ABSTRACT
Objective To investigate the expression of programmed death receptor-1 (PD-1) in CD8+ T cells and FoxP3+CD4+ cells in patients with primary biliary cholangitis (PBC).Methods The peripheral blood and clinical data of 69 PBC patients in Peking Union Medical College Hospital and 58 health controls (HC) were collected.They were divided into initial treatment group and follow-up group according to whether they were treated or not.Patients in the treatment group were further divided into the refractory group and stable group according to treatment response.Flow cytometry was used to detect the expression of PD-1 in CDS+T cells and FoxP3+CD4+ cells.T-test and Person correlation analysis were used for data analysis.Results The PD-1 expression in peripheral blood mononuclear cells (PBMCs) of 69 PBC patients (12±9)％ was lower than that of HC (20±12)％ (t=-3.687,P＜0.01).The percentage of PD-1+ in FoxP3+ CD4+T cells was significantly increased in PBC (5.6±3.7)％ than HC (7.4±2.4)％ (t=2.048,P＜0.01).The proportion of CD8+T cells,PD-1 expression in CD8+T cells and the proportion of FoxP3+CD4+ cells weren't correlated with clinical parameters (P＞0.05).There was a negative correlation between the expression of PD-1 cells in FoxP3+CD4+ cells and GLOBE score (r=-0.307,P＜0.05).Conclusion The expression of PD-1 in peripheral CD8+T lymphocytes of PBC patients is lower than that of HC,and decreases more significantly in the refractory group.The expression of PD-1 on FoxP3+CD4+T cells is higher than that in HC,and is negatively correlated with the prognostic GLOBE score.It suggests that PD-1/PD-L1 pathway participates in the immune mechanism of PBC.
ABSTRACT
PD-1/PD-L1 signaling pathway as a T cell immune response co-stimulatory signaling pathway plays an important role in adaptive immunity. PD-1 is a major co-receptor expressing on T cells, binding with its ligands(PD-L1 and PD-L2), PD-1 can inhibit T cell activation and protect the body against the attacks from its own immune system. In addition to adjusting and maintaining autoimmune tolerance, in tumor cells PD-L1 expression is up-regulated, while in the virus-infected T cells PD-L1 expression is also upregulated. PD-1 / PD-L1 are involved in the tumor and infectious pathogen immune evasion, thus blocking the PD-1 / PD-L1 signaling pathway has become a hot research of cancer and chronic diseases. Currently, there are several anti-PD-1 or PD-L1 monoclonal antibodies approved by the FDA to enter clinical studies, which have shown significant anti-cancer effect.