oIL-2Rβ Tregs home to the GIT and potently suppress activated Tcons. BALB/c mice underwent transplantation with C57BL/6 BM and Tcons to induce aGVHD (n = 5) and were treated with oIL-2Rβ Tregs with daily injections of either PBS (n = 5) or oIL-2 (n = 5). The large intestine was harvested on day 14 for flow cytometry analysis. Data are representative of 2 independent experiments. Frequency (left) and absolute number (right) of INFγ⁺ CD4⁺ (A) and CD8⁺ (B) T cells. Frequency (left) and absolute number (right) of TNFα⁺ CD4⁺ (C) and CD8⁺ (D) T cells. (E) Concentration of TNFα and INFγ⁺ in PB on day 14 after allo-HSCT. (F) aGVHD pathology scores of the large intestine (LI) on day 14 after allo-HSCT (left). Representative histological images of the colon at original magnification ×10 following hematoxylin and eosin staining (right). Student t test with Bonferroni correction for multiple comparisons was used for statistical analysis. Error bars indicate the SD of the mean. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001.