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Updated: Jun 10, 2026

Natural Killer (NK) and CAR-NK Cell Expansion Method using Membrane Bound-IL-21-Modified B Cell Line
Published on: February 8, 2022
Allogeneic natural killer cells for refractory lymphoma
Veronika Bachanova1, Linda J Burns, David H McKenna
1Blood and Marrow, Transplant Program, University of Minnesota, Minneapolis, MN 55455, USA. bach0173@umn.edu
We reported that IL-2 activated autologous NK cells can induce, but not maintain durable remissions in lymphoma patients. We hypothesized that allogeneic NK cells may overcome class I MHC-mediated inhibition of NK cell killing. In a pilot study, we evaluated infusion of haploidentical donor NK cells for antitumor efficacy. Six patients with advanced B cell non-Hodgkin lymphoma (NHL) received rituximab, cyclophosphamide, and fludarabine as immunosupression to permit homeostatic NK cell expansion, followed by CD3-depleted NK cell-enriched cell products followed by subcutaneous IL-2 administration (10 x 10(6) units every other day x 6 doses). At 2 months, four patients showed an objective clinical response. We observed early donor cell persistence in two patients (blood and in tumor-bearing node), but this was not detectable beyond 7 days. All patients demonstrated substantial increases in host-regulatory T cells (Treg) after NK cell and IL-2 therapy (180 +/- 80 cells/microl vs. baseline: 58 +/- 24 cells/microl, p = 0.04) which may have limited donor cell expansion in vivo. These findings suggest safety and feasibility of allogeneic NK cell therapy in patients with lymphoma; however host Treg and inadequate immunodepletion may contribute to a hostile milieu for NK cell survival and expansion. Cell therapy trials should incorporate novel strategies to limit Treg expansion.
We reported that IL-2 activated autologous NK cells can induce, but not maintain durable remissions in lymphoma patients. We hypothesized that allogeneic NK cells may overcome class I MHC-mediated inhibition of NK cell killing. In a pilot study, we evaluated infusion of haploidentical donor NK cells for antitumor efficacy. Six patients with advanced B cell non-Hodgkin lymphoma (NHL) received rituximab, cyclophosphamide, and fludarabine as immunosupression to permit homeostatic NK cell expansion, followed by CD3-depleted NK cell-enriched cell products followed by subcutaneous IL-2 administration (10 x 10(6) units every other day x 6 doses). At 2 months, four patients showed an objective clinical response. We observed early donor cell persistence in two patients (blood and in tumor-bearing node), but this was not detectable beyond 7 days. All patients demonstrated substantial increases in host-regulatory T cells (Treg) after NK cell and IL-2 therapy (180 +/- 80 cells/microl vs. baseline: 58 +/- 24 cells/microl, p = 0.04) which may have limited donor cell expansion in vivo. These findings suggest safety and feasibility of allogeneic NK cell therapy in patients with lymphoma; however host Treg and inadequate immunodepletion may contribute to a hostile milieu for NK cell survival and expansion. Cell therapy trials should incorporate novel strategies to limit Treg expansion.

