD-FU and UC-FU at 24 h). The frequency of mucosal mDC (P < 0.05) and the number of CD40 expressing mucosal mDC is significantly greater in UC and CD compared with non-IBD controls (P < 0.001 versus P < 0.01, respectively). Our data suggest an aberrant LPS response of mDC in IBD patients, resulting in an inflammatory phenotype and possibly intestinal homing in acute flares.

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Figures

Fig. 1
Fig. 1
CD40 expression by myeloid dendritic cells (mDC). More cultured and lipopolysaccharide (LPS)-stimulated, but not freshly isolated (data not shown) mDC, express CD40 in inflammatory bowel disease (IBD) compared with healthy controls. Fluorescence activated cell sorter (FACS) plots from representative experiments. Quadrant thresholds were placed determined according to isotype controls. HC, healthy control; RM, remission; FU, flare-up. (a) Ulcerative colitis. (b) Crohn's disease.
Fig. 1
Fig. 1
CD40 expression by myeloid dendritic cells (mDC). More cultured and lipopolysaccharide (LPS)-stimulated, but not freshly isolated (data not shown) mDC, express CD40 in inflammatory bowel disease (IBD) compared with healthy controls. Fluorescence activated cell sorter (FACS) plots from representative experiments. Quadrant thresholds were placed determined according to isotype controls. HC, healthy control; RM, remission; FU, flare-up. (a) Ulcerative colitis. (b) Crohn's disease.
Fig. 2
Fig. 2
CD40 expression by myeloid dendritic cells (mDC). More cultured and lipopolysaccharide (LPS)-stimulated, but not freshly isolated (data not shown) mDC, express CD40 in IBD compared with healthy controls. Bar graphs summarize data from 10 patients or controls in each category. HC, healthy control; RM, remission; FU, flare-up. Asterisks denote statistical significance *P < 0·05, **P < 0·01, ***P < 0·001. (a) Ulcerative colitis. Cultured (top) and cultured with LPS (bottom). (b) Crohn's disease. Cultured (top) and cultured with LPS (bottom).
Fig. 3
Fig. 3
Tumour necrosis factor (TNF)-α secretion by myeloid dendritic cells (mDC). Lipopolysaccharide (LPS)-stimulated mDC from inflammatory bowel disease (IBD) patients secrete significantly more TNF-α than healthy controls. Bar graphs summarize data from 10 patients or controls in each category. HC, healthy control; RM, remission; FU, flare-up. Asterisks denote statistical significance *P < 0·05, **P < 0·01. (a) Ulcerative colitis. (b) Crohn's disease.
Fig. 4
Fig. 4
Interleukin (IL)-8 secretion by myeloid dendritic cells (mDC). Lipopolysaccharide (LPS)-stimulated mDC from inflammatory bowel disease (IBD) patients secrete significantly more IL-8 than healthy controls. Bar graphs summarize data from 10 patients or controls in each category. HC, healthy control; RM, remission; FU, flare-up. Asterisks denote statistical significance *P < 0·05, **P < 0·01. (a) Ulcerative colitis. (b) Crohn's disease.
Fig. 5
Fig. 5
Toll-like receptor (TLR)-4 and TLR-2 expression. Human myeloid dendritic cells (mDC) from healthy controls, patients with ulcerative colitis and Crohn's disease were analysed for the mRNA expression levels of TLR-4 and TLR-2 using real-time reverse transcription–polymerase chain reaction. Bar graphs summarize data from eight patients or controls in each category. HC, healthy control; RM, remission; FU, flare-up; UC, ulcerative colitis; CD, Crohn's disease. Asterisks denote statistical significance *P < 0·05, **P < 0·01, ***P < 0·001. (a) TLR-4. (b) TLR-2.
Fig. 6
Fig. 6
Increased lipopolysaccharide (LPS) uptake by myeloid dendritic cells (mDC) in active inflammatory bowel disease (IBD). mDC from patients with active IBD take up more Alexa 488-labelled LPS than healthy controls. Mean fluorescence intensity was assessed over 24 h by fluorescence activated cell sorter. Six ulcerative colitis (UC), six Crohn's disease (CD) patients and six healthy controls (HC) were studied and data from five time-points analysed. At linear regression analysis of analysed time-points all curves show an excellent quality of fit (r2 > 0·95). RM, remission; FU, flare-up. Asterisks denote statistical significance *P < 0·05. (a) Ulcerative colitis. Remission (top) and flare-up (bottom) versus healthy control. (b) Crohn's disease. Remission (top) and flare-up (bottom) versus healthy control.
Fig. 7
Fig. 7
Increased frequency of activated mDC in the inflamed mucosa. We found an increased frequency of mDC in patients with active inflammatory bowel disease (IBD) but not in controls. More mucosal mDC from IBD patients display an activated phenotype with an increased fraction of CD40 expressing cells. Quadrant thresholds were placed according to isotype controls. UC, ulcerative colitis; CD, Crohn's disease; HC, non-IBD-control; RM, remission; LPMC, lamina propria mononuclear cells; FU, flare-up. Asterisks denote statistical significance *P < 0·05, **P < 0·01, ***P < 0·001. (a) Fluorescence activated cell sorter plots from representative experiments. (b) Bar graphs summarizing data from 10 patients or controls in each category.
Fig. 7
Fig. 7
Increased frequency of activated mDC in the inflamed mucosa. We found an increased frequency of mDC in patients with active inflammatory bowel disease (IBD) but not in controls. More mucosal mDC from IBD patients display an activated phenotype with an increased fraction of CD40 expressing cells. Quadrant thresholds were placed according to isotype controls. UC, ulcerative colitis; CD, Crohn's disease; HC, non-IBD-control; RM, remission; LPMC, lamina propria mononuclear cells; FU, flare-up. Asterisks denote statistical significance *P < 0·05, **P < 0·01, ***P < 0·001. (a) Fluorescence activated cell sorter plots from representative experiments. (b) Bar graphs summarizing data from 10 patients or controls in each category.
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References

    1. Xavier RJ, Podolsky DK. Unravelling the pathogenesis of inflammatory bowel disease. Nature. 2007;448:427–34. - PubMed
    1. Baumgart DC, Carding SR. Inflammatory bowel disease: cause and immunobiology. Lancet. 2007;369:1627–40. - PubMed
    1. Iwasaki A, Medzhitov R. Toll-like receptor control of the adaptive immune responses. Nat Immunol. 2004;5:987–95. - PubMed
    1. Iwasaki A. Mucosal dendritic cells. Annu Rev Immunol. 2007;25:381–418. - PubMed
    1. Kelsall BL, Leon F. Involvement of intestinal dendritic cells in oral tolerance, immunity to pathogens, and inflammatory bowel disease. Immunol Rev. 2005;206:132–48. - PubMed

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