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Updated: Mar 29, 2026
Deep Proteome Profiling by Isobaric Labeling, Extensive Liquid Chromatography, Mass Spectrometry, and Software-assisted Quantification
Published on: November 15, 2017
Proteomic profiling and pathway analyses reveal molecular signatures and immune networks in pediatric sepsis
Vincenzo Stranges1, Logan R Van Nynatten2,3, David Tweddell4
1Maternal and Child Health and Urological Sciences, Policlinico Umberto I, Rome, Italy.
Insights
Pediatric sepsis involves complex immune and inflammatory pathway dysregulation, not just single protein changes. Identifying key pathways like Interleukin-10 (IL-10) signaling aids in understanding sepsis and developing targeted treatments.
Area of Science:
- Immunology
- Genomics
- Systems Biology
Background:
- Sepsis is a major global cause of childhood mortality, with rapid deaths emphasizing the need for early detection and biologically informed treatments.
- The complex nature of sepsis etiology necessitates approaches beyond single biomarkers to capture its heterogeneity.
- High-throughput proteomic profiling offers a comprehensive method to identify dysregulated pathways in pediatric sepsis.
Purpose of the Study:
- To comprehensively profile plasma proteins in critically ill pediatric sepsis patients using high-throughput proximity extension assay technology.
- To identify dysregulated biological pathways that can inform risk stratification and therapeutic development in pediatric sepsis.
- To define molecular signatures of pediatric sepsis through differential expression, machine learning, and pathway enrichment analyses.
Main Methods:
- Prospective enrollment of study participants based on established pediatric sepsis criteria.
- Quantification of plasma proteins using the Olink proximity extension assay.
- Differential expression, machine learning, and pathway enrichment analyses to identify molecular signatures.
Main Results:
- 626 significantly differentially expressed proteins were identified in pediatric sepsis patients compared to controls (399 upregulated, 227 downregulated).
- A 9-protein signature identified by machine learning accounted for 90% of the discriminatory power between sepsis patients and controls.
- Pathway enrichment analysis revealed significant dysregulation of immune and inflammatory networks, with Interleukin-10 (IL-10) signaling being the most enriched pathway.
Conclusions:
- Pediatric sepsis is characterized by the dysregulation of multiple immune and inflammatory pathways, not isolated protein abnormalities.
- Interleukin-10 (IL-10) and related cytokine signaling pathways are central nodes, offering insights into the hyperinflammation/immunosuppression balance in critically ill children.
- Distinct pathogen types and infection sources trigger specific biological network activation patterns, suggesting potential targets for patient stratification and pathway-directed therapeutics.
Background:
Sepsis remains a leading cause of childhood mortality worldwide. Most deaths occur within the first few days of presentation, underscoring the urgent need for early recognition and biologically informed treatment strategies. The heterogeneous etiology of sepsis involves complex, intertwined biological networks, explaining why single-biomarker approaches have proven inadequate for capturing this complexity. We used high-throughput proximity extension assay technology to comprehensively profile plasma proteins in critically ill pediatric sepsis patients, aiming to identify dysregulated biological pathways that could inform risk stratification and therapeutic development.
Methods:
Study participants were prospectively enrolled based on established pediatric sepsis criteria. Plasma proteins were quantified using the Olink proximity extension assay, with differential expression, machine learning, and pathway enrichment analyses performed to define molecular signatures of pediatric sepsis.
Results:
Analysis of plasma samples from 17 pediatric sepsis patients and 17 age- and sex-matched healthy controls revealed 626 significantly differentially expressed proteins: 399 upregulated and 227 downregulated. The most significantly elevated proteins included calcitonin-related polypeptide α (CALCA), tumor necrosis factor superfamily member 14 (TNFSF14), and asialoglycoprotein receptor 1 (ASGR1). Machine learning identified a minimal 9-protein signature accounting for 90% of discriminatory power between groups. Pathway enrichment analysis revealed profound dysregulation of immune and inflammatory networks. Interleukin-10 (IL-10) signaling emerged as the most significantly enriched pathway, alongside extracellular matrix degradation, IL-4 and IL-13 signaling, and other cytokine signaling pathways. Dysregulated pathways were associated with clinical variables, particularly gram-negative infections and respiratory infection sources.
Conclusions:
Pediatric sepsis is characterized by dysregulation of multiple immune and inflammatory pathways rather than isolated protein abnormalities. IL-10 and related cytokine signaling emerged as central nodes, providing insights into the balance between hyperinflammation and immunosuppression in critically ill children. Associations between pathways and clinical variables suggest that specific pathogen types and infection sources trigger distinct patterns of biological network activation, offering potential targets for patient stratification and pathway-directed therapeutics.
