Figure 3. Genetically identical mice from different vendors develop CD4⁺ T cell-mediated GVHD of varying severity that correlates with MHC-II expression by IEC.

(A) Lethally irradiated B6N mice from the indicated vendors were transplanted with female B6 BM and 0.5 x 10⁶ Marilyn T cells. Female recipients were used as negative controls. Survival by Kaplan-Meier analysis and clinical score on day 7 post BMT, combined from 2 independent experiments (n = 7 – 10). (B, C) Lethally irradiated female B6N mice were transplanted with BALB/c BM and 5 x 10⁶ PC61-treated (regulatory T cell-depleted) CD4⁺ T cells. Recipients of TCD grafts are negative controls. (B) Survival by Kaplan-Meier analysis and clinical score on day 7, combined from 3 independent experiments (n = 15 – 11). (C) Intestinal histopathology scores and representative images on day 8 post BMT (n = 5 per T cell replete group, 4 per TCD from 1 experiment). (D) Lethally irradiated male B6N mice from JAX and CR vendors were transplanted with 1.0 x 10⁶ Marilyn T cells and the mLN and ileum were analyzed on day 4 (n = 9 per group combined from 2 independent experiments) (A-C) Statistical analyses: Day 7: Kruskal-Wallis test (mean ± SEM). (D) t-test with Welch’s correction (mean ± SEM). *P < 0.05, ** P < 0.01, ***p < 0.001, ****p < 0.0001.