Treatment of aGVHD with E18 mAb. (A) Lethally irradiated BALB/c mice were reconstituted with 10⁷ B6 TCD BM cells either alone or together with 10⁶ CD4⁺ (n = 3 experiments) or 8 × 10⁵ CD4⁺CD25⁻ peripheral T cells (n = 2 experiments) from CD90.1-congenic B6 mice. E18 mAb was administered 1 day after the cell transfer. The percentages of animals surviving over time are depicted as Kaplan-Meier graph. (B) Mean clinical scores of recipient animals (n = 5). (C) Representative hematoxylin and eosin stainings of small-bowel and large-bowel sections obtained from mice 6 days after transplantation (original magnification ×200): microscope, LEICA DMIRE2 (Leica Microsystems, Wetzlar, Germany); lens: HC PLAN S 10×/0.40 PH1; mounting medium: Entellan (Merck, Darmstadt, Germany); camera, LEICA DFC300 FX; acquisition software, LEICA IM50 Image Manager. Adobe Photoshop CS3 (Adobe Systems, San Jose, CA) was used to adjust for brightness and contrast and to convert to grayscale. (D) Histopathologic changes were scored on small-bowel and large-bowel sections as detailed in “Methods.” Cumulative scores are depicted for individual animals (○). Horizontal bars represent the medians per group. Data from 3 experiments were pooled. (E) The percentages of Foxp3⁺ cells among donor-derived CD4⁺ cells isolated from spleen, MLN, or liver were determined on day 6 after transplantation. ○ represent individual animals. represent the median values of each group with data from 4 experiments being pooled. Ctrl indicates control mAb treatment.