Brief Article
Copyright ©2010 Baishideng. All rights reserved.
World J Gastroenterol. Feb 7, 2010; 16(5): 618-624
Published online Feb 7, 2010. doi: 10.3748/wjg.v16.i5.618
Natural course of chronic hepatitis B is characterized by changing patterns of programmed death type-1 of CD8-positive T cells
Xue-Song Liang, Ying Zhou, Chen-Zhong Li, Mo-Bin Wan
Xue-Song Liang, Chen-Zhong Li, Mo-Bin Wan, Department of Infectious Diseases, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Ying Zhou, Department of Biochemistry and Molecular Biology, Second Military Medical University, Shanghai 200433, China
Author contributions: Liang XS and Zhou Y contributed equally to this work; Liang XS provided the vital reagents and analytical tools and wrote the manuscript; Zhou Y performed the majority of experiments; Li CZ took the charge of collecting all human materials; Wan MB designed the study and provided the financial support for this work.
Supported by Grants from the “Yucai” Research Program of Changhai Hospital
Correspondence to: Mo-Bin Wan, Professor, Department of Infectious Diseases, Changhai Hospital, Second Military Medical University, Shanghai 200433, China. mobinwan@yahoo.com.cn
Telephone: +86-21-81873504 Fax: +86-21-65518368
Received: September 3, 2009
Revised: December 2, 2009
Accepted: December 9, 2009
Published online: February 7, 2010
Abstract

AIM: To investigate if and how programmed death type-1 (PD-1) expression affects the natural course of hepatitis B virus (HBV) infection.

METHODS: Sixty-four patients in different natural stages of chronic HBV infection were enrolled in this study. PD-1 expression in total T cells was detected by flow cytometry. Levels of total CD8+ T cell responses and proliferation in relation to PD-1 expression levels were analyzed with intracellular staining and PD-1/PD-L1 blockage.

RESULTS: The PD-1 expression in T cells was dynamically changed during the natural course of chronic HBV infection, did not significantly increase in the immune tolerance phase, and returned to normal in the inactive virus carrier stage. Blockage of the PD-1/PD-L1 pathway could not affect the T-cell response in the immune tolerance and inactive virus carrier stages of chronic HBV infection. However, it could significantly restore the T-cell response in the immune clearance stage of chronic HBV infection. Furthermore, the PD-1 expression level in T cells was associated with the alanine aminotransferase level during the immune clearance stage of chronic HBV infection.

CONCLUSION: The PD-l/PD-L1 pathway plays a different role in T-cell response during the natural course of chronic HBV infection.

Keywords: Programmed death type-1, Hepatitis B virus, Chronic hepatitis B, Natural stage, CD8+ T cell, Serum viral load, Programmed death ligand, T cell response