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

Follicular regulatory T (T FR ) 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 T FR cells suppress GC antibody responses mediated by follicular helper T (T FH ) cells and B cells, the helper activity of T FR 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 T FR 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 T FR cell function on T FH , B cells, and antibody response in vivo.