Increased soluble and membrane-bound PD-L1 contributes to immune regulation and disease progression in patients with tuberculous pleural effusion

• Published in: Experimental and therapeutic medicine 2016-10, Vol.12 (4), p.2161-2168
• Main Authors: Pan, Xue, Zhong, Anyuan, Xing, Yufei, Shi, Minhua, Qian, Bin, Zhou, Tong, Chen, Yongjing, Zhang, Xueguang
• Format: Article
• Language: English
• Subjects: antibody; Biopsy; Cloning; Development and progression; Flow cytometry; Heart failure; interferon-γ; Laboratories; Ligands; Lung cancer; Lupus; Lymphocytes; Patients; Pleural effusions; programmed death ligand-1; soluble programmed death ligand-1; Tuberculosis; tuberculous pleural effusion; Tumor necrosis factor-TNF
• ISSN: 1792-0981; 1792-1015
• DOI: 10.3892/etm.2016.3611

Soluble and membrane-bound programmed death ligand-1 (sPD-L1 and mPD-L1, respectively) have been demonstrated to participate in the immune suppression of non-small cell lung cancer. However, the contribution of sPD-L1 and mPD-L1 to immune regulation and disease progression in patients with pleural effusions remains unknown. The present study evaluated the levels of sPD-L1 and membrane-bound PD-1/PD-L1 in the peripheral blood and pleural effusions of patients with tuberculous pleural effusion (TPE), malignant pleural effusion (MPE) and non-tuberculous non-malignant pleural effusion (n-TB n-M). Furthermore, selected T lymphocytes and cluster of differentiation (CD)14+ monocytes were co-cultured to investigate the potential effect of the PD-1/PD-L1 pathway in TPE. Levels of sPD-L1 and PD-L1 on CD14+ monocytes were increased in the TPE group, as compared with the MPE and n-TB n-M groups. Furthermore, sPD-L1 levels and the expression levels of PD-L1 on CD14+ monocytes were demonstrated to be positively correlated with interferon (IFN)-γ concentration in pleural effusions. Therefore, IFN-γ may increase the expression of PD-L1 on CD14+ monocytes in vitro. Cell counting kit-8 analysis demonstrated that anti-PD-L1 antibody was able to partially reverse the proliferation of T lymphocytes in the co-culture system. The results of the present study indicated that sPD-L1 or mPD-L1 are associated with the immune regulation and disease progression of TPE, and may serve as possible biomarkers of TPE. Furthermore, sPD-L1 and the PD-1/PD-L1 pathway of TPE may be associated with the Th1 immune response; therefore, an anti-PD-1/PD-L1 pathway suggests a potential immune therapy strategy for the treatment of TPE.