(A–C) Flow cytometric quantification of CD11c⁺ myeloid DC frequency (A) and CD103⁺CD11c⁺ migratory DC frequency as a percentage of CD45⁺ leukocytes (B) versus CD11c⁺ myeloid DCs (C) in Rag1^KOTslpr^KO (n = 5) and Rag1^KO (n = 5) MLNs following adoptive transfer of naive WT CD4⁺CD25^– T cells. Rag1^KOTslpr^KO tissues were obtained at the moribund state and Rag1^KO samples were harvested on day 15 after T cell transfer. Each dot represents 1 mouse. (D–F) Flow cytometric quantification of CD11c⁺ myeloid DC frequency (D) and CD103⁺CD11c⁺ migratory DC frequency as a percentage of CD45⁺ leukocytes (E) versus CD11c⁺ myeloid DCs (F) in Rag1^KOTslpr^KO (n = 5) and Rag1^KO (n = 5) colon following adoptive transfer of naive WT CD4⁺CD25^– T cells. Rag1^KOTslpr^KO tissues were obtained at the moribund state and Rag1^KO samples were harvested on day 15 after T cell transfer. Each dot represents 1 mouse. (G) Representative H&E staining of colons from Rag1^KOTslpr^KO mice that received WT or Tslpr^KO DC transfer 1 day before adoptive CD4⁺ T cell transfer. Note the loss of goblet cells, moderate inflammation, and crypt hyperplasia in the animals given Tslpr^KO DCs compared with those that received WT DCs before T cell transfer. Scale bars: 50 μm. (H) CD4⁺ T cell counts in Rag1^KOTslpr^KO colons after the transfer of WT (n = 5) versus Tslpr^KO (n = 5) DCs followed by an adoptive naive WT CD4⁺CD25^– T cell transfer. CD3⁺CD4⁺ colonic T cells were quantified in 10 randomly selected HPFs per mouse at the moribund state or on day 15 after T cell transfer. Each dot represents 1 HPF; bar graphs show mean + SD. **P < 0.01; ****P < 0.0001 by unpaired, 2-tailed t test. NS, not significant.