Foxp3+ regulatory T (Treg) cells suppress different types of immune responses to help maintain homeostasis in the body. How T reg cells regulate humoral immunity, including germinal center reactions, is unclear. Here we identify a subset of T reg cells expressing CXCR5 and Bcl-6 that localize to the germinal centers in mice and humans. The expression of CXCR5 on T reg cells depends on Bcl-6. These CXCR5 + Bcl-6 + T reg cells are absent in the thymus but can be generated de novo from CXCR5-Foxp3+ natural T reg precursors. A lack of CXCR5 + T reg cells leads to greater germinal center reactions including germinal center B cells, affinity maturation of antibodies and the differentiation of plasma cells. These results unveil a Bcl-6-CXCR5 axis in T reg cells that drives the development of follicular regulatory T (TFR) cells that function to inhibit the germinal center reactions.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)