CD8⁺ T-cell transfusion therapeutically attenuated platelet clearance and enhanced response to DEX in passive murine model of ITP. In the passive model of ITP, mice were injected with anti-β3 integrin mAb (9D2, 1 μg, intraperitoneally) at day 0 and transfused with 10⁶ CD8⁺ T cells from either WT, naïve β3^−/−, or immunized β3^−/− mice. Control cells are remaining splenocytes following CD8⁺ purification. (A) CD8⁺ T cells significantly increased platelet count in the absence of any DEX treatment. N = 6. *P < .05, **P < .01, ***P < .001 vs PBS. (B) DEX (10 mg/kg) was administered at 4 hours after mAb injection and CD8⁺ T-cell transfusion. N = 6. *P < .05, **P < .01, ***P < .001 vs PBS or indicated groups. Mean ± SD.