Abstract：
LGALS9, also known as Galectin-9 and a member of the β-galactosidase family, plays a crucial role in immune regulation. However, its expression and function in CD8 T cells, as well as its association with cytotoxic T lymphocytes (CTL), remain unclear. This study aims to investigate LGALS9 expression patterns in human circulating CD8 T lymphocytes and elucidate its clinical significance in Systemic Lupus Erythematosus (SLE). Blood samples from 56 healthy controls and 50 new-onset SLE patients were collected. Flow cytometry was utilized to analyze LGALS9 expression in circulating CD8 T lymphocytes via intracellular staining. Compared to LGALS9 + CD8 + T cells, LGALS9-CD8 + T cells showed increased secretion of Granzyme B (GZMB) and Perforin, along with elevated expression levels of GPR56, CX3CR1, KLRD1, KLRF1, PD1, and CD29. A higher proportion of Tn (naive T cells) and TCM (central memory T cells) showed LGALS9 positivity, compared to TEM (effector memory T cells) and TEMRA (terminally differentiated effector memory T cells re-expressing CD45RA). Clinically, the downregulation of LGALS9 expression was significant in SLE patients. LGALS9 + CD8 + T cells exhibited an Area Under the Curve (AUC) of 0.6916, while CX3CR1 + in LGALS9 + CD8 + T cells had an AUC of 0.6478, and KLRF1 + had an AUC of 0.6419, for distinguishing SLE from healthy individuals. In conclusion, CD8 + LGALS9 + T cells display characteristics of low cytotoxicity, and their reduction is evident in SLE patients, potentially implicating them in SLE pathogenesis and providing diagnostic assistance.
摘要：
LGALS9，也称为半乳糖凝集素-9，是β-半乳糖苷酶家族的成员，在免疫调节中起着至关重要的作用。然而,它在CD8T细胞中的表达和功能，以及它与细胞毒性T淋巴细胞（CTL）的关联，仍然不清楚。本研究旨在研究人循环CD8T淋巴细胞中LGALS9的表达模式，并阐明其在系统性红斑狼疮（SLE）中的临床意义。收集来自56名健康对照和50名新发病的SLE患者的血液样本。流式细胞术用于通过细胞内染色分析循环CD8T淋巴细胞中的LGALS9表达。与LGALS9+CD8+T细胞相比，LGALS9-CD8+T细胞显示颗粒酶B（GZMB）和穿孔素的分泌增加，GPR56、CX3CR1、KLRD1、KLRF1、PD1和CD29的表达水平升高。较高比例的Tn（幼稚T细胞）和TCM（中枢记忆T细胞）显示LGALS9阳性，与TEM（效应记忆T细胞）和TEMRA（终末分化的效应记忆T细胞再表达CD45RA）相比。临床上,在SLE患者中LGALS9表达下调显著.LGALS9+CD8+T细胞表现出0.6916的曲线下面积(AUC),而LGALS9+CD8+T细胞中的CX3CR1+具有0.6478的AUC,并且KLRF1+具有0.6419的AUC,用于区分SLE与健康个体。总之,CD8+LGALS9+T细胞显示低细胞毒性特征，在SLE患者中明显减少，可能与SLE发病机制有关并提供诊断帮助。
