Live-cell assay to detect antigen-specific CD4+ T-cell responses by CD154 expression

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• CD4+ T cells are crucial for adaptive immunity.
• Identifying antigen-specific T cells is vital for understanding immune responses.
• Existing methods for T cell analysis often have limitations in preserving cell viability or allowing simultaneous functional assessments.

Purpose of the Study:

• To detail a novel protocol for identifying and purifying antigen-specific CD4+ T cells.
• To enable simultaneous assessment of other cell phenotypes and functions alongside antigen specificity.
• To provide a method compatible with downstream molecular assays while maintaining cell viability.

Main Methods:

• Utilizes detection of CD154 (a costimulatory molecule) on activated CD4+ T cells.
• Involves culturing cells with fluorescently labeled antibodies, antigens, and monensin for 6-24 hours.
• Analysis via flow cytometry or cell sorting after staining for additional markers.

Main Results:

• Successfully identifies CD4+ T cells responding to specific antigens.
• Allows for the purification of live CD4+ T cells with diverse functions.
• Demonstrates compatibility with simultaneous assessment of other cell phenotypes and downstream RNA-based assays.

Conclusions:

• This protocol offers a robust method for analyzing antigen-specific CD4+ T cells.
• The technique preserves cell viability and allows for multi-parametric analysis.
• It provides a valuable tool for immunological research and diagnostics.