Clinical scale isolation of T cell-depleted CD56+ donor lymphocytes in children.
We present a clinical scale method for immunomagnetic separation of CD56+ donor natural killer cells for adoptive immunotherapy of pediatric leukemias after allogeneic transplantation. This time-saving and partially automated procedure employed CD56+ selection followed by CD3+ depletion, resulting in a median purity of 98.6% NK cells and a four-log depletion of T cells. The enriched NK cells demonstrated high cytotoxic activity against K562 target cells and fresh leukemic blasts with low HLA class I expression, which could be further enhanced by IL-2 stimulation. Lysis of NK-insensitive leukemic cells with high HLA class I expression could also be demonstrated via ADCC. Due to the high degree of T cell depletion, alloreactive proliferation in mixed lymphocyte cultures and response to T cell-specific mitogen stimulation was profoundly decreased. Our results suggest that, even in the case of mismatched donors, infusions of donor NK cells with extremely low T cell content may be a promising treatment option for leukemic minimal residual disease after allogeneic transplantation without risk of inducing severe GVHD.
Lang
P
P
Children's University Hospital, University of Tuebingen, Hoppe-Seyler Strasse 1, 72076 Tuebingen, Germany.
Pfeiffer
M
M
Handgretinger
R
R
Schumm
M
M
Demirdelen
B
B
Stanojevic
S
S
Klingebiel
Th
T
Köhl
U
U
Kuci
S
S
Niethammer
D
D
D019002:CD56 Antigen / Q000096:biosynthesis*; D002648:Child; D003601:Cytotoxicity Tests, Immunologic; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods; D016219:Immunotherapy, Adoptive; D007694:Killer Cells, Natural / Q000378:metabolism; D007937:Leukapheresis / Q000379:methods; D008213:Lymphocyte Activation / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D008212:Lymphocyte Depletion / Q000379:methods; D008934:Mitogens / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000378:metabolism* / Q000637:transplantation; D013601:T-Lymphocytes / Q000378:metabolism* / Q000637:transplantation; D014019:Tissue Donors; D014184:Transplantation, Homologous / Q000009:adverse effects
D019002:CD56 Antigen; D008934:Mitogens