USING FLUORESCENT MICRO(NANO)SCOPY TO UNDERSTAND HOW BIOPHYSICAL CUES FINE-TUNE MAST CELL SIGNALING - PROJECT SUMMARY / ABSTRACT THE ACTIVATION AND REGULATION OF MAST CELL SIGNALING THROUGH THE HIGH-AFFINITY IGE RECEPTOR (FCERI) IS A CRITICAL ASPECT OF ALLERGIC RESPONSES. UPON CROSSLINKING BY MULTIVALENT ANTIGENS, FCERI INITIATES SIGNALING CASCADES THAT RESULT IN MAST CELL DEGRANULATION AND CYTOKINE RELEASE, DRIVING ALLERGIC INFLAMMATION. WHILE THE BIOCHEMICAL MECHANISMS OF FCERI ACTIVATION ARE WELL UNDERSTOOD, SIGNIFICANT GAPS REMAIN IN UNDERSTANDING HOW BIOPHYSICAL FACTORS CAN MODULATE MAST CELL RESPONSES. MY F31 RESEARCH WILL ADDRESS THE CENTRAL HYPOTHESIS THAT THE STRENGTH AND SPECIFICITY OF MAST CELL RESPONSES ARE FINE-TUNED BY BIOPHYSICAL CUES THAT MODULATE FCERI SIGNALING. SPECIFICALLY, I PROPOSE THAT FACTORS SUCH AS ANTIGEN PROPERTIES, TISSUE STIFFNESS, AND MECHANOTRANSDUCTION SERVE AS CRITICAL SIGNALS TO MODULATE FCERI ACTIVATION DYNAMICS, ULTIMATELY SHAPING THE MAST CELL'S RESPONSE. TO ADDRESS MY HYPOTHESIS, I WILL: 1) DEFINE HOW ANTIGEN STRUCTURE MODULATES FCERI AGGREGATION AND DOWNSTREAM SIGNALING USING CASHEW-DERIVED ALLERGENS, 2) DETERMINE HOW INTEGRIN-FCERI CROSSTALK REGULATES MAST CELL ACTIVATION, AND 3) EVALUATE THE ROLES OF RECEPTOR PACKING AND MECHANOTRANSDUCTION IN FCERI-MEDIATED SIGNALING AT THE MAST CELL SYNAPSE. A COMBINATION OF CUTTING-EDGE TECHNIQUES WILL BE USED, INCLUDING SUPER-RESOLUTION IMAGING, DNA ORIGAMI NANOSHEETS, TENSION GAUGE TETHERS, ALONG WITH NATURAL ALLERGENS AND MONTE CARLO SIMULATIONS, TO UNCOVER HOW MAST CELLS DECIDE THE SPECIFICITY AND STRENGTH OF THEIR RESPONSE. THE OUTCOMES WILL ADVANCE OUR UNDERSTANDING OF MAST CELL ACTIVATION, INFORM INNOVATIVE THERAPEUTIC STRATEGIES FOR ALLERGIC DISEASES, AND CONTRIBUTE TO OUR FUNDAMENTAL KNOWLEDGE OF IMMUNE RECEPTOR SIGNALING. THROUGH THE TRAINING PLAN, I WILL BUILD EXPERTISE IN IMMUNOBIOLOGY, CELL SIGNALING, MECHANOTRANSDUCTION, ADVANCED CELLULAR IMAGING, BIOPHYSICAL METHODS, AND STRUCTURAL MODELING. THE F31 PROCESS WILL GIVE ME THE RESEARCH EXPERIENCE AND PROFESSIONAL SKILLS NEEDED TO BUILD AN INDEPENDENT RESEARCH CAREER FOCUSING ON UNDERSTANDING IMMUNE CELL SIGNALING.