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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Poster Abstracts
86
38-POS
Board 19
Targeting Liposomes for Uptake into CEACAM-Expressing Human Cells Using a
Bacterial Membrane Protein
Jason Kuhn
, Alison K. Criss, Asya Smirnov, Linda Columbus.
University of Virginia, Charlottesville, VA, USA.
The pathogenic bacteria
Neisseria gonorrhoeae
and
N. meningitidis
induce their own
phagocytosis into human host cells prior to replication. Bacterial cell entry is promoted by the
binding of Neisserial outer membrane opacity-associated (Opa) proteins to human
carcinoembryonic antigen-like cell adhesion molecule (CEACAM) receptors, a widely-
distributed class of cell receptors in the human body. Binding of Opa proteins to either
CEACAM1, CEACAM3, CEACAM5, or CEACAM6 generates intracellular signalling events
which lead to bacterial internalization by both phagocytes and epithelial cells. We are interested
in determining whether Opa proteins reconstituted in liposomes retain the ability to promote
entry of liposomes into epithelial cells similar to
Neisseria
. Because CEACAM receptors
targeted by Opa may demonstrate tissue-specific expression or increased expression in various
cancers, the ability to target Opa-proteoliposomes to CEACAM
+
cells could prove valuable in
therapeutic delivery. Our results indicate that Opa-proteoliposomes target CEACAM
+
cells for
internalization using an active-uptake mechanism. Additionally, Opa-proteoliposome uptake into
CEACAM+ cells correlates with both cell size and CEACAM expression levels. With uptake
established, CEACAM selectivity is currently being investigated.
41-POS
Board 21
H2 Fueled ATP Synthesis on an Electrode: Mimicking Cellular Respiration
Ivan Lopez-Montero
1,2
, Oscar Gutiérrez-Sanz
3
, Paolo Natale
1,2
, Ileana Marquez
3
, Marta C.
Marques
4
, Sonia Zacarias
4
, Marcos Pita
3
, Ines A. Pereira
4
, Antonio L. De Lacey
3
, Marisela
Velez
3
.
1
Complutense University, Madrid, Spain,
2
Instituto Hospital 12 de Octubre, Madrid, Madrid,
Spain,
3
CSIC, Madrid, Madrid, Spain,
4
Universidade Nova de Lisboa, Oeiras, Portugal.
ATP, the molecule used by living organisms to supply energy to many different metabolic
processes, is synthesized mostly by the ATPase synthase using a proton gradient generated
across a lipid membrane. We present evidence that a modified electrode surface integrating a
NiFeSe hydrogenase and a F1Fo-ATPase in a lipid membrane can couple the electrochemical
oxidation of H2 to the synthesis of ATP. This electrode-assisted conversion of H2 gas into ATP
could serve to generate this biochemical fuel locally when required in biomedical devices or
enzymatic synthesis of valuable products.