CD3/TCRαβ knock-down by PEBL prevents GVHD. (A) NSG mice were irradiated with 2.5 Gy and IV injected 1 day later with 1 × 10⁷ T lymphocytes transduced with either anti-CD3 PEBL or GFP only (“Control”; n = 8 per group). Body weight is expressed as change relative to weight on day 3 after irradiation. (B) Hemoglobin levels and (C) platelet counts in peripheral blood. (D) Kaplan-Meier overall survival curves and log-rank test. Mice were euthanized when weight reduction exceeded 20% in 2 consecutive measurements (additional data in supplemental Figure 6 and Table 3). (E) Human CD45⁺ cell counts in blood 18 days after T-cell injection. *P = .0148; ***P < .001.