Mast cell, pro-inflammatory and anti-inflammatory: Jekyll and Hyde, the story continues.

IL-1 family members include inflammatory and anti-inflammatory cytokines. They can be beneficial or detrimental, not only in cancer, but also in inflammatory conditions. Mast cells (MCs) originate from CD34+/CD117+/CD13+ pluripotent hematopoietic stem cells, express c-Kit receptor (c-Kit-R), which regulates the proliferation and sustain the survival, differentiation and maturation of MCs. They are immune cells involved in innate and adaptive immunity, allergy, autoimmunity, cancer and inflammation. MCs along with T cells and macrophages release interleukin (IL)-10, which is a pleiotropic immunoregulatory cytokine with multiple biological effects. IL-10 inhibits Th1 inflammatory cells, in particular TNF mostly generated by macrophages and MCs, and down-regulates IFN-γ, IL-1 and IL-6. IL-37 is a family member cytokine which binds IL-18 receptor α chain and inhibits inflammatory mediators including TNF, IL-1, IL-6, IL-33 and nitric oxide (NO). IL-37 similar to IL-10 inhibits MC inflammatory cytokines in several disorders, including asthma, allergy, arthrtitis and cancer. Here we report a study comparing IL-10 with IL-37, two anti-inflammatory cytokines.