Reduced alloreactivity of SHIP-deficient CD4⁺CD25⁻ effector T cells in vivo. Rag2^−/−γc^−/− hosts on an H2d background received 4 × 10⁵ CD3⁺CD4⁺CD25⁻ T cells from SHIP^−/− or WT C57BL6 (H2b) donors by r.o. injection on day 1. In parallel, a control group of Rag2^−/−γc^−/− hosts received a PBS injection. Disease was monitored on a daily basis. Data represent 2 separate studies that were combined, where n = 5 per treatment group, resulting in an n = 10 per each treatment group. (A) Kaplan-Meier step functions that show survival for the indicated Rag2^−/−γc^−/− cohorts (n = 10). P = .01 for SHIP^−/− versus WT CD25⁻ T-cell-injected cohorts. (B) Histopathologic appearance (hematoxylin and eosin, × 200) of the proximal colon of Rag2^−/−γc^−/− mice after transfer of SHIP^−/− or WT CD4⁺CD25⁻ T cells. These are representative examples that show grading to determine the HPS, using the criteria described in Figure 5. Histology micrographs were taken as described in Figure 5. (C) Table summarizing the assessment of disease in Rag2^−/−γc^−/− mice cohorts receiving CD25⁻ T cells from the indicated genotype or sterile PBS control based on the clinical assessment score (CAS), the HPS and the disease activity index (DAI = CAS + HPS). The CAS is determined as follows: 0 indicates no signs; 1, bristled fur; 2, bristled fur with hunched posture, and/or reduced activity; 3, all of the above and change in stool consistency (eg, soft, sticky); 4, rectal prolapse.