Microglia activation and T cell infiltration in nonclassical GVHD target organs. (A) Representative images showing Imaris-based (Bitplane) 3D reconstruction of Iba-1⁺ microglia cells from BALB/c mice on day 14 after syn-HCT or allo-HCT as indicated. (B) Histology of brain samples immunostained for CD3⁺ T cells (brown) from BALB/c mice on day 14 after allo-HCT. The arrows point toward CD3⁺ T cells. Scale bar, 50 μm. (C) Nonirradiated B6D2F1 mice were injected with 3 × 10⁷ purified EGFP⁺⁺ T cells and 5 × 10⁷ wild-type B6 T cell–depleted bone marrow. The ovaries were analyzed on day +14. EGFP-positive (brown) donor T cells infiltrate in the ovarian follicles beyond the basement membrane. Scale bar, 100 μm.