Treatment with 5-azaC decreased CD11a regulatory sequence methylation and increased CD11a expression in normal CD4+T cells. (A and B) CD11a promoter methylation patterns in (A) untreated CD4+ T cells and (B) 5-azaC-treated CD4+ T cells from five healthy subjects. (C and D) Treatment of CD4+ T cells with 5-azaC caused significant (C) demethylation of the same promoter region accompanied by (D) demethylation of Alu element relative to untreated CD4+ T cells. (E and F) Both (E) mRNA and (F) protein expression of CD11a were more pronounced in 5-azaC-treated CD4+ T cells than in untreated CD4+ T cells. (G) The mean DNA methylation levels of the CD11a promoter were inversely correlated with the relative mRNA level in 5-azaC treated CD4+ T cells.