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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Thursday Speaker Abstracts
38
The Properties and Cellular Uptake Characteristics of Liposome-based Mucosal Vaccines
Karin Norling
1
, Mokhtar Mapar
1
, Valentina Bernasconi
2
, Nils Lycke
2
, Fredrik Höök
1
, Marta
Bally
1
.
1
Chalmers University of Technology, Gothenburg, Sweden,
2
University of Gothenburg,
Gothenburg, Sweden.
Liposomes have attracted attention as promising pharmaceutical carrier candidates. As vaccine
vectors, they have the advantage of possessing inherently adjuvanting properties (1). Their
physicochemical properties are easily customized; however, little is currently known about how
the properties of antigen-carrying liposomes affect their processing by immune cells and how
that in turn influences the elicited immune response. Our aim is to correlate the physicochemical
properties of vaccine particles to their efficacy in vivo and in extension to use this knowledge in
the development of an effective mucosal influenza vaccine. Hence we produce and characterize
liposomal vaccine particles with regards to size, charge and antigen content. Furthermore, we
develop in vitro assays to study the processing by dendritic cells. Currently, we are developing
microscopy-based methods for studying two parts of the processing: the particle uptake and
antigen presentation. For the uptake-assay, cells are grown on a topographically micro-patterned
substrate in order to ensure the particles access to the basal membrane so that TIRF microscopy
can be used to visualize particle attachment and uptake. The trajectories exhibited by the
particles during this process are analyzed using single particle tracking in order to quantify and
categorize different modes of uptake. In order to assess how the packaging of the antigen, and
mode of uptake, affects the extent of the presentation, an antibody against the antigen peptide-
MHC class II complex is used to visualize the amount of antigen functionally presented on the
cell surface. Hopefully these new tools will help us make more informed vaccine design choices
as well as identify promising vaccine formulation candidates at an early stage.
1. Torchilin, V. P. (2005) Recent advances with liposomes as pharmaceutical carriers.
Nature
Reviews Drug Discovery
, 4 (2) 145-160.