The majority of mucosal CD127lo FOXP3+ Helios+ CD4+ T cells express CTLA-4.

(A) Representative plots gated on CD4+ T cells showing the expression of CD127 on FOXP3+ CD4+ T cells derived from nasal mucosa and in PBMC. (B) Representative plots (left) and compiled percentages of CD4+ T cells expressing FOXP3 and Helios in PBMC (n = 13) and in nasal mucosa (n = 11). (C) Representative plots (left) and percentages of intracellular CTLA-4 expression in CD4+ T cells subsets separated on FOXP3 and Helios expression in PBMC n = 5 and nasal mucosa (n = 4). Statistical difference between PMBC and nasal mucosa is indicated, *p