A highly relevant and efficient single step method for simultaneous depletion and isolation of human regulatory T cells in a clinical setting

Regulatory T cells (Tregs) are pivotal in preventing autoimmunity. They play a major but still ambiguous role in cancer and viral infections.Functional studies of human Tregs are often hampered by numerous technical difficulties arising from imperfections in isolating and depleting protocols, together with the usual low cell number available from clinical samples.We standardized a simple procedure (Single Step Method, SSM), based on magnetic beads technology, in which both depletion and isolation of human Tregs with high purities are simultaneously achieved. SSM is suitable when using low cell numbers either fresh or frozen from both patients and healthy individuals. It allows simultaneous Tregs isolation and depletion that can be used for further functional work to monitor suppressive function of isolated Tregs (in vitro suppression assay) and also effector IFN-γ responses of Tregs-depleted cell fraction (OX40 assay).To our knowledge, there is no accurate standardized method for Tregs isolation and depletion in a clinical context. SSM could thus be used and easily standardized across different laboratories.