Single-cell RNA sequencing reveals 2D cytokine assay can model atopic
dermatitis more accurately than immune-competent 3D setup
Abstract
Background: Modelling atopic dermatitis (AD) in vitro is
paramount to understand the disease pathophysiology and identify novel
treatments. Previous studies have shown that the Th2 cytokines IL-4 and
IL-13 induce AD-like features in keratinocytes in vitro. However,
it has not been systematically researched whether the addition of Th2
cells, their supernatants or a 3D structure are superior to model AD
compared to simple 2D cell culture with cytokines. Methods: For
the first time, we investigated what in vitro option most closely
resembles the disease in vivo based on single-cell RNA sequencing
data (scRNA-seq) obtained from skin biopsies in a clinical study and
published datasets of healthy and AD donors. In vitro models were
generated with primary fibroblasts and keratinocytes, subjected to
cytokine treatment or Th2 cell cocultures in 2D/3D. Gene expression
changes were assessed using qPCR and Multiplex Immunoassays.
Results: Of all cytokines tested, incubation of keratinocytes
and fibroblasts with IL-4 and IL-13 induced the closest in
vivo-like AD phenotype which was observed in the scRNA-seq data.
Addition of Th2 cells to fibroblasts failed to model AD due to the
downregulation of ECM-associated genes such as POSTN. While
keratinocytes cultured in 3D showed better stratification than in 2D,
changes induced with AD triggers did not better resemble AD keratinocyte
subtypes observed in vivo. Conclusions: Taken together,
our comprehensive study shows that the simple model using IL-4 or IL-13
in 2D most accurately models AD in fibroblasts and keratinocytes
in vitro, which may aid the discovery of novel treatment options.