Validation of a Flow Cytometric Method to Monitor Regulatory T Cells as Part of Clinical Trials

CYTO 2021 -- Regulatory T cells (Treg) represent a distinct subpopulation of T cells involved in the modulation of immune responses to pathogens, allergens, and auto-antigens.1,2 They suppress inflammation by inhibiting both T cell proliferation and cytokine production. Decrease in Treg cell frequency or function is thought to be a contributing factor in the development of wide variety of autoimmune, lymphoproliferative and inflammatory disorders. Conversely an overabundance of Treg cells may be accountable for weakened immune response to tumor antigens. Hence, the measurement of circulating Treg cells and their relative proportion to effector T cells is becoming an important efficacy and safety biomarker in the evaluation of immune modulating therapeutics. In this assay, percentage and absolute count of Treg cells are evaluated based on expression levels of CD45, CD3, CD4, CD25, CD127 and FoxP3.