Proposed Mechanisms of Suppression of B Cells by nTregs: B Cells as Targets for Suppressive Activity of nTregs

B cells have an important role in immune system due to their role in positive and negative regulation of immune response. As positive regulators, B cells can give rise to antibody-producing plasma cells, are critical cellular adjuvants that facilitate optimal CD4+ T-cell activation. B cells also contribute to immunoregulation through the production of cytokines including IL-4, IL-6, IL-10, interferon-gamma (IFN-gamma) and transforming growth factor-β (TGF-β). In addition, B cells are thought to have specific roles in stimulating Ag-specific CD4+ T-cell proliferation after activation by dendritic cells (DCs). While B cells can play negative regulatory roles during immune responses, particularly during inflammation, autoimmunity, cancer and infection. On the other hand, natural occurring regulatory T cells (nTregs) consider a body guard of immune system and play a pivotal role in the maintenance of homeostasis of immune system and tolerance to self-antigens and tissue graft. nTregs know all languages of the immune system cells and can chat successfully with any abnormal case that happen due to aberration of function of the immune cells. nTregs can use multiple mechanisms to exert their functions. In the current review we will focus on the mechanisms of suppression of B cells by nTregs.