ATriple Co-CultureModeloftheHuman RespiratoryTract to Study Immune Modulatory Effects o fLiposomes and Virosomes
Authors
Rebecca A. M. Blom, Silvia T. Erni, KristõÂna KrempaskaÂ, Olivier Schaerer, R. Maarten van Dijk, Mario Amacker, Christian Moser, Sean R. R. Hall, Christophe von Garnier, Fabian Blank
Institution
University of Bern
Country
Switzerland
Year
2016
Journal
PLOS One
Abstract
The respiratory tract with its ease of access, vast surface area and dense network of antigen-
presenting cells (APCs) represents an ideal target for immune-modulation. Biomimetic
nanocarriers such as virosomes may provide immunomodulatory properties to
treat diseases such as allergic asthma. In our study we employed a triple co-culture model
of epithelial cells, macrophages and dendritic cells to simulate the human airway barrier.
The epithelial cell line 16HBE was grown on inserts and supplemented with human blood
monocyte-derived macrophages (MDMs) and dendritic cells (MDDCs) for exposure to influenza
virosomes and liposomes. Additionally, primary human nasal epithelial cells (PHNEC)
and EpCAM+ epithelial progenitor cell mono-cultures were utilized to simulate epithelium
from large and smaller airways, respectively. To assess particle uptake and phenotype
change, cell cultures were analyzed by flow cytometry and pro-inflammatory cytokine concentrations
were measured by ELISA. All cell types internalized virosomes more efficiently
than liposomes in both mono- and co-cultures. APCs like MDMs and MDDCs showed the
highest uptake capacity. Virosome and liposome treatment caused a moderate degree of
activation in MDDCs from mono-cultures and induced an increased cytokine production in
co-cultures. In epithelial cells, virosome uptake was increased compared to liposomes in
both mono- and co-cultures with EpCAM+ epithelial progenitor cells showing highest uptake
capacity. In conclusion, all cell types successfully internalized both nanocarriers with virosomes
being taken up by a higher proportion of cells and at a higher rate inducing limited
activation of MDDCs. Thus virosomes may represent ideal carrier antigen systems to modulate mucosal immune responses in the respiratory tract without causing excessive inflammatory changes.