The Role of Interleukin-1Beta- Fibrin(ogen) Interaction in Sepsis-Induced Coagulopathy. - PROJECT SUMMARY Sepsis-induced coagulopathy (SIC) is a common problem of sepsis, occurring in up to 60% of patients with severe sepsis. It is characterized by widespread fibrin-rich clot formation in small blood vessels, impeding perfusion to vital organs, resulting in organ dysfunction and death in sepsis patients. Interleukin -1β (IL-1β) is a pro-inflammatory protein implicated in the pathogenesis of SIC. Interestingly, IL-1β can also directly bind to fibrin(ogen) (Fg), which may enhance its biological effects. IL-1β bound to Fg may play a significant role in the pathogenesis of SIC. To investigate this, I propose to study how IL-1β bound to Fg alters clot characteristics and neutrophil engagement in SIC in pediatric patients with sepsis and our swine SIC models. Aim 1: Investigate the effects of IL-1β bound to Fg on clot characteristics in SIC. Hypothesis: IL-1 bound to Fg increases clot formation and density while reducing clot lysis in SIC. I will use biochemical and cellular biology techniques to determine how IL-1β bound to Fg alters clot characteristics (i.e., clot formation, clot lysis, and structure) and clot function (i.e., clot stability and permeability) in septic human and swine plasma. This aim will reveal alteration in the clot characteristics due to IL-1 bound to Fg in SIC. Aim 2: Determine the impact of IL-1β bound to Fg on neutrophil activation in SIC. Hypothesis: IL-1β bound to Fg potentiates neutrophil activation and release of neutrophil extracellular traps (NETs) in SIC. I will isolate neutrophils from patients with and without SIC to study IL-1β bound Fg potentiates neutrophil activation and release of NETs. I will systematically block neutrophil receptor pathways to determine which pathway is critical for the IL-1β bound to Fg effects. The aim will clarify the path involved in the activation of neutrophils and the release of NETs mediated by the interaction between IL-1β and Fg. Aim 3: Compare thromboinflammatory signatures between septic patients with and without SIC. Hypothesis: Septic patients with SIC have a distinct thromboinflammatory endotype compared to those without. I will define and validate thromboinflammatory endotypes by generating and integrating data on disease severity, clot characteristics, IL1-β, Fg, proteomics, and immune profiling using unbiased clustering approach. This aim will identify thromboinflammatory endotypes in patients with SIC in relation to IL-1β bound to Fg. Impact of this proposal: I will determine how IL-1β bound to Fg contributes to SIC and identify septic patients who may benefit from treatments targeting this interaction to reduce their morbidity and mortality. Moreover, I will acquire technical skills (i.e., analyzing clot characteristics, protein-protein interactions, immune profiling, and advanced statistical methodology) and professional skills, which will aid my growth as a physician-scientist in conducting patient-oriented translational research into the mechanisms behind coagulopathy in SIC.
