Mast cells are an important cellular source of tumour necrosis factor α in human intestinal tissue

Bischoff, Stephan C.; Lorentz, Axel; Schwengberg, Silke; Weier, G; Raab, R.; Manns, Michael P.

doi:10.1136/gut.44.5.643

Cited by 151 publications

(121 citation statements)

References 45 publications

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“…All experiments were performed with mast cells cultured in the presence of SCF, because SCF is the only cytokine that provides human mast cell survival and is permanently present in tissues containing mast cells, thus presenting some kind of "physiological condition" as suggested earlier (18,35). Our data suggest that the expression of proinflammatory cytokines occurs constitutively in human intestinal mast cells and may be up-regulated following triggering of the cells with IgE-independent agonists such as bacteria (20). Activation of mast cells by IgE receptor cross-linking also results in an up-regulation of proinflammatory cytokines but in addition induces the expression of Th2-type cytokines.…”

Section: Discussionmentioning

confidence: 73%

“…We found that Gram-negative bacteria are capable of enhancing TNF-␣ production in these cells by an IgE-independent means (20). The first evidence for the induction of TNF-␣ synthesis in mast cells by bacteria came from mice models.…”

Section: Discussionmentioning

confidence: 98%

“…Human lung mast cells were found to express mRNA for IL-4, IL-5, and GM-CSF and to release the products by IgE-dependent activation (15)(16)(17). Using recently developed methods for isolation and culture of human intestinal mast cells (18,19), we could show that these cells are an important source of TNF-␣ and IL-5 in human intestinal tissue in vitro as well as in vivo (20,21). IL-5 production was only observed if mast cells were triggered by IgE receptor cross-linking, whereas TNF-␣ production occurred constitutively but could be enhanced by IgE receptor-dependent activation (20,21).…”

mentioning

confidence: 87%

“…Using recently developed methods for isolation and culture of human intestinal mast cells (18,19), we could show that these cells are an important source of TNF-␣ and IL-5 in human intestinal tissue in vitro as well as in vivo (20,21). IL-5 production was only observed if mast cells were triggered by IgE receptor cross-linking, whereas TNF-␣ production occurred constitutively but could be enhanced by IgE receptor-dependent activation (20,21). Furthermore, we found recently that IL-4, known to play an important role in B and T lymphocyte differentiation, strongly enhances the proliferation and mediator release by human intestinal mast cells and thus may be involved, apart from stem cell factor (SCF), 3 in human mast cell regulation (22).…”

mentioning

confidence: 99%

“…Positive controls for mast cell mRNA were performed using the primer pair for c-kit. To observe relative changes in mRNA expression, duplex PCR according to the "primer-dropping" method was performed as described (20). Duplex PCRs were started with the primer pair for the cytokine of interest, and after a determined number of cycles the primer set of GAPDH was added.…”

Section: Rna Preparation and Semiquantitative Rt-pcrmentioning

confidence: 99%

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Human Intestinal Mast Cells Are Capable of Producing Different Cytokine Profiles: Role of IgE Receptor Cross-Linking and IL-4

Lorentz

Schwengberg

Sellge

et al. 2000

The Journal of Immunology

157

116

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Mast cells are recognized as a new type of immunoregulatory cells capable of producing different cytokines. So far, little is known about the cytokine profile of mature human mast cells isolated from intestinal tissue and cultured in the presence of stem cell factor (SCF). We observed that these cells express the proinflammatory cytokines TNF-α, IL-1β, IL-6, IL-8, IL-16, and IL-18 without further stimulation. Both IgE-dependent and IgE-independent agonists (e.g., Gram-negative bacteria) enhanced expression of TNF-α. Another set of cytokines consisting of IL-3, IL-5, IL-9, and IL-13 was expressed following activation by IgE receptor cross-linking. If mast cells were cultured in the presence of IL-4 and SCF, the production and release of IL-3, IL-5, and IL-13 was increased up to 4-fold compared with mast cells cultured with SCF alone. By contrast, IL-6 expression was completely blocked in response to culture with IL-4. In summary, our data show that mature human mast cells produce proinflammatory cytokines that may be up-regulated following triggering with IgE-independent agonists such as bacteria, whereas activation by IgE receptor cross-linking results in the expression of Th2-type cytokines. IL-4 enhances the expression of Th2-type cytokines but does not affect or even down-regulates proinflammatory cytokines.

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Section: Discussionmentioning

confidence: 73%

Section: Discussionmentioning

confidence: 98%

mentioning

confidence: 87%

mentioning

confidence: 99%

Section: Rna Preparation and Semiquantitative Rt-pcrmentioning

confidence: 99%

See 3 more Smart Citations

Human Intestinal Mast Cells Are Capable of Producing Different Cytokine Profiles: Role of IgE Receptor Cross-Linking and IL-4

Lorentz

Schwengberg

Sellge

et al. 2000

The Journal of Immunology

157

116

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Dependence of Enantioselectivity on the Distribution of a Chiral Hydrogenation Catalyst between an Aqueous and a Micellar Phase: Investigations Using Pulsed Field Gradient Spin Echo NMR Spectroscopy

et al. 2001

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The enantioselectivity obtained from rhodium complex catalyzed hydrogenations conducted in water can often be increased considerably by the addition of amphiphiles. At present the reasons for this increase in selectivity are not fully understood. The application of pulsed field gradient spin echo NMR (PGSE-NMR) spectroscopy to determine the average diffusion coefficients of the catalysts in both known and novel examples of asymmetric hydrogenation shows definitively that the increase in enantioselectivity is coupled with an aggregation of the catalyst to the micelles. This aggregation or solubilization of the catalyst in the micelles leads to the formation of a new colloidal phase in the aqueous solution. This phase has stronger hydrophobic properties, and thus the hydrogenation is more comparable to those conducted in a hydrophobic or less polar organic solvent. In the case of anionic amphiphiles, which form amphiphilic salts with the cationic catalyst, the embedment of the catalyst complex into the micelle is generally complete. The whole hydrogenation then takes place exclusively inside the micelles, leading to high enantioselectivity. If the catalyst is not completely embedded into the micelle, for example in the cases of nonionic or cationic surfactant solutions, the solubility of the substrate plays an important role. For soluble substrates the hydrogenation of the substrate occurs predominately in the aqueous phase itself, leading to very poor enantioselectivities. In these cases, only the use of a large excess of amphiphile, far above the critical micelle concentration (cmc), will lead to higher enantioselectivities due to a shift of the equilibrium towards the micellar bonded forms of catalyst and substrate. In contrast, poorly soluble substrates exhibit a high tendency to be incorporated into micelles, which leads to much higher enantioselectivities if the cmc of the surfactant is small enough. Changes in the cmc of amphiphiles caused by their aggregation with catalysts could also be estimated. The variation in selectivity observed for the catalysts containing seven-membered, flexible chelate rings is apparently due to changes in their conformation in the less polar micellar medium, and this effect is also seen in organic solvents. As expected, catalysts containing smaller chelate rings show this effect to a considerably lower extent since they are conformationally more rigid.

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IgG-dependent activation of human mast cells following up-regulation of FcγRI by IFN-γ

et al. 2001

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Mast cells are an important cellular source of tumour necrosis factor α in human intestinal tissue

Cited by 151 publications

References 45 publications

Human Intestinal Mast Cells Are Capable of Producing Different Cytokine Profiles: Role of IgE Receptor Cross-Linking and IL-4

Human Intestinal Mast Cells Are Capable of Producing Different Cytokine Profiles: Role of IgE Receptor Cross-Linking and IL-4

Dependence of Enantioselectivity on the Distribution of a Chiral Hydrogenation Catalyst between an Aqueous and a Micellar Phase: Investigations Using Pulsed Field Gradient Spin Echo NMR Spectroscopy

IgG-dependent activation of human mast cells following up-regulation of FcγRI by IFN-γ

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