Human CD40 ligand-expressing type 3 innate lymphoid cells induce IL-10-producing immature transitional regulatory B cells.

Background: Type 3 innate lymphoid cells (ILC3s) are involved in maintenance of mucosal homeostasis; however, their role in immunoregulation has been unknown. Immature transitional regulatory B (itBreg) cells are innate-like B cells with immunosuppressive properties, and the in vivo mechanisms by which they are induced have not been fully clarified.

Objective: We aimed to investigate the ILC3-B-cell interaction that probably takes place in human tonsils.