BACKGROUND: We sought to develop a method for the clinical large-scale depletion of alphabeta T lymphocytes from mobilized peripheral stem cells, which would allow the allogeneic transplantation of a graft enriched for stem cells, natural killer (NK) cells and gammadelta T lymphocytes. METHODS: Therefore, we obtained mononuclear cells from either mobilized or non-mobilized healthy adult volunteer donors and incubated the cells with a biotinylated anti-alphabeta T-cell Ab and subsequently with an anti-biotin Ab conjugated with magnetic microbeads. The depletion was then performed using a CliniMACS device. RESULTS: The median T-cell depletion was 3.9 log (range 3.5-4.1 log). The recovery of the gammadelta and NK cells was 92% and 80%, respectively. The recovery of CD34+ stem cells from the mobilized donors was 66%. DISCUSSION: This method had no negative influence on the in vitro colony formation of stem cells, and transplantation of alphabeta-depleted cells into NOD-SCID IL-2 common gamma chain knockout (NOD-scid IL2r (null)) mice resulted in a rapid engraftment of human myeloid and lymphoid cells. This method will allow large-scale depletion of alphabeta T cells from mobilized peripheral blood in clinical trials.
BACKGROUND: We sought to develop a method for the clinical large-scale depletion of alphabeta T lymphocytes from mobilized peripheral stem cells, which would allow the allogeneic transplantation of a graft enriched for stem cells, natural killer (NK) cells and gammadelta T lymphocytes. METHODS: Therefore, we obtained mononuclear cells from either mobilized or non-mobilized healthy adult volunteer donors and incubated the cells with a biotinylated anti-alphabeta T-cell Ab and subsequently with an anti-biotin Ab conjugated with magnetic microbeads. The depletion was then performed using a CliniMACS device. RESULTS: The median T-cell depletion was 3.9 log (range 3.5-4.1 log). The recovery of the gammadelta and NK cells was 92% and 80%, respectively. The recovery of CD34+ stem cells from the mobilized donors was 66%. DISCUSSION: This method had no negative influence on the in vitro colony formation of stem cells, and transplantation of alphabeta-depleted cells into NOD-SCID IL-2 common gamma chain knockout (NOD-scid IL2r (null)) mice resulted in a rapid engraftment of human myeloid and lymphoid cells. This method will allow large-scale depletion of alphabeta T cells from mobilized peripheral blood in clinical trials.
Authors: Moniek A de Witte; Anke Janssen; Klaartje Nijssen; Froso Karaiskaki; Luuk Swanenberg; Anna van Rhenen; Rick Admiraal; Lotte van der Wagen; Monique C Minnema; Eefke Petersen; Reinier A P Raymakers; Kasper Westinga; Trudy Straetemans; Constantijn J M Halkes; Jaap-Jan Boelens; Jürgen Kuball Journal: Blood Adv Date: 2021-01-12