Abstract: This invention provides a highly sensitive assay for the detection of T-cells reactive to an antigen by detecting a soluble factor whose secretion is induced by stimulation of the T-cell by the antigen. The assay includes an antigen-driven proliferation of specific T cells prior to restimulation with irradiated antigen presenting cells (APCs) and antigen. In exemplary embodiments the assay is used to enhance the detection limits of human peripheral blood mononuclear cells (PBMCs) secreting interferon-&ggr; (IFN-Y) and interleukin-2 (IL-2). The assay can be performed on previously frozen PBMCs, providing greater convenience in sample processing, multiple use of a single sample as an internal standard, and simultaneous analysis of samples collected at different time points.

Abstract: This invention provides a highly sensitive assay for the detection of T-cells reactive to an antigen by detecting a soluble factor whose secretion is induced by stimulation of the T-cell by the antigen. The assay includes an antigen-driven proliferation of specific T cells prior to restimulation with irradiated antigen presenting cells (APCs) and antigen. The assay can be performed on previously frozen PBMCs, providing greater convenience in sample processing, multiple use of a single sample as an internal standard, and simultaneous analysis of samples collected at different time points.