Cellular signaling pathways of T cells in giant cell arteritis

Hai-Yan LI; Jun-Nan XU; Zong-Wen SHUAI

摘要：Giant cell arteritis (GCA) is a commonly occurring large vacuities characterized by angiopathy of medium and large-sized vessels.GCA granulomatous formation plays an important role in the pathogenesis of GCA.Analysis of T cell lin-eages and signaling pathways in GCA have revealed the essential role of T cells in the pathology of GCA.T cells are the domin-ant population present in GCA lesions.CD4+ T cell subtypes that are present include Thl,Th2,Th9,Th17,follicular helper T (Tfh)cells,and regulatory T (Treg) cells.CD8 T cells can primarily differentiate into cytotoxic CD8+ T lymphocytes and Treg cells.The instrumental part of GCA is the interplay between dendritic cells,macrophages and endothelial cells,which can result in the vas-cular injury and the characteristics granulomatous infiltrates formation.During the inflammatory loop of GCA,several signaling pathways have been reported to play an essential role in recruiting,activating and differentiating T cells,including T-cell receptor(TCR) signaling,vascular endothelial growth factor (VEGF)-Jagged-Notch signaling and the Janus kinase and signal transducer and activator of transcription (STAT) pathway (JAK-STAT) pathway.In this review,we have focused on the role of T cells and their potential signaling mechanism (s) that are involved in the pathogenesis of GCA.A better understanding of the role of T cells mediated complicated orchestration during the homeostasis and the changes could possibly favor developments of novel treat-ment strategies against immunological disorders associated with GCA.