Natural Th2 (nTh2) cells, interleukin 36 and interleiukin 37 : new elements of innate immunity

This paper presents new elements of innate immunity, such as recently described natural TH2 cells (nTH2 or NHC), interleukin 36 (IL-36) and IL-37. nTH2 cells are located in structures defined as fatassociated lymphoid clusters (FALC), and their role is principally associated with the production of cytokines that are characteristic for TH2 lymphocytes participating in the course of allergic processes and in host defence during invasions of various parasites. The expression of IL-36 was mainly recorded in the thymus, testis and uterus cells. This interleukin indicates suppressive effect on innate immunity, principally by inhibition of pro-inflammatory cytokine production, as well as by creation of an active complex with signalling protein – Smad3 and cooperation with TGF-β. In turn, IL-37 is synthesized in the same places as IL-36, and additionally in macrophages and epithelial cells. It is also considered as an inhibitor of innate immunity.