T regulatory cell separation for clinical application

We selected T regulatory cells (Tregs) from standard leukapheresis using double-negative selection (anti-CD8 and anti-CD19) followed by positive selection (anti-CD25) and 72 procedures were performed. A median of 263 x 10(6) cells (range 143-470 x 10(6)) were recovered with a mean of CD4(+)/CD25(+) cells of 94.5 +/- 2.4% (36.5 +/- 18.6% CD4(+)/CD25(+hi)). FoxP3(+) cells were equal to 79.8%+/- 22.2. CD127(+) cells were 12.5%+/- 8.2. The inhibition assay showed an inhibition rate of 67 +/- 22. Cells isolated by means of this approach can be used in allogeneic hematopoietic stem cell transplantation to reduce the incidence and severity of GvHD without bystander inhibition of general immunity. (C) 2012 Elsevier Ltd. All rights reserved.