Absolute quantitation of binding antibodies from clinical samples

Area of Science:

• Immunology
• Analytical Chemistry
• Biotechnology

Background:

• Accurate quantitation of antibody responses is crucial for vaccine and therapeutic development.
• Current methods often rely on arbitrary reference values, limiting cross-assay comparability.
• Standardized reference materials are essential for reliable measurement of immune responses.

Purpose of the Study:

• To develop a generalizable method for the absolute quantitation of antibodies.
• To overcome limitations in comparing antibody responses across different assays and laboratories.
• To provide a more accurate and reliable way to interpret immune responses in clinical trials.

Main Methods:

• Developed MASCALE (Mass Spectrometry Enabled Conversion to Absolute Levels of ELISA Antibodies).
• Calibrated Enzyme-Linked Immunosorbent Assay (ELISA) reference sera using mass spectrometry.
• Utilized proteotypic peptides as a proxy for human IgG to convert arbitrary ELISA units to absolute amounts.

Main Results:

• Established a method for absolute quantitation of antibodies using mass spectrometry.
• Demonstrated successful comparison of binding assays between two laboratories.
• Evaluated cross-clade magnitude-breadth of immune responses induced by an investigational HIV-1 vaccine.

Conclusions:

• MASCALE provides a robust solution for absolute antibody quantitation.
• The method enhances the interpretation of immune responses in clinical settings.
• MASCALE expands options for comparing immune responses across diverse experimental conditions.