Figure 2.

STAT5 phosphorylation in response to IL-2 is enhanced in carriers of the rs61839660 minor allele. Signal transducer and activator of transcription 5 [STAT5] phosphorylation [pSTAT5] was assessed after 15 min of incubation with 10 IU/ml of recombinant human IL-2 in CD4⁺ effector T cells [T_eff] and regulatory T cells [T_reg]. [a] Minor allele homozygotes [TT] demonstrated increased mean fluorescence intensity [MFI] for pSTAT5 flow cytometry staining compared with heterozygous [CT] and major allele homozygous [CC] subjects in T_eff [TT vs CC p <0.0001; TT vs CT p = 0.0026] and [b] T_reg [TT vs CC p = 0.0004; TT vs CT [p = 0.0085]. [c] The proportion of cells with pSTAT5 staining was also increased in T_eff from TT subjects compared with CC subjects [p = 0.0012]. [d] No differences were detected in T_reg when comparing the percentage of pSTAT5 stained cells between the genotypes. [e] There was no difference in pSTAT5 staining MFI or [f] proportion of pSTAT5-positive cells in T_eff or [g‐h] T_reg between healthy controls [HC] and Crohn’s disease [CD] patients in carriers of the minor allele. Mean ± SEM plotted. Statistical analyses performed using one-way ANOVA, Tukey post hoc test, for comparisons involving more than two groups and unpaired t tests for comparisons involving two groups. TT: n = 16, CT: n = 19, CC: n = 19. *p <0.05, ** p <0.01, ***p <0.001, ****p <0.0001. SEM, standard error of the mean; ANOVA, analysis of variance; ns = not significant.