%0 Journal Article
%T Inflammatory Arthritis and Bone Metabolism Regulated by Type 2 Innate and Adaptive Immunity.
%A Omata Y
%A Frech M
%A Saito T
%A Schett G
%A Zaiss MM
%A Tanaka S
%J Int J Mol Sci
%V 23
%N 3
%D Jan 2022 20
%M 35163028
%F 6.208
%R 10.3390/ijms23031104
%X While type 2 immunity has traditionally been associated with the control of parasitic infections and allergic reactions, increasing evidence suggests that type 2 immunity exerts regulatory functions on inflammatory diseases such as arthritis, and also on bone homeostasis. This review summarizes the current evidence of the regulatory role of type 2 immunity in arthritis and bone. Key type 2 cytokines, like interleukin (IL)-4 and IL-13, but also others such as IL-5, IL-9, IL-25, and IL-33, exert regulatory properties on arthritis, dampening inflammation and inducing resolution of joint swelling. Furthermore, these cytokines share anti-osteoclastogenic properties and thereby reduce bone resorption and protect bone. Cellular effectors of this action are both T cells (i.e., Th2 and Th9 cells), but also non-T cells, like type 2 innate lymphoid cells (ILC2). Key regulatory actions mediated by type 2 cytokines and immune cells on both inflammation as well as bone homeostasis are discussed.