Differential proteomic analysis of virus-enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue

International audienceBackground: Dengue is the most widespread mosquito-borne viral disease of public health concern. In some patients, endothelial cell and platelet dysfunction lead to life-threatening hemorrhagic dengue fever or dengue shock syndrome. Prognostication of disease severity is urgently required to improve patient management. The pathogenesis of severe dengue has not been fully elucidated, and the role of host proteins associated with viral particles has received little exploration. Methods: The proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue were compared. Virions were purified by ultracentrifugation combined with a water-insoluble polyelectrolyte-based technique. Following in-gel hydrolysis, peptides were analyzed by nano-liquid chromatography coupled to ion trap mass spectrometry and identified using data libraries.Results: Both dengue fever and severe dengue viral-enriched fractions contained identifiable viral envelope proteins and host cellular proteins. Canonical pathway analysis revealed the identified host proteins are mainly involved in the coagulation cascade, complement pathway or acute phase response signaling pathway. Some host proteins were over- or under-represented in plasma from patients with severe dengue compared to patients with dengue fever. ELISAs were used to validate differential expression of a selection of identified host proteins in individual plasma samples of patients with dengue fever compared to patients with severe dengue. Among 22 host proteins tested, two could differentiate between dengue fever and severe dengue in two independent cohorts (olfactomedin-4: area under the curve (AUC), 0.958; and platelet factor-4: AUC, 0.836).Conclusion: A novel technique of virion-enrichment from plasma has allowed to identify two host proteins that have prognostic value for classifying patients with acute dengue who are more likely to develop a severe dengue. The impact of these host proteins on pathogenicity and disease outcome are discussed

Additional file 2: of Differential proteomic analysis of virus-enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue

Expression levels and relationship of the proteins identified by LC-MS/MS in the Acute Phase Response Signaling (2), the Complement system (3) and the Coagulation system (4). Diagrams have been obtained using the IPA software. Proteins are displayed by various shapes that represent the functional classes of proteins. Proteins in red correspond to proteins found over-represented in the SD pool. Proteins in green correspond to proteins found over-represented in the DF pool. Proteins in grey are only identified in the SD pool. The color intensity of each node is related to the level of expression. Uncolored node: no data available. (ZIP 815 kb

Additional file 3: of Differential proteomic analysis of virus-enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue

Network of the proteins identified by LC-MS/MS. The nature of the relationship between proteins is indicated by various line styles. Proteins are displayed by shapes that represent the functional classes of proteins. Proteins in red correspond to proteins found over-represented in the SD pool. Proteins in green correspond to proteins found over-represented in the DF pool. Proteins in grey are only identified in the SD pool. The color intensity of each node is related to the level of expression. (TIF 441 kb