Characterization of donor-derived MSCs and Treg cells.

<p>(A) Culture-expanded MSCs were distinguishable from hematopoietic cells by being positive for Sca-1, CD44, and CD29, but were negative for the cell surface markers c-kit, CD11b, CD34, CD106, CD45, and CD31. (B) The purity of Treg cells was greater than 96% by flow cytometry. Treg cells were analyzed by FACS for intracellular Foxp3, CTLA-4, PD-1, GITR, ICAM-1, and ICOS, and surface expression of the indicated cellular markers CD44, CD62L, and CD103 in the gated CD4⁺ T cell population.