ABSTRACT
Background : Anaphylaxis is the most severe manifestation of
allergic disorders. Diagnostic and understanding of molecular mechanisms
need to improve. Extracellular vesicles (EVs) play a key role in
cellular communication offering new possibilities to unravel
patient-based particularities. The aim of this study is to analyze the
protein profile of anaphylaxis-derived EVs providing a resource of
potential markers for anaphylactic reactions, and to characterize their
molecular mechanisms.
Methods: EVs were isolated from 86 plasma samples (collected
from 43 patients) during the acute phase of anaphylaxis (AnEVs) and at
their baseline (BEVs). For comparison, EVs were characterized and their
protein patterns were analyzed by mass spectrometry-based quantitative
proteomics (LC-MS/MS). System Biology Analysis (SBA) was applied to
identify main canonical pathways and molecules involved. In addition,in vitro permeability assays based on EVs-endothelial cells (ECs)
were performed.
Results: Differential proteomic analysis performed in 10 EVs
paired patients’ samples identified 1206 proteins of which 99 were
modulated in the AnEVs signature. CDC42, Ficolin-2 and S100A9 enrichment
was confirmed in a larger cohort of patients. SBA revealed diverse group
of immune proteins as the main canonical pathways altered in AnEVs.
Thus, leukocyte extravasation and granulocyte adhesion-diapedesis
processes stand out. In addition, marked-EVs from anaphylactic patients
were captured by ECs decreasing the resistance of human endothelial
monolayers.
Conclusion : Our findings identify for the first time a
differential EVs pattern signature in anaphylaxis revealing a source of
potential biomarkers. Furthermore, these vesicles could participate in
altered immune molecular mechanisms and present a role increasing
vascular permeability.