‘effector memory’ T lymphocytes are primarily detected in the peripheral blood, express perforin and effector cytokines (including IFN-γ, IL-4, and IL-17A) in response to TCR stimulation, but fail to produce IL-2 [34,39]. Recently, tissue-specific CREMα expression patterns have been documented in naïve and memory CD4+ T lymphocytes. CREMα is increased in cells that express IL-17A and fail to express IL-2 (‘effector memory’ CD4+ T cells), leading us to conclude that CREMα contributes to subset-specific CpG methylation of the IL2 and IL17A promoters, determining the amount of gene expression, and thus contributing to CD4+ T cell subset distribution [34].
