Methods for quantitating antigen-specific T cell responses using functional assays in rhesus macaques.

Area of Science:

• Immunology
• Vaccinology
• Cellular Biology

Background:

• Evaluating T cell-based vaccine immunogenicity requires ex vivo enumeration of antigen-specific T cells.
• Common methods include Enzyme-Linked Immuno Spot (ELISpot), Intracellular Cytokine Staining (ICS), and Tetramer assays, each providing distinct information.

Purpose of the Study:

• To discuss two functional assays, ELISpot and ICS, used for quantifying cellular immune responses.
• To explain how these assays assess T cell frequency and cytokine expression profiles.

Main Methods:

• Both ELISpot and ICS assays involve short-term in vitro stimulation of cells.
• ELISpot quantifies cytokine-producing cells by scoring captured cytokine spots.
• ICS utilizes flow cytometry to analyze individual cells for surface markers and intracellular cytokine production.

Main Results:

• ELISpot provides a measure of cytokine-secreting cells.
• ICS offers detailed profiling of individual cells, including cytokine production and surface marker expression.

Conclusions:

• ELISpot and ICS are valuable functional assays for assessing T cell responses.
• These methods provide complementary data for understanding vaccine-induced immunogenicity.