Division of Hepatobiliary Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
Hepatobiliary Pancreat Dis Int. 2013 Aug;12(4):394-9. doi: 10.1016/s1499-3872(13)60061-2.
The role of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) in persistent HBV infection is controversial. Increasing PD-1 and PD-L1 expression has been found in hepatitis B patients during immune clearance phase, but not in HBV-tolerant patients. We investigated PD-1 and PD-L1 expression and inflammation in chronic hepatitis B.
Twenty patients with chronic hepatitis B participated in this study. Fifteen patients were in the immune clearance phase, and 5 were in the immune inactive phase. Circulating HBV-specific T cells were analyzed by flow cytometric detection of major histocompatibility complex (MHC) class I peptide complexes, known as pentamers. Intra-hepatic PD-1 and PD-L1 expressions were analyzed by immunostaining.
The frequency of pentamers, including core 18-27 (1.88%+/-0.36%), env 335-343 (1.85%+/-0.37%), and pol 575-583 (1.56%+/-0.29%) was 8.30-, 7.71- and 8.48-fold greater during immune clearance phase than those during the immune inactive phase. In addition, more than 70% of circulating pentamers were PD-1 positive. During immune clearance phase, the numbers of intra-hepatic PD-1 and PD-L1 positive cells were 108+/-23/HPF and 97+/-20/HPF respectively, in contrast, there was a paucity of PD-1 and PD-L1 positive cells in the immune inactive phase. The numbers of intra-hepatic PD-1 and PD-L1 positive cells were positively correlated with serum alanine aminotransferase and the number of intra-hepatic CD8+ T cells. Immunofluorescence showed that almost all of the intra-hepatic CD8+ T cells were PD-1 and CCR6 positive. These cells aggregated around macrophage inflammatory protein-3 alpha (MIP3alpha) positive cells and mixed with PD-L1 positive cells.
PD-1 and PD-L1 expressions were significantly correlated with inflammation. CCR6 and PD-1 co-expressed in the same cells; these cells were increased both in circulation and the inflamed liver and aggregated around MIP3alpha positive cells. The mixture of CCR6 and PD-1, MIP3alpha and PD-L1 positive cells created immune response compartments which played an important role in specific immune response in HBV immune clearance.
程序性死亡受体 1（PD-1）和程序性死亡配体 1（PD-L1）在持续性乙型肝炎病毒（HBV）感染中的作用存在争议。在免疫清除期已发现乙型肝炎患者的 PD-1 和 PD-L1 表达增加，但在 HBV 耐受患者中未发现。我们研究了慢性乙型肝炎中的 PD-1 和 PD-L1 表达和炎症。
20 名慢性乙型肝炎患者参与了本研究。15 名患者处于免疫清除期，5 名患者处于免疫非活动期。通过 MHC 类 I 肽复合物（称为五聚体）的流式细胞术检测分析循环 HBV 特异性 T 细胞。通过免疫染色分析肝内 PD-1 和 PD-L1 表达。
在免疫清除期，核心 18-27（1.88%+/-0.36%）、env 335-343（1.85%+/-0.37%）和 pol 575-583（1.56%+/-0.29%）五聚体的频率分别比免疫非活动期高 8.30 倍、7.71 倍和 8.48 倍。此外，超过 70%的循环五聚体为 PD-1 阳性。在免疫清除期，肝内 PD-1 和 PD-L1 阳性细胞的数量分别为 108+/-23/高倍视野和 97+/-20/高倍视野，相比之下，免疫非活动期 PD-1 和 PD-L1 阳性细胞数量较少。肝内 PD-1 和 PD-L1 阳性细胞的数量与血清丙氨酸氨基转移酶和肝内 CD8+T 细胞的数量呈正相关。免疫荧光显示，几乎所有的肝内 CD8+T 细胞均为 PD-1 和 CCR6 阳性。这些细胞聚集在巨噬细胞炎症蛋白 3α（MIP3alpha）阳性细胞周围，并与 PD-L1 阳性细胞混合。
PD-1 和 PD-L1 的表达与炎症明显相关。CCR6 和 PD-1 在同一细胞中共同表达；这些细胞在循环中以及炎症肝中均增加，并聚集在 MIP3alpha 阳性细胞周围。CCR6 和 PD-1、MIP3alpha 和 PD-L1 阳性细胞的混合物形成了免疫反应区室，在乙型肝炎病毒免疫清除的特异性免疫反应中发挥了重要作用。
