目的：检测食管鳞状细胞癌（ESCC）患者血清中高迁移率族蛋白B1（HMGB1）和吲哚胺-2，3-双加氧酶（IDO）的表达水平并探讨两者与临床病理特征及淋巴细胞亚群的相关性。方法：选取2021 年3月至2022 年8月在河北医科大学第四医院初次住院治疗的95 例ESCC 患者作为ESCC 组，另选取40 例健康体检人群作为对照组。ELISA 法检测全部研究对象的血清HMGB1和IDO水平及不同组ESCC细胞培养上清中HMGB1、IDO和p65水平，流式细胞术检测全部研究对象外周血淋巴细胞亚群水平。WB法检测仅敲低HMGB1基因表达或敲低HMGB1后再加入NF-κB信号通路激活剂对ESCC细胞HMGB1、IDO和p65表达的影响。结果：ESCC 组患者血清HMGB1 和IDO 水平明显高于对照组（均P<0.01）；血清HMGB1 和IDO 表达水平升高是ESCC 临床进展的独立危险因素（均P<0.01），二者联合检测对ESCC 临床进展预测价值更高（P<0.01）；血清HMGB1 和IDO 与ESCC患者的T分期、N分期和临床分期有明显关联（均P<0.05）； ESCC组患者血清HMGB1与外周血CD3+ T细胞、CD4+ T细胞、 B细胞和NK细胞绝对计数值呈显著负相关，而与Treg 细胞百分率呈显著正相关（均P<0.05），血清IDO 与外周血CD3+ T细胞百分率和绝对计数值、CD4+ T细胞百分率和绝对计数值、CD8+ T细胞和B细胞绝对计数值呈显著负相关，而与Treg 细胞百分率呈显著正相关（均P<0.05）；血清HMGB1和IDO表达水平呈显著正相关（P<0.01）。si-HMGB1组KYSE30和ECA109 细胞及其培养上清液中IDO和p65 表达水平明显低于si-NC 组和si-HMGB1+PMA组（均P<0.05）。结论：血清HMGB1和IDO与ESCC临床进展和机体免疫功能密切相关，具有成为ESCC 肿瘤标志物和免疫治疗新靶点的潜力。HMGB1 可能通过NF-κB信号通路促进IDO表达，进行双靶点联合治疗可能会取得更好的疗效。

Objective: To investigate the expression levels of high mobility group protein 1 (HMGB1) and indoleamine-2, 3-dioxygenase (IDO) in serum of patients with esophageal squamous cell carcinoma (ESCC) and their correlation with clinicopathologic features and lymphocyte subsets. Methods: Ninety-five ESCC patients initially hospitalized in the Fourth Hospital of Hebei Medical University from March 2021 to August 2022 were selected as the ESCC group, and the other 40 healthy subjects who underwent physical examination were selected as the control group. The serum levels of HMGB1 and IDO of all subjects and the contents of HMGB1, IDO and p65 in the supernatant of ESCC cell culture in different groups were detected by ELISA. The lymphocyte subsets in the peripheral blood of all subjects were detected by flow cytometry. WB was performed to determine the effect of HMGB1 knockdown as well as HMGB1 knockdown followed by addition of NF-κB signaling pathway activator on the expression levels of HMGB1, IDO and p65 in ESCC cells. Results:The serum levels of HMGB1 and IDO in ESCC group were significantly higher than those in control group (all P<0.01). Elevated serum HMGB1 and IDO levels were the independent risk factors for clinical progression of ESCC (all P<0.01), and their combined detection showed a higher predictive value for the clinical progression of ESCC (P<0.01). Serum HMGB1 and IDO levels were significantly correlated with T stage, N stage and clinical stage in ESCC patients (all P<0.05); Serum HMGB1 levels in ESCC group was negatively correlated with the absolute counts of CD3+ T cells, CD4+ T cells, B cells and NK cells in peripheral blood, and positively correlated with Treg cell percentage (all P<0.05); while serum IDO levels was negatively correlated with percentage and absolute count of CD3+ T cells, CD4+ T cells, and absolute counts of CD8+ T cells and B cells in peripheral blood,but positively correlated with the percentage of Treg cells (all P<0.05). Serum HMGB1 was positively correlated with IDO (P<0.01). The expression levels of IDO and p65 in KYSE30 and ECA109 cells and their culture supernatant in si-HMGB1 group were significantly lower than those in si-NC group and si-HMGB1+PMA group (all P<0.05). Conclusion: Serum HMGB1 and IDO are closely related to the clinical progression of ESCC and immune function of ESCC patients, and have the potential to serve as tumor markers and new immunotherapy targets of ESCC. HMGB1 may promote IDO expression through NF-κB signaling pathway, and dual-target combination therapy may achieve better efficacy.

河北省财政厅政府资助临床医学优秀人才课题（冀财预复[2020]397 号）；河北省三三三人才工程资助课题（No. A20203003）