Tim-3／Galectin-9途径——移植免疫耐受中新的信号通路

A New Signaling for Transplantation Tolerance： Tim-3-Galectin-9 Pathway

T细胞免疫球蛋白粘蛋白分子-3（Tim-3）是一种I型膜蛋白分子，属于新近发现的T细胞免疫球蛋白粘蛋白分子家族的一员。Tim-3分子选择性表达于分化的Th1细胞而不是Th2细胞．可与表达在CD4^＋CD25^＋调节性T细胞和／或抗原提呈细胞上的配体半乳凝集素-9（galectin-9）相互作用，在免疫效应阶段通过清除效应性Th1细胞而抑制Thl免疫应答并可诱导免疫耐受，为诱导移植物耐受提供了一条新的通路。

T cell immunoglobulin domain and mucin domain molecule-3 （Tim-3） is a type-I transmembrane protein and belongs to the recently identified Tim gene family. It is preferentially ex- pressed on terminally differentiated Thl cells but Th2 cells. Acting as a negative regulator, Tim-3 can suppress Thl-cell responses by interacting with its potential ligand galeetin-9 mainly expressed on CD4 ＋ CD25 ＋ regulatory T cells and/or antigen presenting cells, and clearing away Thl cells. Tim-3- galectin-9 pathway plays a crucial role in transplantation immune tolerance, providing a new way for the induction of transnlantation tolerance.