TH2, allergy and group 2 innate lymphoid cells

Abstract

The initiation of type 2 immune responses by the epithelial cell-derived cytokines IL-25, IL-33 and TSLP has been an area of extensive research in the past decade. Such studies have led to the identification of a new innate lymphoid subset that produces the canonical type 2 cytokines IL-5, IL-9 and IL-13 in response to IL-25 and IL-33. These group 2 or type 2 innate lymphoid cells (ILC2 cells) represent a critical source of type 2 cytokines in vivo and serve an important role in orchestrating the type 2 response to helminths and allergens. Further characterization of ILC2 cell biology will enhance the understanding of type 2 responses and may identify new treatments for asthma, allergies and parasitic infections. Interactions between ILC2 cells and the adaptive immune system, as well as examination of potential roles for ILC2 cells in the maintenance of homeostasis, promise to be particularly fruitful areas of future research.

Interleukin-33 drives hepatic fibrosis through activation of hepatic stellate cells

“…34 Furthermore, ST2 signals via the JNK/ERK/p38-MAPK pathway, thereby regulating inflammation within innate lymphoid cells, macrophages and HSCs. 17,35,36 Because IL-33 has an important role in immune regulation, we aimed to verify whether the population of liver-infiltrating mononuclear cells is dependent on IL-33/ST2 signaling. We observed decreased Th1 cells, neutrophils and macrophages in ST2-KO mice, which could be due to the reduced hepatic injury and inflammation.…”

Type-2 Innate Lymphoid Cells in Asthma and Allergy

“…Recent comprehensive reviews have described the identification and phenotypic characterization of ILC (3)(4)(5)(6)20). This review focuses on the most recent advances in our understanding of the factors that regulate ILC2 development and how these cells contribute to allergy and lung inflammation.…”

“…ILCs produce many Th cell-associated cytokines but do not express cell surface markers associated with other immune cell lineages (lineage-negative [Lin 2 ]) and do not express a T-cell receptor. The ILC family now includes ILC1 (predominantly IFN-g-expressing cells), ILC2 (predominantly IL-5-and IL-13-expressing cells), and ILC3 (predominantly IL-22-and IL-17-expressing cells) (3)(4)(5)(6). Due to their recent discovery, our knowledge of these cells is still rather rudimentary, but major roles are emerging for ILCs in protective immunity against parasitic helminths (ILC2) (7)(8)(9) and bacteria (ILC1 and ILC3) (10)(11)(12), and in autoimmune disorders (ILC1 and ILC3) (13), allergic disease (ILC2) (14)(15)(16), and obesity (17)(18)(19).…”

B Cell–Intrinsic MyD88 Signaling Is Essential for IgE Responses in Lungs Exposed to Pollen Allergens

“…These mast cell-derived molecules contribute to the development of early-and late-phase responses and chronic inflammation in asthma (2,3). Although several immunological pathways other than IgE also participate in allergic inflammation (4,5), a deeper understanding of the generation of Ag-specific IgE might help to develop new therapeutic options for the treatment of allergic diseases.…”