Posttransplant Tc17 cells express a distinct transcription factor and gene expression profile. (A-C) CD8⁺YFP⁺ and CD8⁺YFP^neg T-cell transcription factor expression after allogeneic (B6.IL-17^CreRosa26^eYFP→B6D2F1) transplant. (A) YFP⁺ and YFP^neg CD8⁺ T cells isolated from spleen, mLNs, and liver by FACS on d7 and d21 followed by qPCR (mean ± SEM, n = 3-4 independent experiments each consisting of 10 pooled mice/group; *P < .05). (B) Representative flow cytometry data from transcription factor staining of CD8⁺ T-cell populations isolated from pooled spleen, mLNs, and liver d7 posttransplant. (C) Frequencies of transcription factor–expressing CD8⁺ T cells gated on YFP expression 7 days posttransplant (mean ± SEM, n = 4 independent experiments each consisting of 10 pooled mice/group; **P < .01). (D) Eomes and RORγt expression 21 days posttransplant in YFP⁺ and YFP^neg CD8⁺ T cells isolated from pooled spleen, mLNs, and liver. (E-H) Microarray analysis of CD8⁺YFP⁺ and CD8⁺YFP^neg T-cell gene expression after allogeneic (B6.IL-17^CreRosa26^eYFP→ B6D2F1) transplant. (E) Gene expression heat map d7 posttransplant showing 299 gene probes differentially expressed between CD8⁺YFP⁺ and CD8⁺YFP^neg T cells sorted from 4 independent experiments consisting of 10 mice pooled/group. Genes were identified by unpaired Student t test (P < .05) after false discovery rate (Benjamini-Hochberg) P value correction. (F) Volcano plot showing the distribution of expression in all genes expressed by either CD8⁺YFP⁺ or CD8⁺YFP^neg T cells. Blue data points represent genes with a >1.2 fold differential expression with an uncorrected P value < .001. (G) Scatter plot highlighting the 299 gene probes shown in (D). Red scatter data points highlight differentially expressed genes of interest. (H) Twenty-five selected immunologically relevant genes differentially regulated in CD8⁺YFP⁺ and CD8⁺YFP^neg T cells. FC, fold change. See also supplemental Tables 2 and 3).