Analysis of the In Vivo Function of Follicular Regulatory T (TFR) Cells in the Regulation of Antibody Response.

Follicular regulatory T (TFR) cells, a subset of Foxp3+ regulatory T cells (Tregs), play an essential role in the regulation of germinal center (GC) response and humoral self-tolerance. Although it is generally accepted that TFR cells suppress GC antibody responses mediated by follicular helper T (TFH) cells and B cells, the helper activity of TFR cells on GC responses has also been recently reported. Because of this, it is critical to develop specific assays that are able to precisely assess TFR cell function, particularly its in vivo activity, independent of differentiation and other Tregs. Here we describe an adoptive transfer approach in conjugation with flow cytometry and ELISA to evaluate the TFR cell function on TFH, B cells, and antibody response in vivo.