IL-17RA signaling in both hematopoietic and nonhematopoietic recipient tissue attenuates acute GVHD. (A) Lethally irradiated IL-17RA^−/− chimeras were transplanted with T-cell replete (n = 13 per group) or TCD (n = 7 per group) G-CSF mobilized BALB/c.WT donor splenocytes. Survival is represented by Kaplan-Meier analysis. Combined data from 2 replicate experiments are shown. Survival: **P = .004, WT → WT chimera (red filled squares) vs IL-17RA^−/− → IL-17RA^−/− chimera (purple filled circles); *P = .028, WT → WT chimera (red filled squares) vs WT → IL-17RA^-−/− chimera (blue open squares); *P = .024, WT → WT chimera (red filled squares) vs IL-17RA^−/− → WT chimera (green open circles). (B) Lethally irradiated IL-17A^−/− chimeras were transplanted with G-CSF mobilized BALB/c.WT donor splenocytes (n = 12 per group). Survival is represented by Kaplan-Meier analysis. Combined data from 2 replicate experiments are shown. Survival: ****P < .0001, WT → WT chimera (purple filled triangles) vs IL-17A^−/− → IL-17A^−/− chimera (red open squares); ****P < .001, WT → WT chimera (purple filled triangles) vs WT → IL-17A^-−/− chimera (green filled squares); ***P = .0006, WT → WT chimera (purple filled triangles) vs IL-17A^−/− → WT chimera (blue filled circles).