Enhanced Siglec-G interaction with the CD24 fusion protein mitigates GVHD. (A) Survival. WT-B6 mice were lethally irradiated with 13 Gy and infused with 2.5 × 106 CD90+ T cells along with 5 × 106 TCD-BM cells from either syngeneic B6 or allogeneic MHC-mismatched BALB/c donors. The recipients were injected with the CD24 Fc protein on day −1 (5 mg/kg) or diluent control on day −1 before allo-HCT (n = 4 to 25 per group, pooled from 3 experiments). For ▲ vs △, P = .03. The bar shows the mean ± SEM. (B) Siglec-G−/− mice were lethally irradiated with 13 Gy and infused with 2.5 × 106 CD90+ T cells along with 5 × 106 TCD-BM cells from either syngeneic B6 or allogeneic MHC-mismatched BALB/c donors. The recipients were injected with the CD24 Fc protein on day −1 (5 mg/kg) or diluent control on day −1 before allo-HCT (n = 4 to 12 per group, pooled from 2 experiments). The bar shows the mean ± SEM.
