Flow-cytometric screening for the modulation of receptor-mediated endocytosis in human dendritic cells: implications for the development of an in vitro technique for predictive testing of contact sensitizers

Becker, Detlef; Kühn, Ulrich; Lempertz, Uwe; Enk, Alexander H.; Saloga, Joachim; Knop, Jürgen

doi:10.1016/s0022-1759(97)00024-0

Cited by 32 publications

(15 citation statements)

References 25 publications

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“…Although FITC-OVA is taken up exclusively by fluid phase endocytosis, HRP and FITC-dextran appear to be taken up via both fluid phase and mannose receptor-dependent endocytosis (30,(37)(38)(39). Flow cytometric analysis shows that extracellular acidosis (pH range from 7.0 to 6.0) increased the uptake of FITC-OVA by DCs, being the strongest effect observed at pH 6.5 (Fig.…”

Section: Extracellular Acidosis Increases Endocytosis By Dcsmentioning

confidence: 96%

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Acidosis Improves Uptake of Antigens and MHC Class I-Restricted Presentation by Dendritic Cells

Vermeulen

Giordano

Trevani

et al. 2004

The Journal of Immunology

115

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It is widely appreciated that inflammatory responses in peripheral tissues are usually associated to the development of acidic microenvironments. Despite this, there are few studies aimed to analyze the effect of extracellular pH on immune cell functions. We analyzed the impact of acidosis on the behavior of dendritic cells (DCs) derived from murine bone marrow. We found that extracellular acidosis (pH 6.5) markedly stimulated the uptake of FITC-OVA, FITC-dextran, and HRP by DCs. In fact, to reach similar levels of endocytosis, DCs cultured at pH 7.3 required concentrations of Ag in the extracellular medium almost 10-fold higher compared with DCs cultured at pH 6.5. Not only the endocytic capacity of DCs was up-regulated by extracellular acidosis, but also the expression of CD11c, MHC class II, CD40, and CD86 as well as the acquisition of extracellular Ags by DCs for MHC class I-restricted presentation. Importantly, DCs pulsed with Ag under acidosis showed an improved efficacy to induce both specific CD8+ CTLs and specific Ab responses in vivo. Our results suggest that extracellular acidosis improves the Ag-presenting capacity of DCs.

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Section: Extracellular Acidosis Increases Endocytosis By Dcsmentioning

confidence: 96%

“…If so, and considering that FITC fluorescence is quenched at acidic pH values (39), the endocytic responses showed in Fig. 1, A and B, might be over-or underestimated.…”

Section: Extracellular Acidosis Increases Endocytosis By Dcsmentioning

confidence: 99%

Acidosis Improves Uptake of Antigens and MHC Class I-Restricted Presentation by Dendritic Cells

Vermeulen

Giordano

Trevani

et al. 2004

The Journal of Immunology

115

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“…However, no clear results were obtained for the induction of intracellular IL-1b. Degwert et al (1997) and Becker et al (1997) reported an increase in receptor-mediated endocytosis of HLA-DR in monocyte-derived DC exposed to several strong contact allergens. Less potent sensitizers and irritants failed to produce a significant effect on HLA-DR internalization (Becker et al, 1997).…”

Section: First-generation Approaches Using Dendritic Cells: Changes Imentioning

confidence: 99%

Interactions of Contact Allergens with Dendritic Cells: Opportunities and Challenges for the Development of Novel Approaches to Hazard Assessment

Ryan¹,

Gerberick²,

Gildea³

et al. 2005

Toxicological Sciences

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The identification of potential skin sensitizing chemicals is a key step in the overall skin safety risk assessment process. Traditionally, predictive testing has been conducted in guinea pigs. More recently, the murine local lymph node assay (LLNA) has become the preferred test method for assessing skin sensitization potential. However, even with the significant animal welfare benefits provided by the LLNA, there is a need to develop non-animal test methods for skin sensitization. Mechanistic understanding of allergic contact dermatitis has increased substantially in recent years. For example, a number of changes are known to occur in epidermal Langerhans cells, the principal antigen-presenting dendritic cell in the skin, as a result of exposure to chemical allergens, including the internalization of surface major histocompatibility complex (MHC) class II molecules via endocytosis, the induction of tyrosine phosphorylation, the modulation of cell surface markers, and cytokine expression. The application of this knowledge to the design of predictive in vitro alternative tests provides both unique opportunities and challenges. In this review, we have focused specifically on the impact of chemical exposure on dendritic cells and the potential use of that information in the development of cell-based assays for assessing skin sensitization potential of chemicals in vitro.

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“…As APCs are difficult to isolate from the skin, methods have been developed to generate dendritic cells (DCs) from human peripheral blood mononuclear cells or CD34 + haematopoietic progenitor cells cultured in the presence of specific cytokines. It is then possible to follow the expression of CD86/CD54 (82), interleukin‐1b release (83) or internalization of major histocompatibility complex class II molecules (84) in the presence of chemicals. However, generation of DC‐like cells takes several days and requires complicated procedures.…”

Section: In Vitro Assays Targeting the Sensitization Phasementioning

confidence: 99%

The critical review of methodologies and approaches to assess the inherent skin sensitization potential (skin allergies) of chemicals Part I

et al. 2012

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Flow-cytometric screening for the modulation of receptor-mediated endocytosis in human dendritic cells: implications for the development of an in vitro technique for predictive testing of contact sensitizers

Cited by 32 publications

References 25 publications

Acidosis Improves Uptake of Antigens and MHC Class I-Restricted Presentation by Dendritic Cells

Acidosis Improves Uptake of Antigens and MHC Class I-Restricted Presentation by Dendritic Cells

Interactions of Contact Allergens with Dendritic Cells: Opportunities and Challenges for the Development of Novel Approaches to Hazard Assessment

The critical review of methodologies and approaches to assess the inherent skin sensitization potential (skin allergies) of chemicals Part I

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