Suppressive Characteristics of Umbilical Cord Blood–derived Regulatory T Cells After Ex Vivo Expansion on Autologous and Allogeneic T Effectors and Various Lymphoblastic Cells

The third-party umbilical cord blood (UCB)-derived regulatory T cells (Treg) are an alternative to donor-derived Treg as cellular therapy of graft-versus-host disease following hematopoietic stem cell transplantation. However, their suppressive characteristics against autologous and allogeneic T effector cells (Teff) have rarely been documented. The exact role of UCB-Treg in hematologic malignancies is also uncertain. Here, we investigated the direct effects of UCB-Treg on the proliferation of autologous Teff, as compared with allogeneic Teff, and also determined cellular fates of lymphoblasts after UCB-Treg co-culture. UCB-Treg were isolated from 8 UCB samples using 2-step immunomagnetic bead sorting. After 10-day ex vivo expansion, up to 60-fold increase in cell number with 76.7%±4.9% of CD4+CD25+CD127loFoxP+ UCB-Treg was obtained. Further characterization showed that ex vivo-expanded UCB-Treg contained a higher proportion of CD95+CD45RAloCCR4hiTreg-B subpopulation compared with the CD95−CD45RAhiCCR4loTreg-A subpopulation (13.0%±4.8% vs. 0.8%±0.7%; P
Source: Journal of Immunotherapy - Category: Allergy & Immunology Tags: Basic Studies Source Type: research