Identification and Purification of Human Memory T Helper Cells from Peripheral Blood.

T helper (Th) cells are involved in various physiopathological systems, including response to infections, vaccination, cancer, and autoimmunity. The isolation of viable human Th cells is a procedure that allows a broad study of both phenotypical and functional features of each Th subset, and thus, it is necessary to study these cells in different contexts. In particular, the purification of human memory Th cells from peripheral blood is preparatory for further complex experiments on these cells, such as global transcriptional analysis, coculture assays, silencing experiments, and drug assays.Here, we describe the method for the identification and isolation of pure memory human Th1, Th2, Th17, Th1/17, and T regulatory cells, derived from peripheral blood mononuclear cells. Moreover, we show the purity of each purified Th subset, verified by the analysis of specific transcription factors.