Figure 3. IL-22 is produced post-BMT by IL-23-responsive host ILCs that are eliminated during GVHD.

Detection of CD45⁺CD3⁻RORγt⁺ ILCs two weeks after BMT by flow cytometry of small intestine lamina propria cells following five hours of IL-23 stimulation in vitro. (A-D) B6→BALB/c BMT was performed with T cell-depleted marrow alone or with marrow and T cells. (A) Graph shows frequency of CD3⁻RORγt⁺ ILCs among CD45⁺ lamina propria cells and total numbers of CD45⁺CD3⁻RORγt⁺ lamina propria ILCs from recipients with (“BM + T cells”) or without (“BM only”) GVHD. (B) Plots show concatenated frequencies of IL-22-producing RORγt⁺ ILCs. Bar graph shows frequencies of IL-22⁺RORγt⁺ ILCs among all RORγt⁺ ILCs (C) Plot shows detection of H-2^d+ host-derived cells among IL-22-producing ILCs identified after BM only BMT shown in B. (D) Graph shows total host IL-22-producing ILCs after B6→BALB/c BMT. (E-F) LP→B6 BMT was performed with T cell-depleted marrow alone or with marrow and T cells. (E) Graph shows total host IL-22-producing ILCs after LP→B6BMT (F) Plots show NKp46⁻IL-7Rα⁺CCR6⁺ phenotype of IL-22-producing CD45⁺CD3⁻RORγt⁺ ILCs after BM only BMT. (A-D) Data are representative of three independent experiments and at least thirteen mice per group; (E-F) data are representative of two independent experiments and at least six mice per group; bar graphs show mean and standard error. *p<.05, **p<.01.