NativeSkin®, an immunocompetent human skin model to study antigen uptake and processing by Langerhans cells
USING NATIVESKIN IMMUNOCOMPETENT EX VIVO SKIN MODEL
Research by E. Pagès (Genoskin), L. Mondoulet (DBV Technologies), E. Bonnefont (Genoskin), E. Braun (Genoskin), V. Dhelft (DBV Technologies), C. Dupont (Hôpital Necker, Université Paris-Descartes), H. Sampson (DBV Technologies), P. Descargues (Genoskin)
Allergen applied to the skin during epicutaneous immunotherapy (EPIT) with Viaskin® patches seemed to induce tolerance in sensitized mice (Dioszeghy, Clin Exp Allergy 2014). Safety and adequate dose for treatment with Viaskin® Peanut in peanut allergic patients was studied in earlier Phase 1 and Phase 2 clinical trials and completed Phase 3 safety and efficacy trial. In preliminary studies in sensitized mice, DBV Technologies showed that allergen delivered by Viaskin® is mainly takenup by Langerhans cells (LCs) and transported to regional lymph nodes. The aim of this study was to determine whether similar allergen uptake occurred in an ex vivo human skin model.
Treatment with Viaskin® placebo Viaskin® peanut (A-647) during 24H
Experimental Workflow
The experiment was performed on 2 donors and in triplicate by condition. Viaskin® patches were applied on the skin after the production of NativeSkin® models.
Macroscopical and histological evaluation of tissue integrity during treatment
Study of allergen penetration and colocalization with Langerhans cells on tissue sections
Allergen penetration in the epidermis & colocalization with Langerhans cells
Representative pictures for donor 2, on merged pictures, cell nuclei stained with DAPI (Grey), LC with anti-CD1a (Blue) and anti-CD207 (Green) and peanut (Red). On Peanut pictures, allergen particles appear in black, blue arrows point Peanut in the epidermis, and orange arrows target allergen colocalizing with CD1a positive cells (visible in black on the last line).
Quantification of allergen penetration and colocalization with Langerhans cells
Variable kinetics of penetration between donors
Peanut in the epidermis (Blue) and colocalization with LC (orange) were detected using Fiji for donors 1 and 2 on skin cross-sections.
Results are presented for Viaskin® Peanut. The analysis was performed for Viaskin® Placebo, no Peanut signal was detected.
Observation of in situ immunostaining on detached epidermal sheet after 24H of treatment with Viaskin® peanut using confocal microscopy
After Viaskin® application, similar detection of cytokines between peanut and placebo could explain the absence of inflammation occuring during treatment
Measurements of cytokines released in the culture medium during 24h of treatment with Viaskin®
Cytokines detected in culture medium (after 24 hours of treatment with Viaskin®). A human 27-Plex® kit (Bioplex®, Biorad) was used for the quantitative detection of cytokine in culture medium. Only 3 cytokines were detected above the limit of quantification: IL-6, IL-8, MCP1. Results are presented for donor 1 and are similar for donor 2. The bars represent the mean ± SD of triplicates.
