Figure 6.
Attenuation of A2-specific platelet transfusion refractoriness by A2Fc. (A) TKO mice were divided into 3 groups with different combinations of PA2.1 cell infusion and A2Fc treatment, as indicated. The minus signs (−) mean no cell infusion or A2Fc treatment; no placebo was administered. Two weeks after cell infusion and treatment, A2+ human platelets were transfused via intravenous injection, followed by bleeding at 10, 60, and 120 minutes for platelet enumeration. (B) Enumeration of human and murine platelets (hPlt and mPlt) by flow cytometry. Representative gating for platelets and CountBright absolute counting beads on the left. Right panel: hPlt and mPlt were distinguished by staining for hCD41 and mCD41 markers, respectively. (C) Representative flow cytometry of platelets in the indicated mice. Posttransfusion counts of hPlt and mPlt at 10, 60, and 120 minutes are shown (number of platelets per 5000 counting beads). (D) Time course of raw hPlt counts for 3 groups of TKO mice. Mean ± SD. (E-F) Normalized hPlt counts (E) and mPlt counts (F) at 10, 60, and 120 minutes for the indicated groups of mice. Counts were normalized to mean platelet counts from control mice as 100% at each time point within each experimental cohort. Points are normalized counts; bars and error bars are mean ± SD. (D-F) Data are from 6 to 8 mice per group from 3 experiments. n.s., not significant; ∗P < .05; ∗∗P < .01, compared with PA2.1 by Mann-Whitney test.