SOLUBLE LYMPHOCYTE ACTIVATION GENE-3 (s-LAG-3) AND INSULIN m-RNA: A POTENTIAL SURROGATE MARKERS FOR DISEASE PROGRESSION AND IMMUNOTHERAPY

PROJECT ABSTRACT Early biomarker detection is crucial for identifying disease onset and evaluating therapy effectiveness, especially in autoimmune diseases like type 1 diabetes (T1D). Detecting T1D before symptoms arise can greatly improve prevention strategies and enable personalized treatments. However, current biomarkers are insufficient to predict each stage of T1D development1. The need for early detection biomarkers remains unmet, as current standards rely on autoantibody conversion, which occurs late in the disease process. Identifying markers that detect disease before autoantibody development could help preserve β-cell mass and delay progression. Autoantibody generation relies on interactions between B cells and activated T cells3. High- risk individuals can be distinguished from later-stage patients using pre-symptomatic biomarkers, which may uncover disease pathways and enable earlier interventions4. T cell activation, critical in T1D, results in the release of soluble lymphocyte activation gene-3 (sLAG3), a marker of immune system activation. Activated, self-reactive T cells damage β cells, triggering stress responses, including the integrated stress response (ISR), which produces extracellular vesicles (EVs) containing β-cell stress markers such as insulin mRNA. Early studies show increasing sLAG3 levels in at-risk individuals, suggesting early immune activation. We recently developed an assay system using plasma and peripheral blood leukocytes (PBLs) to detect immune system changes before autoantibody formation. By employing tetramer technology, we can detect autoreactive T cells at the single-cell level, assessing sLAG3 levels and insulin mRNA. Our objectives are to evaluate if sLAG3, tetramer-positive T cells, and insulin mRNA can predict T1D onset and to incorporate these biomarkers into a multiplex nanoplasmonic assay for simultaneous detection.