A genetically encoded sensor for visualizing leukotriene B4 gradients in vivo

Area of Science:

• Immunology
• Molecular Biology
• Biochemistry

Background:

• Leukotriene B4 (LTB4) is a key chemoattractant in inflammation, allergy, autoimmunity, and metabolic diseases.
• LTB4 gradients guide leukocyte recruitment to infection and injury sites.
• Current methods lack tools to monitor LTB4 dynamics in vivo, hindering research.

Purpose of the Study:

• To develop a genetically encoded biosensor for real-time LTB4 visualization.
• To enable the study of LTB4 gradient formation and spread in live tissues.
• To provide a tool for analyzing LTB4 dynamics in diverse experimental models.

Main Methods:

• Development of GEM-LTB4, a green fluorescent biosensor based on the human BLT1 receptor.
• Assessing GEM-LTB4 sensitivity, specificity, and impact on cellular signaling.
• Utilizing GEM-LTB4 for ex vivo LTB4 measurement in murine neutrophils.
• Employing transgenic GEM-LTB4 expression in zebrafish for in vivo LTB4 gradient imaging.

Main Results:

• GEM-LTB4 demonstrates high sensitivity and specificity for LTB4 detection.
• The biosensor exhibits a robust fluorescence increase upon LTB4 binding without altering downstream signaling.
• GEM-LTB4 successfully visualized LTB4 production in neutrophils and LTB4 gradients in zebrafish.
• Real-time imaging of LTB4 gradients was achieved in live zebrafish.

Conclusions:

• GEM-LTB4 is a sensitive and specific tool for monitoring LTB4.
• This biosensor facilitates the study of LTB4 dynamics in various biological contexts.
• GEM-LTB4 offers a valuable platform for investigating inflammatory processes and leukocyte behavior.