Studying antigen-specific T cells through a streamlined, whole blood-based extracellular approach

Area of Science:

• Immunology
• Translational Research
• Clinical Assays

Background:

• Current methods for studying antigen-specific T-cell responses are often labor-intensive and less informative.
• This limits their application in translational research across fields like oncology, infectious diseases, and vaccination.
• There is a need for more accessible and efficient techniques to study T-cell immunity.

Purpose of the Study:

• To develop a standardized, easy-to-use flow cytometry-based approach for studying antigen-specific T-cell responses.
• To facilitate the inclusion of T-cell response analysis in routine clinical research.
• To compare the novel approach with established methods like ELISpot and intracellular cytokine staining (ICS).

Main Methods:

• A streamlined assay using whole blood, termed whole blood activation-induced markers (WAIM).
• WAIM relies on the expression of extracellular activation markers (CD154, CD137, CD107a).
• Comparison with enzyme-linked immunospot (ELISpot) and intracellular cytokine staining (ICS) in 20 individuals vaccinated against COVID-19, assessing SARS-CoV-2 and cytomegalovirus (CMV) responses.

Main Results:

• The WAIM technique demonstrated a significant correlation with both ELISpot and ICS methods.
• WAIM proved simple to implement using whole blood and extracellular markers.
• The chosen extracellular markers offered higher orthogonality compared to cytokines typically used in ICS.

Conclusions:

• The WAIM assay provides a user-friendly and effective method for assessing antigen-specific T-cell responses.
• This approach enhances the feasibility of incorporating T-cell immunity studies into clinical research.
• WAIM shows potential for patient stratification due to its marker orthogonality.