Follicular helper T (Tfh) cells play a key role in B cell activation and differentiation. Within recent years, distinct subsets of follicular T cells, including regulatory and cytotoxic T cells, have been identified. Apart from classical Tfh cells in secondary lymphoid organs, Tfh-like cells are found in chronically inflamed nonlymphoid tissues. Here, we provide protocols to identify different follicular T cell subsets in murine and human tissues by flow cytometry. This chapter also contains an immunization protocol for the induction of large numbers of Tfh cells in mice.
Keywords: Adjuvants; Flow cytometry; Follicular T cells; Germinal center; NKTfh cells; Tfc cells; Tfh cells; Tfh-like cells; Tfr cells.