CD4+ T helper cells play crucial roles in adaptive immune response against pathogens, as well as in host immune homeostasis. Upon TCR activation, naïve CD4+ T cells differentiate into one of several lineages of Th cells, with hallmark transcription factors, cytokine production, and functions in vivo, according to the particular cytokine milieu. To study the regulating mechanism and function of Th cells, in vitro CD4+ T-cell differentiation is crucial. The following protocols describe the methods to induce naïve CD4+ T-cell differentiate into Th1, Th2, Th17 and Treg by activating TCR, together with the different cytokines and blocking antibodies in vitro. The efficiency of T helper cell differentiation is examined by detecting the expression of hallmark cytokines and transcription factors.
Keywords: CD4+ T cells; Cytokines; Flow cytometry; T-cell differentiation; TCR activation.