Development of Luminescent Biosensors for Calprotectin

Area of Science:

• Biochemistry
• Immunology
• Biotechnology

Background:

• Calprotectin is a vital innate immune protein and a biomarker for inflammatory and infectious diseases.
• Current enzyme-linked immunosorbent assays (ELISAs) for calprotectin lack convenience and accessibility.
• There is a need for novel, user-friendly methods for calprotectin quantification.

Purpose of the Study:

• To develop and validate a novel, quantitative assay for calprotectin measurement.
• To introduce the Fab-Enabled Split-luciferase Calprotectin Assay (FESCA) as a convenient alternative to ELISAs.
• To demonstrate FESCA's utility in detecting physiologically relevant calprotectin levels in various biological samples.

Main Methods:

• Development of two new fragment antigen binding proteins (Fabs), CP16 and CP17, targeting calprotectin.
• Fusion of Fabs with split NanoLuc luciferase fragments for signal generation upon calprotectin binding.
• Quantitative measurement of luminescence output using standard laboratory equipment and consumer-grade cell phone cameras.

Main Results:

• FESCA successfully quantifies calprotectin in serum, plasma, and whole blood samples.
• The assay can detect physiologically relevant concentrations of calprotectin.
• FESCA demonstrated the ability to identify elevated calprotectin levels in tuberculosis patients.

Conclusions:

• FESCA provides a convenient, low-cost, and quantitative method for calprotectin assessment.
• The assay has potential for improved diagnosis and monitoring of inflammatory diseases.
• FESCA is suitable for point-of-care and at-home testing settings.