Interleukin (IL)-35 is a relatively newly discovered member of IL-12 cytokine family that is unique in that it is a dimer formed by two subunits. The review documents the structure, secretion and signal transduction of IL-35, the regulation effect of IL-35 on B cells and T cells as well as the adoptive transfer of IL-35+ regulatory B cells (Breg), therapeutic prospects of recombinant IL-35 (rIL-35) and IL-35 regulation role in various diseases. B-cell regulation expands the regulatory range of IL-35 and alters the view that IL-10 is the chief immune mechanism for Breg cells which secrete IL-35. IL-35 induces Breg cells, which then can induce Treg cells. IL-35 also plays an immunomodulatory role in the human body.
Keywords: B cells; Interleukin −35; T cells.