A novel method for detecting antigen-specific human regulatory T cells

Antigenic epitopes recognized by FoxP3+ regulatory T cells (Treg) are poorly defined, largely due to a lack of assays for determining Treg specificity. We have developed a novel approach for detecting human Treg specific to peptide antigen, utilizing down-regulation of surface CD3 as a read-out of antigen recognition. Culture conditions and re-stimulation time have been optimized, allowing the detection of even very rare Treg, such as those specific to tumor antigens.