Human monocyte isolation methods influence cytokine production from <i>in vitro</i> generated dendritic cells

Elkord, Eyad; Williams, Paul; Kynaston, Howard; Rowbottom, Anthony W.

doi:10.1111/j.1365-2567.2004.02076.x

Cited by 139 publications

(115 citation statements)

References 39 publications

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“…Chieppa et al (42) have reported that cross-linking of the mannose receptor on MDDC induces the production of anti-inflammatory cytokines and produces chemokines that direct Th2 and regulatory T cells and negatively regulate Th1 polarization. It has also been reported that MDDC derived from monocytes isolated by positive selection via anti-CD14 microbeads had a reduced capacity to produce IL-12, IL-10, and TNF-␣ in response to LPS stimulation as compared with MDDC generated from monocytes isolated by plastic adherence (43). In the case of PDC, cross-linking HLA-DR on CD40L-matured PDC, but not freshly isolated cells, has been shown to induce apoptosis of these cells (34).…”

Section: Discussionmentioning

confidence: 99%

Receptor Cross-Linking on Human Plasmacytoid Dendritic Cells Leads to the Regulation of IFN-α Production

Fanning

George²,

Feng

et al. 2006

The Journal of Immunology

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Plasmacytoid dendritic cells (PDC) are the natural type I IFN-producing cells that produce large amounts of IFN-α in response to viral stimulation. During attempts to isolate PDC from human PBMC, we observed that cross-linking a variety of cell surface receptors, including blood DC Ag (BDCA)-2, BDCA-4, CD4, or CD123 with Abs and immunobeads on PDC leads to inhibition of IFN-α production in response to HSV. To understand the mechanisms involved, a number of parameters were investigated. Cross-linking did not inhibit endocytosis of soluble Ag by PDC. Flow cytometry for annexin V and activated caspase-3 indicated that PDC are not undergoing apoptosis after receptor cross-linking. Cross-linking of CD123, but not the other receptors, caused the up-regulation of costimulatory molecules CD80 and CD86, as well as the down-regulation of CD62L, indicating PDC maturation. Thus, anti-CD123 Ab may be acting similar to the natural ligand, IL-3. Anti-phosphotyrosine Ab, as well as Ab to the IFN regulatory factor, IRF-7, was used in intracellular flow cytometry to elucidate the signaling pathways involved. Tyrosine phosphorylation occurred after cross-linking BDCA-2 and BDCA-4, but not CD4. Cross-linking did not affect IRF-7 levels in PDC, however, cross-linking BDCA-2, BDCA-4, and CD4, but not CD123, inhibited the ability of IRF-7 to translocate to the nucleus. Taken together, these results suggest that cross-linking BDCA-2, BDCA-4, and CD4 on PDC regulates IFN-α production at the level of IRF-7, while the decrease in IFN-α production after CD123 cross-linking is due to stimulation of the IL-3R and induction of PDC maturation.

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Section: Discussionmentioning

confidence: 99%

Receptor Cross-Linking on Human Plasmacytoid Dendritic Cells Leads to the Regulation of IFN-α Production

Fanning

George²,

Feng

et al. 2006

The Journal of Immunology

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“…For example, LPS from E. coli has been shown to induce both IL-10 and IL-12 production in the murine models. [56][57][58][59][60] In the human system, the production of IL-12 in response to LPS has been shown to be variable and is affected by the way that DCs are generated 61 and by the amount of serum used in the culture media. 62 In addition, the amount of IL-12 produced in response to LPS can be affected by the amount of IL-10 endogenously produced.…”

Section: Discussionmentioning

confidence: 99%

Qualitatively distinct patterns of cytokines are released by human dendritic cells in response to different pathogens

et al. 2005

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Summary Dendritic cells produce cytokines that regulate the class of the adaptive immune response. Microbial recognition is mediated, at least in part, by pattern recognition receptors such as Toll‐like receptors, which influence dendritic cell maturation. In humans it is not yet clear how intact pathogens modulate the developing immune response. To address the effects of intact pathogens on the maturation and effector functions of human dendritic cells, we investigated their responses to a number of microbial pathogens. We studied a range of micro‐organisms including Gram‐negative bacteria (Escherichia coli and Salmonella enterica sv. typhimurium), Gram‐positive cocci (Staphylococcus aureus) and atypical bacteria (Mycobacterium tuberculosis and Mycoplasma hominis) as well as the human protozoal parasite Trichomonas vaginalis. The micro‐organisms were fixed in formaldehyde to prevent replication whilst preserving surface morphology. All the pathogens induced similar up‐regulation of dendritic cell activation‐associated cell surface markers but there was a profound difference in the patterns of cytokines produced by the stimulated dendritic cells. Some pathogens (E. coli, Salmonella enterica sv. typhimurium and S. aureus) induced interleukin‐12 (IL‐12), IL‐10 and interferon‐α whereas others (M. tuberculosis, Mycoplasma hominis and T. vaginalis) induced only IL‐10. This differential effect was not altered by costimulation of the dendritic cells through CD40. These results support the notion that human dendritic cells are plastic in their response to microbial stimuli and that the nature of the pathogen dictates the response of the dendritic cell.

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“…21 Other investigators have found that LPS stimulates intestinal epithelial cells to produce TNF 22,23 and PAF. 24 Thus, it is possible that LPS may directly stimulate enterocytes to express CXCL2 via the activation of NFjB, and this effect may be mediated via endogenous production of TNF and PAF.…”

mentioning

confidence: 99%

Lipopolysaccharide induces CXCL2/macrophage inflammatory protein‐2 gene expression in enterocytes via NF‐κB activation: independence from endogenous TNF‐α and platelet‐activating factor

Plaen¹,

Han²,

Liu³

et al. 2006

Immunology

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SummaryCXCL2 (macrophage inflammatory protein-2 (MIP-2)), a critical chemokine for neutrophils, has been shown to be produced in the rat intestine in response to platelet-activating factor (PAF) and to mediate intestinal inflammation and injury. The intestinal epithelium, constantly exposed to bacterial products, is the first line of defence against micro-organisms. It has been reported that enterocytes produce proinflammatory mediators, including tumour necrosis factor (TNF) and PAF, and we showed that lipopolysaccharide (LPS) and TNF activate nuclear factor (NF)-jB in enterocytes. However, it remains elusive whether enterocytes release CXCL2 in response to LPS and TNF via a NF-jB-dependent pathway and whether this involves the endogenous production of TNF and PAF. In this study, we found that TNF and LPS markedly induced CXCL2 gene expression in IEC-6 cells, TNF within 30 min, peaking at 45 min, while LPS more slowly, peaking after 2 hr. TNF-and LPS-induced CXCL2 gene expression and protein release were completely blocked by pyrrolidine dithiocarbamate (PDTC) and helenalin, two potent NF-jB inhibitors. NEMO-binding domain peptide, a specific inhibitor of inhibitor protein jB kinase (IKK) activation, a major upstream kinase mediating NF-jB activation, significantly blocked CXCL2 gene expression and protein release induced by LPS. WEB2170 (PAF antagonist) and anti-TNF antibodies had no effect on LPS-induced CXCL2 expression. In conclusion, CXCL2 gene is expressed in enterocytes in response to both TNF and LPS. LPS-induced CXCL2 expression is dependent on NF-jB activation via the IKK pathway. The effect of LPS is independent of endogenous TNF and PAF.

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Human monocyte isolation methods influence cytokine production from in vitro generated dendritic cells

Cited by 139 publications

References 39 publications

Receptor Cross-Linking on Human Plasmacytoid Dendritic Cells Leads to the Regulation of IFN-α Production

Receptor Cross-Linking on Human Plasmacytoid Dendritic Cells Leads to the Regulation of IFN-α Production

Qualitatively distinct patterns of cytokines are released by human dendritic cells in response to different pathogens

Lipopolysaccharide induces CXCL2/macrophage inflammatory protein‐2 gene expression in enterocytes via NF‐κB activation: independence from endogenous TNF‐α and platelet‐activating factor

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